(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
    typeof define === 'function' && define.amd ? define(factory) :
    (global.createREGL = factory());
}(this, (function () { 'use strict';

var extend = function (base, opts) {
  var keys = Object.keys(opts)
  for (var i = 0; i < keys.length; ++i) {
    base[keys[i]] = opts[keys[i]]
  }
  return base
}

var VARIABLE_COUNTER = 0

var DYN_FUNC = 0
var DYN_CONSTANT = 5
var DYN_ARRAY = 6

function DynamicVariable (type, data) {
  this.id = (VARIABLE_COUNTER++)
  this.type = type
  this.data = data
}

function escapeStr (str) {
  return str.replace(/\\/g, '\\\\').replace(/"/g, '\\"')
}

function splitParts (str) {
  if (str.length === 0) {
    return []
  }

  var firstChar = str.charAt(0)
  var lastChar = str.charAt(str.length - 1)

  if (str.length > 1 &&
      firstChar === lastChar &&
      (firstChar === '"' || firstChar === "'")) {
    return ['"' + escapeStr(str.substr(1, str.length - 2)) + '"']
  }

  var parts = /\[(false|true|null|\d+|'[^']*'|"[^"]*")\]/.exec(str)
  if (parts) {
    return (
      splitParts(str.substr(0, parts.index))
        .concat(splitParts(parts[1]))
        .concat(splitParts(str.substr(parts.index + parts[0].length)))
    )
  }

  var subparts = str.split('.')
  if (subparts.length === 1) {
    return ['"' + escapeStr(str) + '"']
  }

  var result = []
  for (var i = 0; i < subparts.length; ++i) {
    result = result.concat(splitParts(subparts[i]))
  }
  return result
}

function toAccessorString (str) {
  return '[' + splitParts(str).join('][') + ']'
}

function defineDynamic (type, data) {
  return new DynamicVariable(type, toAccessorString(data + ''))
}

function isDynamic (x) {
  return (typeof x === 'function' && !x._reglType) || (x instanceof DynamicVariable)
}

function unbox (x, path) {
  if (typeof x === 'function') {
    return new DynamicVariable(DYN_FUNC, x)
  } else if (typeof x === 'number' || typeof x === 'boolean') {
    return new DynamicVariable(DYN_CONSTANT, x)
  } else if (Array.isArray(x)) {
    return new DynamicVariable(DYN_ARRAY, x.map(function (y, i) { return unbox(y, path + '[' + i + ']') }))
  } else if (x instanceof DynamicVariable) {
    return x
  }
  
}

var dynamic = {
  DynamicVariable: DynamicVariable,
  define: defineDynamic,
  isDynamic: isDynamic,
  unbox: unbox,
  accessor: toAccessorString
};

/* globals requestAnimationFrame, cancelAnimationFrame */
var raf = {
  next: typeof requestAnimationFrame === 'function'
    ? function (cb) { return requestAnimationFrame(cb) }
    : function (cb) { return setTimeout(cb, 16) },
  cancel: typeof cancelAnimationFrame === 'function'
    ? function (raf) { return cancelAnimationFrame(raf) }
    : clearTimeout
};

/* globals performance */
var clock = (typeof performance !== 'undefined' && performance.now)
    ? function () { return performance.now() }
    : function () { return +(new Date()) };

function createStringStore () {
  var stringIds = { '': 0 }
  var stringValues = ['']
  return {
    id: function (str) {
      var result = stringIds[str]
      if (result) {
        return result
      }
      result = stringIds[str] = stringValues.length
      stringValues.push(str)
      return result
    },

    str: function (id) {
      return stringValues[id]
    }
  }
}

// Context and canvas creation helper functions

function createCanvas (element, onDone, pixelRatio) {
  var canvas = document.createElement('canvas')
  extend(canvas.style, {
    border: 0,
    margin: 0,
    padding: 0,
    top: 0,
    left: 0,
    width: '100%',
    height: '100%'
  })
  element.appendChild(canvas)

  if (element === document.body) {
    canvas.style.position = 'absolute'
    extend(element.style, {
      margin: 0,
      padding: 0
    })
  }

  function resize () {
    var w = window.innerWidth
    var h = window.innerHeight
    if (element !== document.body) {
      var bounds = canvas.getBoundingClientRect()
      w = bounds.right - bounds.left
      h = bounds.bottom - bounds.top
    }
    canvas.width = pixelRatio * w
    canvas.height = pixelRatio * h
  }

  var resizeObserver
  if (element !== document.body && typeof ResizeObserver === 'function') {
    // ignore 'ResizeObserver' is not defined
    // eslint-disable-next-line
    resizeObserver = new ResizeObserver(function () {
      // setTimeout to avoid flicker
      setTimeout(resize)
    })
    resizeObserver.observe(element)
  } else {
    window.addEventListener('resize', resize, false)
  }

  function onDestroy () {
    if (resizeObserver) {
      resizeObserver.disconnect()
    } else {
      window.removeEventListener('resize', resize)
    }
    element.removeChild(canvas)
  }

  resize()

  return {
    canvas: canvas,
    onDestroy: onDestroy
  }
}

function createContext (canvas, contextAttributes) {
  function get (name) {
    try {
      return canvas.getContext(name, contextAttributes)
    } catch (e) {
      return null
    }
  }
  return (
    get('webgl') ||
    get('experimental-webgl') ||
    get('webgl-experimental')
  )
}

function isHTMLElement (obj) {
  return (
    typeof obj.nodeName === 'string' &&
    typeof obj.appendChild === 'function' &&
    typeof obj.getBoundingClientRect === 'function'
  )
}

function isWebGLContext (obj) {
  return (
    typeof obj.drawArrays === 'function' ||
    typeof obj.drawElements === 'function'
  )
}

function parseExtensions (input) {
  if (typeof input === 'string') {
    return input.split()
  }
  
  return input
}

function getElement (desc) {
  if (typeof desc === 'string') {
    
    return document.querySelector(desc)
  }
  return desc
}

function parseArgs (args_) {
  var args = args_ || {}
  var element, container, canvas, gl
  var contextAttributes = {}
  var extensions = []
  var optionalExtensions = []
  var pixelRatio = (typeof window === 'undefined' ? 1 : window.devicePixelRatio)
  var profile = false
  var cachedCode = {}
  var onDone = function (err) {
    if (err) {
      
    }
  }
  var onDestroy = function () {}
  if (typeof args === 'string') {
    
    element = document.querySelector(args)
    
  } else if (typeof args === 'object') {
    if (isHTMLElement(args)) {
      element = args
    } else if (isWebGLContext(args)) {
      gl = args
      canvas = gl.canvas
    } else {
      
      if ('gl' in args) {
        gl = args.gl
      } else if ('canvas' in args) {
        canvas = getElement(args.canvas)
      } else if ('container' in args) {
        container = getElement(args.container)
      }
      if ('attributes' in args) {
        contextAttributes = args.attributes
        
      }
      if ('extensions' in args) {
        extensions = parseExtensions(args.extensions)
      }
      if ('optionalExtensions' in args) {
        optionalExtensions = parseExtensions(args.optionalExtensions)
      }
      if ('onDone' in args) {
        
        onDone = args.onDone
      }
      if ('profile' in args) {
        profile = !!args.profile
      }
      if ('pixelRatio' in args) {
        pixelRatio = +args.pixelRatio
        
      }
      if ('cachedCode' in args) {
        
        cachedCode = args.cachedCode
      }
    }
  } else {
    
  }

  if (element) {
    if (element.nodeName.toLowerCase() === 'canvas') {
      canvas = element
    } else {
      container = element
    }
  }

  if (!gl) {
    if (!canvas) {
      
      var result = createCanvas(container || document.body, onDone, pixelRatio)
      if (!result) {
        return null
      }
      canvas = result.canvas
      onDestroy = result.onDestroy
    }
    // workaround for chromium bug, premultiplied alpha value is platform dependent
    if (contextAttributes.premultipliedAlpha === undefined) contextAttributes.premultipliedAlpha = true
    gl = createContext(canvas, contextAttributes)
  }

  if (!gl) {
    onDestroy()
    onDone('webgl not supported, try upgrading your browser or graphics drivers http://get.webgl.org')
    return null
  }

  return {
    gl: gl,
    canvas: canvas,
    container: container,
    extensions: extensions,
    optionalExtensions: optionalExtensions,
    pixelRatio: pixelRatio,
    profile: profile,
    cachedCode: cachedCode,
    onDone: onDone,
    onDestroy: onDestroy
  }
}

function createExtensionCache (gl, config) {
  var extensions = {}

  function tryLoadExtension (name_) {
    
    var name = name_.toLowerCase()
    var ext
    try {
      ext = extensions[name] = gl.getExtension(name)
    } catch (e) {}
    return !!ext
  }

  for (var i = 0; i < config.extensions.length; ++i) {
    var name = config.extensions[i]
    if (!tryLoadExtension(name)) {
      config.onDestroy()
      config.onDone('"' + name + '" extension is not supported by the current WebGL context, try upgrading your system or a different browser')
      return null
    }
  }

  config.optionalExtensions.forEach(tryLoadExtension)

  return {
    extensions: extensions,
    restore: function () {
      Object.keys(extensions).forEach(function (name) {
        if (extensions[name] && !tryLoadExtension(name)) {
          throw new Error('(regl): error restoring extension ' + name)
        }
      })
    }
  }
}

function loop (n, f) {
  var result = Array(n)
  for (var i = 0; i < n; ++i) {
    result[i] = f(i)
  }
  return result
}

var GL_BYTE = 5120
var GL_UNSIGNED_BYTE$1 = 5121
var GL_SHORT = 5122
var GL_UNSIGNED_SHORT = 5123
var GL_INT = 5124
var GL_UNSIGNED_INT = 5125
var GL_FLOAT$1 = 5126

function nextPow16 (v) {
  for (var i = 16; i <= (1 << 28); i *= 16) {
    if (v <= i) {
      return i
    }
  }
  return 0
}

function log2 (v) {
  var r, shift
  r = (v > 0xFFFF) << 4
  v >>>= r
  shift = (v > 0xFF) << 3
  v >>>= shift; r |= shift
  shift = (v > 0xF) << 2
  v >>>= shift; r |= shift
  shift = (v > 0x3) << 1
  v >>>= shift; r |= shift
  return r | (v >> 1)
}

function createPool () {
  var bufferPool = loop(8, function () {
    return []
  })

  function alloc (n) {
    var sz = nextPow16(n)
    var bin = bufferPool[log2(sz) >> 2]
    if (bin.length > 0) {
      return bin.pop()
    }
    return new ArrayBuffer(sz)
  }

  function free (buf) {
    bufferPool[log2(buf.byteLength) >> 2].push(buf)
  }

  function allocType (type, n) {
    var result = null
    switch (type) {
      case GL_BYTE:
        result = new Int8Array(alloc(n), 0, n)
        break
      case GL_UNSIGNED_BYTE$1:
        result = new Uint8Array(alloc(n), 0, n)
        break
      case GL_SHORT:
        result = new Int16Array(alloc(2 * n), 0, n)
        break
      case GL_UNSIGNED_SHORT:
        result = new Uint16Array(alloc(2 * n), 0, n)
        break
      case GL_INT:
        result = new Int32Array(alloc(4 * n), 0, n)
        break
      case GL_UNSIGNED_INT:
        result = new Uint32Array(alloc(4 * n), 0, n)
        break
      case GL_FLOAT$1:
        result = new Float32Array(alloc(4 * n), 0, n)
        break
      default:
        return null
    }
    if (result.length !== n) {
      return result.subarray(0, n)
    }
    return result
  }

  function freeType (array) {
    free(array.buffer)
  }

  return {
    alloc: alloc,
    free: free,
    allocType: allocType,
    freeType: freeType
  }
}

var pool = createPool()

// zero pool for initial zero data
pool.zero = createPool()

var GL_SUBPIXEL_BITS = 0x0D50
var GL_RED_BITS = 0x0D52
var GL_GREEN_BITS = 0x0D53
var GL_BLUE_BITS = 0x0D54
var GL_ALPHA_BITS = 0x0D55
var GL_DEPTH_BITS = 0x0D56
var GL_STENCIL_BITS = 0x0D57

var GL_ALIASED_POINT_SIZE_RANGE = 0x846D
var GL_ALIASED_LINE_WIDTH_RANGE = 0x846E

var GL_MAX_TEXTURE_SIZE = 0x0D33
var GL_MAX_VIEWPORT_DIMS = 0x0D3A
var GL_MAX_VERTEX_ATTRIBS = 0x8869
var GL_MAX_VERTEX_UNIFORM_VECTORS = 0x8DFB
var GL_MAX_VARYING_VECTORS = 0x8DFC
var GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS = 0x8B4D
var GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS = 0x8B4C
var GL_MAX_TEXTURE_IMAGE_UNITS = 0x8872
var GL_MAX_FRAGMENT_UNIFORM_VECTORS = 0x8DFD
var GL_MAX_CUBE_MAP_TEXTURE_SIZE = 0x851C
var GL_MAX_RENDERBUFFER_SIZE = 0x84E8

var GL_VENDOR = 0x1F00
var GL_RENDERER = 0x1F01
var GL_VERSION = 0x1F02
var GL_SHADING_LANGUAGE_VERSION = 0x8B8C

var GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT = 0x84FF

var GL_MAX_COLOR_ATTACHMENTS_WEBGL = 0x8CDF
var GL_MAX_DRAW_BUFFERS_WEBGL = 0x8824

var GL_TEXTURE_2D = 0x0DE1
var GL_TEXTURE_CUBE_MAP = 0x8513
var GL_TEXTURE_CUBE_MAP_POSITIVE_X = 0x8515
var GL_TEXTURE0 = 0x84C0
var GL_RGBA = 0x1908
var GL_FLOAT = 0x1406
var GL_UNSIGNED_BYTE = 0x1401
var GL_FRAMEBUFFER = 0x8D40
var GL_FRAMEBUFFER_COMPLETE = 0x8CD5
var GL_COLOR_ATTACHMENT0 = 0x8CE0
var GL_COLOR_BUFFER_BIT$1 = 0x4000

var wrapLimits = function (gl, extensions) {
  var maxAnisotropic = 1
  if (extensions.ext_texture_filter_anisotropic) {
    maxAnisotropic = gl.getParameter(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT)
  }

  var maxDrawbuffers = 1
  var maxColorAttachments = 1
  if (extensions.webgl_draw_buffers) {
    maxDrawbuffers = gl.getParameter(GL_MAX_DRAW_BUFFERS_WEBGL)
    maxColorAttachments = gl.getParameter(GL_MAX_COLOR_ATTACHMENTS_WEBGL)
  }

  // detect if reading float textures is available (Safari doesn't support)
  var readFloat = !!extensions.oes_texture_float
  if (readFloat) {
    var readFloatTexture = gl.createTexture()
    gl.bindTexture(GL_TEXTURE_2D, readFloatTexture)
    gl.texImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_FLOAT, null)

    var fbo = gl.createFramebuffer()
    gl.bindFramebuffer(GL_FRAMEBUFFER, fbo)
    gl.framebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, readFloatTexture, 0)
    gl.bindTexture(GL_TEXTURE_2D, null)

    if (gl.checkFramebufferStatus(GL_FRAMEBUFFER) !== GL_FRAMEBUFFER_COMPLETE) readFloat = false

    else {
      gl.viewport(0, 0, 1, 1)
      gl.clearColor(1.0, 0.0, 0.0, 1.0)
      gl.clear(GL_COLOR_BUFFER_BIT$1)
      var pixels = pool.allocType(GL_FLOAT, 4)
      gl.readPixels(0, 0, 1, 1, GL_RGBA, GL_FLOAT, pixels)

      if (gl.getError()) readFloat = false
      else {
        gl.deleteFramebuffer(fbo)
        gl.deleteTexture(readFloatTexture)

        readFloat = pixels[0] === 1.0
      }

      pool.freeType(pixels)
    }
  }

  // detect non power of two cube textures support (IE doesn't support)
  var isIE = typeof navigator !== 'undefined' && (/MSIE/.test(navigator.userAgent) || /Trident\//.test(navigator.appVersion) || /Edge/.test(navigator.userAgent))

  var npotTextureCube = true

  if (!isIE) {
    var cubeTexture = gl.createTexture()
    var data = pool.allocType(GL_UNSIGNED_BYTE, 36)
    gl.activeTexture(GL_TEXTURE0)
    gl.bindTexture(GL_TEXTURE_CUBE_MAP, cubeTexture)
    gl.texImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X, 0, GL_RGBA, 3, 3, 0, GL_RGBA, GL_UNSIGNED_BYTE, data)
    pool.freeType(data)
    gl.bindTexture(GL_TEXTURE_CUBE_MAP, null)
    gl.deleteTexture(cubeTexture)
    npotTextureCube = !gl.getError()
  }

  return {
    // drawing buffer bit depth
    colorBits: [
      gl.getParameter(GL_RED_BITS),
      gl.getParameter(GL_GREEN_BITS),
      gl.getParameter(GL_BLUE_BITS),
      gl.getParameter(GL_ALPHA_BITS)
    ],
    depthBits: gl.getParameter(GL_DEPTH_BITS),
    stencilBits: gl.getParameter(GL_STENCIL_BITS),
    subpixelBits: gl.getParameter(GL_SUBPIXEL_BITS),

    // supported extensions
    extensions: Object.keys(extensions).filter(function (ext) {
      return !!extensions[ext]
    }),

    // max aniso samples
    maxAnisotropic: maxAnisotropic,

    // max draw buffers
    maxDrawbuffers: maxDrawbuffers,
    maxColorAttachments: maxColorAttachments,

    // point and line size ranges
    pointSizeDims: gl.getParameter(GL_ALIASED_POINT_SIZE_RANGE),
    lineWidthDims: gl.getParameter(GL_ALIASED_LINE_WIDTH_RANGE),
    maxViewportDims: gl.getParameter(GL_MAX_VIEWPORT_DIMS),
    maxCombinedTextureUnits: gl.getParameter(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS),
    maxCubeMapSize: gl.getParameter(GL_MAX_CUBE_MAP_TEXTURE_SIZE),
    maxRenderbufferSize: gl.getParameter(GL_MAX_RENDERBUFFER_SIZE),
    maxTextureUnits: gl.getParameter(GL_MAX_TEXTURE_IMAGE_UNITS),
    maxTextureSize: gl.getParameter(GL_MAX_TEXTURE_SIZE),
    maxAttributes: gl.getParameter(GL_MAX_VERTEX_ATTRIBS),
    maxVertexUniforms: gl.getParameter(GL_MAX_VERTEX_UNIFORM_VECTORS),
    maxVertexTextureUnits: gl.getParameter(GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS),
    maxVaryingVectors: gl.getParameter(GL_MAX_VARYING_VECTORS),
    maxFragmentUniforms: gl.getParameter(GL_MAX_FRAGMENT_UNIFORM_VECTORS),

    // vendor info
    glsl: gl.getParameter(GL_SHADING_LANGUAGE_VERSION),
    renderer: gl.getParameter(GL_RENDERER),
    vendor: gl.getParameter(GL_VENDOR),
    version: gl.getParameter(GL_VERSION),

    // quirks
    readFloat: readFloat,
    npotTextureCube: npotTextureCube
  }
}

var isTypedArray = function (x) {
  return (
    x instanceof Uint8Array ||
    x instanceof Uint16Array ||
    x instanceof Uint32Array ||
    x instanceof Int8Array ||
    x instanceof Int16Array ||
    x instanceof Int32Array ||
    x instanceof Float32Array ||
    x instanceof Float64Array ||
    x instanceof Uint8ClampedArray
  )
}

function isNDArrayLike (obj) {
  return (
    !!obj &&
    typeof obj === 'object' &&
    Array.isArray(obj.shape) &&
    Array.isArray(obj.stride) &&
    typeof obj.offset === 'number' &&
    obj.shape.length === obj.stride.length &&
    (Array.isArray(obj.data) ||
      isTypedArray(obj.data)))
}

var values = function (obj) {
  return Object.keys(obj).map(function (key) { return obj[key] })
}

var flattenUtils = {
  shape: arrayShape$1,
  flatten: flattenArray
};

function flatten1D (array, nx, out) {
  for (var i = 0; i < nx; ++i) {
    out[i] = array[i]
  }
}

function flatten2D (array, nx, ny, out) {
  var ptr = 0
  for (var i = 0; i < nx; ++i) {
    var row = array[i]
    for (var j = 0; j < ny; ++j) {
      out[ptr++] = row[j]
    }
  }
}

function flatten3D (array, nx, ny, nz, out, ptr_) {
  var ptr = ptr_
  for (var i = 0; i < nx; ++i) {
    var row = array[i]
    for (var j = 0; j < ny; ++j) {
      var col = row[j]
      for (var k = 0; k < nz; ++k) {
        out[ptr++] = col[k]
      }
    }
  }
}

function flattenRec (array, shape, level, out, ptr) {
  var stride = 1
  for (var i = level + 1; i < shape.length; ++i) {
    stride *= shape[i]
  }
  var n = shape[level]
  if (shape.length - level === 4) {
    var nx = shape[level + 1]
    var ny = shape[level + 2]
    var nz = shape[level + 3]
    for (i = 0; i < n; ++i) {
      flatten3D(array[i], nx, ny, nz, out, ptr)
      ptr += stride
    }
  } else {
    for (i = 0; i < n; ++i) {
      flattenRec(array[i], shape, level + 1, out, ptr)
      ptr += stride
    }
  }
}

function flattenArray (array, shape, type, out_) {
  var sz = 1
  if (shape.length) {
    for (var i = 0; i < shape.length; ++i) {
      sz *= shape[i]
    }
  } else {
    sz = 0
  }
  var out = out_ || pool.allocType(type, sz)
  switch (shape.length) {
    case 0:
      break
    case 1:
      flatten1D(array, shape[0], out)
      break
    case 2:
      flatten2D(array, shape[0], shape[1], out)
      break
    case 3:
      flatten3D(array, shape[0], shape[1], shape[2], out, 0)
      break
    default:
      flattenRec(array, shape, 0, out, 0)
  }
  return out
}

function arrayShape$1 (array_) {
  var shape = []
  for (var array = array_; array.length; array = array[0]) {
    shape.push(array.length)
  }
  return shape
}

var arrayTypes = {
	"[object Int8Array]": 5120,
	"[object Int16Array]": 5122,
	"[object Int32Array]": 5124,
	"[object Uint8Array]": 5121,
	"[object Uint8ClampedArray]": 5121,
	"[object Uint16Array]": 5123,
	"[object Uint32Array]": 5125,
	"[object Float32Array]": 5126,
	"[object Float64Array]": 5121,
	"[object ArrayBuffer]": 5121
};

var int8 = 5120;
var int16 = 5122;
var int32 = 5124;
var uint8 = 5121;
var uint16 = 5123;
var uint32 = 5125;
var float = 5126;
var float32 = 5126;
var glTypes = {
	int8: int8,
	int16: int16,
	int32: int32,
	uint8: uint8,
	uint16: uint16,
	uint32: uint32,
	float: float,
	float32: float32
};

var dynamic$1 = 35048;
var stream = 35040;
var usageTypes = {
	dynamic: dynamic$1,
	stream: stream,
	"static": 35044
};

var arrayFlatten = flattenUtils.flatten
var arrayShape = flattenUtils.shape

var GL_STATIC_DRAW = 0x88E4
var GL_STREAM_DRAW = 0x88E0

var GL_UNSIGNED_BYTE$2 = 5121
var GL_FLOAT$2 = 5126

var DTYPES_SIZES = []
DTYPES_SIZES[5120] = 1 // int8
DTYPES_SIZES[5122] = 2 // int16
DTYPES_SIZES[5124] = 4 // int32
DTYPES_SIZES[5121] = 1 // uint8
DTYPES_SIZES[5123] = 2 // uint16
DTYPES_SIZES[5125] = 4 // uint32
DTYPES_SIZES[5126] = 4 // float32

function typedArrayCode (data) {
  return arrayTypes[Object.prototype.toString.call(data)] | 0
}

function copyArray (out, inp) {
  for (var i = 0; i < inp.length; ++i) {
    out[i] = inp[i]
  }
}

function transpose (
  result, data, shapeX, shapeY, strideX, strideY, offset) {
  var ptr = 0
  for (var i = 0; i < shapeX; ++i) {
    for (var j = 0; j < shapeY; ++j) {
      result[ptr++] = data[strideX * i + strideY * j + offset]
    }
  }
}

function wrapBufferState (gl, stats, config, destroyBuffer) {
  var bufferCount = 0
  var bufferSet = {}

  function REGLBuffer (type) {
    this.id = bufferCount++
    this.buffer = gl.createBuffer()
    this.type = type
    this.usage = GL_STATIC_DRAW
    this.byteLength = 0
    this.dimension = 1
    this.dtype = GL_UNSIGNED_BYTE$2

    this.persistentData = null

    if (config.profile) {
      this.stats = { size: 0 }
    }
  }

  REGLBuffer.prototype.bind = function () {
    gl.bindBuffer(this.type, this.buffer)
  }

  REGLBuffer.prototype.destroy = function () {
    destroy(this)
  }

  var streamPool = []

  function createStream (type, data) {
    var buffer = streamPool.pop()
    if (!buffer) {
      buffer = new REGLBuffer(type)
    }
    buffer.bind()
    initBufferFromData(buffer, data, GL_STREAM_DRAW, 0, 1, false)
    return buffer
  }

  function destroyStream (stream$$1) {
    streamPool.push(stream$$1)
  }

  function initBufferFromTypedArray (buffer, data, usage) {
    buffer.byteLength = data.byteLength
    gl.bufferData(buffer.type, data, usage)
  }

  function initBufferFromData (buffer, data, usage, dtype, dimension, persist) {
    var shape
    buffer.usage = usage
    if (Array.isArray(data)) {
      buffer.dtype = dtype || GL_FLOAT$2
      if (data.length > 0) {
        var flatData
        if (Array.isArray(data[0])) {
          shape = arrayShape(data)
          var dim = 1
          for (var i = 1; i < shape.length; ++i) {
            dim *= shape[i]
          }
          buffer.dimension = dim
          flatData = arrayFlatten(data, shape, buffer.dtype)
          initBufferFromTypedArray(buffer, flatData, usage)
          if (persist) {
            buffer.persistentData = flatData
          } else {
            pool.freeType(flatData)
          }
        } else if (typeof data[0] === 'number') {
          buffer.dimension = dimension
          var typedData = pool.allocType(buffer.dtype, data.length)
          copyArray(typedData, data)
          initBufferFromTypedArray(buffer, typedData, usage)
          if (persist) {
            buffer.persistentData = typedData
          } else {
            pool.freeType(typedData)
          }
        } else if (isTypedArray(data[0])) {
          buffer.dimension = data[0].length
          buffer.dtype = dtype || typedArrayCode(data[0]) || GL_FLOAT$2
          flatData = arrayFlatten(
            data,
            [data.length, data[0].length],
            buffer.dtype)
          initBufferFromTypedArray(buffer, flatData, usage)
          if (persist) {
            buffer.persistentData = flatData
          } else {
            pool.freeType(flatData)
          }
        } else {
          
        }
      }
    } else if (isTypedArray(data)) {
      buffer.dtype = dtype || typedArrayCode(data)
      buffer.dimension = dimension
      initBufferFromTypedArray(buffer, data, usage)
      if (persist) {
        buffer.persistentData = new Uint8Array(new Uint8Array(data.buffer))
      }
    } else if (isNDArrayLike(data)) {
      shape = data.shape
      var stride = data.stride
      var offset = data.offset

      var shapeX = 0
      var shapeY = 0
      var strideX = 0
      var strideY = 0
      if (shape.length === 1) {
        shapeX = shape[0]
        shapeY = 1
        strideX = stride[0]
        strideY = 0
      } else if (shape.length === 2) {
        shapeX = shape[0]
        shapeY = shape[1]
        strideX = stride[0]
        strideY = stride[1]
      } else {
        
      }

      buffer.dtype = dtype || typedArrayCode(data.data) || GL_FLOAT$2
      buffer.dimension = shapeY

      var transposeData = pool.allocType(buffer.dtype, shapeX * shapeY)
      transpose(transposeData,
        data.data,
        shapeX, shapeY,
        strideX, strideY,
        offset)
      initBufferFromTypedArray(buffer, transposeData, usage)
      if (persist) {
        buffer.persistentData = transposeData
      } else {
        pool.freeType(transposeData)
      }
    } else if (data instanceof ArrayBuffer) {
      buffer.dtype = GL_UNSIGNED_BYTE$2
      buffer.dimension = dimension
      initBufferFromTypedArray(buffer, data, usage)
      if (persist) {
        buffer.persistentData = new Uint8Array(new Uint8Array(data))
      }
    } else {
      
    }
  }

  function destroy (buffer) {
    stats.bufferCount--

    // remove attribute link
    destroyBuffer(buffer)

    var handle = buffer.buffer
    
    gl.deleteBuffer(handle)
    buffer.buffer = null
    delete bufferSet[buffer.id]
  }

  function createBuffer (options, type, deferInit, persistent) {
    stats.bufferCount++

    var buffer = new REGLBuffer(type)
    bufferSet[buffer.id] = buffer

    function reglBuffer (options) {
      var usage = GL_STATIC_DRAW
      var data = null
      var byteLength = 0
      var dtype = 0
      var dimension = 1
      if (Array.isArray(options) ||
          isTypedArray(options) ||
          isNDArrayLike(options) ||
          options instanceof ArrayBuffer) {
        data = options
      } else if (typeof options === 'number') {
        byteLength = options | 0
      } else if (options) {
        

        if ('data' in options) {
          
          data = options.data
        }

        if ('usage' in options) {
          
          usage = usageTypes[options.usage]
        }

        if ('type' in options) {
          
          dtype = glTypes[options.type]
        }

        if ('dimension' in options) {
          
          dimension = options.dimension | 0
        }

        if ('length' in options) {
          
          byteLength = options.length | 0
        }
      }

      buffer.bind()
      if (!data) {
        // #475
        if (byteLength) gl.bufferData(buffer.type, byteLength, usage)
        buffer.dtype = dtype || GL_UNSIGNED_BYTE$2
        buffer.usage = usage
        buffer.dimension = dimension
        buffer.byteLength = byteLength
      } else {
        initBufferFromData(buffer, data, usage, dtype, dimension, persistent)
      }

      if (config.profile) {
        buffer.stats.size = buffer.byteLength * DTYPES_SIZES[buffer.dtype]
      }

      return reglBuffer
    }

    function setSubData (data, offset) {
      

      gl.bufferSubData(buffer.type, offset, data)
    }

    function subdata (data, offset_) {
      var offset = (offset_ || 0) | 0
      var shape
      buffer.bind()
      if (isTypedArray(data) || data instanceof ArrayBuffer) {
        setSubData(data, offset)
      } else if (Array.isArray(data)) {
        if (data.length > 0) {
          if (typeof data[0] === 'number') {
            var converted = pool.allocType(buffer.dtype, data.length)
            copyArray(converted, data)
            setSubData(converted, offset)
            pool.freeType(converted)
          } else if (Array.isArray(data[0]) || isTypedArray(data[0])) {
            shape = arrayShape(data)
            var flatData = arrayFlatten(data, shape, buffer.dtype)
            setSubData(flatData, offset)
            pool.freeType(flatData)
          } else {
            
          }
        }
      } else if (isNDArrayLike(data)) {
        shape = data.shape
        var stride = data.stride

        var shapeX = 0
        var shapeY = 0
        var strideX = 0
        var strideY = 0
        if (shape.length === 1) {
          shapeX = shape[0]
          shapeY = 1
          strideX = stride[0]
          strideY = 0
        } else if (shape.length === 2) {
          shapeX = shape[0]
          shapeY = shape[1]
          strideX = stride[0]
          strideY = stride[1]
        } else {
          
        }
        var dtype = Array.isArray(data.data)
          ? buffer.dtype
          : typedArrayCode(data.data)

        var transposeData = pool.allocType(dtype, shapeX * shapeY)
        transpose(transposeData,
          data.data,
          shapeX, shapeY,
          strideX, strideY,
          data.offset)
        setSubData(transposeData, offset)
        pool.freeType(transposeData)
      } else {
        
      }
      return reglBuffer
    }

    if (!deferInit) {
      reglBuffer(options)
    }

    reglBuffer._reglType = 'buffer'
    reglBuffer._buffer = buffer
    reglBuffer.subdata = subdata
    if (config.profile) {
      reglBuffer.stats = buffer.stats
    }
    reglBuffer.destroy = function () { destroy(buffer) }

    return reglBuffer
  }

  function restoreBuffers () {
    values(bufferSet).forEach(function (buffer) {
      buffer.buffer = gl.createBuffer()
      gl.bindBuffer(buffer.type, buffer.buffer)
      gl.bufferData(
        buffer.type, buffer.persistentData || buffer.byteLength, buffer.usage)
    })
  }

  if (config.profile) {
    stats.getTotalBufferSize = function () {
      var total = 0
      // TODO: Right now, the streams are not part of the total count.
      Object.keys(bufferSet).forEach(function (key) {
        total += bufferSet[key].stats.size
      })
      return total
    }
  }

  return {
    create: createBuffer,

    createStream: createStream,
    destroyStream: destroyStream,

    clear: function () {
      values(bufferSet).forEach(destroy)
      streamPool.forEach(destroy)
    },

    getBuffer: function (wrapper) {
      if (wrapper && wrapper._buffer instanceof REGLBuffer) {
        return wrapper._buffer
      }
      return null
    },

    restore: restoreBuffers,

    _initBuffer: initBufferFromData
  }
}

var points = 0;
var point = 0;
var lines = 1;
var line = 1;
var triangles = 4;
var triangle = 4;
var primTypes = {
	points: points,
	point: point,
	lines: lines,
	line: line,
	triangles: triangles,
	triangle: triangle,
	"line loop": 2,
	"line strip": 3,
	"triangle strip": 5,
	"triangle fan": 6
};

var GL_POINTS = 0
var GL_LINES = 1
var GL_TRIANGLES = 4

var GL_BYTE$1 = 5120
var GL_UNSIGNED_BYTE$3 = 5121
var GL_SHORT$1 = 5122
var GL_UNSIGNED_SHORT$1 = 5123
var GL_INT$1 = 5124
var GL_UNSIGNED_INT$1 = 5125

var GL_ELEMENT_ARRAY_BUFFER = 34963

var GL_STREAM_DRAW$1 = 0x88E0
var GL_STATIC_DRAW$1 = 0x88E4

function wrapElementsState (gl, extensions, bufferState, stats) {
  var elementSet = {}
  var elementCount = 0

  var elementTypes = {
    'uint8': GL_UNSIGNED_BYTE$3,
    'uint16': GL_UNSIGNED_SHORT$1
  }

  if (extensions.oes_element_index_uint) {
    elementTypes.uint32 = GL_UNSIGNED_INT$1
  }

  function REGLElementBuffer (buffer) {
    this.id = elementCount++
    elementSet[this.id] = this
    this.buffer = buffer
    this.primType = GL_TRIANGLES
    this.vertCount = 0
    this.type = 0
  }

  REGLElementBuffer.prototype.bind = function () {
    this.buffer.bind()
  }

  var bufferPool = []

  function createElementStream (data) {
    var result = bufferPool.pop()
    if (!result) {
      result = new REGLElementBuffer(bufferState.create(
        null,
        GL_ELEMENT_ARRAY_BUFFER,
        true,
        false)._buffer)
    }
    initElements(result, data, GL_STREAM_DRAW$1, -1, -1, 0, 0)
    return result
  }

  function destroyElementStream (elements) {
    bufferPool.push(elements)
  }

  function initElements (
    elements,
    data,
    usage,
    prim,
    count,
    byteLength,
    type) {
    elements.buffer.bind()
    var dtype
    if (data) {
      var predictedType = type
      if (!type && (
        !isTypedArray(data) ||
         (isNDArrayLike(data) && !isTypedArray(data.data)))) {
        predictedType = extensions.oes_element_index_uint
          ? GL_UNSIGNED_INT$1
          : GL_UNSIGNED_SHORT$1
      }
      bufferState._initBuffer(
        elements.buffer,
        data,
        usage,
        predictedType,
        3)
    } else {
      gl.bufferData(GL_ELEMENT_ARRAY_BUFFER, byteLength, usage)
      elements.buffer.dtype = dtype || GL_UNSIGNED_BYTE$3
      elements.buffer.usage = usage
      elements.buffer.dimension = 3
      elements.buffer.byteLength = byteLength
    }

    dtype = type
    if (!type) {
      switch (elements.buffer.dtype) {
        case GL_UNSIGNED_BYTE$3:
        case GL_BYTE$1:
          dtype = GL_UNSIGNED_BYTE$3
          break

        case GL_UNSIGNED_SHORT$1:
        case GL_SHORT$1:
          dtype = GL_UNSIGNED_SHORT$1
          break

        case GL_UNSIGNED_INT$1:
        case GL_INT$1:
          dtype = GL_UNSIGNED_INT$1
          break

        default:
          
      }
      elements.buffer.dtype = dtype
    }
    elements.type = dtype

    // Check oes_element_index_uint extension
    

    // try to guess default primitive type and arguments
    var vertCount = count
    if (vertCount < 0) {
      vertCount = elements.buffer.byteLength
      if (dtype === GL_UNSIGNED_SHORT$1) {
        vertCount >>= 1
      } else if (dtype === GL_UNSIGNED_INT$1) {
        vertCount >>= 2
      }
    }
    elements.vertCount = vertCount

    // try to guess primitive type from cell dimension
    var primType = prim
    if (prim < 0) {
      primType = GL_TRIANGLES
      var dimension = elements.buffer.dimension
      if (dimension === 1) primType = GL_POINTS
      if (dimension === 2) primType = GL_LINES
      if (dimension === 3) primType = GL_TRIANGLES
    }
    elements.primType = primType
  }

  function destroyElements (elements) {
    stats.elementsCount--

    
    delete elementSet[elements.id]
    elements.buffer.destroy()
    elements.buffer = null
  }

  function createElements (options, persistent) {
    var buffer = bufferState.create(null, GL_ELEMENT_ARRAY_BUFFER, true)
    var elements = new REGLElementBuffer(buffer._buffer)
    stats.elementsCount++

    function reglElements (options) {
      if (!options) {
        buffer()
        elements.primType = GL_TRIANGLES
        elements.vertCount = 0
        elements.type = GL_UNSIGNED_BYTE$3
      } else if (typeof options === 'number') {
        buffer(options)
        elements.primType = GL_TRIANGLES
        elements.vertCount = options | 0
        elements.type = GL_UNSIGNED_BYTE$3
      } else {
        var data = null
        var usage = GL_STATIC_DRAW$1
        var primType = -1
        var vertCount = -1
        var byteLength = 0
        var dtype = 0
        if (Array.isArray(options) ||
            isTypedArray(options) ||
            isNDArrayLike(options)) {
          data = options
        } else {
          
          if ('data' in options) {
            data = options.data
            
          }
          if ('usage' in options) {
            
            usage = usageTypes[options.usage]
          }
          if ('primitive' in options) {
            
            primType = primTypes[options.primitive]
          }
          if ('count' in options) {
            
            vertCount = options.count | 0
          }
          if ('type' in options) {
            
            dtype = elementTypes[options.type]
          }
          if ('length' in options) {
            byteLength = options.length | 0
          } else {
            byteLength = vertCount
            if (dtype === GL_UNSIGNED_SHORT$1 || dtype === GL_SHORT$1) {
              byteLength *= 2
            } else if (dtype === GL_UNSIGNED_INT$1 || dtype === GL_INT$1) {
              byteLength *= 4
            }
          }
        }
        initElements(
          elements,
          data,
          usage,
          primType,
          vertCount,
          byteLength,
          dtype)
      }

      return reglElements
    }

    reglElements(options)

    reglElements._reglType = 'elements'
    reglElements._elements = elements
    reglElements.subdata = function (data, offset) {
      buffer.subdata(data, offset)
      return reglElements
    }
    reglElements.destroy = function () {
      destroyElements(elements)
    }

    return reglElements
  }

  return {
    create: createElements,
    createStream: createElementStream,
    destroyStream: destroyElementStream,
    getElements: function (elements) {
      if (typeof elements === 'function' &&
          elements._elements instanceof REGLElementBuffer) {
        return elements._elements
      }
      return null
    },
    clear: function () {
      values(elementSet).forEach(destroyElements)
    }
  }
}

var FLOAT = new Float32Array(1)
var INT = new Uint32Array(FLOAT.buffer)

var GL_UNSIGNED_SHORT$3 = 5123

function convertToHalfFloat (array) {
  var ushorts = pool.allocType(GL_UNSIGNED_SHORT$3, array.length)

  for (var i = 0; i < array.length; ++i) {
    if (isNaN(array[i])) {
      ushorts[i] = 0xffff
    } else if (array[i] === Infinity) {
      ushorts[i] = 0x7c00
    } else if (array[i] === -Infinity) {
      ushorts[i] = 0xfc00
    } else {
      FLOAT[0] = array[i]
      var x = INT[0]

      var sgn = (x >>> 31) << 15
      var exp = ((x << 1) >>> 24) - 127
      var frac = (x >> 13) & ((1 << 10) - 1)

      if (exp < -24) {
        // round non-representable denormals to 0
        ushorts[i] = sgn
      } else if (exp < -14) {
        // handle denormals
        var s = -14 - exp
        ushorts[i] = sgn + ((frac + (1 << 10)) >> s)
      } else if (exp > 15) {
        // round overflow to +/- Infinity
        ushorts[i] = sgn + 0x7c00
      } else {
        // otherwise convert directly
        ushorts[i] = sgn + ((exp + 15) << 10) + frac
      }
    }
  }

  return ushorts
}

function isArrayLike (s) {
  return Array.isArray(s) || isTypedArray(s)
}

var GL_COMPRESSED_TEXTURE_FORMATS = 0x86A3

var GL_TEXTURE_2D$1 = 0x0DE1
var GL_TEXTURE_CUBE_MAP$1 = 0x8513
var GL_TEXTURE_CUBE_MAP_POSITIVE_X$1 = 0x8515

var GL_RGBA$1 = 0x1908
var GL_ALPHA = 0x1906
var GL_RGB = 0x1907
var GL_LUMINANCE = 0x1909
var GL_LUMINANCE_ALPHA = 0x190A

var GL_RGBA4 = 0x8056
var GL_RGB5_A1 = 0x8057
var GL_RGB565 = 0x8D62

var GL_UNSIGNED_SHORT_4_4_4_4 = 0x8033
var GL_UNSIGNED_SHORT_5_5_5_1 = 0x8034
var GL_UNSIGNED_SHORT_5_6_5 = 0x8363
var GL_UNSIGNED_INT_24_8_WEBGL = 0x84FA

var GL_DEPTH_COMPONENT = 0x1902
var GL_DEPTH_STENCIL = 0x84F9

var GL_SRGB_EXT = 0x8C40
var GL_SRGB_ALPHA_EXT = 0x8C42

var GL_HALF_FLOAT_OES = 0x8D61

var GL_COMPRESSED_RGB_S3TC_DXT1_EXT = 0x83F0
var GL_COMPRESSED_RGBA_S3TC_DXT1_EXT = 0x83F1
var GL_COMPRESSED_RGBA_S3TC_DXT3_EXT = 0x83F2
var GL_COMPRESSED_RGBA_S3TC_DXT5_EXT = 0x83F3

var GL_COMPRESSED_RGB_ATC_WEBGL = 0x8C92
var GL_COMPRESSED_RGBA_ATC_EXPLICIT_ALPHA_WEBGL = 0x8C93
var GL_COMPRESSED_RGBA_ATC_INTERPOLATED_ALPHA_WEBGL = 0x87EE

var GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG = 0x8C00
var GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG = 0x8C01
var GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG = 0x8C02
var GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG = 0x8C03

var GL_COMPRESSED_RGB_ETC1_WEBGL = 0x8D64

var GL_UNSIGNED_BYTE$4 = 0x1401
var GL_UNSIGNED_SHORT$2 = 0x1403
var GL_UNSIGNED_INT$2 = 0x1405
var GL_FLOAT$3 = 0x1406

var GL_TEXTURE_WRAP_S = 0x2802
var GL_TEXTURE_WRAP_T = 0x2803

var GL_REPEAT = 0x2901
var GL_CLAMP_TO_EDGE = 0x812F
var GL_MIRRORED_REPEAT = 0x8370

var GL_TEXTURE_MAG_FILTER = 0x2800
var GL_TEXTURE_MIN_FILTER = 0x2801

var GL_NEAREST = 0x2600
var GL_LINEAR = 0x2601
var GL_NEAREST_MIPMAP_NEAREST = 0x2700
var GL_LINEAR_MIPMAP_NEAREST = 0x2701
var GL_NEAREST_MIPMAP_LINEAR = 0x2702
var GL_LINEAR_MIPMAP_LINEAR = 0x2703

var GL_GENERATE_MIPMAP_HINT = 0x8192
var GL_DONT_CARE = 0x1100
var GL_FASTEST = 0x1101
var GL_NICEST = 0x1102

var GL_TEXTURE_MAX_ANISOTROPY_EXT = 0x84FE

var GL_UNPACK_ALIGNMENT = 0x0CF5
var GL_UNPACK_FLIP_Y_WEBGL = 0x9240
var GL_UNPACK_PREMULTIPLY_ALPHA_WEBGL = 0x9241
var GL_UNPACK_COLORSPACE_CONVERSION_WEBGL = 0x9243

var GL_BROWSER_DEFAULT_WEBGL = 0x9244

var GL_TEXTURE0$1 = 0x84C0

var MIPMAP_FILTERS = [
  GL_NEAREST_MIPMAP_NEAREST,
  GL_NEAREST_MIPMAP_LINEAR,
  GL_LINEAR_MIPMAP_NEAREST,
  GL_LINEAR_MIPMAP_LINEAR
]

var CHANNELS_FORMAT = [
  0,
  GL_LUMINANCE,
  GL_LUMINANCE_ALPHA,
  GL_RGB,
  GL_RGBA$1
]

var FORMAT_CHANNELS = {}
FORMAT_CHANNELS[GL_LUMINANCE] =
FORMAT_CHANNELS[GL_ALPHA] =
FORMAT_CHANNELS[GL_DEPTH_COMPONENT] = 1
FORMAT_CHANNELS[GL_DEPTH_STENCIL] =
FORMAT_CHANNELS[GL_LUMINANCE_ALPHA] = 2
FORMAT_CHANNELS[GL_RGB] =
FORMAT_CHANNELS[GL_SRGB_EXT] = 3
FORMAT_CHANNELS[GL_RGBA$1] =
FORMAT_CHANNELS[GL_SRGB_ALPHA_EXT] = 4

function objectName (str) {
  return '[object ' + str + ']'
}

var CANVAS_CLASS = objectName('HTMLCanvasElement')
var OFFSCREENCANVAS_CLASS = objectName('OffscreenCanvas')
var CONTEXT2D_CLASS = objectName('CanvasRenderingContext2D')
var BITMAP_CLASS = objectName('ImageBitmap')
var IMAGE_CLASS = objectName('HTMLImageElement')
var VIDEO_CLASS = objectName('HTMLVideoElement')

var PIXEL_CLASSES = Object.keys(arrayTypes).concat([
  CANVAS_CLASS,
  OFFSCREENCANVAS_CLASS,
  CONTEXT2D_CLASS,
  BITMAP_CLASS,
  IMAGE_CLASS,
  VIDEO_CLASS
])

// for every texture type, store
// the size in bytes.
var TYPE_SIZES = []
TYPE_SIZES[GL_UNSIGNED_BYTE$4] = 1
TYPE_SIZES[GL_FLOAT$3] = 4
TYPE_SIZES[GL_HALF_FLOAT_OES] = 2

TYPE_SIZES[GL_UNSIGNED_SHORT$2] = 2
TYPE_SIZES[GL_UNSIGNED_INT$2] = 4

var FORMAT_SIZES_SPECIAL = []
FORMAT_SIZES_SPECIAL[GL_RGBA4] = 2
FORMAT_SIZES_SPECIAL[GL_RGB5_A1] = 2
FORMAT_SIZES_SPECIAL[GL_RGB565] = 2
FORMAT_SIZES_SPECIAL[GL_DEPTH_STENCIL] = 4

FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGB_S3TC_DXT1_EXT] = 0.5
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_S3TC_DXT1_EXT] = 0.5
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_S3TC_DXT3_EXT] = 1
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_S3TC_DXT5_EXT] = 1

FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGB_ATC_WEBGL] = 0.5
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_ATC_EXPLICIT_ALPHA_WEBGL] = 1
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_ATC_INTERPOLATED_ALPHA_WEBGL] = 1

FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG] = 0.5
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG] = 0.25
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG] = 0.5
FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG] = 0.25

FORMAT_SIZES_SPECIAL[GL_COMPRESSED_RGB_ETC1_WEBGL] = 0.5

function isNumericArray (arr) {
  return (
    Array.isArray(arr) &&
    (arr.length === 0 ||
    typeof arr[0] === 'number'))
}

function isRectArray (arr) {
  if (!Array.isArray(arr)) {
    return false
  }
  var width = arr.length
  if (width === 0 || !isArrayLike(arr[0])) {
    return false
  }
  return true
}

function classString (x) {
  return Object.prototype.toString.call(x)
}

function isCanvasElement (object) {
  return classString(object) === CANVAS_CLASS
}

function isOffscreenCanvas (object) {
  return classString(object) === OFFSCREENCANVAS_CLASS
}

function isContext2D (object) {
  return classString(object) === CONTEXT2D_CLASS
}

function isBitmap (object) {
  return classString(object) === BITMAP_CLASS
}

function isImageElement (object) {
  return classString(object) === IMAGE_CLASS
}

function isVideoElement (object) {
  return classString(object) === VIDEO_CLASS
}

function isPixelData (object) {
  if (!object) {
    return false
  }
  var className = classString(object)
  if (PIXEL_CLASSES.indexOf(className) >= 0) {
    return true
  }
  return (
    isNumericArray(object) ||
    isRectArray(object) ||
    isNDArrayLike(object))
}

function typedArrayCode$1 (data) {
  return arrayTypes[Object.prototype.toString.call(data)] | 0
}

function convertData (result, data) {
  var n = data.length
  switch (result.type) {
    case GL_UNSIGNED_BYTE$4:
    case GL_UNSIGNED_SHORT$2:
    case GL_UNSIGNED_INT$2:
    case GL_FLOAT$3:
      var converted = pool.allocType(result.type, n)
      converted.set(data)
      result.data = converted
      break

    case GL_HALF_FLOAT_OES:
      result.data = convertToHalfFloat(data)
      break

    default:
      
  }
}

function preConvert (image, n) {
  return pool.allocType(
    image.type === GL_HALF_FLOAT_OES
      ? GL_FLOAT$3
      : image.type, n)
}

function postConvert (image, data) {
  if (image.type === GL_HALF_FLOAT_OES) {
    image.data = convertToHalfFloat(data)
    pool.freeType(data)
  } else {
    image.data = data
  }
}

function transposeData (image, array, strideX, strideY, strideC, offset) {
  var w = image.width
  var h = image.height
  var c = image.channels
  var n = w * h * c
  var data = preConvert(image, n)

  var p = 0
  for (var i = 0; i < h; ++i) {
    for (var j = 0; j < w; ++j) {
      for (var k = 0; k < c; ++k) {
        data[p++] = array[strideX * j + strideY * i + strideC * k + offset]
      }
    }
  }

  postConvert(image, data)
}

function getTextureSize (format, type, width, height, isMipmap, isCube) {
  var s
  if (typeof FORMAT_SIZES_SPECIAL[format] !== 'undefined') {
    // we have a special array for dealing with weird color formats such as RGB5A1
    s = FORMAT_SIZES_SPECIAL[format]
  } else {
    s = FORMAT_CHANNELS[format] * TYPE_SIZES[type]
  }

  if (isCube) {
    s *= 6
  }

  if (isMipmap) {
    // compute the total size of all the mipmaps.
    var total = 0

    var w = width
    while (w >= 1) {
      // we can only use mipmaps on a square image,
      // so we can simply use the width and ignore the height:
      total += s * w * w
      w /= 2
    }
    return total
  } else {
    return s * width * height
  }
}

function createTextureSet (
  gl, extensions, limits, reglPoll, contextState, stats, config) {
  // -------------------------------------------------------
  // Initialize constants and parameter tables here
  // -------------------------------------------------------
  var mipmapHint = {
    "don't care": GL_DONT_CARE,
    'dont care': GL_DONT_CARE,
    'nice': GL_NICEST,
    'fast': GL_FASTEST
  }

  var wrapModes = {
    'repeat': GL_REPEAT,
    'clamp': GL_CLAMP_TO_EDGE,
    'mirror': GL_MIRRORED_REPEAT
  }

  var magFilters = {
    'nearest': GL_NEAREST,
    'linear': GL_LINEAR
  }

  var minFilters = extend({
    'mipmap': GL_LINEAR_MIPMAP_LINEAR,
    'nearest mipmap nearest': GL_NEAREST_MIPMAP_NEAREST,
    'linear mipmap nearest': GL_LINEAR_MIPMAP_NEAREST,
    'nearest mipmap linear': GL_NEAREST_MIPMAP_LINEAR,
    'linear mipmap linear': GL_LINEAR_MIPMAP_LINEAR
  }, magFilters)

  var colorSpace = {
    'none': 0,
    'browser': GL_BROWSER_DEFAULT_WEBGL
  }

  var textureTypes = {
    'uint8': GL_UNSIGNED_BYTE$4,
    'rgba4': GL_UNSIGNED_SHORT_4_4_4_4,
    'rgb565': GL_UNSIGNED_SHORT_5_6_5,
    'rgb5 a1': GL_UNSIGNED_SHORT_5_5_5_1
  }

  var textureFormats = {
    'alpha': GL_ALPHA,
    'luminance': GL_LUMINANCE,
    'luminance alpha': GL_LUMINANCE_ALPHA,
    'rgb': GL_RGB,
    'rgba': GL_RGBA$1,
    'rgba4': GL_RGBA4,
    'rgb5 a1': GL_RGB5_A1,
    'rgb565': GL_RGB565
  }

  var compressedTextureFormats = {}

  if (extensions.ext_srgb) {
    textureFormats.srgb = GL_SRGB_EXT
    textureFormats.srgba = GL_SRGB_ALPHA_EXT
  }

  if (extensions.oes_texture_float) {
    textureTypes.float32 = textureTypes.float = GL_FLOAT$3
  }

  if (extensions.oes_texture_half_float) {
    textureTypes['float16'] = textureTypes['half float'] = GL_HALF_FLOAT_OES
  }

  if (extensions.webgl_depth_texture) {
    extend(textureFormats, {
      'depth': GL_DEPTH_COMPONENT,
      'depth stencil': GL_DEPTH_STENCIL
    })

    extend(textureTypes, {
      'uint16': GL_UNSIGNED_SHORT$2,
      'uint32': GL_UNSIGNED_INT$2,
      'depth stencil': GL_UNSIGNED_INT_24_8_WEBGL
    })
  }

  if (extensions.webgl_compressed_texture_s3tc) {
    extend(compressedTextureFormats, {
      'rgb s3tc dxt1': GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
      'rgba s3tc dxt1': GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
      'rgba s3tc dxt3': GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,
      'rgba s3tc dxt5': GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
    })
  }

  if (extensions.webgl_compressed_texture_atc) {
    extend(compressedTextureFormats, {
      'rgb atc': GL_COMPRESSED_RGB_ATC_WEBGL,
      'rgba atc explicit alpha': GL_COMPRESSED_RGBA_ATC_EXPLICIT_ALPHA_WEBGL,
      'rgba atc interpolated alpha': GL_COMPRESSED_RGBA_ATC_INTERPOLATED_ALPHA_WEBGL
    })
  }

  if (extensions.webgl_compressed_texture_pvrtc) {
    extend(compressedTextureFormats, {
      'rgb pvrtc 4bppv1': GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG,
      'rgb pvrtc 2bppv1': GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG,
      'rgba pvrtc 4bppv1': GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG,
      'rgba pvrtc 2bppv1': GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG
    })
  }

  if (extensions.webgl_compressed_texture_etc1) {
    compressedTextureFormats['rgb etc1'] = GL_COMPRESSED_RGB_ETC1_WEBGL
  }

  // Copy over all texture formats
  var supportedCompressedFormats = Array.prototype.slice.call(
    gl.getParameter(GL_COMPRESSED_TEXTURE_FORMATS))
  Object.keys(compressedTextureFormats).forEach(function (name) {
    var format = compressedTextureFormats[name]
    if (supportedCompressedFormats.indexOf(format) >= 0) {
      textureFormats[name] = format
    }
  })

  var supportedFormats = Object.keys(textureFormats)
  limits.textureFormats = supportedFormats

  // associate with every format string its
  // corresponding GL-value.
  var textureFormatsInvert = []
  Object.keys(textureFormats).forEach(function (key) {
    var val = textureFormats[key]
    textureFormatsInvert[val] = key
  })

  // associate with every type string its
  // corresponding GL-value.
  var textureTypesInvert = []
  Object.keys(textureTypes).forEach(function (key) {
    var val = textureTypes[key]
    textureTypesInvert[val] = key
  })

  var magFiltersInvert = []
  Object.keys(magFilters).forEach(function (key) {
    var val = magFilters[key]
    magFiltersInvert[val] = key
  })

  var minFiltersInvert = []
  Object.keys(minFilters).forEach(function (key) {
    var val = minFilters[key]
    minFiltersInvert[val] = key
  })

  var wrapModesInvert = []
  Object.keys(wrapModes).forEach(function (key) {
    var val = wrapModes[key]
    wrapModesInvert[val] = key
  })

  // colorFormats[] gives the format (channels) associated to an
  // internalformat
  var colorFormats = supportedFormats.reduce(function (color, key) {
    var glenum = textureFormats[key]
    if (glenum === GL_LUMINANCE ||
        glenum === GL_ALPHA ||
        glenum === GL_LUMINANCE ||
        glenum === GL_LUMINANCE_ALPHA ||
        glenum === GL_DEPTH_COMPONENT ||
        glenum === GL_DEPTH_STENCIL ||
        (extensions.ext_srgb &&
                (glenum === GL_SRGB_EXT ||
                 glenum === GL_SRGB_ALPHA_EXT))) {
      color[glenum] = glenum
    } else if (glenum === GL_RGB5_A1 || key.indexOf('rgba') >= 0) {
      color[glenum] = GL_RGBA$1
    } else {
      color[glenum] = GL_RGB
    }
    return color
  }, {})

  function TexFlags () {
    // format info
    this.internalformat = GL_RGBA$1
    this.format = GL_RGBA$1
    this.type = GL_UNSIGNED_BYTE$4
    this.compressed = false

    // pixel storage
    this.premultiplyAlpha = false
    this.flipY = false
    this.unpackAlignment = 1
    this.colorSpace = GL_BROWSER_DEFAULT_WEBGL

    // shape info
    this.width = 0
    this.height = 0
    this.channels = 0
  }

  function copyFlags (result, other) {
    result.internalformat = other.internalformat
    result.format = other.format
    result.type = other.type
    result.compressed = other.compressed

    result.premultiplyAlpha = other.premultiplyAlpha
    result.flipY = other.flipY
    result.unpackAlignment = other.unpackAlignment
    result.colorSpace = other.colorSpace

    result.width = other.width
    result.height = other.height
    result.channels = other.channels
  }

  function parseFlags (flags, options) {
    if (typeof options !== 'object' || !options) {
      return
    }

    if ('premultiplyAlpha' in options) {
      
      flags.premultiplyAlpha = options.premultiplyAlpha
    }

    if ('flipY' in options) {
      
      flags.flipY = options.flipY
    }

    if ('alignment' in options) {
      
      flags.unpackAlignment = options.alignment
    }

    if ('colorSpace' in options) {
      
      flags.colorSpace = colorSpace[options.colorSpace]
    }

    if ('type' in options) {
      var type = options.type
      
      
      
      
      flags.type = textureTypes[type]
    }

    var w = flags.width
    var h = flags.height
    var c = flags.channels
    var hasChannels = false
    if ('shape' in options) {
      
      w = options.shape[0]
      h = options.shape[1]
      if (options.shape.length === 3) {
        c = options.shape[2]
        
        hasChannels = true
      }
      
      
    } else {
      if ('radius' in options) {
        w = h = options.radius
        
      }
      if ('width' in options) {
        w = options.width
        
      }
      if ('height' in options) {
        h = options.height
        
      }
      if ('channels' in options) {
        c = options.channels
        
        hasChannels = true
      }
    }
    flags.width = w | 0
    flags.height = h | 0
    flags.channels = c | 0

    var hasFormat = false
    if ('format' in options) {
      var formatStr = options.format
      
      
      var internalformat = flags.internalformat = textureFormats[formatStr]
      flags.format = colorFormats[internalformat]
      if (formatStr in textureTypes) {
        if (!('type' in options)) {
          flags.type = textureTypes[formatStr]
        }
      }
      if (formatStr in compressedTextureFormats) {
        flags.compressed = true
      }
      hasFormat = true
    }

    // Reconcile channels and format
    if (!hasChannels && hasFormat) {
      flags.channels = FORMAT_CHANNELS[flags.format]
    } else if (hasChannels && !hasFormat) {
      if (flags.channels !== CHANNELS_FORMAT[flags.format]) {
        flags.format = flags.internalformat = CHANNELS_FORMAT[flags.channels]
      }
    } else if (hasFormat && hasChannels) {
      
    }
  }

  function setFlags (flags) {
    gl.pixelStorei(GL_UNPACK_FLIP_Y_WEBGL, flags.flipY)
    gl.pixelStorei(GL_UNPACK_PREMULTIPLY_ALPHA_WEBGL, flags.premultiplyAlpha)
    gl.pixelStorei(GL_UNPACK_COLORSPACE_CONVERSION_WEBGL, flags.colorSpace)
    gl.pixelStorei(GL_UNPACK_ALIGNMENT, flags.unpackAlignment)
  }

  // -------------------------------------------------------
  // Tex image data
  // -------------------------------------------------------
  function TexImage () {
    TexFlags.call(this)

    this.xOffset = 0
    this.yOffset = 0

    // data
    this.data = null
    this.needsFree = false

    // html element
    this.element = null

    // copyTexImage info
    this.needsCopy = false
  }

  function parseImage (image, options) {
    var data = null
    if (isPixelData(options)) {
      data = options
    } else if (options) {
      
      parseFlags(image, options)
      if ('x' in options) {
        image.xOffset = options.x | 0
      }
      if ('y' in options) {
        image.yOffset = options.y | 0
      }
      if (isPixelData(options.data)) {
        data = options.data
      }
    }

    

    if (options.copy) {
      
      var viewW = contextState.viewportWidth
      var viewH = contextState.viewportHeight
      image.width = image.width || (viewW - image.xOffset)
      image.height = image.height || (viewH - image.yOffset)
      image.needsCopy = true
      
    } else if (!data) {
      image.width = image.width || 1
      image.height = image.height || 1
      image.channels = image.channels || 4
    } else if (isTypedArray(data)) {
      image.channels = image.channels || 4
      image.data = data
      if (!('type' in options) && image.type === GL_UNSIGNED_BYTE$4) {
        image.type = typedArrayCode$1(data)
      }
    } else if (isNumericArray(data)) {
      image.channels = image.channels || 4
      convertData(image, data)
      image.alignment = 1
      image.needsFree = true
    } else if (isNDArrayLike(data)) {
      var array = data.data
      if (!Array.isArray(array) && image.type === GL_UNSIGNED_BYTE$4) {
        image.type = typedArrayCode$1(array)
      }
      var shape = data.shape
      var stride = data.stride
      var shapeX, shapeY, shapeC, strideX, strideY, strideC
      if (shape.length === 3) {
        shapeC = shape[2]
        strideC = stride[2]
      } else {
        
        shapeC = 1
        strideC = 1
      }
      shapeX = shape[0]
      shapeY = shape[1]
      strideX = stride[0]
      strideY = stride[1]
      image.alignment = 1
      image.width = shapeX
      image.height = shapeY
      image.channels = shapeC
      image.format = image.internalformat = CHANNELS_FORMAT[shapeC]
      image.needsFree = true
      transposeData(image, array, strideX, strideY, strideC, data.offset)
    } else if (isCanvasElement(data) || isOffscreenCanvas(data) || isContext2D(data)) {
      if (isCanvasElement(data) || isOffscreenCanvas(data)) {
        image.element = data
      } else {
        image.element = data.canvas
      }
      image.width = image.element.width
      image.height = image.element.height
      image.channels = 4
    } else if (isBitmap(data)) {
      image.element = data
      image.width = data.width
      image.height = data.height
      image.channels = 4
    } else if (isImageElement(data)) {
      image.element = data
      image.width = data.naturalWidth
      image.height = data.naturalHeight
      image.channels = 4
    } else if (isVideoElement(data)) {
      image.element = data
      image.width = data.videoWidth
      image.height = data.videoHeight
      image.channels = 4
    } else if (isRectArray(data)) {
      var w = image.width || data[0].length
      var h = image.height || data.length
      var c = image.channels
      if (isArrayLike(data[0][0])) {
        c = c || data[0][0].length
      } else {
        c = c || 1
      }
      var arrayShape = flattenUtils.shape(data)
      var n = 1
      for (var dd = 0; dd < arrayShape.length; ++dd) {
        n *= arrayShape[dd]
      }
      var allocData = preConvert(image, n)
      flattenUtils.flatten(data, arrayShape, '', allocData)
      postConvert(image, allocData)
      image.alignment = 1
      image.width = w
      image.height = h
      image.channels = c
      image.format = image.internalformat = CHANNELS_FORMAT[c]
      image.needsFree = true
    }

    if (image.type === GL_FLOAT$3) {
      
    } else if (image.type === GL_HALF_FLOAT_OES) {
      
    }

    // do compressed texture  validation here.
  }

  function setImage (info, target, miplevel) {
    var element = info.element
    var data = info.data
    var internalformat = info.internalformat
    var format = info.format
    var type = info.type
    var width = info.width
    var height = info.height

    setFlags(info)

    if (element) {
      gl.texImage2D(target, miplevel, format, format, type, element)
    } else if (info.compressed) {
      gl.compressedTexImage2D(target, miplevel, internalformat, width, height, 0, data)
    } else if (info.needsCopy) {
      reglPoll()
      gl.copyTexImage2D(
        target, miplevel, format, info.xOffset, info.yOffset, width, height, 0)
    } else {
      gl.texImage2D(target, miplevel, format, width, height, 0, format, type, data || null)
    }
  }

  function setSubImage (info, target, x, y, miplevel) {
    var element = info.element
    var data = info.data
    var internalformat = info.internalformat
    var format = info.format
    var type = info.type
    var width = info.width
    var height = info.height

    setFlags(info)

    if (element) {
      gl.texSubImage2D(
        target, miplevel, x, y, format, type, element)
    } else if (info.compressed) {
      gl.compressedTexSubImage2D(
        target, miplevel, x, y, internalformat, width, height, data)
    } else if (info.needsCopy) {
      reglPoll()
      gl.copyTexSubImage2D(
        target, miplevel, x, y, info.xOffset, info.yOffset, width, height)
    } else {
      gl.texSubImage2D(
        target, miplevel, x, y, width, height, format, type, data)
    }
  }

  // texImage pool
  var imagePool = []

  function allocImage () {
    return imagePool.pop() || new TexImage()
  }

  function freeImage (image) {
    if (image.needsFree) {
      pool.freeType(image.data)
    }
    TexImage.call(image)
    imagePool.push(image)
  }

  // -------------------------------------------------------
  // Mip map
  // -------------------------------------------------------
  function MipMap () {
    TexFlags.call(this)

    this.genMipmaps = false
    this.mipmapHint = GL_DONT_CARE
    this.mipmask = 0
    this.images = Array(16)
  }

  function parseMipMapFromShape (mipmap, width, height) {
    var img = mipmap.images[0] = allocImage()
    mipmap.mipmask = 1
    img.width = mipmap.width = width
    img.height = mipmap.height = height
    img.channels = mipmap.channels = 4
  }

  function parseMipMapFromObject (mipmap, options) {
    var imgData = null
    if (isPixelData(options)) {
      imgData = mipmap.images[0] = allocImage()
      copyFlags(imgData, mipmap)
      parseImage(imgData, options)
      mipmap.mipmask = 1
    } else {
      parseFlags(mipmap, options)
      if (Array.isArray(options.mipmap)) {
        var mipData = options.mipmap
        for (var i = 0; i < mipData.length; ++i) {
          imgData = mipmap.images[i] = allocImage()
          copyFlags(imgData, mipmap)
          imgData.width >>= i
          imgData.height >>= i
          parseImage(imgData, mipData[i])
          mipmap.mipmask |= (1 << i)
        }
      } else {
        imgData = mipmap.images[0] = allocImage()
        copyFlags(imgData, mipmap)
        parseImage(imgData, options)
        mipmap.mipmask = 1
      }
    }
    copyFlags(mipmap, mipmap.images[0])

    // For textures of the compressed format WEBGL_compressed_texture_s3tc
    // we must have that
    //
    // "When level equals zero width and height must be a multiple of 4.
    // When level is greater than 0 width and height must be 0, 1, 2 or a multiple of 4. "
    //
    // but we do not yet support having multiple mipmap levels for compressed textures,
    // so we only test for level zero.

    if (
      mipmap.compressed &&
      (
        mipmap.internalformat === GL_COMPRESSED_RGB_S3TC_DXT1_EXT ||
        mipmap.internalformat === GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
        mipmap.internalformat === GL_COMPRESSED_RGBA_S3TC_DXT3_EXT ||
        mipmap.internalformat === GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
      )
    ) {
      
    }
  }

  function setMipMap (mipmap, target) {
    var images = mipmap.images
    for (var i = 0; i < images.length; ++i) {
      if (!images[i]) {
        return
      }
      setImage(images[i], target, i)
    }
  }

  var mipPool = []

  function allocMipMap () {
    var result = mipPool.pop() || new MipMap()
    TexFlags.call(result)
    result.mipmask = 0
    for (var i = 0; i < 16; ++i) {
      result.images[i] = null
    }
    return result
  }

  function freeMipMap (mipmap) {
    var images = mipmap.images
    for (var i = 0; i < images.length; ++i) {
      if (images[i]) {
        freeImage(images[i])
      }
      images[i] = null
    }
    mipPool.push(mipmap)
  }

  // -------------------------------------------------------
  // Tex info
  // -------------------------------------------------------
  function TexInfo () {
    this.minFilter = GL_NEAREST
    this.magFilter = GL_NEAREST

    this.wrapS = GL_CLAMP_TO_EDGE
    this.wrapT = GL_CLAMP_TO_EDGE

    this.anisotropic = 1

    this.genMipmaps = false
    this.mipmapHint = GL_DONT_CARE
  }

  function parseTexInfo (info, options) {
    if ('min' in options) {
      var minFilter = options.min
      
      info.minFilter = minFilters[minFilter]
      if (MIPMAP_FILTERS.indexOf(info.minFilter) >= 0 && !('faces' in options)) {
        info.genMipmaps = true
      }
    }

    if ('mag' in options) {
      var magFilter = options.mag
      
      info.magFilter = magFilters[magFilter]
    }

    var wrapS = info.wrapS
    var wrapT = info.wrapT
    if ('wrap' in options) {
      var wrap = options.wrap
      if (typeof wrap === 'string') {
        
        wrapS = wrapT = wrapModes[wrap]
      } else if (Array.isArray(wrap)) {
        
        
        wrapS = wrapModes[wrap[0]]
        wrapT = wrapModes[wrap[1]]
      }
    } else {
      if ('wrapS' in options) {
        var optWrapS = options.wrapS
        
        wrapS = wrapModes[optWrapS]
      }
      if ('wrapT' in options) {
        var optWrapT = options.wrapT
        
        wrapT = wrapModes[optWrapT]
      }
    }
    info.wrapS = wrapS
    info.wrapT = wrapT

    if ('anisotropic' in options) {
      var anisotropic = options.anisotropic
      
      info.anisotropic = options.anisotropic
    }

    if ('mipmap' in options) {
      var hasMipMap = false
      switch (typeof options.mipmap) {
        case 'string':
          
          info.mipmapHint = mipmapHint[options.mipmap]
          info.genMipmaps = true
          hasMipMap = true
          break

        case 'boolean':
          hasMipMap = info.genMipmaps = options.mipmap
          break

        case 'object':
          
          info.genMipmaps = false
          hasMipMap = true
          break

        default:
          
      }
      if (hasMipMap && !('min' in options)) {
        info.minFilter = GL_NEAREST_MIPMAP_NEAREST
      }
    }
  }

  function setTexInfo (info, target) {
    gl.texParameteri(target, GL_TEXTURE_MIN_FILTER, info.minFilter)
    gl.texParameteri(target, GL_TEXTURE_MAG_FILTER, info.magFilter)
    gl.texParameteri(target, GL_TEXTURE_WRAP_S, info.wrapS)
    gl.texParameteri(target, GL_TEXTURE_WRAP_T, info.wrapT)
    if (extensions.ext_texture_filter_anisotropic) {
      gl.texParameteri(target, GL_TEXTURE_MAX_ANISOTROPY_EXT, info.anisotropic)
    }
    if (info.genMipmaps) {
      gl.hint(GL_GENERATE_MIPMAP_HINT, info.mipmapHint)
      gl.generateMipmap(target)
    }
  }

  // -------------------------------------------------------
  // Full texture object
  // -------------------------------------------------------
  var textureCount = 0
  var textureSet = {}
  var numTexUnits = limits.maxTextureUnits
  var textureUnits = Array(numTexUnits).map(function () {
    return null
  })

  function REGLTexture (target) {
    TexFlags.call(this)
    this.mipmask = 0
    this.internalformat = GL_RGBA$1

    this.id = textureCount++

    this.refCount = 1

    this.target = target
    this.texture = gl.createTexture()

    this.unit = -1
    this.bindCount = 0

    this.texInfo = new TexInfo()

    if (config.profile) {
      this.stats = { size: 0 }
    }
  }

  function tempBind (texture) {
    gl.activeTexture(GL_TEXTURE0$1)
    gl.bindTexture(texture.target, texture.texture)
  }

  function tempRestore () {
    var prev = textureUnits[0]
    if (prev) {
      gl.bindTexture(prev.target, prev.texture)
    } else {
      gl.bindTexture(GL_TEXTURE_2D$1, null)
    }
  }

  function destroy (texture) {
    var handle = texture.texture
    
    var unit = texture.unit
    var target = texture.target
    if (unit >= 0) {
      gl.activeTexture(GL_TEXTURE0$1 + unit)
      gl.bindTexture(target, null)
      textureUnits[unit] = null
    }
    gl.deleteTexture(handle)
    texture.texture = null
    texture.params = null
    texture.pixels = null
    texture.refCount = 0
    delete textureSet[texture.id]
    stats.textureCount--
  }

  extend(REGLTexture.prototype, {
    bind: function () {
      var texture = this
      texture.bindCount += 1
      var unit = texture.unit
      if (unit < 0) {
        for (var i = 0; i < numTexUnits; ++i) {
          var other = textureUnits[i]
          if (other) {
            if (other.bindCount > 0) {
              continue
            }
            other.unit = -1
          }
          textureUnits[i] = texture
          unit = i
          break
        }
        if (unit >= numTexUnits) {
          
        }
        if (config.profile && stats.maxTextureUnits < (unit + 1)) {
          stats.maxTextureUnits = unit + 1 // +1, since the units are zero-based
        }
        texture.unit = unit
        gl.activeTexture(GL_TEXTURE0$1 + unit)
        gl.bindTexture(texture.target, texture.texture)
      }
      return unit
    },

    unbind: function () {
      this.bindCount -= 1
    },

    decRef: function () {
      if (--this.refCount <= 0) {
        destroy(this)
      }
    }
  })

  function createTexture2D (a, b) {
    var texture = new REGLTexture(GL_TEXTURE_2D$1)
    textureSet[texture.id] = texture
    stats.textureCount++

    function reglTexture2D (a, b) {
      var texInfo = texture.texInfo
      TexInfo.call(texInfo)
      var mipData = allocMipMap()

      if (typeof a === 'number') {
        if (typeof b === 'number') {
          parseMipMapFromShape(mipData, a | 0, b | 0)
        } else {
          parseMipMapFromShape(mipData, a | 0, a | 0)
        }
      } else if (a) {
        
        parseTexInfo(texInfo, a)
        parseMipMapFromObject(mipData, a)
      } else {
        // empty textures get assigned a default shape of 1x1
        parseMipMapFromShape(mipData, 1, 1)
      }

      if (texInfo.genMipmaps) {
        mipData.mipmask = (mipData.width << 1) - 1
      }
      texture.mipmask = mipData.mipmask

      copyFlags(texture, mipData)

      
      texture.internalformat = mipData.internalformat

      reglTexture2D.width = mipData.width
      reglTexture2D.height = mipData.height

      tempBind(texture)
      setMipMap(mipData, GL_TEXTURE_2D$1)
      setTexInfo(texInfo, GL_TEXTURE_2D$1)
      tempRestore()

      freeMipMap(mipData)

      if (config.profile) {
        texture.stats.size = getTextureSize(
          texture.internalformat,
          texture.type,
          mipData.width,
          mipData.height,
          texInfo.genMipmaps,
          false)
      }
      reglTexture2D.format = textureFormatsInvert[texture.internalformat]
      reglTexture2D.type = textureTypesInvert[texture.type]

      reglTexture2D.mag = magFiltersInvert[texInfo.magFilter]
      reglTexture2D.min = minFiltersInvert[texInfo.minFilter]

      reglTexture2D.wrapS = wrapModesInvert[texInfo.wrapS]
      reglTexture2D.wrapT = wrapModesInvert[texInfo.wrapT]

      return reglTexture2D
    }

    function subimage (image, x_, y_, level_) {
      

      var x = x_ | 0
      var y = y_ | 0
      var level = level_ | 0

      var imageData = allocImage()
      copyFlags(imageData, texture)
      imageData.width = 0
      imageData.height = 0
      parseImage(imageData, image)
      imageData.width = imageData.width || ((texture.width >> level) - x)
      imageData.height = imageData.height || ((texture.height >> level) - y)

      
      
      
      

      tempBind(texture)
      setSubImage(imageData, GL_TEXTURE_2D$1, x, y, level)
      tempRestore()

      freeImage(imageData)

      return reglTexture2D
    }

    function resize (w_, h_) {
      var w = w_ | 0
      var h = (h_ | 0) || w
      if (w === texture.width && h === texture.height) {
        return reglTexture2D
      }

      reglTexture2D.width = texture.width = w
      reglTexture2D.height = texture.height = h

      tempBind(texture)

      for (var i = 0; texture.mipmask >> i; ++i) {
        var _w = w >> i
        var _h = h >> i
        if (!_w || !_h) break
        gl.texImage2D(
          GL_TEXTURE_2D$1,
          i,
          texture.format,
          _w,
          _h,
          0,
          texture.format,
          texture.type,
          null)
      }
      tempRestore()

      // also, recompute the texture size.
      if (config.profile) {
        texture.stats.size = getTextureSize(
          texture.internalformat,
          texture.type,
          w,
          h,
          false,
          false)
      }

      return reglTexture2D
    }

    reglTexture2D(a, b)

    reglTexture2D.subimage = subimage
    reglTexture2D.resize = resize
    reglTexture2D._reglType = 'texture2d'
    reglTexture2D._texture = texture
    if (config.profile) {
      reglTexture2D.stats = texture.stats
    }
    reglTexture2D.destroy = function () {
      texture.decRef()
    }

    return reglTexture2D
  }

  function createTextureCube (a0, a1, a2, a3, a4, a5) {
    var texture = new REGLTexture(GL_TEXTURE_CUBE_MAP$1)
    textureSet[texture.id] = texture
    stats.cubeCount++

    var faces = new Array(6)

    function reglTextureCube (a0, a1, a2, a3, a4, a5) {
      var i
      var texInfo = texture.texInfo
      TexInfo.call(texInfo)
      for (i = 0; i < 6; ++i) {
        faces[i] = allocMipMap()
      }

      if (typeof a0 === 'number' || !a0) {
        var s = (a0 | 0) || 1
        for (i = 0; i < 6; ++i) {
          parseMipMapFromShape(faces[i], s, s)
        }
      } else if (typeof a0 === 'object') {
        if (a1) {
          parseMipMapFromObject(faces[0], a0)
          parseMipMapFromObject(faces[1], a1)
          parseMipMapFromObject(faces[2], a2)
          parseMipMapFromObject(faces[3], a3)
          parseMipMapFromObject(faces[4], a4)
          parseMipMapFromObject(faces[5], a5)
        } else {
          parseTexInfo(texInfo, a0)
          parseFlags(texture, a0)
          if ('faces' in a0) {
            var faceInput = a0.faces
            
            for (i = 0; i < 6; ++i) {
              
              copyFlags(faces[i], texture)
              parseMipMapFromObject(faces[i], faceInput[i])
            }
          } else {
            for (i = 0; i < 6; ++i) {
              parseMipMapFromObject(faces[i], a0)
            }
          }
        }
      } else {
        
      }

      copyFlags(texture, faces[0])
      

      if (texInfo.genMipmaps) {
        texture.mipmask = (faces[0].width << 1) - 1
      } else {
        texture.mipmask = faces[0].mipmask
      }

      
      texture.internalformat = faces[0].internalformat

      reglTextureCube.width = faces[0].width
      reglTextureCube.height = faces[0].height

      tempBind(texture)
      for (i = 0; i < 6; ++i) {
        setMipMap(faces[i], GL_TEXTURE_CUBE_MAP_POSITIVE_X$1 + i)
      }
      setTexInfo(texInfo, GL_TEXTURE_CUBE_MAP$1)
      tempRestore()

      if (config.profile) {
        texture.stats.size = getTextureSize(
          texture.internalformat,
          texture.type,
          reglTextureCube.width,
          reglTextureCube.height,
          texInfo.genMipmaps,
          true)
      }

      reglTextureCube.format = textureFormatsInvert[texture.internalformat]
      reglTextureCube.type = textureTypesInvert[texture.type]

      reglTextureCube.mag = magFiltersInvert[texInfo.magFilter]
      reglTextureCube.min = minFiltersInvert[texInfo.minFilter]

      reglTextureCube.wrapS = wrapModesInvert[texInfo.wrapS]
      reglTextureCube.wrapT = wrapModesInvert[texInfo.wrapT]

      for (i = 0; i < 6; ++i) {
        freeMipMap(faces[i])
      }

      return reglTextureCube
    }

    function subimage (face, image, x_, y_, level_) {
      
      

      var x = x_ | 0
      var y = y_ | 0
      var level = level_ | 0

      var imageData = allocImage()
      copyFlags(imageData, texture)
      imageData.width = 0
      imageData.height = 0
      parseImage(imageData, image)
      imageData.width = imageData.width || ((texture.width >> level) - x)
      imageData.height = imageData.height || ((texture.height >> level) - y)

      
      
      
      

      tempBind(texture)
      setSubImage(imageData, GL_TEXTURE_CUBE_MAP_POSITIVE_X$1 + face, x, y, level)
      tempRestore()

      freeImage(imageData)

      return reglTextureCube
    }

    function resize (radius_) {
      var radius = radius_ | 0
      if (radius === texture.width) {
        return
      }

      reglTextureCube.width = texture.width = radius
      reglTextureCube.height = texture.height = radius

      tempBind(texture)
      for (var i = 0; i < 6; ++i) {
        for (var j = 0; texture.mipmask >> j; ++j) {
          gl.texImage2D(
            GL_TEXTURE_CUBE_MAP_POSITIVE_X$1 + i,
            j,
            texture.format,
            radius >> j,
            radius >> j,
            0,
            texture.format,
            texture.type,
            null)
        }
      }
      tempRestore()

      if (config.profile) {
        texture.stats.size = getTextureSize(
          texture.internalformat,
          texture.type,
          reglTextureCube.width,
          reglTextureCube.height,
          false,
          true)
      }

      return reglTextureCube
    }

    reglTextureCube(a0, a1, a2, a3, a4, a5)

    reglTextureCube.subimage = subimage
    reglTextureCube.resize = resize
    reglTextureCube._reglType = 'textureCube'
    reglTextureCube._texture = texture
    if (config.profile) {
      reglTextureCube.stats = texture.stats
    }
    reglTextureCube.destroy = function () {
      texture.decRef()
    }

    return reglTextureCube
  }

  // Called when regl is destroyed
  function destroyTextures () {
    for (var i = 0; i < numTexUnits; ++i) {
      gl.activeTexture(GL_TEXTURE0$1 + i)
      gl.bindTexture(GL_TEXTURE_2D$1, null)
      textureUnits[i] = null
    }
    values(textureSet).forEach(destroy)

    stats.cubeCount = 0
    stats.textureCount = 0
  }

  if (config.profile) {
    stats.getTotalTextureSize = function () {
      var total = 0
      Object.keys(textureSet).forEach(function (key) {
        total += textureSet[key].stats.size
      })
      return total
    }
  }

  function restoreTextures () {
    for (var i = 0; i < numTexUnits; ++i) {
      var tex = textureUnits[i]
      if (tex) {
        tex.bindCount = 0
        tex.unit = -1
        textureUnits[i] = null
      }
    }

    values(textureSet).forEach(function (texture) {
      texture.texture = gl.createTexture()
      gl.bindTexture(texture.target, texture.texture)
      for (var i = 0; i < 32; ++i) {
        if ((texture.mipmask & (1 << i)) === 0) {
          continue
        }
        if (texture.target === GL_TEXTURE_2D$1) {
          gl.texImage2D(GL_TEXTURE_2D$1,
            i,
            texture.internalformat,
            texture.width >> i,
            texture.height >> i,
            0,
            texture.internalformat,
            texture.type,
            null)
        } else {
          for (var j = 0; j < 6; ++j) {
            gl.texImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X$1 + j,
              i,
              texture.internalformat,
              texture.width >> i,
              texture.height >> i,
              0,
              texture.internalformat,
              texture.type,
              null)
          }
        }
      }
      setTexInfo(texture.texInfo, texture.target)
    })
  }

  function refreshTextures () {
    for (var i = 0; i < numTexUnits; ++i) {
      var tex = textureUnits[i]
      if (tex) {
        tex.bindCount = 0
        tex.unit = -1
        textureUnits[i] = null
      }
      gl.activeTexture(GL_TEXTURE0$1 + i)
      gl.bindTexture(GL_TEXTURE_2D$1, null)
      gl.bindTexture(GL_TEXTURE_CUBE_MAP$1, null)
    }
  }

  return {
    create2D: createTexture2D,
    createCube: createTextureCube,
    clear: destroyTextures,
    getTexture: function (wrapper) {
      return null
    },
    restore: restoreTextures,
    refresh: refreshTextures
  }
}

var GL_RENDERBUFFER = 0x8D41

var GL_RGBA4$1 = 0x8056
var GL_RGB5_A1$1 = 0x8057
var GL_RGB565$1 = 0x8D62
var GL_DEPTH_COMPONENT16 = 0x81A5
var GL_STENCIL_INDEX8 = 0x8D48
var GL_DEPTH_STENCIL$1 = 0x84F9

var GL_SRGB8_ALPHA8_EXT = 0x8C43

var GL_RGBA32F_EXT = 0x8814

var GL_RGBA16F_EXT = 0x881A
var GL_RGB16F_EXT = 0x881B

var FORMAT_SIZES = []

FORMAT_SIZES[GL_RGBA4$1] = 2
FORMAT_SIZES[GL_RGB5_A1$1] = 2
FORMAT_SIZES[GL_RGB565$1] = 2

FORMAT_SIZES[GL_DEPTH_COMPONENT16] = 2
FORMAT_SIZES[GL_STENCIL_INDEX8] = 1
FORMAT_SIZES[GL_DEPTH_STENCIL$1] = 4

FORMAT_SIZES[GL_SRGB8_ALPHA8_EXT] = 4
FORMAT_SIZES[GL_RGBA32F_EXT] = 16
FORMAT_SIZES[GL_RGBA16F_EXT] = 8
FORMAT_SIZES[GL_RGB16F_EXT] = 6

function getRenderbufferSize (format, width, height) {
  return FORMAT_SIZES[format] * width * height
}

var wrapRenderbuffers = function (gl, extensions, limits, stats, config) {
  var formatTypes = {
    'rgba4': GL_RGBA4$1,
    'rgb565': GL_RGB565$1,
    'rgb5 a1': GL_RGB5_A1$1,
    'depth': GL_DEPTH_COMPONENT16,
    'stencil': GL_STENCIL_INDEX8,
    'depth stencil': GL_DEPTH_STENCIL$1
  }

  if (extensions.ext_srgb) {
    formatTypes['srgba'] = GL_SRGB8_ALPHA8_EXT
  }

  if (extensions.ext_color_buffer_half_float) {
    formatTypes['rgba16f'] = GL_RGBA16F_EXT
    formatTypes['rgb16f'] = GL_RGB16F_EXT
  }

  if (extensions.webgl_color_buffer_float) {
    formatTypes['rgba32f'] = GL_RGBA32F_EXT
  }

  var formatTypesInvert = []
  Object.keys(formatTypes).forEach(function (key) {
    var val = formatTypes[key]
    formatTypesInvert[val] = key
  })

  var renderbufferCount = 0
  var renderbufferSet = {}

  function REGLRenderbuffer (renderbuffer) {
    this.id = renderbufferCount++
    this.refCount = 1

    this.renderbuffer = renderbuffer

    this.format = GL_RGBA4$1
    this.width = 0
    this.height = 0

    if (config.profile) {
      this.stats = { size: 0 }
    }
  }

  REGLRenderbuffer.prototype.decRef = function () {
    if (--this.refCount <= 0) {
      destroy(this)
    }
  }

  function destroy (rb) {
    var handle = rb.renderbuffer
    
    gl.bindRenderbuffer(GL_RENDERBUFFER, null)
    gl.deleteRenderbuffer(handle)
    rb.renderbuffer = null
    rb.refCount = 0
    delete renderbufferSet[rb.id]
    stats.renderbufferCount--
  }

  function createRenderbuffer (a, b) {
    var renderbuffer = new REGLRenderbuffer(gl.createRenderbuffer())
    renderbufferSet[renderbuffer.id] = renderbuffer
    stats.renderbufferCount++

    function reglRenderbuffer (a, b) {
      var w = 0
      var h = 0
      var format = GL_RGBA4$1

      if (typeof a === 'object' && a) {
        var options = a
        if ('shape' in options) {
          var shape = options.shape
          
          w = shape[0] | 0
          h = shape[1] | 0
        } else {
          if ('radius' in options) {
            w = h = options.radius | 0
          }
          if ('width' in options) {
            w = options.width | 0
          }
          if ('height' in options) {
            h = options.height | 0
          }
        }
        if ('format' in options) {
          
          format = formatTypes[options.format]
        }
      } else if (typeof a === 'number') {
        w = a | 0
        if (typeof b === 'number') {
          h = b | 0
        } else {
          h = w
        }
      } else if (!a) {
        w = h = 1
      } else {
        
      }

      // check shape
      

      if (w === renderbuffer.width &&
          h === renderbuffer.height &&
          format === renderbuffer.format) {
        return
      }

      reglRenderbuffer.width = renderbuffer.width = w
      reglRenderbuffer.height = renderbuffer.height = h
      renderbuffer.format = format

      gl.bindRenderbuffer(GL_RENDERBUFFER, renderbuffer.renderbuffer)
      gl.renderbufferStorage(GL_RENDERBUFFER, format, w, h)

      

      if (config.profile) {
        renderbuffer.stats.size = getRenderbufferSize(renderbuffer.format, renderbuffer.width, renderbuffer.height)
      }
      reglRenderbuffer.format = formatTypesInvert[renderbuffer.format]

      return reglRenderbuffer
    }

    function resize (w_, h_) {
      var w = w_ | 0
      var h = (h_ | 0) || w

      if (w === renderbuffer.width && h === renderbuffer.height) {
        return reglRenderbuffer
      }

      // check shape
      

      reglRenderbuffer.width = renderbuffer.width = w
      reglRenderbuffer.height = renderbuffer.height = h

      gl.bindRenderbuffer(GL_RENDERBUFFER, renderbuffer.renderbuffer)
      gl.renderbufferStorage(GL_RENDERBUFFER, renderbuffer.format, w, h)

      

      // also, recompute size.
      if (config.profile) {
        renderbuffer.stats.size = getRenderbufferSize(
          renderbuffer.format, renderbuffer.width, renderbuffer.height)
      }

      return reglRenderbuffer
    }

    reglRenderbuffer(a, b)

    reglRenderbuffer.resize = resize
    reglRenderbuffer._reglType = 'renderbuffer'
    reglRenderbuffer._renderbuffer = renderbuffer
    if (config.profile) {
      reglRenderbuffer.stats = renderbuffer.stats
    }
    reglRenderbuffer.destroy = function () {
      renderbuffer.decRef()
    }

    return reglRenderbuffer
  }

  if (config.profile) {
    stats.getTotalRenderbufferSize = function () {
      var total = 0
      Object.keys(renderbufferSet).forEach(function (key) {
        total += renderbufferSet[key].stats.size
      })
      return total
    }
  }

  function restoreRenderbuffers () {
    values(renderbufferSet).forEach(function (rb) {
      rb.renderbuffer = gl.createRenderbuffer()
      gl.bindRenderbuffer(GL_RENDERBUFFER, rb.renderbuffer)
      gl.renderbufferStorage(GL_RENDERBUFFER, rb.format, rb.width, rb.height)
    })
    gl.bindRenderbuffer(GL_RENDERBUFFER, null)
  }

  return {
    create: createRenderbuffer,
    clear: function () {
      values(renderbufferSet).forEach(destroy)
    },
    restore: restoreRenderbuffers
  }
}

// We store these constants so that the minifier can inline them
var GL_FRAMEBUFFER$1 = 0x8D40
var GL_RENDERBUFFER$1 = 0x8D41

var GL_TEXTURE_2D$2 = 0x0DE1
var GL_TEXTURE_CUBE_MAP_POSITIVE_X$2 = 0x8515

var GL_COLOR_ATTACHMENT0$1 = 0x8CE0
var GL_DEPTH_ATTACHMENT = 0x8D00
var GL_STENCIL_ATTACHMENT = 0x8D20
var GL_DEPTH_STENCIL_ATTACHMENT = 0x821A

var GL_FRAMEBUFFER_COMPLETE$1 = 0x8CD5
var GL_HALF_FLOAT_OES$1 = 0x8D61
var GL_UNSIGNED_BYTE$5 = 0x1401
var GL_FLOAT$4 = 0x1406

var GL_RGB$1 = 0x1907
var GL_RGBA$2 = 0x1908

// for every texture format, store
// the number of channels
var textureFormatChannels = []
textureFormatChannels[GL_RGBA$2] = 4
textureFormatChannels[GL_RGB$1] = 3

// for every texture type, store
// the size in bytes.
var textureTypeSizes = []
textureTypeSizes[GL_UNSIGNED_BYTE$5] = 1
textureTypeSizes[GL_FLOAT$4] = 4
textureTypeSizes[GL_HALF_FLOAT_OES$1] = 2

function wrapFBOState (
  gl,
  extensions,
  limits,
  textureState,
  renderbufferState,
  stats) {
  var framebufferState = {
    cur: null,
    next: null,
    dirty: false,
    setFBO: null
  }

  var colorTextureFormats = ['rgba']
  var colorRenderbufferFormats = ['rgba4', 'rgb565', 'rgb5 a1']

  if (extensions.ext_srgb) {
    colorRenderbufferFormats.push('srgba')
  }

  if (extensions.ext_color_buffer_half_float) {
    colorRenderbufferFormats.push('rgba16f', 'rgb16f')
  }

  if (extensions.webgl_color_buffer_float) {
    colorRenderbufferFormats.push('rgba32f')
  }

  var colorTypes = ['uint8']
  if (extensions.oes_texture_half_float) {
    colorTypes.push('half float', 'float16')
  }
  if (extensions.oes_texture_float) {
    colorTypes.push('float', 'float32')
  }

  function FramebufferAttachment (target, texture, renderbuffer) {
    this.target = target
    this.texture = texture
    this.renderbuffer = renderbuffer

    var w = 0
    var h = 0
    if (texture) {
      w = texture.width
      h = texture.height
    } else if (renderbuffer) {
      w = renderbuffer.width
      h = renderbuffer.height
    }
    this.width = w
    this.height = h
  }

  function decRef (attachment) {
    if (attachment) {
      if (attachment.texture) {
        attachment.texture._texture.decRef()
      }
      if (attachment.renderbuffer) {
        attachment.renderbuffer._renderbuffer.decRef()
      }
    }
  }

  function incRefAndCheckShape (attachment, width, height) {
    if (!attachment) {
      return
    }
    if (attachment.texture) {
      var texture = attachment.texture._texture
      var tw = Math.max(1, texture.width)
      var th = Math.max(1, texture.height)
      
      texture.refCount += 1
    } else {
      var renderbuffer = attachment.renderbuffer._renderbuffer
      
      renderbuffer.refCount += 1
    }
  }

  function attach (location, attachment) {
    if (attachment) {
      if (attachment.texture) {
        gl.framebufferTexture2D(
          GL_FRAMEBUFFER$1,
          location,
          attachment.target,
          attachment.texture._texture.texture,
          0)
      } else {
        gl.framebufferRenderbuffer(
          GL_FRAMEBUFFER$1,
          location,
          GL_RENDERBUFFER$1,
          attachment.renderbuffer._renderbuffer.renderbuffer)
      }
    }
  }

  function parseAttachment (attachment) {
    var target = GL_TEXTURE_2D$2
    var texture = null
    var renderbuffer = null

    var data = attachment
    if (typeof attachment === 'object') {
      data = attachment.data
      if ('target' in attachment) {
        target = attachment.target | 0
      }
    }

    

    var type = data._reglType
    if (type === 'texture2d') {
      texture = data
      
    } else if (type === 'textureCube') {
      texture = data
      
    } else if (type === 'renderbuffer') {
      renderbuffer = data
      target = GL_RENDERBUFFER$1
    } else {
      
    }

    return new FramebufferAttachment(target, texture, renderbuffer)
  }

  function allocAttachment (
    width,
    height,
    isTexture,
    format,
    type) {
    if (isTexture) {
      var texture = textureState.create2D({
        width: width,
        height: height,
        format: format,
        type: type
      })
      texture._texture.refCount = 0
      return new FramebufferAttachment(GL_TEXTURE_2D$2, texture, null)
    } else {
      var rb = renderbufferState.create({
        width: width,
        height: height,
        format: format
      })
      rb._renderbuffer.refCount = 0
      return new FramebufferAttachment(GL_RENDERBUFFER$1, null, rb)
    }
  }

  function unwrapAttachment (attachment) {
    return attachment && (attachment.texture || attachment.renderbuffer)
  }

  function resizeAttachment (attachment, w, h) {
    if (attachment) {
      if (attachment.texture) {
        attachment.texture.resize(w, h)
      } else if (attachment.renderbuffer) {
        attachment.renderbuffer.resize(w, h)
      }
      attachment.width = w
      attachment.height = h
    }
  }

  var framebufferCount = 0
  var framebufferSet = {}

  function REGLFramebuffer () {
    this.id = framebufferCount++
    framebufferSet[this.id] = this

    this.framebuffer = gl.createFramebuffer()
    this.width = 0
    this.height = 0

    this.colorAttachments = []
    this.depthAttachment = null
    this.stencilAttachment = null
    this.depthStencilAttachment = null
  }

  function decFBORefs (framebuffer) {
    framebuffer.colorAttachments.forEach(decRef)
    decRef(framebuffer.depthAttachment)
    decRef(framebuffer.stencilAttachment)
    decRef(framebuffer.depthStencilAttachment)
  }

  function destroy (framebuffer) {
    var handle = framebuffer.framebuffer
    
    gl.deleteFramebuffer(handle)
    framebuffer.framebuffer = null
    stats.framebufferCount--
    delete framebufferSet[framebuffer.id]
  }

  function updateFramebuffer (framebuffer) {
    var i

    gl.bindFramebuffer(GL_FRAMEBUFFER$1, framebuffer.framebuffer)
    var colorAttachments = framebuffer.colorAttachments
    for (i = 0; i < colorAttachments.length; ++i) {
      attach(GL_COLOR_ATTACHMENT0$1 + i, colorAttachments[i])
    }
    for (i = colorAttachments.length; i < limits.maxColorAttachments; ++i) {
      gl.framebufferTexture2D(
        GL_FRAMEBUFFER$1,
        GL_COLOR_ATTACHMENT0$1 + i,
        GL_TEXTURE_2D$2,
        null,
        0)
    }

    gl.framebufferTexture2D(
      GL_FRAMEBUFFER$1,
      GL_DEPTH_STENCIL_ATTACHMENT,
      GL_TEXTURE_2D$2,
      null,
      0)
    gl.framebufferTexture2D(
      GL_FRAMEBUFFER$1,
      GL_DEPTH_ATTACHMENT,
      GL_TEXTURE_2D$2,
      null,
      0)
    gl.framebufferTexture2D(
      GL_FRAMEBUFFER$1,
      GL_STENCIL_ATTACHMENT,
      GL_TEXTURE_2D$2,
      null,
      0)

    attach(GL_DEPTH_ATTACHMENT, framebuffer.depthAttachment)
    attach(GL_STENCIL_ATTACHMENT, framebuffer.stencilAttachment)
    attach(GL_DEPTH_STENCIL_ATTACHMENT, framebuffer.depthStencilAttachment)

    // Check status code
    var status = gl.checkFramebufferStatus(GL_FRAMEBUFFER$1)
    if (!gl.isContextLost() && status !== GL_FRAMEBUFFER_COMPLETE$1) {
      
    }

    gl.bindFramebuffer(GL_FRAMEBUFFER$1, framebufferState.next ? framebufferState.next.framebuffer : null)
    framebufferState.cur = framebufferState.next

    // FIXME: Clear error code here.  This is a work around for a bug in
    // headless-gl
    gl.getError()
  }

  function createFBO (a0, a1) {
    var framebuffer = new REGLFramebuffer()
    stats.framebufferCount++

    function reglFramebuffer (a, b) {
      var i

      

      var width = 0
      var height = 0

      var needsDepth = true
      var needsStencil = true

      var colorBuffer = null
      var colorTexture = true
      var colorFormat = 'rgba'
      var colorType = 'uint8'
      var colorCount = 1

      var depthBuffer = null
      var stencilBuffer = null
      var depthStencilBuffer = null
      var depthStencilTexture = false

      if (typeof a === 'number') {
        width = a | 0
        height = (b | 0) || width
      } else if (!a) {
        width = height = 1
      } else {
        
        var options = a

        if ('shape' in options) {
          var shape = options.shape
          
          width = shape[0]
          height = shape[1]
        } else {
          if ('radius' in options) {
            width = height = options.radius
          }
          if ('width' in options) {
            width = options.width
          }
          if ('height' in options) {
            height = options.height
          }
        }

        if ('color' in options ||
            'colors' in options) {
          colorBuffer =
            options.color ||
            options.colors
          if (Array.isArray(colorBuffer)) {
            
          }
        }

        if (!colorBuffer) {
          if ('colorCount' in options) {
            colorCount = options.colorCount | 0
            
          }

          if ('colorTexture' in options) {
            colorTexture = !!options.colorTexture
            colorFormat = 'rgba4'
          }

          if ('colorType' in options) {
            colorType = options.colorType
            if (!colorTexture) {
              if (colorType === 'half float' || colorType === 'float16') {
                
                colorFormat = 'rgba16f'
              } else if (colorType === 'float' || colorType === 'float32') {
                
                colorFormat = 'rgba32f'
              }
            } else {
              
              
            }
            
          }

          if ('colorFormat' in options) {
            colorFormat = options.colorFormat
            if (colorTextureFormats.indexOf(colorFormat) >= 0) {
              colorTexture = true
            } else if (colorRenderbufferFormats.indexOf(colorFormat) >= 0) {
              colorTexture = false
            } else {
              
            }
          }
        }

        if ('depthTexture' in options || 'depthStencilTexture' in options) {
          depthStencilTexture = !!(options.depthTexture ||
            options.depthStencilTexture)
          
        }

        if ('depth' in options) {
          if (typeof options.depth === 'boolean') {
            needsDepth = options.depth
          } else {
            depthBuffer = options.depth
            needsStencil = false
          }
        }

        if ('stencil' in options) {
          if (typeof options.stencil === 'boolean') {
            needsStencil = options.stencil
          } else {
            stencilBuffer = options.stencil
            needsDepth = false
          }
        }

        if ('depthStencil' in options) {
          if (typeof options.depthStencil === 'boolean') {
            needsDepth = needsStencil = options.depthStencil
          } else {
            depthStencilBuffer = options.depthStencil
            needsDepth = false
            needsStencil = false
          }
        }
      }

      // parse attachments
      var colorAttachments = null
      var depthAttachment = null
      var stencilAttachment = null
      var depthStencilAttachment = null

      // Set up color attachments
      if (Array.isArray(colorBuffer)) {
        colorAttachments = colorBuffer.map(parseAttachment)
      } else if (colorBuffer) {
        colorAttachments = [parseAttachment(colorBuffer)]
      } else {
        colorAttachments = new Array(colorCount)
        for (i = 0; i < colorCount; ++i) {
          colorAttachments[i] = allocAttachment(
            width,
            height,
            colorTexture,
            colorFormat,
            colorType)
        }
      }

      
      

      width = width || colorAttachments[0].width
      height = height || colorAttachments[0].height

      if (depthBuffer) {
        depthAttachment = parseAttachment(depthBuffer)
      } else if (needsDepth && !needsStencil) {
        depthAttachment = allocAttachment(
          width,
          height,
          depthStencilTexture,
          'depth',
          'uint32')
      }

      if (stencilBuffer) {
        stencilAttachment = parseAttachment(stencilBuffer)
      } else if (needsStencil && !needsDepth) {
        stencilAttachment = allocAttachment(
          width,
          height,
          false,
          'stencil',
          'uint8')
      }

      if (depthStencilBuffer) {
        depthStencilAttachment = parseAttachment(depthStencilBuffer)
      } else if (!depthBuffer && !stencilBuffer && needsStencil && needsDepth) {
        depthStencilAttachment = allocAttachment(
          width,
          height,
          depthStencilTexture,
          'depth stencil',
          'depth stencil')
      }

      

      var commonColorAttachmentSize = null

      for (i = 0; i < colorAttachments.length; ++i) {
        incRefAndCheckShape(colorAttachments[i], width, height)
        

        if (colorAttachments[i] && colorAttachments[i].texture) {
          var colorAttachmentSize =
              textureFormatChannels[colorAttachments[i].texture._texture.format] *
              textureTypeSizes[colorAttachments[i].texture._texture.type]

          if (commonColorAttachmentSize === null) {
            commonColorAttachmentSize = colorAttachmentSize
          } else {
            // We need to make sure that all color attachments have the same number of bitplanes
            // (that is, the same numer of bits per pixel)
            // This is required by the GLES2.0 standard. See the beginning of Chapter 4 in that document.
            
          }
        }
      }
      incRefAndCheckShape(depthAttachment, width, height)
      
      incRefAndCheckShape(stencilAttachment, width, height)
      
      incRefAndCheckShape(depthStencilAttachment, width, height)
      

      // decrement references
      decFBORefs(framebuffer)

      framebuffer.width = width
      framebuffer.height = height

      framebuffer.colorAttachments = colorAttachments
      framebuffer.depthAttachment = depthAttachment
      framebuffer.stencilAttachment = stencilAttachment
      framebuffer.depthStencilAttachment = depthStencilAttachment

      reglFramebuffer.color = colorAttachments.map(unwrapAttachment)
      reglFramebuffer.depth = unwrapAttachment(depthAttachment)
      reglFramebuffer.stencil = unwrapAttachment(stencilAttachment)
      reglFramebuffer.depthStencil = unwrapAttachment(depthStencilAttachment)

      reglFramebuffer.width = framebuffer.width
      reglFramebuffer.height = framebuffer.height

      updateFramebuffer(framebuffer)

      return reglFramebuffer
    }

    function resize (w_, h_) {
      

      var w = Math.max(w_ | 0, 1)
      var h = Math.max((h_ | 0) || w, 1)
      if (w === framebuffer.width && h === framebuffer.height) {
        return reglFramebuffer
      }

      // resize all buffers
      var colorAttachments = framebuffer.colorAttachments
      for (var i = 0; i < colorAttachments.length; ++i) {
        resizeAttachment(colorAttachments[i], w, h)
      }
      resizeAttachment(framebuffer.depthAttachment, w, h)
      resizeAttachment(framebuffer.stencilAttachment, w, h)
      resizeAttachment(framebuffer.depthStencilAttachment, w, h)

      framebuffer.width = reglFramebuffer.width = w
      framebuffer.height = reglFramebuffer.height = h

      updateFramebuffer(framebuffer)

      return reglFramebuffer
    }

    reglFramebuffer(a0, a1)

    return extend(reglFramebuffer, {
      resize: resize,
      _reglType: 'framebuffer',
      _framebuffer: framebuffer,
      destroy: function () {
        destroy(framebuffer)
        decFBORefs(framebuffer)
      },
      use: function (block) {
        framebufferState.setFBO({
          framebuffer: reglFramebuffer
        }, block)
      }
    })
  }

  function createCubeFBO (options) {
    var faces = Array(6)

    function reglFramebufferCube (a) {
      var i

      

      var params = {
        color: null
      }

      var radius = 0

      var colorBuffer = null
      var colorFormat = 'rgba'
      var colorType = 'uint8'
      var colorCount = 1

      if (typeof a === 'number') {
        radius = a | 0
      } else if (!a) {
        radius = 1
      } else {
        
        var options = a

        if ('shape' in options) {
          var shape = options.shape
          
          
          radius = shape[0]
        } else {
          if ('radius' in options) {
            radius = options.radius | 0
          }
          if ('width' in options) {
            radius = options.width | 0
            if ('height' in options) {
              
            }
          } else if ('height' in options) {
            radius = options.height | 0
          }
        }

        if ('color' in options ||
            'colors' in options) {
          colorBuffer =
            options.color ||
            options.colors
          if (Array.isArray(colorBuffer)) {
            
          }
        }

        if (!colorBuffer) {
          if ('colorCount' in options) {
            colorCount = options.colorCount | 0
            
          }

          if ('colorType' in options) {
            
            colorType = options.colorType
          }

          if ('colorFormat' in options) {
            colorFormat = options.colorFormat
            
          }
        }

        if ('depth' in options) {
          params.depth = options.depth
        }

        if ('stencil' in options) {
          params.stencil = options.stencil
        }

        if ('depthStencil' in options) {
          params.depthStencil = options.depthStencil
        }
      }

      var colorCubes
      if (colorBuffer) {
        if (Array.isArray(colorBuffer)) {
          colorCubes = []
          for (i = 0; i < colorBuffer.length; ++i) {
            colorCubes[i] = colorBuffer[i]
          }
        } else {
          colorCubes = [ colorBuffer ]
        }
      } else {
        colorCubes = Array(colorCount)
        var cubeMapParams = {
          radius: radius,
          format: colorFormat,
          type: colorType
        }
        for (i = 0; i < colorCount; ++i) {
          colorCubes[i] = textureState.createCube(cubeMapParams)
        }
      }

      // Check color cubes
      params.color = Array(colorCubes.length)
      for (i = 0; i < colorCubes.length; ++i) {
        var cube = colorCubes[i]
        
        radius = radius || cube.width
        
        params.color[i] = {
          target: GL_TEXTURE_CUBE_MAP_POSITIVE_X$2,
          data: colorCubes[i]
        }
      }

      for (i = 0; i < 6; ++i) {
        for (var j = 0; j < colorCubes.length; ++j) {
          params.color[j].target = GL_TEXTURE_CUBE_MAP_POSITIVE_X$2 + i
        }
        // reuse depth-stencil attachments across all cube maps
        if (i > 0) {
          params.depth = faces[0].depth
          params.stencil = faces[0].stencil
          params.depthStencil = faces[0].depthStencil
        }
        if (faces[i]) {
          (faces[i])(params)
        } else {
          faces[i] = createFBO(params)
        }
      }

      return extend(reglFramebufferCube, {
        width: radius,
        height: radius,
        color: colorCubes
      })
    }

    function resize (radius_) {
      var i
      var radius = radius_ | 0
      

      if (radius === reglFramebufferCube.width) {
        return reglFramebufferCube
      }

      var colors = reglFramebufferCube.color
      for (i = 0; i < colors.length; ++i) {
        colors[i].resize(radius)
      }

      for (i = 0; i < 6; ++i) {
        faces[i].resize(radius)
      }

      reglFramebufferCube.width = reglFramebufferCube.height = radius

      return reglFramebufferCube
    }

    reglFramebufferCube(options)

    return extend(reglFramebufferCube, {
      faces: faces,
      resize: resize,
      _reglType: 'framebufferCube',
      destroy: function () {
        faces.forEach(function (f) {
          f.destroy()
        })
      }
    })
  }

  function restoreFramebuffers () {
    framebufferState.cur = null
    framebufferState.next = null
    framebufferState.dirty = true
    values(framebufferSet).forEach(function (fb) {
      fb.framebuffer = gl.createFramebuffer()
      updateFramebuffer(fb)
    })
  }

  return extend(framebufferState, {
    getFramebuffer: function (object) {
      if (typeof object === 'function' && object._reglType === 'framebuffer') {
        var fbo = object._framebuffer
        if (fbo instanceof REGLFramebuffer) {
          return fbo
        }
      }
      return null
    },
    create: createFBO,
    createCube: createCubeFBO,
    clear: function () {
      values(framebufferSet).forEach(destroy)
    },
    restore: restoreFramebuffers
  })
}

var GL_FLOAT$5 = 5126
var GL_ARRAY_BUFFER$1 = 34962
var GL_ELEMENT_ARRAY_BUFFER$1 = 34963

function AttributeRecord () {
  this.state = 0

  this.x = 0.0
  this.y = 0.0
  this.z = 0.0
  this.w = 0.0

  this.buffer = null
  this.size = 0
  this.normalized = false
  this.type = GL_FLOAT$5
  this.offset = 0
  this.stride = 0
  this.divisor = 0
}

function wrapAttributeState (
  gl,
  extensions,
  limits,
  stats,
  bufferState,
  elementState,
  drawState) {
  var NUM_ATTRIBUTES = limits.maxAttributes
  var attributeBindings = new Array(NUM_ATTRIBUTES)
  for (var i = 0; i < NUM_ATTRIBUTES; ++i) {
    attributeBindings[i] = new AttributeRecord()
  }
  var vaoCount = 0
  var vaoSet = {}

  var state = {
    Record: AttributeRecord,
    scope: {},
    state: attributeBindings,
    currentVAO: null,
    targetVAO: null,
    restore: extVAO() ? restoreVAO : function () {},
    createVAO: createVAO,
    getVAO: getVAO,
    destroyBuffer: destroyBuffer,
    setVAO: extVAO() ? setVAOEXT : setVAOEmulated,
    clear: extVAO() ? destroyVAOEXT : function () {}
  }

  function destroyBuffer (buffer) {
    for (var i = 0; i < attributeBindings.length; ++i) {
      var record = attributeBindings[i]
      if (record.buffer === buffer) {
        gl.disableVertexAttribArray(i)
        record.buffer = null
      }
    }
  }

  function extVAO () {
    return extensions.oes_vertex_array_object
  }

  function extInstanced () {
    return extensions.angle_instanced_arrays
  }

  function getVAO (vao) {
    if (typeof vao === 'function' && vao._vao) {
      return vao._vao
    }
    return null
  }

  function setVAOEXT (vao) {
    if (vao === state.currentVAO) {
      return
    }
    var ext = extVAO()
    if (vao) {
      ext.bindVertexArrayOES(vao.vao)
    } else {
      ext.bindVertexArrayOES(null)
    }
    state.currentVAO = vao
  }

  function setVAOEmulated (vao) {
    if (vao === state.currentVAO) {
      return
    }
    if (vao) {
      vao.bindAttrs()
    } else {
      var exti = extInstanced()
      for (var i = 0; i < attributeBindings.length; ++i) {
        var binding = attributeBindings[i]
        if (binding.buffer) {
          gl.enableVertexAttribArray(i)
          binding.buffer.bind()
          gl.vertexAttribPointer(i, binding.size, binding.type, binding.normalized, binding.stride, binding.offfset)
          if (exti && binding.divisor) {
            exti.vertexAttribDivisorANGLE(i, binding.divisor)
          }
        } else {
          gl.disableVertexAttribArray(i)
          gl.vertexAttrib4f(i, binding.x, binding.y, binding.z, binding.w)
        }
      }
      if (drawState.elements) {
        gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER$1, drawState.elements.buffer.buffer)
      } else {
        gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER$1, null)
      }
    }
    state.currentVAO = vao
  }

  function destroyVAOEXT () {
    values(vaoSet).forEach(function (vao) {
      vao.destroy()
    })
  }

  function REGLVAO () {
    this.id = ++vaoCount
    this.attributes = []
    this.elements = null
    this.ownsElements = false
    this.count = 0
    this.offset = 0
    this.instances = -1
    this.primitive = 4
    var extension = extVAO()
    if (extension) {
      this.vao = extension.createVertexArrayOES()
    } else {
      this.vao = null
    }
    vaoSet[this.id] = this
    this.buffers = []
  }

  REGLVAO.prototype.bindAttrs = function () {
    var exti = extInstanced()
    var attributes = this.attributes
    for (var i = 0; i < attributes.length; ++i) {
      var attr = attributes[i]
      if (attr.buffer) {
        gl.enableVertexAttribArray(i)
        gl.bindBuffer(GL_ARRAY_BUFFER$1, attr.buffer.buffer)
        gl.vertexAttribPointer(i, attr.size, attr.type, attr.normalized, attr.stride, attr.offset)
        if (exti && attr.divisor) {
          exti.vertexAttribDivisorANGLE(i, attr.divisor)
        }
      } else {
        gl.disableVertexAttribArray(i)
        gl.vertexAttrib4f(i, attr.x, attr.y, attr.z, attr.w)
      }
    }
    for (var j = attributes.length; j < NUM_ATTRIBUTES; ++j) {
      gl.disableVertexAttribArray(j)
    }
    var elements = elementState.getElements(this.elements)
    if (elements) {
      gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER$1, elements.buffer.buffer)
    } else {
      gl.bindBuffer(GL_ELEMENT_ARRAY_BUFFER$1, null)
    }
  }

  REGLVAO.prototype.refresh = function () {
    var ext = extVAO()
    if (ext) {
      ext.bindVertexArrayOES(this.vao)
      this.bindAttrs()
      state.currentVAO = null
      ext.bindVertexArrayOES(null)
    }
  }

  REGLVAO.prototype.destroy = function () {
    if (this.vao) {
      var extension = extVAO()
      if (this === state.currentVAO) {
        state.currentVAO = null
        extension.bindVertexArrayOES(null)
      }
      extension.deleteVertexArrayOES(this.vao)
      this.vao = null
    }
    if (this.ownsElements) {
      this.elements.destroy()
      this.elements = null
      this.ownsElements = false
    }
    if (vaoSet[this.id]) {
      delete vaoSet[this.id]
      stats.vaoCount -= 1
    }
  }

  function restoreVAO () {
    var ext = extVAO()
    if (ext) {
      values(vaoSet).forEach(function (vao) {
        vao.refresh()
      })
    }
  }

  function createVAO (_attr) {
    var vao = new REGLVAO()
    stats.vaoCount += 1

    function updateVAO (options) {
      var attributes
      if (Array.isArray(options)) {
        attributes = options
        if (vao.elements && vao.ownsElements) {
          vao.elements.destroy()
        }
        vao.elements = null
        vao.ownsElements = false
        vao.offset = 0
        vao.count = 0
        vao.instances = -1
        vao.primitive = 4
      } else {
        
        
        if (options.elements) {
          var elements = options.elements
          if (vao.ownsElements) {
            if (typeof elements === 'function' && elements._reglType === 'elements') {
              vao.elements.destroy()
              vao.ownsElements = false
            } else {
              vao.elements(elements)
              vao.ownsElements = false
            }
          } else if (elementState.getElements(options.elements)) {
            vao.elements = options.elements
            vao.ownsElements = false
          } else {
            vao.elements = elementState.create(options.elements)
            vao.ownsElements = true
          }
        } else {
          vao.elements = null
          vao.ownsElements = false
        }
        attributes = options.attributes

        // set default vao
        vao.offset = 0
        vao.count = -1
        vao.instances = -1
        vao.primitive = 4

        // copy element properties
        if (vao.elements) {
          vao.count = vao.elements._elements.vertCount
          vao.primitive = vao.elements._elements.primType
        }

        if ('offset' in options) {
          vao.offset = options.offset | 0
        }
        if ('count' in options) {
          vao.count = options.count | 0
        }
        if ('instances' in options) {
          vao.instances = options.instances | 0
        }
        if ('primitive' in options) {
          
          vao.primitive = primTypes[options.primitive]
        }

        
        
      }

      
      

      var bufUpdated = {}
      var nattributes = vao.attributes
      nattributes.length = attributes.length
      for (var i = 0; i < attributes.length; ++i) {
        var spec = attributes[i]
        var rec = nattributes[i] = new AttributeRecord()
        var data = spec.data || spec
        if (Array.isArray(data) || isTypedArray(data) || isNDArrayLike(data)) {
          var buf
          if (vao.buffers[i]) {
            buf = vao.buffers[i]
            if (isTypedArray(data) && buf._buffer.byteLength >= data.byteLength) {
              buf.subdata(data)
            } else {
              buf.destroy()
              vao.buffers[i] = null
            }
          }
          if (!vao.buffers[i]) {
            buf = vao.buffers[i] = bufferState.create(spec, GL_ARRAY_BUFFER$1, false, true)
          }
          rec.buffer = bufferState.getBuffer(buf)
          rec.size = rec.buffer.dimension | 0
          rec.normalized = false
          rec.type = rec.buffer.dtype
          rec.offset = 0
          rec.stride = 0
          rec.divisor = 0
          rec.state = 1
          bufUpdated[i] = 1
        } else if (bufferState.getBuffer(spec)) {
          rec.buffer = bufferState.getBuffer(spec)
          rec.size = rec.buffer.dimension | 0
          rec.normalized = false
          rec.type = rec.buffer.dtype
          rec.offset = 0
          rec.stride = 0
          rec.divisor = 0
          rec.state = 1
        } else if (bufferState.getBuffer(spec.buffer)) {
          rec.buffer = bufferState.getBuffer(spec.buffer)
          rec.size = ((+spec.size) || rec.buffer.dimension) | 0
          rec.normalized = !!spec.normalized || false
          if ('type' in spec) {
            
            rec.type = glTypes[spec.type]
          } else {
            rec.type = rec.buffer.dtype
          }
          rec.offset = (spec.offset || 0) | 0
          rec.stride = (spec.stride || 0) | 0
          rec.divisor = (spec.divisor || 0) | 0
          rec.state = 1

          
          
          
          
          
        } else if ('x' in spec) {
          
          rec.x = +spec.x || 0
          rec.y = +spec.y || 0
          rec.z = +spec.z || 0
          rec.w = +spec.w || 0
          rec.state = 2
        } else {
          
        }
      }

      // retire unused buffers
      for (var j = 0; j < vao.buffers.length; ++j) {
        if (!bufUpdated[j] && vao.buffers[j]) {
          vao.buffers[j].destroy()
          vao.buffers[j] = null
        }
      }

      vao.refresh()
      return updateVAO
    }

    updateVAO.destroy = function () {
      for (var j = 0; j < vao.buffers.length; ++j) {
        if (vao.buffers[j]) {
          vao.buffers[j].destroy()
        }
      }
      vao.buffers.length = 0

      if (vao.ownsElements) {
        vao.elements.destroy()
        vao.elements = null
        vao.ownsElements = false
      }

      vao.destroy()
    }

    updateVAO._vao = vao
    updateVAO._reglType = 'vao'

    return updateVAO(_attr)
  }

  return state
}

var GL_FRAGMENT_SHADER = 35632
var GL_VERTEX_SHADER = 35633

var GL_ACTIVE_UNIFORMS = 0x8B86
var GL_ACTIVE_ATTRIBUTES = 0x8B89

function wrapShaderState (gl, stringStore, stats, config) {
  // ===================================================
  // glsl compilation and linking
  // ===================================================
  var fragShaders = {}
  var vertShaders = {}

  function ActiveInfo (name, id, location, info) {
    this.name = name
    this.id = id
    this.location = location
    this.info = info
  }

  function insertActiveInfo (list, info) {
    for (var i = 0; i < list.length; ++i) {
      if (list[i].id === info.id) {
        list[i].location = info.location
        return
      }
    }
    list.push(info)
  }

  function getShader (type, id, command) {
    var cache = type === GL_FRAGMENT_SHADER ? fragShaders : vertShaders
    var shader = cache[id]

    if (!shader) {
      var source = stringStore.str(id)
      shader = gl.createShader(type)
      gl.shaderSource(shader, source)
      gl.compileShader(shader)
      
      cache[id] = shader
    }

    return shader
  }

  // ===================================================
  // program linking
  // ===================================================
  var programCache = {}
  var programList = []

  var PROGRAM_COUNTER = 0

  function REGLProgram (fragId, vertId) {
    this.id = PROGRAM_COUNTER++
    this.fragId = fragId
    this.vertId = vertId
    this.program = null
    this.uniforms = []
    this.attributes = []
    this.refCount = 1

    if (config.profile) {
      this.stats = {
        uniformsCount: 0,
        attributesCount: 0
      }
    }
  }

  function linkProgram (desc, command, attributeLocations) {
    var i, info

    // -------------------------------
    // compile & link
    // -------------------------------
    var fragShader = getShader(GL_FRAGMENT_SHADER, desc.fragId)
    var vertShader = getShader(GL_VERTEX_SHADER, desc.vertId)

    var program = desc.program = gl.createProgram()
    gl.attachShader(program, fragShader)
    gl.attachShader(program, vertShader)
    if (attributeLocations) {
      for (i = 0; i < attributeLocations.length; ++i) {
        var binding = attributeLocations[i]
        gl.bindAttribLocation(program, binding[0], binding[1])
      }
    }

    gl.linkProgram(program)
    

    // -------------------------------
    // grab uniforms
    // -------------------------------
    var numUniforms = gl.getProgramParameter(program, GL_ACTIVE_UNIFORMS)
    if (config.profile) {
      desc.stats.uniformsCount = numUniforms
    }
    var uniforms = desc.uniforms
    for (i = 0; i < numUniforms; ++i) {
      info = gl.getActiveUniform(program, i)
      if (info) {
        if (info.size > 1) {
          for (var j = 0; j < info.size; ++j) {
            var name = info.name.replace('[0]', '[' + j + ']')
            insertActiveInfo(uniforms, new ActiveInfo(
              name,
              stringStore.id(name),
              gl.getUniformLocation(program, name),
              info))
          }
        } else {
          insertActiveInfo(uniforms, new ActiveInfo(
            info.name,
            stringStore.id(info.name),
            gl.getUniformLocation(program, info.name),
            info))
        }
      }
    }

    // -------------------------------
    // grab attributes
    // -------------------------------
    var numAttributes = gl.getProgramParameter(program, GL_ACTIVE_ATTRIBUTES)
    if (config.profile) {
      desc.stats.attributesCount = numAttributes
    }

    var attributes = desc.attributes
    for (i = 0; i < numAttributes; ++i) {
      info = gl.getActiveAttrib(program, i)
      if (info) {
        insertActiveInfo(attributes, new ActiveInfo(
          info.name,
          stringStore.id(info.name),
          gl.getAttribLocation(program, info.name),
          info))
      }
    }
  }

  if (config.profile) {
    stats.getMaxUniformsCount = function () {
      var m = 0
      programList.forEach(function (desc) {
        if (desc.stats.uniformsCount > m) {
          m = desc.stats.uniformsCount
        }
      })
      return m
    }

    stats.getMaxAttributesCount = function () {
      var m = 0
      programList.forEach(function (desc) {
        if (desc.stats.attributesCount > m) {
          m = desc.stats.attributesCount
        }
      })
      return m
    }
  }

  function restoreShaders () {
    fragShaders = {}
    vertShaders = {}
    for (var i = 0; i < programList.length; ++i) {
      linkProgram(programList[i], null, programList[i].attributes.map(function (info) {
        return [info.location, info.name]
      }))
    }
  }

  return {
    clear: function () {
      var deleteShader = gl.deleteShader.bind(gl)
      values(fragShaders).forEach(deleteShader)
      fragShaders = {}
      values(vertShaders).forEach(deleteShader)
      vertShaders = {}

      programList.forEach(function (desc) {
        gl.deleteProgram(desc.program)
      })
      programList.length = 0
      programCache = {}

      stats.shaderCount = 0
    },

    program: function (vertId, fragId, command, attribLocations) {
      
      

      var cache = programCache[fragId]
      if (!cache) {
        cache = programCache[fragId] = {}
      }
      var prevProgram = cache[vertId]
      if (prevProgram) {
        prevProgram.refCount++
        if (!attribLocations) {
          return prevProgram
        }
      }
      var program = new REGLProgram(fragId, vertId)
      stats.shaderCount++
      linkProgram(program, command, attribLocations)
      if (!prevProgram) {
        cache[vertId] = program
      }
      programList.push(program)
      return extend(program, {
        destroy: function () {
          program.refCount--
          if (program.refCount <= 0) {
            gl.deleteProgram(program.program)
            var idx = programList.indexOf(program)
            programList.splice(idx, 1)
            stats.shaderCount--
          }
          // no program is linked to this vert anymore
          if (cache[program.vertId].refCount <= 0) {
            gl.deleteShader(vertShaders[program.vertId])
            delete vertShaders[program.vertId]
            delete programCache[program.fragId][program.vertId]
          }
          // no program is linked to this frag anymore
          if (!Object.keys(programCache[program.fragId]).length) {
            gl.deleteShader(fragShaders[program.fragId])
            delete fragShaders[program.fragId]
            delete programCache[program.fragId]
          }
        }
      })
    },

    restore: restoreShaders,

    shader: getShader,

    frag: -1,
    vert: -1
  }
}

var GL_RGBA$3 = 6408
var GL_UNSIGNED_BYTE$6 = 5121
var GL_PACK_ALIGNMENT = 0x0D05
var GL_FLOAT$6 = 0x1406 // 5126

function wrapReadPixels (
  gl,
  framebufferState,
  reglPoll,
  context,
  glAttributes,
  extensions,
  limits) {
  function readPixelsImpl (input) {
    var type
    if (framebufferState.next === null) {
      
      type = GL_UNSIGNED_BYTE$6
    } else {
      
      type = framebufferState.next.colorAttachments[0].texture._texture.type

      
    }

    var x = 0
    var y = 0
    var width = context.framebufferWidth
    var height = context.framebufferHeight
    var data = null

    if (isTypedArray(input)) {
      data = input
    } else if (input) {
      
      x = input.x | 0
      y = input.y | 0
      
      
      width = (input.width || (context.framebufferWidth - x)) | 0
      height = (input.height || (context.framebufferHeight - y)) | 0
      data = input.data || null
    }

    // sanity check input.data
    if (data) {
      if (type === GL_UNSIGNED_BYTE$6) {
        
      } else if (type === GL_FLOAT$6) {
        
      }
    }

    
    

    // Update WebGL state
    reglPoll()

    // Compute size
    var size = width * height * 4

    // Allocate data
    if (!data) {
      if (type === GL_UNSIGNED_BYTE$6) {
        data = new Uint8Array(size)
      } else if (type === GL_FLOAT$6) {
        data = data || new Float32Array(size)
      }
    }

    // Type check
    
    

    // Run read pixels
    gl.pixelStorei(GL_PACK_ALIGNMENT, 4)
    gl.readPixels(x, y, width, height, GL_RGBA$3,
      type,
      data)

    return data
  }

  function readPixelsFBO (options) {
    var result
    framebufferState.setFBO({
      framebuffer: options.framebuffer
    }, function () {
      result = readPixelsImpl(options)
    })
    return result
  }

  function readPixels (options) {
    if (!options || !('framebuffer' in options)) {
      return readPixelsImpl(options)
    } else {
      return readPixelsFBO(options)
    }
  }

  return readPixels
}

/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
 * in FIPS 180-2
 * Version 2.2 Copyright Angel Marin, Paul Johnston 2000 - 2009.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for details.
 * Also http://anmar.eu.org/projects/jssha2/
 */

/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
var hexcase = 0;  /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad  = ""; /* base-64 pad character. "=" for strict RFC compliance   */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
function hex_sha256(s)    { return rstr2hex(rstr_sha256(str2rstr_utf8(s))); }
/*
 * Calculate the sha256 of a raw string
 */
function rstr_sha256(s)
{
  return binb2rstr(binb_sha256(rstr2binb(s), s.length * 8));
}

/*
 * Calculate the HMAC-sha256 of a key and some data (raw strings)
 */
function rstr_hmac_sha256(key, data)
{
  var bkey = rstr2binb(key);
  if(bkey.length > 16) bkey = binb_sha256(bkey, key.length * 8);

  var ipad = Array(16), opad = Array(16);
  for(var i = 0; i < 16; i++)
  {
    ipad[i] = bkey[i] ^ 0x36363636;
    opad[i] = bkey[i] ^ 0x5C5C5C5C;
  }

  var hash = binb_sha256(ipad.concat(rstr2binb(data)), 512 + data.length * 8);
  return binb2rstr(binb_sha256(opad.concat(hash), 512 + 256));
}

/*
 * Convert a raw string to a hex string
 */
function rstr2hex(input)
{
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var output = "";
  var x;
  for(var i = 0; i < input.length; i++)
  {
    x = input.charCodeAt(i);
    output += hex_tab.charAt((x >>> 4) & 0x0F)
           +  hex_tab.charAt( x        & 0x0F);
  }
  return output;
}

/*
 * Convert a raw string to a base-64 string
 */
function rstr2b64(input)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var output = "";
  var len = input.length;
  for(var i = 0; i < len; i += 3)
  {
    var triplet = (input.charCodeAt(i) << 16)
                | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
                | (i + 2 < len ? input.charCodeAt(i+2)      : 0);
    for(var j = 0; j < 4; j++)
    {
      if(i * 8 + j * 6 > input.length * 8) output += b64pad;
      else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
    }
  }
  return output;
}

/*
 * Convert a raw string to an arbitrary string encoding
 */
function rstr2any(input, encoding)
{
  var divisor = encoding.length;
  var remainders = Array();
  var i, q, x, quotient;

  /* Convert to an array of 16-bit big-endian values, forming the dividend */
  var dividend = Array(Math.ceil(input.length / 2));
  for(i = 0; i < dividend.length; i++)
  {
    dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
  }

  /*
   * Repeatedly perform a long division. The binary array forms the dividend,
   * the length of the encoding is the divisor. Once computed, the quotient
   * forms the dividend for the next step. We stop when the dividend is zero.
   * All remainders are stored for later use.
   */
  while(dividend.length > 0)
  {
    quotient = Array();
    x = 0;
    for(i = 0; i < dividend.length; i++)
    {
      x = (x << 16) + dividend[i];
      q = Math.floor(x / divisor);
      x -= q * divisor;
      if(quotient.length > 0 || q > 0)
        quotient[quotient.length] = q;
    }
    remainders[remainders.length] = x;
    dividend = quotient;
  }

  /* Convert the remainders to the output string */
  var output = "";
  for(i = remainders.length - 1; i >= 0; i--)
    output += encoding.charAt(remainders[i]);

  /* Append leading zero equivalents */
  var full_length = Math.ceil(input.length * 8 /
                                    (Math.log(encoding.length) / Math.log(2)))
  for(i = output.length; i < full_length; i++)
    output = encoding[0] + output;

  return output;
}

/*
 * Encode a string as utf-8.
 * For efficiency, this assumes the input is valid utf-16.
 */
function str2rstr_utf8(input)
{
  var output = "";
  var i = -1;
  var x, y;

  while(++i < input.length)
  {
    /* Decode utf-16 surrogate pairs */
    x = input.charCodeAt(i);
    y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
    if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF)
    {
      x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
      i++;
    }

    /* Encode output as utf-8 */
    if(x <= 0x7F)
      output += String.fromCharCode(x);
    else if(x <= 0x7FF)
      output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),
                                    0x80 | ( x         & 0x3F));
    else if(x <= 0xFFFF)
      output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
                                    0x80 | ((x >>> 6 ) & 0x3F),
                                    0x80 | ( x         & 0x3F));
    else if(x <= 0x1FFFFF)
      output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
                                    0x80 | ((x >>> 12) & 0x3F),
                                    0x80 | ((x >>> 6 ) & 0x3F),
                                    0x80 | ( x         & 0x3F));
  }
  return output;
}

/*
 * Convert a raw string to an array of big-endian words
 * Characters >255 have their high-byte silently ignored.
 */
function rstr2binb(input)
{
  var output = Array(input.length >> 2);
  for(var i = 0; i < output.length; i++)
    output[i] = 0;
  for(var i = 0; i < input.length * 8; i += 8)
    output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32);
  return output;
}

/*
 * Convert an array of big-endian words to a string
 */
function binb2rstr(input)
{
  var output = "";
  for(var i = 0; i < input.length * 32; i += 8)
    output += String.fromCharCode((input[i>>5] >>> (24 - i % 32)) & 0xFF);
  return output;
}

/*
 * Main sha256 function, with its support functions
 */
function sha256_S (X, n) {return ( X >>> n ) | (X << (32 - n));}
function sha256_R (X, n) {return ( X >>> n );}
function sha256_Ch(x, y, z) {return ((x & y) ^ ((~x) & z));}
function sha256_Maj(x, y, z) {return ((x & y) ^ (x & z) ^ (y & z));}
function sha256_Sigma0256(x) {return (sha256_S(x, 2) ^ sha256_S(x, 13) ^ sha256_S(x, 22));}
function sha256_Sigma1256(x) {return (sha256_S(x, 6) ^ sha256_S(x, 11) ^ sha256_S(x, 25));}
function sha256_Gamma0256(x) {return (sha256_S(x, 7) ^ sha256_S(x, 18) ^ sha256_R(x, 3));}
function sha256_Gamma1256(x) {return (sha256_S(x, 17) ^ sha256_S(x, 19) ^ sha256_R(x, 10));}
var sha256_K = new Array
(
  1116352408, 1899447441, -1245643825, -373957723, 961987163, 1508970993,
  -1841331548, -1424204075, -670586216, 310598401, 607225278, 1426881987,
  1925078388, -2132889090, -1680079193, -1046744716, -459576895, -272742522,
  264347078, 604807628, 770255983, 1249150122, 1555081692, 1996064986,
  -1740746414, -1473132947, -1341970488, -1084653625, -958395405, -710438585,
  113926993, 338241895, 666307205, 773529912, 1294757372, 1396182291,
  1695183700, 1986661051, -2117940946, -1838011259, -1564481375, -1474664885,
  -1035236496, -949202525, -778901479, -694614492, -200395387, 275423344,
  430227734, 506948616, 659060556, 883997877, 958139571, 1322822218,
  1537002063, 1747873779, 1955562222, 2024104815, -2067236844, -1933114872,
  -1866530822, -1538233109, -1090935817, -965641998
);

function binb_sha256(m, l)
{
  var HASH = new Array(1779033703, -1150833019, 1013904242, -1521486534,
                       1359893119, -1694144372, 528734635, 1541459225);
  var W = new Array(64);
  var a, b, c, d, e, f, g, h;
  var i, j, T1, T2;

  /* append padding */
  m[l >> 5] |= 0x80 << (24 - l % 32);
  m[((l + 64 >> 9) << 4) + 15] = l;

  for(i = 0; i < m.length; i += 16)
  {
    a = HASH[0];
    b = HASH[1];
    c = HASH[2];
    d = HASH[3];
    e = HASH[4];
    f = HASH[5];
    g = HASH[6];
    h = HASH[7];

    for(j = 0; j < 64; j++)
    {
      if (j < 16) W[j] = m[j + i];
      else W[j] = safe_add(safe_add(safe_add(sha256_Gamma1256(W[j - 2]), W[j - 7]),
                                            sha256_Gamma0256(W[j - 15])), W[j - 16]);

      T1 = safe_add(safe_add(safe_add(safe_add(h, sha256_Sigma1256(e)), sha256_Ch(e, f, g)),
                                                          sha256_K[j]), W[j]);
      T2 = safe_add(sha256_Sigma0256(a), sha256_Maj(a, b, c));
      h = g;
      g = f;
      f = e;
      e = safe_add(d, T1);
      d = c;
      c = b;
      b = a;
      a = safe_add(T1, T2);
    }

    HASH[0] = safe_add(a, HASH[0]);
    HASH[1] = safe_add(b, HASH[1]);
    HASH[2] = safe_add(c, HASH[2]);
    HASH[3] = safe_add(d, HASH[3]);
    HASH[4] = safe_add(e, HASH[4]);
    HASH[5] = safe_add(f, HASH[5]);
    HASH[6] = safe_add(g, HASH[6]);
    HASH[7] = safe_add(h, HASH[7]);
  }
  return HASH;
}

function safe_add (x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

function slice (x) {
  return Array.prototype.slice.call(x)
}

function join (x) {
  return slice(x).join('')
}

function createEnvironment (options) {
  var cache = options && options.cache

  // Unique variable id counter
  var varCounter = 0

  // Linked values are passed from this scope into the generated code block
  // Calling link() passes a value into the generated scope and returns
  // the variable name which it is bound to
  var linkedNames = []
  var linkedValues = []
  var isStable = []
  function link (value, options) {
    var stable = options && options.stable
    if (!stable) {
      for (var i = 0; i < linkedValues.length; ++i) {
        if (linkedValues[i] === value && !isStable[i]) {
          return linkedNames[i]
        }
      }
    }

    var name = 'g' + (varCounter++)
    linkedNames.push(name)
    linkedValues.push(value)
    isStable.push(stable)
    return name
  }

  // create a code block
  function block () {
    var code = []
    function push () {
      code.push.apply(code, slice(arguments))
    }

    var vars = []
    function def () {
      var name = 'v' + (varCounter++)
      vars.push(name)

      if (arguments.length > 0) {
        code.push(name, '=')
        code.push.apply(code, slice(arguments))
        code.push(';')
      }

      return name
    }

    return extend(push, {
      def: def,
      toString: function () {
        return join([
          (vars.length > 0 ? 'var ' + vars.join(',') + ';' : ''),
          join(code)
        ])
      }
    })
  }

  function scope () {
    var entry = block()
    var exit = block()

    var entryToString = entry.toString
    var exitToString = exit.toString

    function save (object, prop) {
      exit(object, prop, '=', entry.def(object, prop), ';')
    }

    return extend(function () {
      entry.apply(entry, slice(arguments))
    }, {
      def: entry.def,
      entry: entry,
      exit: exit,
      save: save,
      set: function (object, prop, value) {
        save(object, prop)
        entry(object, prop, '=', value, ';')
      },
      toString: function () {
        return entryToString() + exitToString()
      }
    })
  }

  function conditional () {
    var pred = join(arguments)
    var thenBlock = scope()
    var elseBlock = scope()

    var thenToString = thenBlock.toString
    var elseToString = elseBlock.toString

    return extend(thenBlock, {
      then: function () {
        thenBlock.apply(thenBlock, slice(arguments))
        return this
      },
      else: function () {
        elseBlock.apply(elseBlock, slice(arguments))
        return this
      },
      toString: function () {
        var elseClause = elseToString()
        if (elseClause) {
          elseClause = 'else{' + elseClause + '}'
        }
        return join([
          'if(', pred, '){',
          thenToString(),
          '}', elseClause
        ])
      }
    })
  }

  // procedure list
  var globalBlock = block()
  var procedures = {}
  function proc (name, count) {
    var args = []
    function arg () {
      var name = 'a' + args.length
      args.push(name)
      return name
    }

    count = count || 0
    for (var i = 0; i < count; ++i) {
      arg()
    }

    var body = scope()
    var bodyToString = body.toString

    var result = procedures[name] = extend(body, {
      arg: arg,
      toString: function () {
        return join([
          'function(', args.join(), '){',
          bodyToString(),
          '}'
        ])
      }
    })

    return result
  }

  function compile () {
    var code = ['"use strict";',
      globalBlock,
      'return {']
    Object.keys(procedures).forEach(function (name) {
      code.push('"', name, '":', procedures[name].toString(), ',')
    })
    code.push('}')
    var src = join(code)
      .replace(/;/g, ';\n')
      .replace(/}/g, '}\n')
      .replace(/{/g, '{\n')

    var key
    if (cache) {
      key = hex_sha256(src);

      if (cache[key]) {
        return cache[key].apply(null, linkedValues)
      }
    }

    var proc = Function.apply(null, linkedNames.concat(src))

    if (cache) {
      cache[key] = proc
    }
    return proc.apply(null, linkedValues)
  }

  return {
    global: globalBlock,
    link: link,
    block: block,
    proc: proc,
    scope: scope,
    cond: conditional,
    compile: compile
  }
}

// "cute" names for vector components
var CUTE_COMPONENTS = 'xyzw'.split('')

var GL_UNSIGNED_BYTE$7 = 5121

var ATTRIB_STATE_POINTER = 1
var ATTRIB_STATE_CONSTANT = 2

var DYN_FUNC$1 = 0
var DYN_PROP$1 = 1
var DYN_CONTEXT$1 = 2
var DYN_STATE$1 = 3
var DYN_THUNK = 4
var DYN_CONSTANT$1 = 5
var DYN_ARRAY$1 = 6

var S_DITHER = 'dither'
var S_BLEND_ENABLE = 'blend.enable'
var S_BLEND_COLOR = 'blend.color'
var S_BLEND_EQUATION = 'blend.equation'
var S_BLEND_FUNC = 'blend.func'
var S_DEPTH_ENABLE = 'depth.enable'
var S_DEPTH_FUNC = 'depth.func'
var S_DEPTH_RANGE = 'depth.range'
var S_DEPTH_MASK = 'depth.mask'
var S_COLOR_MASK = 'colorMask'
var S_CULL_ENABLE = 'cull.enable'
var S_CULL_FACE = 'cull.face'
var S_FRONT_FACE = 'frontFace'
var S_LINE_WIDTH = 'lineWidth'
var S_POLYGON_OFFSET_ENABLE = 'polygonOffset.enable'
var S_POLYGON_OFFSET_OFFSET = 'polygonOffset.offset'
var S_SAMPLE_ALPHA = 'sample.alpha'
var S_SAMPLE_ENABLE = 'sample.enable'
var S_SAMPLE_COVERAGE = 'sample.coverage'
var S_STENCIL_ENABLE = 'stencil.enable'
var S_STENCIL_MASK = 'stencil.mask'
var S_STENCIL_FUNC = 'stencil.func'
var S_STENCIL_OPFRONT = 'stencil.opFront'
var S_STENCIL_OPBACK = 'stencil.opBack'
var S_SCISSOR_ENABLE = 'scissor.enable'
var S_SCISSOR_BOX = 'scissor.box'
var S_VIEWPORT = 'viewport'

var S_PROFILE = 'profile'

var S_FRAMEBUFFER = 'framebuffer'
var S_VERT = 'vert'
var S_FRAG = 'frag'
var S_ELEMENTS = 'elements'
var S_PRIMITIVE = 'primitive'
var S_COUNT = 'count'
var S_OFFSET = 'offset'
var S_INSTANCES = 'instances'
var S_VAO = 'vao'

var SUFFIX_WIDTH = 'Width'
var SUFFIX_HEIGHT = 'Height'

var S_FRAMEBUFFER_WIDTH = S_FRAMEBUFFER + SUFFIX_WIDTH
var S_FRAMEBUFFER_HEIGHT = S_FRAMEBUFFER + SUFFIX_HEIGHT
var S_VIEWPORT_WIDTH = S_VIEWPORT + SUFFIX_WIDTH
var S_VIEWPORT_HEIGHT = S_VIEWPORT + SUFFIX_HEIGHT
var S_DRAWINGBUFFER = 'drawingBuffer'
var S_DRAWINGBUFFER_WIDTH = S_DRAWINGBUFFER + SUFFIX_WIDTH
var S_DRAWINGBUFFER_HEIGHT = S_DRAWINGBUFFER + SUFFIX_HEIGHT

var NESTED_OPTIONS = [
  S_BLEND_FUNC,
  S_BLEND_EQUATION,
  S_STENCIL_FUNC,
  S_STENCIL_OPFRONT,
  S_STENCIL_OPBACK,
  S_SAMPLE_COVERAGE,
  S_VIEWPORT,
  S_SCISSOR_BOX,
  S_POLYGON_OFFSET_OFFSET
]

var GL_ARRAY_BUFFER$2 = 34962
var GL_ELEMENT_ARRAY_BUFFER$2 = 34963

var GL_CULL_FACE = 0x0B44
var GL_BLEND = 0x0BE2
var GL_DITHER = 0x0BD0
var GL_STENCIL_TEST = 0x0B90
var GL_DEPTH_TEST = 0x0B71
var GL_SCISSOR_TEST = 0x0C11
var GL_POLYGON_OFFSET_FILL = 0x8037
var GL_SAMPLE_ALPHA_TO_COVERAGE = 0x809E
var GL_SAMPLE_COVERAGE = 0x80A0

var GL_FLOAT$7 = 5126
var GL_FLOAT_VEC2 = 35664
var GL_FLOAT_VEC3 = 35665
var GL_FLOAT_VEC4 = 35666
var GL_INT$2 = 5124
var GL_INT_VEC2 = 35667
var GL_INT_VEC3 = 35668
var GL_INT_VEC4 = 35669
var GL_BOOL = 35670
var GL_BOOL_VEC2 = 35671
var GL_BOOL_VEC3 = 35672
var GL_BOOL_VEC4 = 35673
var GL_FLOAT_MAT2 = 35674
var GL_FLOAT_MAT3 = 35675
var GL_FLOAT_MAT4 = 35676
var GL_SAMPLER_2D = 35678
var GL_SAMPLER_CUBE = 35680

var GL_TRIANGLES$1 = 4

var GL_FRONT = 1028
var GL_BACK = 1029
var GL_CW = 0x0900
var GL_CCW = 0x0901
var GL_MIN_EXT = 0x8007
var GL_MAX_EXT = 0x8008
var GL_ALWAYS = 519
var GL_KEEP = 7680
var GL_ZERO = 0
var GL_ONE = 1
var GL_FUNC_ADD = 0x8006
var GL_LESS = 513

var GL_FRAMEBUFFER$2 = 0x8D40
var GL_COLOR_ATTACHMENT0$2 = 0x8CE0

var blendFuncs = {
  '0': 0,
  '1': 1,
  'zero': 0,
  'one': 1,
  'src color': 768,
  'one minus src color': 769,
  'src alpha': 770,
  'one minus src alpha': 771,
  'dst color': 774,
  'one minus dst color': 775,
  'dst alpha': 772,
  'one minus dst alpha': 773,
  'constant color': 32769,
  'one minus constant color': 32770,
  'constant alpha': 32771,
  'one minus constant alpha': 32772,
  'src alpha saturate': 776
}

var compareFuncs = {
  'never': 512,
  'less': 513,
  '<': 513,
  'equal': 514,
  '=': 514,
  '==': 514,
  '===': 514,
  'lequal': 515,
  '<=': 515,
  'greater': 516,
  '>': 516,
  'notequal': 517,
  '!=': 517,
  '!==': 517,
  'gequal': 518,
  '>=': 518,
  'always': 519
}

var stencilOps = {
  '0': 0,
  'zero': 0,
  'keep': 7680,
  'replace': 7681,
  'increment': 7682,
  'decrement': 7683,
  'increment wrap': 34055,
  'decrement wrap': 34056,
  'invert': 5386
}

var orientationType = {
  'cw': GL_CW,
  'ccw': GL_CCW
}

function isBufferArgs (x) {
  return Array.isArray(x) ||
    isTypedArray(x) ||
    isNDArrayLike(x)
}

// Make sure viewport is processed first
function sortState (state) {
  return state.sort(function (a, b) {
    if (a === S_VIEWPORT) {
      return -1
    } else if (b === S_VIEWPORT) {
      return 1
    }
    return (a < b) ? -1 : 1
  })
}

function Declaration (thisDep, contextDep, propDep, append) {
  this.thisDep = thisDep
  this.contextDep = contextDep
  this.propDep = propDep
  this.append = append
}

function isStatic (decl) {
  return decl && !(decl.thisDep || decl.contextDep || decl.propDep)
}

function createStaticDecl (append) {
  return new Declaration(false, false, false, append)
}

function createDynamicDecl (dyn, append) {
  var type = dyn.type
  if (type === DYN_FUNC$1) {
    var numArgs = dyn.data.length
    return new Declaration(
      true,
      numArgs >= 1,
      numArgs >= 2,
      append)
  } else if (type === DYN_THUNK) {
    var data = dyn.data
    return new Declaration(
      data.thisDep,
      data.contextDep,
      data.propDep,
      append)
  } else if (type === DYN_CONSTANT$1) {
    return new Declaration(
      false,
      false,
      false,
      append)
  } else if (type === DYN_ARRAY$1) {
    var thisDep = false
    var contextDep = false
    var propDep = false
    for (var i = 0; i < dyn.data.length; ++i) {
      var subDyn = dyn.data[i]
      if (subDyn.type === DYN_PROP$1) {
        propDep = true
      } else if (subDyn.type === DYN_CONTEXT$1) {
        contextDep = true
      } else if (subDyn.type === DYN_STATE$1) {
        thisDep = true
      } else if (subDyn.type === DYN_FUNC$1) {
        thisDep = true
        var subArgs = subDyn.data
        if (subArgs >= 1) {
          contextDep = true
        }
        if (subArgs >= 2) {
          propDep = true
        }
      } else if (subDyn.type === DYN_THUNK) {
        thisDep = thisDep || subDyn.data.thisDep
        contextDep = contextDep || subDyn.data.contextDep
        propDep = propDep || subDyn.data.propDep
      }
    }
    return new Declaration(
      thisDep,
      contextDep,
      propDep,
      append)
  } else {
    return new Declaration(
      type === DYN_STATE$1,
      type === DYN_CONTEXT$1,
      type === DYN_PROP$1,
      append)
  }
}

var SCOPE_DECL = new Declaration(false, false, false, function () {})

function reglCore (
  gl,
  stringStore,
  extensions,
  limits,
  bufferState,
  elementState,
  textureState,
  framebufferState,
  uniformState,
  attributeState,
  shaderState,
  drawState,
  contextState,
  timer,
  cachedCode,
  config) {
  var AttributeRecord = attributeState.Record

  var blendEquations = {
    'add': 32774,
    'subtract': 32778,
    'reverse subtract': 32779
  }
  if (extensions.ext_blend_minmax) {
    blendEquations.min = GL_MIN_EXT
    blendEquations.max = GL_MAX_EXT
  }

  var extInstancing = extensions.angle_instanced_arrays
  var extDrawBuffers = extensions.webgl_draw_buffers
  var extVertexArrays = extensions.oes_vertex_array_object

  // ===================================================
  // ===================================================
  // WEBGL STATE
  // ===================================================
  // ===================================================
  var currentState = {
    dirty: true,
    profile: config.profile
  }
  var nextState = {}
  var GL_STATE_NAMES = []
  var GL_FLAGS = {}
  var GL_VARIABLES = {}

  function propName (name) {
    return name.replace('.', '_')
  }

  function stateFlag (sname, cap, init) {
    var name = propName(sname)
    GL_STATE_NAMES.push(sname)
    nextState[name] = currentState[name] = !!init
    GL_FLAGS[name] = cap
  }

  function stateVariable (sname, func, init) {
    var name = propName(sname)
    GL_STATE_NAMES.push(sname)
    if (Array.isArray(init)) {
      currentState[name] = init.slice()
      nextState[name] = init.slice()
    } else {
      currentState[name] = nextState[name] = init
    }
    GL_VARIABLES[name] = func
  }
  
  function hasVariableReference (exp) {
    if (!isNaN(exp)) {
      return false;
    }
    // strengthen this function if variable values can be non-(null/number) literals.
    return true;
  }

  // Dithering
  stateFlag(S_DITHER, GL_DITHER)

  // Blending
  stateFlag(S_BLEND_ENABLE, GL_BLEND)
  stateVariable(S_BLEND_COLOR, 'blendColor', [0, 0, 0, 0])
  stateVariable(S_BLEND_EQUATION, 'blendEquationSeparate',
    [GL_FUNC_ADD, GL_FUNC_ADD])
  stateVariable(S_BLEND_FUNC, 'blendFuncSeparate',
    [GL_ONE, GL_ZERO, GL_ONE, GL_ZERO])

  // Depth
  stateFlag(S_DEPTH_ENABLE, GL_DEPTH_TEST, true)
  stateVariable(S_DEPTH_FUNC, 'depthFunc', GL_LESS)
  stateVariable(S_DEPTH_RANGE, 'depthRange', [0, 1])
  stateVariable(S_DEPTH_MASK, 'depthMask', true)

  // Color mask
  stateVariable(S_COLOR_MASK, S_COLOR_MASK, [true, true, true, true])

  // Face culling
  stateFlag(S_CULL_ENABLE, GL_CULL_FACE)
  stateVariable(S_CULL_FACE, 'cullFace', GL_BACK)

  // Front face orientation
  stateVariable(S_FRONT_FACE, S_FRONT_FACE, GL_CCW)

  // Line width
  stateVariable(S_LINE_WIDTH, S_LINE_WIDTH, 1)

  // Polygon offset
  stateFlag(S_POLYGON_OFFSET_ENABLE, GL_POLYGON_OFFSET_FILL)
  stateVariable(S_POLYGON_OFFSET_OFFSET, 'polygonOffset', [0, 0])

  // Sample coverage
  stateFlag(S_SAMPLE_ALPHA, GL_SAMPLE_ALPHA_TO_COVERAGE)
  stateFlag(S_SAMPLE_ENABLE, GL_SAMPLE_COVERAGE)
  stateVariable(S_SAMPLE_COVERAGE, 'sampleCoverage', [1, false])

  // Stencil
  stateFlag(S_STENCIL_ENABLE, GL_STENCIL_TEST)
  stateVariable(S_STENCIL_MASK, 'stencilMask', -1)
  stateVariable(S_STENCIL_FUNC, 'stencilFunc', [GL_ALWAYS, 0, -1])
  stateVariable(S_STENCIL_OPFRONT, 'stencilOpSeparate',
    [GL_FRONT, GL_KEEP, GL_KEEP, GL_KEEP])
  stateVariable(S_STENCIL_OPBACK, 'stencilOpSeparate',
    [GL_BACK, GL_KEEP, GL_KEEP, GL_KEEP])

  // Scissor
  stateFlag(S_SCISSOR_ENABLE, GL_SCISSOR_TEST)
  stateVariable(S_SCISSOR_BOX, 'scissor',
    [0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight])

  // Viewport
  stateVariable(S_VIEWPORT, S_VIEWPORT,
    [0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight])

  // ===================================================
  // ===================================================
  // ENVIRONMENT
  // ===================================================
  // ===================================================
  var sharedState = {
    gl: gl,
    context: contextState,
    strings: stringStore,
    next: nextState,
    current: currentState,
    draw: drawState,
    elements: elementState,
    buffer: bufferState,
    shader: shaderState,
    attributes: attributeState.state,
    vao: attributeState,
    uniforms: uniformState,
    framebuffer: framebufferState,
    extensions: extensions,

    timer: timer,
    isBufferArgs: isBufferArgs
  }

  var sharedConstants = {
    primTypes: primTypes,
    compareFuncs: compareFuncs,
    blendFuncs: blendFuncs,
    blendEquations: blendEquations,
    stencilOps: stencilOps,
    glTypes: glTypes,
    orientationType: orientationType
  }

  

  if (extDrawBuffers) {
    sharedConstants.backBuffer = [GL_BACK]
    sharedConstants.drawBuffer = loop(limits.maxDrawbuffers, function (i) {
      if (i === 0) {
        return [0]
      }
      return loop(i, function (j) {
        return GL_COLOR_ATTACHMENT0$2 + j
      })
    })
  }

  var drawCallCounter = 0
  function createREGLEnvironment () {
    var env = createEnvironment({cache: cachedCode})
    var link = env.link
    var global = env.global
    env.id = drawCallCounter++

    env.batchId = '0'

    // link shared state
    var SHARED = link(sharedState)
    var shared = env.shared = {
      props: 'a0'
    }
    Object.keys(sharedState).forEach(function (prop) {
      shared[prop] = global.def(SHARED, '.', prop)
    })

    // Inject runtime assertion stuff for debug builds
    

    // Copy GL state variables over
    var nextVars = env.next = {}
    var currentVars = env.current = {}
    Object.keys(GL_VARIABLES).forEach(function (variable) {
      if (Array.isArray(currentState[variable])) {
        nextVars[variable] = global.def(shared.next, '.', variable)
        currentVars[variable] = global.def(shared.current, '.', variable)
      }
    })

    // Initialize shared constants
    var constants = env.constants = {}
    Object.keys(sharedConstants).forEach(function (name) {
      constants[name] = global.def(JSON.stringify(sharedConstants[name]))
    })

    // Helper function for calling a block
    env.invoke = function (block, x) {
      switch (x.type) {
        case DYN_FUNC$1:
          var argList = [
            'this',
            shared.context,
            shared.props,
            env.batchId
          ]
          return block.def(
            link(x.data), '.call(',
            argList.slice(0, Math.max(x.data.length + 1, 4)),
            ')')
        case DYN_PROP$1:
          return block.def(shared.props, x.data)
        case DYN_CONTEXT$1:
          return block.def(shared.context, x.data)
        case DYN_STATE$1:
          return block.def('this', x.data)
        case DYN_THUNK:
          x.data.append(env, block)
          return x.data.ref
        case DYN_CONSTANT$1:
          return x.data.toString()
        case DYN_ARRAY$1:
          return x.data.map(function (y) {
            return env.invoke(block, y)
          })
      }
    }

    env.attribCache = {}

    var scopeAttribs = {}
    env.scopeAttrib = function (name) {
      var id = stringStore.id(name)
      if (id in scopeAttribs) {
        return scopeAttribs[id]
      }
      var binding = attributeState.scope[id]
      if (!binding) {
        binding = attributeState.scope[id] = new AttributeRecord()
      }
      var result = scopeAttribs[id] = link(binding)
      return result
    }

    return env
  }

  // ===================================================
  // ===================================================
  // PARSING
  // ===================================================
  // ===================================================
  function parseProfile (options) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    var profileEnable
    if (S_PROFILE in staticOptions) {
      var value = !!staticOptions[S_PROFILE]
      profileEnable = createStaticDecl(function (env, scope) {
        return value
      })
      profileEnable.enable = value
    } else if (S_PROFILE in dynamicOptions) {
      var dyn = dynamicOptions[S_PROFILE]
      profileEnable = createDynamicDecl(dyn, function (env, scope) {
        return env.invoke(scope, dyn)
      })
    }

    return profileEnable
  }

  function parseFramebuffer (options, env) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    if (S_FRAMEBUFFER in staticOptions) {
      var framebuffer = staticOptions[S_FRAMEBUFFER]
      if (framebuffer) {
        framebuffer = framebufferState.getFramebuffer(framebuffer)
        
        return createStaticDecl(function (env, block) {
          var FRAMEBUFFER = env.link(framebuffer)
          var shared = env.shared
          block.set(
            shared.framebuffer,
            '.next',
            FRAMEBUFFER)
          var CONTEXT = shared.context
          block.set(
            CONTEXT,
            '.' + S_FRAMEBUFFER_WIDTH,
            FRAMEBUFFER + '.width')
          block.set(
            CONTEXT,
            '.' + S_FRAMEBUFFER_HEIGHT,
            FRAMEBUFFER + '.height')
          return FRAMEBUFFER
        })
      } else {
        return createStaticDecl(function (env, scope) {
          var shared = env.shared
          scope.set(
            shared.framebuffer,
            '.next',
            'null')
          var CONTEXT = shared.context
          scope.set(
            CONTEXT,
            '.' + S_FRAMEBUFFER_WIDTH,
            CONTEXT + '.' + S_DRAWINGBUFFER_WIDTH)
          scope.set(
            CONTEXT,
            '.' + S_FRAMEBUFFER_HEIGHT,
            CONTEXT + '.' + S_DRAWINGBUFFER_HEIGHT)
          return 'null'
        })
      }
    } else if (S_FRAMEBUFFER in dynamicOptions) {
      var dyn = dynamicOptions[S_FRAMEBUFFER]
      return createDynamicDecl(dyn, function (env, scope) {
        var FRAMEBUFFER_FUNC = env.invoke(scope, dyn)
        var shared = env.shared
        var FRAMEBUFFER_STATE = shared.framebuffer
        var FRAMEBUFFER = scope.def(
          FRAMEBUFFER_STATE, '.getFramebuffer(', FRAMEBUFFER_FUNC, ')')

        

        scope.set(
          FRAMEBUFFER_STATE,
          '.next',
          FRAMEBUFFER)
        var CONTEXT = shared.context
        scope.set(
          CONTEXT,
          '.' + S_FRAMEBUFFER_WIDTH,
          FRAMEBUFFER + '?' + FRAMEBUFFER + '.width:' +
          CONTEXT + '.' + S_DRAWINGBUFFER_WIDTH)
        scope.set(
          CONTEXT,
          '.' + S_FRAMEBUFFER_HEIGHT,
          FRAMEBUFFER +
          '?' + FRAMEBUFFER + '.height:' +
          CONTEXT + '.' + S_DRAWINGBUFFER_HEIGHT)
        return FRAMEBUFFER
      })
    } else {
      return null
    }
  }

  function parseViewportScissor (options, framebuffer, env) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    function parseBox (param) {
      if (param in staticOptions) {
        var box = staticOptions[param]
        

        var isStatic = true
        var x = box.x | 0
        var y = box.y | 0
        var w, h
        if ('width' in box) {
          w = box.width | 0
          
        } else {
          isStatic = false
        }
        if ('height' in box) {
          h = box.height | 0
          
        } else {
          isStatic = false
        }

        return new Declaration(
          !isStatic && framebuffer && framebuffer.thisDep,
          !isStatic && framebuffer && framebuffer.contextDep,
          !isStatic && framebuffer && framebuffer.propDep,
          function (env, scope) {
            var CONTEXT = env.shared.context
            var BOX_W = w
            if (!('width' in box)) {
              BOX_W = scope.def(CONTEXT, '.', S_FRAMEBUFFER_WIDTH, '-', x)
            }
            var BOX_H = h
            if (!('height' in box)) {
              BOX_H = scope.def(CONTEXT, '.', S_FRAMEBUFFER_HEIGHT, '-', y)
            }
            return [x, y, BOX_W, BOX_H]
          })
      } else if (param in dynamicOptions) {
        var dynBox = dynamicOptions[param]
        var result = createDynamicDecl(dynBox, function (env, scope) {
          var BOX = env.invoke(scope, dynBox)

          

          var CONTEXT = env.shared.context
          var BOX_X = scope.def(BOX, '.x|0')
          var BOX_Y = scope.def(BOX, '.y|0')
          var BOX_W = scope.def(
            '"width" in ', BOX, '?', BOX, '.width|0:',
            '(', CONTEXT, '.', S_FRAMEBUFFER_WIDTH, '-', BOX_X, ')')
          var BOX_H = scope.def(
            '"height" in ', BOX, '?', BOX, '.height|0:',
            '(', CONTEXT, '.', S_FRAMEBUFFER_HEIGHT, '-', BOX_Y, ')')

          

          return [BOX_X, BOX_Y, BOX_W, BOX_H]
        })
        if (framebuffer) {
          result.thisDep = result.thisDep || framebuffer.thisDep
          result.contextDep = result.contextDep || framebuffer.contextDep
          result.propDep = result.propDep || framebuffer.propDep
        }
        return result
      } else if (framebuffer) {
        return new Declaration(
          framebuffer.thisDep,
          framebuffer.contextDep,
          framebuffer.propDep,
          function (env, scope) {
            var CONTEXT = env.shared.context
            return [
              0, 0,
              scope.def(CONTEXT, '.', S_FRAMEBUFFER_WIDTH),
              scope.def(CONTEXT, '.', S_FRAMEBUFFER_HEIGHT)]
          })
      } else {
        return null
      }
    }

    var viewport = parseBox(S_VIEWPORT)

    if (viewport) {
      var prevViewport = viewport
      viewport = new Declaration(
        viewport.thisDep,
        viewport.contextDep,
        viewport.propDep,
        function (env, scope) {
          var VIEWPORT = prevViewport.append(env, scope)
          var CONTEXT = env.shared.context
          scope.set(
            CONTEXT,
            '.' + S_VIEWPORT_WIDTH,
            VIEWPORT[2])
          scope.set(
            CONTEXT,
            '.' + S_VIEWPORT_HEIGHT,
            VIEWPORT[3])
          return VIEWPORT
        })
    }

    return {
      viewport: viewport,
      scissor_box: parseBox(S_SCISSOR_BOX)
    }
  }

  function parseAttribLocations (options, attributes) {
    var staticOptions = options.static
    var staticProgram =
      typeof staticOptions[S_FRAG] === 'string' &&
      typeof staticOptions[S_VERT] === 'string'
    if (staticProgram) {
      if (Object.keys(attributes.dynamic).length > 0) {
        return null
      }
      var staticAttributes = attributes.static
      var sAttributes = Object.keys(staticAttributes)
      if (sAttributes.length > 0 && typeof staticAttributes[sAttributes[0]] === 'number') {
        var bindings = []
        for (var i = 0; i < sAttributes.length; ++i) {
          
          bindings.push([staticAttributes[sAttributes[i]] | 0, sAttributes[i]])
        }
        return bindings
      }
    }
    return null
  }

  function parseProgram (options, env, attribLocations) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    function parseShader (name) {
      if (name in staticOptions) {
        var id = stringStore.id(staticOptions[name])
        
        var result = createStaticDecl(function () {
          return id
        })
        result.id = id
        return result
      } else if (name in dynamicOptions) {
        var dyn = dynamicOptions[name]
        return createDynamicDecl(dyn, function (env, scope) {
          var str = env.invoke(scope, dyn)
          var id = scope.def(env.shared.strings, '.id(', str, ')')
          
          return id
        })
      }
      return null
    }

    var frag = parseShader(S_FRAG)
    var vert = parseShader(S_VERT)

    var program = null
    var progVar
    if (isStatic(frag) && isStatic(vert)) {
      program = shaderState.program(vert.id, frag.id, null, attribLocations)
      progVar = createStaticDecl(function (env, scope) {
        return env.link(program)
      })
    } else {
      progVar = new Declaration(
        (frag && frag.thisDep) || (vert && vert.thisDep),
        (frag && frag.contextDep) || (vert && vert.contextDep),
        (frag && frag.propDep) || (vert && vert.propDep),
        function (env, scope) {
          var SHADER_STATE = env.shared.shader
          var fragId
          if (frag) {
            fragId = frag.append(env, scope)
          } else {
            fragId = scope.def(SHADER_STATE, '.', S_FRAG)
          }
          var vertId
          if (vert) {
            vertId = vert.append(env, scope)
          } else {
            vertId = scope.def(SHADER_STATE, '.', S_VERT)
          }
          var progDef = SHADER_STATE + '.program(' + vertId + ',' + fragId
          
          return scope.def(progDef + ')')
        })
    }

    return {
      frag: frag,
      vert: vert,
      progVar: progVar,
      program: program
    }
  }

  function parseDraw (options, env) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    // TODO: should use VAO to get default values for offset properties
    // should move vao parse into here and out of the old stuff

    var staticDraw = {}
    var vaoActive = false

    function parseVAO () {
      if (S_VAO in staticOptions) {
        var vao = staticOptions[S_VAO]
        if (vao !== null && attributeState.getVAO(vao) === null) {
          vao = attributeState.createVAO(vao)
        }

        vaoActive = true
        staticDraw.vao = vao

        return createStaticDecl(function (env) {
          var vaoRef = attributeState.getVAO(vao)
          if (vaoRef) {
            return env.link(vaoRef)
          } else {
            return 'null'
          }
        })
      } else if (S_VAO in dynamicOptions) {
        vaoActive = true
        var dyn = dynamicOptions[S_VAO]
        return createDynamicDecl(dyn, function (env, scope) {
          var vaoRef = env.invoke(scope, dyn)
          return scope.def(env.shared.vao + '.getVAO(' + vaoRef + ')')
        })
      }
      return null
    }

    var vao = parseVAO()

    var elementsActive = false

    function parseElements () {
      if (S_ELEMENTS in staticOptions) {
        var elements = staticOptions[S_ELEMENTS]
        staticDraw.elements = elements
        if (isBufferArgs(elements)) {
          var e = staticDraw.elements = elementState.create(elements, true)
          elements = elementState.getElements(e)
          elementsActive = true
        } else if (elements) {
          elements = elementState.getElements(elements)
          elementsActive = true
          
        }

        var result = createStaticDecl(function (env, scope) {
          if (elements) {
            var result = env.link(elements)
            env.ELEMENTS = result
            return result
          }
          env.ELEMENTS = null
          return null
        })
        result.value = elements
        return result
      } else if (S_ELEMENTS in dynamicOptions) {
        elementsActive = true

        var dyn = dynamicOptions[S_ELEMENTS]
        return createDynamicDecl(dyn, function (env, scope) {
          var shared = env.shared

          var IS_BUFFER_ARGS = shared.isBufferArgs
          var ELEMENT_STATE = shared.elements

          var elementDefn = env.invoke(scope, dyn)
          var elements = scope.def('null')
          var elementStream = scope.def(IS_BUFFER_ARGS, '(', elementDefn, ')')

          var ifte = env.cond(elementStream)
            .then(elements, '=', ELEMENT_STATE, '.createStream(', elementDefn, ');')
            .else(elements, '=', ELEMENT_STATE, '.getElements(', elementDefn, ');')

          

          scope.entry(ifte)
          scope.exit(
            env.cond(elementStream)
              .then(ELEMENT_STATE, '.destroyStream(', elements, ');'))

          env.ELEMENTS = elements

          return elements
        })
      } else if (vaoActive) {
        return new Declaration(
          vao.thisDep,
          vao.contextDep,
          vao.propDep,
          function (env, scope) {
            return scope.def(env.shared.vao + '.currentVAO?' + env.shared.elements + '.getElements(' + env.shared.vao + '.currentVAO.elements):null')
          })
      }
      return null
    }

    var elements = parseElements()

    function parsePrimitive () {
      if (S_PRIMITIVE in staticOptions) {
        var primitive = staticOptions[S_PRIMITIVE]
        staticDraw.primitive = primitive
        
        return createStaticDecl(function (env, scope) {
          return primTypes[primitive]
        })
      } else if (S_PRIMITIVE in dynamicOptions) {
        var dynPrimitive = dynamicOptions[S_PRIMITIVE]
        return createDynamicDecl(dynPrimitive, function (env, scope) {
          var PRIM_TYPES = env.constants.primTypes
          var prim = env.invoke(scope, dynPrimitive)
          
          return scope.def(PRIM_TYPES, '[', prim, ']')
        })
      } else if (elementsActive) {
        if (isStatic(elements)) {
          if (elements.value) {
            return createStaticDecl(function (env, scope) {
              return scope.def(env.ELEMENTS, '.primType')
            })
          } else {
            return createStaticDecl(function () {
              return GL_TRIANGLES$1
            })
          }
        } else {
          return new Declaration(
            elements.thisDep,
            elements.contextDep,
            elements.propDep,
            function (env, scope) {
              var elements = env.ELEMENTS
              return scope.def(elements, '?', elements, '.primType:', GL_TRIANGLES$1)
            })
        }
      } else if (vaoActive) {
        return new Declaration(
          vao.thisDep,
          vao.contextDep,
          vao.propDep,
          function (env, scope) {
            return scope.def(env.shared.vao + '.currentVAO?' + env.shared.vao + '.currentVAO.primitive:' + GL_TRIANGLES$1)
          })
      }
      return null
    }

    function parseParam (param, isOffset) {
      if (param in staticOptions) {
        var value = staticOptions[param] | 0
        if (isOffset) {
          staticDraw.offset = value
        } else {
          staticDraw.instances = value
        }
        
        return createStaticDecl(function (env, scope) {
          if (isOffset) {
            env.OFFSET = value
          }
          return value
        })
      } else if (param in dynamicOptions) {
        var dynValue = dynamicOptions[param]
        return createDynamicDecl(dynValue, function (env, scope) {
          var result = env.invoke(scope, dynValue)
          if (isOffset) {
            env.OFFSET = result
            
          }
          return result
        })
      } else if (isOffset) {
        if (elementsActive) {
          return createStaticDecl(function (env, scope) {
            env.OFFSET = 0
            return 0
          })
        } else if (vaoActive) {
          return new Declaration(
            vao.thisDep,
            vao.contextDep,
            vao.propDep,
            function (env, scope) {
              return scope.def(env.shared.vao + '.currentVAO?' + env.shared.vao + '.currentVAO.offset:0')
            })
        }
      } else if (vaoActive) {
        return new Declaration(
          vao.thisDep,
          vao.contextDep,
          vao.propDep,
          function (env, scope) {
            return scope.def(env.shared.vao + '.currentVAO?' + env.shared.vao + '.currentVAO.instances:-1')
          })
      }
      return null
    }

    var OFFSET = parseParam(S_OFFSET, true)

    function parseVertCount () {
      if (S_COUNT in staticOptions) {
        var count = staticOptions[S_COUNT] | 0
        staticDraw.count = count
        
        return createStaticDecl(function () {
          return count
        })
      } else if (S_COUNT in dynamicOptions) {
        var dynCount = dynamicOptions[S_COUNT]
        return createDynamicDecl(dynCount, function (env, scope) {
          var result = env.invoke(scope, dynCount)
          
          return result
        })
      } else if (elementsActive) {
        if (isStatic(elements)) {
          if (elements) {
            if (OFFSET) {
              return new Declaration(
                OFFSET.thisDep,
                OFFSET.contextDep,
                OFFSET.propDep,
                function (env, scope) {
                  var result = scope.def(
                    env.ELEMENTS, '.vertCount-', env.OFFSET)

                  

                  return result
                })
            } else {
              return createStaticDecl(function (env, scope) {
                return scope.def(env.ELEMENTS, '.vertCount')
              })
            }
          } else {
            var result = createStaticDecl(function () {
              return -1
            })
            
            return result
          }
        } else {
          var variable = new Declaration(
            elements.thisDep || OFFSET.thisDep,
            elements.contextDep || OFFSET.contextDep,
            elements.propDep || OFFSET.propDep,
            function (env, scope) {
              var elements = env.ELEMENTS
              if (env.OFFSET) {
                return scope.def(elements, '?', elements, '.vertCount-',
                  env.OFFSET, ':-1')
              }
              return scope.def(elements, '?', elements, '.vertCount:-1')
            })
          
          return variable
        }
      } else if (vaoActive) {
        var countVariable = new Declaration(
          vao.thisDep,
          vao.contextDep,
          vao.propDep,
          function (env, scope) {
            return scope.def(env.shared.vao, '.currentVAO?', env.shared.vao, '.currentVAO.count:-1')
          })
        return countVariable
      }
      return null
    }

    var primitive = parsePrimitive()
    var count = parseVertCount()
    var instances = parseParam(S_INSTANCES, false)

    return {
      elements: elements,
      primitive: primitive,
      count: count,
      instances: instances,
      offset: OFFSET,
      vao: vao,

      vaoActive: vaoActive,
      elementsActive: elementsActive,

      // static draw props
      static: staticDraw
    }
  }

  function parseGLState (options, env) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    var STATE = {}

    GL_STATE_NAMES.forEach(function (prop) {
      var param = propName(prop)

      function parseParam (parseStatic, parseDynamic) {
        if (prop in staticOptions) {
          var value = parseStatic(staticOptions[prop])
          STATE[param] = createStaticDecl(function () {
            return value
          })
        } else if (prop in dynamicOptions) {
          var dyn = dynamicOptions[prop]
          STATE[param] = createDynamicDecl(dyn, function (env, scope) {
            return parseDynamic(env, scope, env.invoke(scope, dyn))
          })
        }
      }

      switch (prop) {
        case S_CULL_ENABLE:
        case S_BLEND_ENABLE:
        case S_DITHER:
        case S_STENCIL_ENABLE:
        case S_DEPTH_ENABLE:
        case S_SCISSOR_ENABLE:
        case S_POLYGON_OFFSET_ENABLE:
        case S_SAMPLE_ALPHA:
        case S_SAMPLE_ENABLE:
        case S_DEPTH_MASK:
          return parseParam(
            function (value) {
              
              return value
            },
            function (env, scope, value) {
              
              return value
            })

        case S_DEPTH_FUNC:
          return parseParam(
            function (value) {
              
              return compareFuncs[value]
            },
            function (env, scope, value) {
              var COMPARE_FUNCS = env.constants.compareFuncs
              
              return scope.def(COMPARE_FUNCS, '[', value, ']')
            })

        case S_DEPTH_RANGE:
          return parseParam(
            function (value) {
              
              return value
            },
            function (env, scope, value) {
              

              var Z_NEAR = scope.def('+', value, '[0]')
              var Z_FAR = scope.def('+', value, '[1]')
              return [Z_NEAR, Z_FAR]
            })

        case S_BLEND_FUNC:
          return parseParam(
            function (value) {
              
              var srcRGB = ('srcRGB' in value ? value.srcRGB : value.src)
              var srcAlpha = ('srcAlpha' in value ? value.srcAlpha : value.src)
              var dstRGB = ('dstRGB' in value ? value.dstRGB : value.dst)
              var dstAlpha = ('dstAlpha' in value ? value.dstAlpha : value.dst)
              
              
              
              

              

              return [
                blendFuncs[srcRGB],
                blendFuncs[dstRGB],
                blendFuncs[srcAlpha],
                blendFuncs[dstAlpha]
              ]
            },
            function (env, scope, value) {
              var BLEND_FUNCS = env.constants.blendFuncs

              

              function read (prefix, suffix) {
                var func = scope.def(
                  '"', prefix, suffix, '" in ', value,
                  '?', value, '.', prefix, suffix,
                  ':', value, '.', prefix)

                

                return func
              }

              var srcRGB = read('src', 'RGB')
              var dstRGB = read('dst', 'RGB')

              

              var SRC_RGB = scope.def(BLEND_FUNCS, '[', srcRGB, ']')
              var SRC_ALPHA = scope.def(BLEND_FUNCS, '[', read('src', 'Alpha'), ']')
              var DST_RGB = scope.def(BLEND_FUNCS, '[', dstRGB, ']')
              var DST_ALPHA = scope.def(BLEND_FUNCS, '[', read('dst', 'Alpha'), ']')

              return [SRC_RGB, DST_RGB, SRC_ALPHA, DST_ALPHA]
            })

        case S_BLEND_EQUATION:
          return parseParam(
            function (value) {
              if (typeof value === 'string') {
                
                return [
                  blendEquations[value],
                  blendEquations[value]
                ]
              } else if (typeof value === 'object') {
                
                
                return [
                  blendEquations[value.rgb],
                  blendEquations[value.alpha]
                ]
              } else {
                
              }
            },
            function (env, scope, value) {
              var BLEND_EQUATIONS = env.constants.blendEquations

              var RGB = scope.def()
              var ALPHA = scope.def()

              var ifte = env.cond('typeof ', value, '==="string"')

              

              ifte.then(
                RGB, '=', ALPHA, '=', BLEND_EQUATIONS, '[', value, '];')
              ifte.else(
                RGB, '=', BLEND_EQUATIONS, '[', value, '.rgb];',
                ALPHA, '=', BLEND_EQUATIONS, '[', value, '.alpha];')

              scope(ifte)

              return [RGB, ALPHA]
            })

        case S_BLEND_COLOR:
          return parseParam(
            function (value) {
              
              return loop(4, function (i) {
                return +value[i]
              })
            },
            function (env, scope, value) {
              
              return loop(4, function (i) {
                return scope.def('+', value, '[', i, ']')
              })
            })

        case S_STENCIL_MASK:
          return parseParam(
            function (value) {
              
              return value | 0
            },
            function (env, scope, value) {
              
              return scope.def(value, '|0')
            })

        case S_STENCIL_FUNC:
          return parseParam(
            function (value) {
              
              var cmp = value.cmp || 'keep'
              var ref = value.ref || 0
              var mask = 'mask' in value ? value.mask : -1
              
              
              
              return [
                compareFuncs[cmp],
                ref,
                mask
              ]
            },
            function (env, scope, value) {
              var COMPARE_FUNCS = env.constants.compareFuncs
              
              var cmp = scope.def(
                '"cmp" in ', value,
                '?', COMPARE_FUNCS, '[', value, '.cmp]',
                ':', GL_KEEP)
              var ref = scope.def(value, '.ref|0')
              var mask = scope.def(
                '"mask" in ', value,
                '?', value, '.mask|0:-1')
              return [cmp, ref, mask]
            })

        case S_STENCIL_OPFRONT:
        case S_STENCIL_OPBACK:
          return parseParam(
            function (value) {
              
              var fail = value.fail || 'keep'
              var zfail = value.zfail || 'keep'
              var zpass = value.zpass || 'keep'
              
              
              
              return [
                prop === S_STENCIL_OPBACK ? GL_BACK : GL_FRONT,
                stencilOps[fail],
                stencilOps[zfail],
                stencilOps[zpass]
              ]
            },
            function (env, scope, value) {
              var STENCIL_OPS = env.constants.stencilOps

              

              function read (name) {
                

                return scope.def(
                  '"', name, '" in ', value,
                  '?', STENCIL_OPS, '[', value, '.', name, ']:',
                  GL_KEEP)
              }

              return [
                prop === S_STENCIL_OPBACK ? GL_BACK : GL_FRONT,
                read('fail'),
                read('zfail'),
                read('zpass')
              ]
            })

        case S_POLYGON_OFFSET_OFFSET:
          return parseParam(
            function (value) {
              
              var factor = value.factor | 0
              var units = value.units | 0
              
              
              return [factor, units]
            },
            function (env, scope, value) {
              

              var FACTOR = scope.def(value, '.factor|0')
              var UNITS = scope.def(value, '.units|0')

              return [FACTOR, UNITS]
            })

        case S_CULL_FACE:
          return parseParam(
            function (value) {
              var face = 0
              if (value === 'front') {
                face = GL_FRONT
              } else if (value === 'back') {
                face = GL_BACK
              }
              
              return face
            },
            function (env, scope, value) {
              
              return scope.def(value, '==="front"?', GL_FRONT, ':', GL_BACK)
            })

        case S_LINE_WIDTH:
          return parseParam(
            function (value) {
              
              return value
            },
            function (env, scope, value) {
              

              return value
            })

        case S_FRONT_FACE:
          return parseParam(
            function (value) {
              
              return orientationType[value]
            },
            function (env, scope, value) {
              
              return scope.def(value + '==="cw"?' + GL_CW + ':' + GL_CCW)
            })

        case S_COLOR_MASK:
          return parseParam(
            function (value) {
              
              return value.map(function (v) { return !!v })
            },
            function (env, scope, value) {
              
              return loop(4, function (i) {
                return '!!' + value + '[' + i + ']'
              })
            })

        case S_SAMPLE_COVERAGE:
          return parseParam(
            function (value) {
              
              var sampleValue = 'value' in value ? value.value : 1
              var sampleInvert = !!value.invert
              
              return [sampleValue, sampleInvert]
            },
            function (env, scope, value) {
              
              var VALUE = scope.def(
                '"value" in ', value, '?+', value, '.value:1')
              var INVERT = scope.def('!!', value, '.invert')
              return [VALUE, INVERT]
            })
      }
    })

    return STATE
  }

  function parseUniforms (uniforms, env) {
    var staticUniforms = uniforms.static
    var dynamicUniforms = uniforms.dynamic

    var UNIFORMS = {}

    Object.keys(staticUniforms).forEach(function (name) {
      var value = staticUniforms[name]
      var result
      if (typeof value === 'number' ||
          typeof value === 'boolean') {
        result = createStaticDecl(function () {
          return value
        })
      } else if (typeof value === 'function') {
        var reglType = value._reglType
        if (reglType === 'texture2d' ||
            reglType === 'textureCube') {
          result = createStaticDecl(function (env) {
            return env.link(value)
          })
        } else if (reglType === 'framebuffer' ||
                   reglType === 'framebufferCube') {
          
          result = createStaticDecl(function (env) {
            return env.link(value.color[0])
          })
        } else {
          
        }
      } else if (isArrayLike(value)) {
        result = createStaticDecl(function (env) {
          var ITEM = env.global.def('[',
            loop(value.length, function (i) {
              
              return value[i]
            }), ']')
          return ITEM
        })
      } else {
        
      }
      result.value = value
      UNIFORMS[name] = result
    })

    Object.keys(dynamicUniforms).forEach(function (key) {
      var dyn = dynamicUniforms[key]
      UNIFORMS[key] = createDynamicDecl(dyn, function (env, scope) {
        return env.invoke(scope, dyn)
      })
    })

    return UNIFORMS
  }

  function parseAttributes (attributes, env) {
    var staticAttributes = attributes.static
    var dynamicAttributes = attributes.dynamic

    var attributeDefs = {}

    Object.keys(staticAttributes).forEach(function (attribute) {
      var value = staticAttributes[attribute]
      var id = stringStore.id(attribute)

      var record = new AttributeRecord()
      if (isBufferArgs(value)) {
        record.state = ATTRIB_STATE_POINTER
        record.buffer = bufferState.getBuffer(
          bufferState.create(value, GL_ARRAY_BUFFER$2, false, true))
        record.type = 0
      } else {
        var buffer = bufferState.getBuffer(value)
        if (buffer) {
          record.state = ATTRIB_STATE_POINTER
          record.buffer = buffer
          record.type = 0
        } else {
          
          if ('constant' in value) {
            var constant = value.constant
            record.buffer = 'null'
            record.state = ATTRIB_STATE_CONSTANT
            if (typeof constant === 'number') {
              record.x = constant
            } else {
              
              CUTE_COMPONENTS.forEach(function (c, i) {
                if (i < constant.length) {
                  record[c] = constant[i]
                }
              })
            }
          } else {
            if (isBufferArgs(value.buffer)) {
              buffer = bufferState.getBuffer(
                bufferState.create(value.buffer, GL_ARRAY_BUFFER$2, false, true))
            } else {
              buffer = bufferState.getBuffer(value.buffer)
            }
            

            var offset = value.offset | 0
            

            var stride = value.stride | 0
            

            var size = value.size | 0
            

            var normalized = !!value.normalized

            var type = 0
            if ('type' in value) {
              
              type = glTypes[value.type]
            }

            var divisor = value.divisor | 0
            

            record.buffer = buffer
            record.state = ATTRIB_STATE_POINTER
            record.size = size
            record.normalized = normalized
            record.type = type || buffer.dtype
            record.offset = offset
            record.stride = stride
            record.divisor = divisor
          }
        }
      }

      attributeDefs[attribute] = createStaticDecl(function (env, scope) {
        var cache = env.attribCache
        if (id in cache) {
          return cache[id]
        }
        var result = {
          isStream: false
        }
        Object.keys(record).forEach(function (key) {
          result[key] = record[key]
        })
        if (record.buffer) {
          result.buffer = env.link(record.buffer)
          result.type = result.type || (result.buffer + '.dtype')
        }
        cache[id] = result
        return result
      })
    })

    Object.keys(dynamicAttributes).forEach(function (attribute) {
      var dyn = dynamicAttributes[attribute]

      function appendAttributeCode (env, block) {
        var VALUE = env.invoke(block, dyn)

        var shared = env.shared
        var constants = env.constants

        var IS_BUFFER_ARGS = shared.isBufferArgs
        var BUFFER_STATE = shared.buffer

        // Perform validation on attribute
        

        // allocate names for result
        var result = {
          isStream: block.def(false)
        }
        var defaultRecord = new AttributeRecord()
        defaultRecord.state = ATTRIB_STATE_POINTER
        Object.keys(defaultRecord).forEach(function (key) {
          result[key] = block.def('' + defaultRecord[key])
        })

        var BUFFER = result.buffer
        var TYPE = result.type
        block(
          'if(', IS_BUFFER_ARGS, '(', VALUE, ')){',
          result.isStream, '=true;',
          BUFFER, '=', BUFFER_STATE, '.createStream(', GL_ARRAY_BUFFER$2, ',', VALUE, ');',
          TYPE, '=', BUFFER, '.dtype;',
          '}else{',
          BUFFER, '=', BUFFER_STATE, '.getBuffer(', VALUE, ');',
          'if(', BUFFER, '){',
          TYPE, '=', BUFFER, '.dtype;',
          '}else if("constant" in ', VALUE, '){',
          result.state, '=', ATTRIB_STATE_CONSTANT, ';',
          'if(typeof ' + VALUE + '.constant === "number"){',
          result[CUTE_COMPONENTS[0]], '=', VALUE, '.constant;',
          CUTE_COMPONENTS.slice(1).map(function (n) {
            return result[n]
          }).join('='), '=0;',
          '}else{',
          CUTE_COMPONENTS.map(function (name, i) {
            return (
              result[name] + '=' + VALUE + '.constant.length>' + i +
              '?' + VALUE + '.constant[' + i + ']:0;'
            )
          }).join(''),
          '}}else{',
          'if(', IS_BUFFER_ARGS, '(', VALUE, '.buffer)){',
          BUFFER, '=', BUFFER_STATE, '.createStream(', GL_ARRAY_BUFFER$2, ',', VALUE, '.buffer);',
          '}else{',
          BUFFER, '=', BUFFER_STATE, '.getBuffer(', VALUE, '.buffer);',
          '}',
          TYPE, '="type" in ', VALUE, '?',
          constants.glTypes, '[', VALUE, '.type]:', BUFFER, '.dtype;',
          result.normalized, '=!!', VALUE, '.normalized;')
        function emitReadRecord (name) {
          block(result[name], '=', VALUE, '.', name, '|0;')
        }
        emitReadRecord('size')
        emitReadRecord('offset')
        emitReadRecord('stride')
        emitReadRecord('divisor')

        block('}}')

        block.exit(
          'if(', result.isStream, '){',
          BUFFER_STATE, '.destroyStream(', BUFFER, ');',
          '}')

        return result
      }

      attributeDefs[attribute] = createDynamicDecl(dyn, appendAttributeCode)
    })

    return attributeDefs
  }

  function parseContext (context) {
    var staticContext = context.static
    var dynamicContext = context.dynamic
    var result = {}

    Object.keys(staticContext).forEach(function (name) {
      var value = staticContext[name]
      result[name] = createStaticDecl(function (env, scope) {
        if (typeof value === 'number' || typeof value === 'boolean') {
          return '' + value
        } else {
          return env.link(value)
        }
      })
    })

    Object.keys(dynamicContext).forEach(function (name) {
      var dyn = dynamicContext[name]
      result[name] = createDynamicDecl(dyn, function (env, scope) {
        return env.invoke(scope, dyn)
      })
    })

    return result
  }

  function parseArguments (options, attributes, uniforms, context, env) {
    var staticOptions = options.static
    var dynamicOptions = options.dynamic

    

    var attribLocations = parseAttribLocations(options, attributes)

    var framebuffer = parseFramebuffer(options, env)
    var viewportAndScissor = parseViewportScissor(options, framebuffer, env)
    var draw = parseDraw(options, env)
    var state = parseGLState(options, env)
    var shader = parseProgram(options, env, attribLocations)

    function copyBox (name) {
      var defn = viewportAndScissor[name]
      if (defn) {
        state[name] = defn
      }
    }
    copyBox(S_VIEWPORT)
    copyBox(propName(S_SCISSOR_BOX))

    var dirty = Object.keys(state).length > 0

    var result = {
      framebuffer: framebuffer,
      draw: draw,
      shader: shader,
      state: state,
      dirty: dirty,
      scopeVAO: null,
      drawVAO: null,
      useVAO: false,
      attributes: {}
    }

    result.profile = parseProfile(options, env)
    result.uniforms = parseUniforms(uniforms, env)
    result.drawVAO = result.scopeVAO = draw.vao
    // special case: check if we can statically allocate a vertex array object for this program
    if (!result.drawVAO &&
      shader.program &&
      !attribLocations &&
      extensions.angle_instanced_arrays &&
      draw.static.elements) {
      var useVAO = true
      var staticBindings = shader.program.attributes.map(function (attr) {
        var binding = attributes.static[attr]
        useVAO = useVAO && !!binding
        return binding
      })
      if (useVAO && staticBindings.length > 0) {
        var vao = attributeState.getVAO(attributeState.createVAO({
          attributes: staticBindings,
          elements: draw.static.elements
        }))
        result.drawVAO = new Declaration(null, null, null, function (env, scope) {
          return env.link(vao)
        })
        result.useVAO = true
      }
    }
    if (attribLocations) {
      result.useVAO = true
    } else {
      result.attributes = parseAttributes(attributes, env)
    }
    result.context = parseContext(context, env)
    return result
  }

  // ===================================================
  // ===================================================
  // COMMON UPDATE FUNCTIONS
  // ===================================================
  // ===================================================
  function emitContext (env, scope, context) {
    var shared = env.shared
    var CONTEXT = shared.context

    var contextEnter = env.scope()

    Object.keys(context).forEach(function (name) {
      scope.save(CONTEXT, '.' + name)
      var defn = context[name]
      var value = defn.append(env, scope)
      if (Array.isArray(value)) {
        contextEnter(CONTEXT, '.', name, '=[', value.join(), '];')
      } else {
        contextEnter(CONTEXT, '.', name, '=', value, ';')
      }
    })

    scope(contextEnter)
  }

  // ===================================================
  // ===================================================
  // COMMON DRAWING FUNCTIONS
  // ===================================================
  // ===================================================
  function emitPollFramebuffer (env, scope, framebuffer, skipCheck) {
    var shared = env.shared

    var GL = shared.gl
    var FRAMEBUFFER_STATE = shared.framebuffer
    var EXT_DRAW_BUFFERS
    if (extDrawBuffers) {
      EXT_DRAW_BUFFERS = scope.def(shared.extensions, '.webgl_draw_buffers')
    }

    var constants = env.constants

    var DRAW_BUFFERS = constants.drawBuffer
    var BACK_BUFFER = constants.backBuffer

    var NEXT
    if (framebuffer) {
      NEXT = framebuffer.append(env, scope)
    } else {
      NEXT = scope.def(FRAMEBUFFER_STATE, '.next')
    }

    if (!skipCheck) {
      scope('if(', NEXT, '!==', FRAMEBUFFER_STATE, '.cur){')
    }
    scope(
      'if(', NEXT, '){',
      GL, '.bindFramebuffer(', GL_FRAMEBUFFER$2, ',', NEXT, '.framebuffer);')
    if (extDrawBuffers) {
      scope(EXT_DRAW_BUFFERS, '.drawBuffersWEBGL(',
        DRAW_BUFFERS, '[', NEXT, '.colorAttachments.length]);')
    }
    scope('}else{',
      GL, '.bindFramebuffer(', GL_FRAMEBUFFER$2, ',null);')
    if (extDrawBuffers) {
      scope(EXT_DRAW_BUFFERS, '.drawBuffersWEBGL(', BACK_BUFFER, ');')
    }
    scope(
      '}',
      FRAMEBUFFER_STATE, '.cur=', NEXT, ';')
    if (!skipCheck) {
      scope('}')
    }
  }

  function emitPollState (env, scope, args) {
    var shared = env.shared

    var GL = shared.gl

    var CURRENT_VARS = env.current
    var NEXT_VARS = env.next
    var CURRENT_STATE = shared.current
    var NEXT_STATE = shared.next

    var block = env.cond(CURRENT_STATE, '.dirty')

    GL_STATE_NAMES.forEach(function (prop) {
      var param = propName(prop)
      if (param in args.state) {
        return
      }

      var NEXT, CURRENT
      if (param in NEXT_VARS) {
        NEXT = NEXT_VARS[param]
        CURRENT = CURRENT_VARS[param]
        var parts = loop(currentState[param].length, function (i) {
          return block.def(NEXT, '[', i, ']')
        })
        block(env.cond(parts.map(function (p, i) {
          return p + '!==' + CURRENT + '[' + i + ']'
        }).join('||'))
          .then(
            GL, '.', GL_VARIABLES[param], '(', parts, ');',
            parts.map(function (p, i) {
              return CURRENT + '[' + i + ']=' + p
            }).join(';'), ';'))
      } else {
        NEXT = block.def(NEXT_STATE, '.', param)
        var ifte = env.cond(NEXT, '!==', CURRENT_STATE, '.', param)
        block(ifte)
        if (param in GL_FLAGS) {
          ifte(
            env.cond(NEXT)
              .then(GL, '.enable(', GL_FLAGS[param], ');')
              .else(GL, '.disable(', GL_FLAGS[param], ');'),
            CURRENT_STATE, '.', param, '=', NEXT, ';')
        } else {
          ifte(
            GL, '.', GL_VARIABLES[param], '(', NEXT, ');',
            CURRENT_STATE, '.', param, '=', NEXT, ';')
        }
      }
    })
    if (Object.keys(args.state).length === 0) {
      block(CURRENT_STATE, '.dirty=false;')
    }
    scope(block)
  }

  function emitSetOptions (env, scope, options, filter) {
    var shared = env.shared
    var CURRENT_VARS = env.current
    var CURRENT_STATE = shared.current
    var GL = shared.gl
    var VALUE
    sortState(Object.keys(options)).forEach(function (param) {
      var defn = options[param]
      if (filter && !filter(defn)) {
        return
      }
      var variable = defn.append(env, scope)
      if (GL_FLAGS[param]) {
        var flag = GL_FLAGS[param]
        if (isStatic(defn)) {
          VALUE = env.link(variable, {stable: true})
          scope(env.cond(VALUE)
            .then(GL, '.enable(', flag, ');')
            .else(GL, '.disable(', flag, ');'))
          scope(CURRENT_STATE, '.', param, '=', VALUE, ';')
        } else {
          scope(env.cond(variable)
            .then(GL, '.enable(', flag, ');')
            .else(GL, '.disable(', flag, ');'))
          scope(CURRENT_STATE, '.', param, '=', variable, ';')
        }
      } else if (isArrayLike(variable)) {
        var CURRENT = CURRENT_VARS[param]
        scope(
          GL, '.', GL_VARIABLES[param], '(', variable, ');',
          variable.map(function (v, i) {
            return CURRENT + '[' + i + ']=' + v
          }).join(';'), ';')
      } else {
        if (isStatic(defn)) {
          VALUE = env.link(variable, {stable: true})
          scope(
            GL, '.', GL_VARIABLES[param], '(', VALUE, ');',
            CURRENT_STATE, '.', param, '=', VALUE, ';')
        } else {
          scope(
            GL, '.', GL_VARIABLES[param], '(', variable, ');',
            CURRENT_STATE, '.', param, '=', variable, ';')
        }
      }
    })
  }

  function injectExtensions (env, scope) {
    if (extInstancing) {
      env.instancing = scope.def(
        env.shared.extensions, '.angle_instanced_arrays')
    }
  }

  function emitProfile (env, scope, args, useScope, incrementCounter) {
    var shared = env.shared
    var STATS = env.stats
    var CURRENT_STATE = shared.current
    var TIMER = shared.timer
    var profileArg = args.profile

    function perfCounter () {
      if (typeof performance === 'undefined') {
        return 'Date.now()'
      } else {
        return 'performance.now()'
      }
    }

    var CPU_START, QUERY_COUNTER
    function emitProfileStart (block) {
      CPU_START = scope.def()
      block(CPU_START, '=', perfCounter(), ';')
      if (typeof incrementCounter === 'string') {
        block(STATS, '.count+=', incrementCounter, ';')
      } else {
        block(STATS, '.count++;')
      }
      if (timer) {
        if (useScope) {
          QUERY_COUNTER = scope.def()
          block(QUERY_COUNTER, '=', TIMER, '.getNumPendingQueries();')
        } else {
          block(TIMER, '.beginQuery(', STATS, ');')
        }
      }
    }

    function emitProfileEnd (block) {
      block(STATS, '.cpuTime+=', perfCounter(), '-', CPU_START, ';')
      if (timer) {
        if (useScope) {
          block(TIMER, '.pushScopeStats(',
            QUERY_COUNTER, ',',
            TIMER, '.getNumPendingQueries(),',
            STATS, ');')
        } else {
          block(TIMER, '.endQuery();')
        }
      }
    }

    function scopeProfile (value) {
      var prev = scope.def(CURRENT_STATE, '.profile')
      scope(CURRENT_STATE, '.profile=', value, ';')
      scope.exit(CURRENT_STATE, '.profile=', prev, ';')
    }

    var USE_PROFILE
    if (profileArg) {
      if (isStatic(profileArg)) {
        if (profileArg.enable) {
          emitProfileStart(scope)
          emitProfileEnd(scope.exit)
          scopeProfile('true')
        } else {
          scopeProfile('false')
        }
        return
      }
      USE_PROFILE = profileArg.append(env, scope)
      scopeProfile(USE_PROFILE)
    } else {
      USE_PROFILE = scope.def(CURRENT_STATE, '.profile')
    }

    var start = env.block()
    emitProfileStart(start)
    scope('if(', USE_PROFILE, '){', start, '}')
    var end = env.block()
    emitProfileEnd(end)
    scope.exit('if(', USE_PROFILE, '){', end, '}')
  }

  function emitAttributes (env, scope, args, attributes, filter) {
    var shared = env.shared

    function typeLength (x) {
      switch (x) {
        case GL_FLOAT_VEC2:
        case GL_INT_VEC2:
        case GL_BOOL_VEC2:
          return 2
        case GL_FLOAT_VEC3:
        case GL_INT_VEC3:
        case GL_BOOL_VEC3:
          return 3
        case GL_FLOAT_VEC4:
        case GL_INT_VEC4:
        case GL_BOOL_VEC4:
          return 4
        default:
          return 1
      }
    }

    function emitBindAttribute (ATTRIBUTE, size, record) {
      var GL = shared.gl

      var LOCATION = scope.def(ATTRIBUTE, '.location')
      var BINDING = scope.def(shared.attributes, '[', LOCATION, ']')

      var STATE = record.state
      var BUFFER = record.buffer
      var CONST_COMPONENTS = [
        record.x,
        record.y,
        record.z,
        record.w
      ]

      var COMMON_KEYS = [
        'buffer',
        'normalized',
        'offset',
        'stride'
      ]

      function emitBuffer () {
        scope(
          'if(!', BINDING, '.buffer){',
          GL, '.enableVertexAttribArray(', LOCATION, ');}')

        var TYPE = record.type
        var SIZE
        if (!record.size) {
          SIZE = size
        } else {
          SIZE = scope.def(record.size, '||', size)
        }

        scope('if(',
          BINDING, '.type!==', TYPE, '||',
          BINDING, '.size!==', SIZE, '||',
          COMMON_KEYS.map(function (key) {
            return BINDING + '.' + key + '!==' + record[key]
          }).join('||'),
          '){',
          GL, '.bindBuffer(', GL_ARRAY_BUFFER$2, ',', BUFFER, '.buffer);',
          GL, '.vertexAttribPointer(', [
            LOCATION,
            SIZE,
            TYPE,
            record.normalized,
            record.stride,
            record.offset
          ], ');',
          BINDING, '.type=', TYPE, ';',
          BINDING, '.size=', SIZE, ';',
          COMMON_KEYS.map(function (key) {
            return BINDING + '.' + key + '=' + record[key] + ';'
          }).join(''),
          '}')

        if (extInstancing) {
          var DIVISOR = record.divisor
          scope(
            'if(', BINDING, '.divisor!==', DIVISOR, '){',
            env.instancing, '.vertexAttribDivisorANGLE(', [LOCATION, DIVISOR], ');',
            BINDING, '.divisor=', DIVISOR, ';}')
        }
      }

      function emitConstant () {
        scope(
          'if(', BINDING, '.buffer){',
          GL, '.disableVertexAttribArray(', LOCATION, ');',
          BINDING, '.buffer=null;',
          '}if(', CUTE_COMPONENTS.map(function (c, i) {
            return BINDING + '.' + c + '!==' + CONST_COMPONENTS[i]
          }).join('||'), '){',
          GL, '.vertexAttrib4f(', LOCATION, ',', CONST_COMPONENTS, ');',
          CUTE_COMPONENTS.map(function (c, i) {
            return BINDING + '.' + c + '=' + CONST_COMPONENTS[i] + ';'
          }).join(''),
          '}')
      }

      if (STATE === ATTRIB_STATE_POINTER) {
        emitBuffer()
      } else if (STATE === ATTRIB_STATE_CONSTANT) {
        emitConstant()
      } else {
        scope('if(', STATE, '===', ATTRIB_STATE_POINTER, '){')
        emitBuffer()
        scope('}else{')
        emitConstant()
        scope('}')
      }
    }

    attributes.forEach(function (attribute) {
      var name = attribute.name
      var arg = args.attributes[name]
      var record
      if (arg) {
        if (!filter(arg)) {
          return
        }
        record = arg.append(env, scope)
      } else {
        if (!filter(SCOPE_DECL)) {
          return
        }
        var scopeAttrib = env.scopeAttrib(name)
        
        record = {}
        Object.keys(new AttributeRecord()).forEach(function (key) {
          record[key] = scope.def(scopeAttrib, '.', key)
        })
      }
      emitBindAttribute(
        env.link(attribute), typeLength(attribute.info.type), record)
    })
  }

  function emitUniforms (env, scope, args, uniforms, filter, isBatchInnerLoop) {
    var shared = env.shared
    var GL = shared.gl

    var infix
    for (var i = 0; i < uniforms.length; ++i) {
      var uniform = uniforms[i]
      var name = uniform.name
      var type = uniform.info.type
      var arg = args.uniforms[name]
      var UNIFORM = env.link(uniform)
      var LOCATION = UNIFORM + '.location'

      var VALUE
      if (arg) {
        if (!filter(arg)) {
          continue
        }
        if (isStatic(arg)) {
          var value = arg.value
          
          if (type === GL_SAMPLER_2D || type === GL_SAMPLER_CUBE) {
            
            var TEX_VALUE = env.link(value._texture || value.color[0]._texture)
            scope(GL, '.uniform1i(', LOCATION, ',', TEX_VALUE + '.bind());')
            scope.exit(TEX_VALUE, '.unbind();')
          } else if (
            type === GL_FLOAT_MAT2 ||
            type === GL_FLOAT_MAT3 ||
            type === GL_FLOAT_MAT4) {
            
            var MAT_VALUE = env.global.def('new Float32Array([' +
              Array.prototype.slice.call(value) + '])')
            var dim = 2
            if (type === GL_FLOAT_MAT3) {
              dim = 3
            } else if (type === GL_FLOAT_MAT4) {
              dim = 4
            }
            scope(
              GL, '.uniformMatrix', dim, 'fv(',
              LOCATION, ',false,', MAT_VALUE, ');')
          } else {
            switch (type) {
              case GL_FLOAT$7:
                
                infix = '1f'
                break
              case GL_FLOAT_VEC2:
                
                infix = '2f'
                break
              case GL_FLOAT_VEC3:
                
                infix = '3f'
                break
              case GL_FLOAT_VEC4:
                
                infix = '4f'
                break
              case GL_BOOL:
                
                infix = '1i'
                break
              case GL_INT$2:
                
                infix = '1i'
                break
              case GL_BOOL_VEC2:
                
                infix = '2i'
                break
              case GL_INT_VEC2:
                
                infix = '2i'
                break
              case GL_BOOL_VEC3:
                
                infix = '3i'
                break
              case GL_INT_VEC3:
                
                infix = '3i'
                break
              case GL_BOOL_VEC4:
                
                infix = '4i'
                break
              case GL_INT_VEC4:
                
                infix = '4i'
                break
            }
            scope(GL, '.uniform', infix, '(', LOCATION, ',',
              isArrayLike(value) ? Array.prototype.slice.call(value) : value,
              ');')
          }
          continue
        } else {
          VALUE = arg.append(env, scope)
        }
      } else {
        if (!filter(SCOPE_DECL)) {
          continue
        }
        VALUE = scope.def(shared.uniforms, '[', stringStore.id(name), ']')
      }

      if (type === GL_SAMPLER_2D) {
        
        scope(
          'if(', VALUE, '&&', VALUE, '._reglType==="framebuffer"){',
          VALUE, '=', VALUE, '.color[0];',
          '}')
      } else if (type === GL_SAMPLER_CUBE) {
        
        scope(
          'if(', VALUE, '&&', VALUE, '._reglType==="framebufferCube"){',
          VALUE, '=', VALUE, '.color[0];',
          '}')
      }

      // perform type validation
      

      var unroll = 1
      switch (type) {
        case GL_SAMPLER_2D:
        case GL_SAMPLER_CUBE:
          var TEX = scope.def(VALUE, '._texture')
          scope(GL, '.uniform1i(', LOCATION, ',', TEX, '.bind());')
          scope.exit(TEX, '.unbind();')
          continue

        case GL_INT$2:
        case GL_BOOL:
          infix = '1i'
          break

        case GL_INT_VEC2:
        case GL_BOOL_VEC2:
          infix = '2i'
          unroll = 2
          break

        case GL_INT_VEC3:
        case GL_BOOL_VEC3:
          infix = '3i'
          unroll = 3
          break

        case GL_INT_VEC4:
        case GL_BOOL_VEC4:
          infix = '4i'
          unroll = 4
          break

        case GL_FLOAT$7:
          infix = '1f'
          break

        case GL_FLOAT_VEC2:
          infix = '2f'
          unroll = 2
          break

        case GL_FLOAT_VEC3:
          infix = '3f'
          unroll = 3
          break

        case GL_FLOAT_VEC4:
          infix = '4f'
          unroll = 4
          break

        case GL_FLOAT_MAT2:
          infix = 'Matrix2fv'
          break

        case GL_FLOAT_MAT3:
          infix = 'Matrix3fv'
          break

        case GL_FLOAT_MAT4:
          infix = 'Matrix4fv'
          break
      }

      if (infix.charAt(0) === 'M') {
        scope(GL, '.uniform', infix, '(', LOCATION, ',')
        var matSize = Math.pow(type - GL_FLOAT_MAT2 + 2, 2)
        var STORAGE = env.global.def('new Float32Array(', matSize, ')')
        if (Array.isArray(VALUE)) {
          scope(
            'false,(',
            loop(matSize, function (i) {
              return STORAGE + '[' + i + ']=' + VALUE[i]
            }), ',', STORAGE, ')')
        } else {
          scope(
            'false,(Array.isArray(', VALUE, ')||', VALUE, ' instanceof Float32Array)?', VALUE, ':(',
            loop(matSize, function (i) {
              return STORAGE + '[' + i + ']=' + VALUE + '[' + i + ']'
            }), ',', STORAGE, ')')
        }
        scope(');')
      } else if (unroll > 1) {
        var prev = []
        var cur = []
        for (var j = 0; j < unroll; ++j) {
          if (Array.isArray(VALUE)) {
            cur.push(VALUE[j])
          } else {
            cur.push(scope.def(VALUE + '[' + j + ']'))
          }
          if (isBatchInnerLoop) {
            prev.push(scope.def())
          }
        }
        if (isBatchInnerLoop) {
          scope('if(!', env.batchId, '||', prev.map(function (p, i) {
            return p + '!==' + cur[i]
          }).join('||'), '){', prev.map(function (p, i) {
            return p + '=' + cur[i] + ';'
          }).join(''))
        }
        scope(GL, '.uniform', infix, '(', LOCATION, ',', cur.join(','), ');')
        if (isBatchInnerLoop) {
          scope('}')
        }
      } else {
        
        if (isBatchInnerLoop) {
          var prevS = scope.def()
          scope('if(!', env.batchId, '||', prevS, '!==', VALUE, '){',
            prevS, '=', VALUE, ';')
        }
        scope(GL, '.uniform', infix, '(', LOCATION, ',', VALUE, ');')
        if (isBatchInnerLoop) {
          scope('}')
        }
      }
    }
  }

  function emitDraw (env, outer, inner, args) {
    var shared = env.shared
    var GL = shared.gl
    var DRAW_STATE = shared.draw

    var drawOptions = args.draw

    function emitElements () {
      var defn = drawOptions.elements
      var ELEMENTS
      var scope = outer
      if (defn) {
        if ((defn.contextDep && args.contextDynamic) || defn.propDep) {
          scope = inner
        }
        ELEMENTS = defn.append(env, scope)
        if (drawOptions.elementsActive) {
          scope(
            'if(' + ELEMENTS + ')' +
            GL + '.bindBuffer(' + GL_ELEMENT_ARRAY_BUFFER$2 + ',' + ELEMENTS + '.buffer.buffer);')
        }
      } else {
        ELEMENTS = scope.def()
        scope(
          ELEMENTS, '=', DRAW_STATE, '.', S_ELEMENTS, ';',
          'if(', ELEMENTS, '){',
          GL, '.bindBuffer(', GL_ELEMENT_ARRAY_BUFFER$2, ',', ELEMENTS, '.buffer.buffer);}',
          'else if(', shared.vao, '.currentVAO){',
          ELEMENTS, '=', env.shared.elements + '.getElements(' + shared.vao, '.currentVAO.elements);',
          (!extVertexArrays ? 'if(' + ELEMENTS + ')' + GL + '.bindBuffer(' + GL_ELEMENT_ARRAY_BUFFER$2 + ',' + ELEMENTS + '.buffer.buffer);' : ''),
          '}')
      }
      return ELEMENTS
    }

    function emitCount () {
      var defn = drawOptions.count
      var COUNT
      var scope = outer
      if (defn) {
        if ((defn.contextDep && args.contextDynamic) || defn.propDep) {
          scope = inner
        }
        COUNT = defn.append(env, scope)
        
      } else {
        COUNT = scope.def(DRAW_STATE, '.', S_COUNT)
        
      }
      return COUNT
    }

    var ELEMENTS = emitElements()
    function emitValue (name) {
      var defn = drawOptions[name]
      if (defn) {
        if ((defn.contextDep && args.contextDynamic) || defn.propDep) {
          return defn.append(env, inner)
        } else {
          return defn.append(env, outer)
        }
      } else {
        return outer.def(DRAW_STATE, '.', name)
      }
    }

    var PRIMITIVE = emitValue(S_PRIMITIVE)
    var OFFSET = emitValue(S_OFFSET)

    var COUNT = emitCount()
    if (typeof COUNT === 'number') {
      if (COUNT === 0) {
        return
      }
    } else {
      inner('if(', COUNT, '){')
      inner.exit('}')
    }

    var INSTANCES, EXT_INSTANCING
    if (extInstancing) {
      INSTANCES = emitValue(S_INSTANCES)
      EXT_INSTANCING = env.instancing
    }

    var ELEMENT_TYPE = ELEMENTS + '.type'

    var elementsStatic = drawOptions.elements && isStatic(drawOptions.elements) && !drawOptions.vaoActive

    function emitInstancing () {
      function drawElements () {
        inner(EXT_INSTANCING, '.drawElementsInstancedANGLE(', [
          PRIMITIVE,
          COUNT,
          ELEMENT_TYPE,
          OFFSET + '<<((' + ELEMENT_TYPE + '-' + GL_UNSIGNED_BYTE$7 + ')>>1)',
          INSTANCES
        ], ');')
      }

      function drawArrays () {
        inner(EXT_INSTANCING, '.drawArraysInstancedANGLE(',
          [PRIMITIVE, OFFSET, COUNT, INSTANCES], ');')
      }

      if (ELEMENTS && ELEMENTS !== 'null') {
        if (!elementsStatic) {
          inner('if(', ELEMENTS, '){')
          drawElements()
          inner('}else{')
          drawArrays()
          inner('}')
        } else {
          drawElements()
        }
      } else {
        drawArrays()
      }
    }

    function emitRegular () {
      function drawElements () {
        inner(GL + '.drawElements(' + [
          PRIMITIVE,
          COUNT,
          ELEMENT_TYPE,
          OFFSET + '<<((' + ELEMENT_TYPE + '-' + GL_UNSIGNED_BYTE$7 + ')>>1)'
        ] + ');')
      }

      function drawArrays () {
        inner(GL + '.drawArrays(' + [PRIMITIVE, OFFSET, COUNT] + ');')
      }

      if (ELEMENTS && ELEMENTS !== 'null') {
        if (!elementsStatic) {
          inner('if(', ELEMENTS, '){')
          drawElements()
          inner('}else{')
          drawArrays()
          inner('}')
        } else {
          drawElements()
        }
      } else {
        drawArrays()
      }
    }

    if (extInstancing && (typeof INSTANCES !== 'number' || INSTANCES >= 0)) {
      if (typeof INSTANCES === 'string') {
        inner('if(', INSTANCES, '>0){')
        emitInstancing()
        inner('}else if(', INSTANCES, '<0){')
        emitRegular()
        inner('}')
      } else {
        emitInstancing()
      }
    } else {
      emitRegular()
    }
  }

  function createBody (emitBody, parentEnv, args, program, count) {
    var env = createREGLEnvironment()
    var scope = env.proc('body', count)
    
    if (extInstancing) {
      env.instancing = scope.def(
        env.shared.extensions, '.angle_instanced_arrays')
    }
    emitBody(env, scope, args, program)
    return env.compile().body
  }

  // ===================================================
  // ===================================================
  // DRAW PROC
  // ===================================================
  // ===================================================
  function emitDrawBody (env, draw, args, program) {
    injectExtensions(env, draw)
    if (args.useVAO) {
      if (args.drawVAO) {
        draw(env.shared.vao, '.setVAO(', args.drawVAO.append(env, draw), ');')
      } else {
        draw(env.shared.vao, '.setVAO(', env.shared.vao, '.targetVAO);')
      }
    } else {
      draw(env.shared.vao, '.setVAO(null);')
      emitAttributes(env, draw, args, program.attributes, function () {
        return true
      })
    }
    emitUniforms(env, draw, args, program.uniforms, function () {
      return true
    }, false)
    emitDraw(env, draw, draw, args)
  }

  function emitDrawProc (env, args) {
    var draw = env.proc('draw', 1)

    injectExtensions(env, draw)

    emitContext(env, draw, args.context)
    emitPollFramebuffer(env, draw, args.framebuffer)

    emitPollState(env, draw, args)
    emitSetOptions(env, draw, args.state)

    emitProfile(env, draw, args, false, true)

    var program = args.shader.progVar.append(env, draw)
    draw(env.shared.gl, '.useProgram(', program, '.program);')

    if (args.shader.program) {
      emitDrawBody(env, draw, args, args.shader.program)
    } else {
      draw(env.shared.vao, '.setVAO(null);')
      var drawCache = env.global.def('{}')
      var PROG_ID = draw.def(program, '.id')
      var CACHED_PROC = draw.def(drawCache, '[', PROG_ID, ']')
      draw(
        env.cond(CACHED_PROC)
          .then(CACHED_PROC, '.call(this,a0);')
          .else(
            CACHED_PROC, '=', drawCache, '[', PROG_ID, ']=',
            env.link(function (program) {
              return createBody(emitDrawBody, env, args, program, 1)
            }), '(', program, ');',
            CACHED_PROC, '.call(this,a0);'))
    }

    if (Object.keys(args.state).length > 0) {
      draw(env.shared.current, '.dirty=true;')
    }
    if (env.shared.vao) {
      draw(env.shared.vao, '.setVAO(null);')
    }
  }

  // ===================================================
  // ===================================================
  // BATCH PROC
  // ===================================================
  // ===================================================

  function emitBatchDynamicShaderBody (env, scope, args, program) {
    env.batchId = 'a1'

    injectExtensions(env, scope)

    function all () {
      return true
    }

    emitAttributes(env, scope, args, program.attributes, all)
    emitUniforms(env, scope, args, program.uniforms, all, false)
    emitDraw(env, scope, scope, args)
  }

  function emitBatchBody (env, scope, args, program) {
    injectExtensions(env, scope)

    var contextDynamic = args.contextDep

    var BATCH_ID = scope.def()
    var PROP_LIST = 'a0'
    var NUM_PROPS = 'a1'
    var PROPS = scope.def()
    env.shared.props = PROPS
    env.batchId = BATCH_ID

    var outer = env.scope()
    var inner = env.scope()

    scope(
      outer.entry,
      'for(', BATCH_ID, '=0;', BATCH_ID, '<', NUM_PROPS, ';++', BATCH_ID, '){',
      PROPS, '=', PROP_LIST, '[', BATCH_ID, '];',
      inner,
      '}',
      outer.exit)

    function isInnerDefn (defn) {
      return ((defn.contextDep && contextDynamic) || defn.propDep)
    }

    function isOuterDefn (defn) {
      return !isInnerDefn(defn)
    }

    if (args.needsContext) {
      emitContext(env, inner, args.context)
    }
    if (args.needsFramebuffer) {
      emitPollFramebuffer(env, inner, args.framebuffer)
    }
    emitSetOptions(env, inner, args.state, isInnerDefn)

    if (args.profile && isInnerDefn(args.profile)) {
      emitProfile(env, inner, args, false, true)
    }

    if (!program) {
      var progCache = env.global.def('{}')
      var PROGRAM = args.shader.progVar.append(env, inner)
      var PROG_ID = inner.def(PROGRAM, '.id')
      var CACHED_PROC = inner.def(progCache, '[', PROG_ID, ']')
      inner(
        env.shared.gl, '.useProgram(', PROGRAM, '.program);',
        'if(!', CACHED_PROC, '){',
        CACHED_PROC, '=', progCache, '[', PROG_ID, ']=',
        env.link(function (program) {
          return createBody(
            emitBatchDynamicShaderBody, env, args, program, 2)
        }), '(', PROGRAM, ');}',
        CACHED_PROC, '.call(this,a0[', BATCH_ID, '],', BATCH_ID, ');')
    } else {
      if (args.useVAO) {
        if (args.drawVAO) {
          if (isInnerDefn(args.drawVAO)) {
            // vao is a prop
            inner(env.shared.vao, '.setVAO(', args.drawVAO.append(env, inner), ');')
          } else {
            // vao is invariant
            outer(env.shared.vao, '.setVAO(', args.drawVAO.append(env, outer), ');')
          }
        } else {
          // scoped vao binding
          outer(env.shared.vao, '.setVAO(', env.shared.vao, '.targetVAO);')
        }
      } else {
        outer(env.shared.vao, '.setVAO(null);')
        emitAttributes(env, outer, args, program.attributes, isOuterDefn)
        emitAttributes(env, inner, args, program.attributes, isInnerDefn)
      }
      emitUniforms(env, outer, args, program.uniforms, isOuterDefn, false)
      emitUniforms(env, inner, args, program.uniforms, isInnerDefn, true)
      emitDraw(env, outer, inner, args)
    }
  }

  function emitBatchProc (env, args) {
    var batch = env.proc('batch', 2)
    env.batchId = '0'

    injectExtensions(env, batch)

    // Check if any context variables depend on props
    var contextDynamic = false
    var needsContext = true
    Object.keys(args.context).forEach(function (name) {
      contextDynamic = contextDynamic || args.context[name].propDep
    })
    if (!contextDynamic) {
      emitContext(env, batch, args.context)
      needsContext = false
    }

    // framebuffer state affects framebufferWidth/height context vars
    var framebuffer = args.framebuffer
    var needsFramebuffer = false
    if (framebuffer) {
      if (framebuffer.propDep) {
        contextDynamic = needsFramebuffer = true
      } else if (framebuffer.contextDep && contextDynamic) {
        needsFramebuffer = true
      }
      if (!needsFramebuffer) {
        emitPollFramebuffer(env, batch, framebuffer)
      }
    } else {
      emitPollFramebuffer(env, batch, null)
    }

    // viewport is weird because it can affect context vars
    if (args.state.viewport && args.state.viewport.propDep) {
      contextDynamic = true
    }

    function isInnerDefn (defn) {
      return (defn.contextDep && contextDynamic) || defn.propDep
    }

    // set webgl options
    emitPollState(env, batch, args)
    emitSetOptions(env, batch, args.state, function (defn) {
      return !isInnerDefn(defn)
    })

    if (!args.profile || !isInnerDefn(args.profile)) {
      emitProfile(env, batch, args, false, 'a1')
    }

    // Save these values to args so that the batch body routine can use them
    args.contextDep = contextDynamic
    args.needsContext = needsContext
    args.needsFramebuffer = needsFramebuffer

    // determine if shader is dynamic
    var progDefn = args.shader.progVar
    if ((progDefn.contextDep && contextDynamic) || progDefn.propDep) {
      emitBatchBody(
        env,
        batch,
        args,
        null)
    } else {
      var PROGRAM = progDefn.append(env, batch)
      batch(env.shared.gl, '.useProgram(', PROGRAM, '.program);')
      if (args.shader.program) {
        emitBatchBody(
          env,
          batch,
          args,
          args.shader.program)
      } else {
        batch(env.shared.vao, '.setVAO(null);')
        var batchCache = env.global.def('{}')
        var PROG_ID = batch.def(PROGRAM, '.id')
        var CACHED_PROC = batch.def(batchCache, '[', PROG_ID, ']')
        batch(
          env.cond(CACHED_PROC)
            .then(CACHED_PROC, '.call(this,a0,a1);')
            .else(
              CACHED_PROC, '=', batchCache, '[', PROG_ID, ']=',
              env.link(function (program) {
                return createBody(emitBatchBody, env, args, program, 2)
              }), '(', PROGRAM, ');',
              CACHED_PROC, '.call(this,a0,a1);'))
      }
    }

    if (Object.keys(args.state).length > 0) {
      batch(env.shared.current, '.dirty=true;')
    }

    if (env.shared.vao) {
      batch(env.shared.vao, '.setVAO(null);')
    }
  }

  // ===================================================
  // ===================================================
  // SCOPE COMMAND
  // ===================================================
  // ===================================================
  function emitScopeProc (env, args) {
    var scope = env.proc('scope', 3)
    env.batchId = 'a2'

    var shared = env.shared
    var CURRENT_STATE = shared.current

    emitContext(env, scope, args.context)

    if (args.framebuffer) {
      args.framebuffer.append(env, scope)
    }

    sortState(Object.keys(args.state)).forEach(function (name) {
      var defn = args.state[name]
      var value = defn.append(env, scope)
      if (isArrayLike(value)) {
        value.forEach(function (v, i) {
          if (hasVariableReference(v)) {
            scope.set(env.next[name], '[' + i + ']', v)
          } else {
            scope.set(env.next[name], '[' + i + ']', env.link(v, {stable: true}))
          }
        })
      } else {
        if (isStatic(defn)) {
          scope.set(shared.next, '.' + name, env.link(value, {stable: true}))
        } else {
          scope.set(shared.next, '.' + name, value)
        }
      }
    })

    emitProfile(env, scope, args, true, true)

    ;[S_ELEMENTS, S_OFFSET, S_COUNT, S_INSTANCES, S_PRIMITIVE].forEach(
      function (opt) {
        var variable = args.draw[opt]
        if (!variable) {
          return
        }
        var VARIABLE = variable.append(env, scope)
        if (hasVariableReference(VARIABLE)) {
          scope.set(shared.draw, '.' + opt, VARIABLE)
        } else {
          scope.set(shared.draw, '.' + opt, env.link(VARIABLE), {stable: true})
        }
      })

    Object.keys(args.uniforms).forEach(function (opt) {
      var value = args.uniforms[opt].append(env, scope)
      if (Array.isArray(value)) {
        value = '[' + value.map(function (v) {
          if (hasVariableReference(v)) {
            return v;
          } else {
            return env.link(v, {stable: true})
          }
        }) + ']'
      }
      scope.set(
        shared.uniforms,
        '[' + env.link(stringStore.id(opt), {stable: true}) + ']',
        value)
    })

    Object.keys(args.attributes).forEach(function (name) {
      var record = args.attributes[name].append(env, scope)
      var scopeAttrib = env.scopeAttrib(name)
      Object.keys(new AttributeRecord()).forEach(function (prop) {
        scope.set(scopeAttrib, '.' + prop, record[prop])
      })
    })

    if (args.scopeVAO) {
      var VARIABLE = args.scopeVAO.append(env, scope)
      if (hasVariableReference(VARIABLE)) {
        scope.set(shared.vao, '.targetVAO', VARIABLE)
      } else {
        scope.set(shared.vao, '.targetVAO', env.link(VARIABLE, {stable: true}))
      }
    }

    function saveShader (name) {
      var shader = args.shader[name]
      if (shader) {
        var VARIABLE = shader.append(env, scope)
        if (hasVariableReference(VARIABLE)) {
          scope.set(shared.shader, '.' + name, VARIABLE)
        } else {
          scope.set(shared.shader, '.' + name, env.link(VARIABLE, {stable: true}))
        }
      }
    }
    saveShader(S_VERT)
    saveShader(S_FRAG)

    if (Object.keys(args.state).length > 0) {
      scope(CURRENT_STATE, '.dirty=true;')
      scope.exit(CURRENT_STATE, '.dirty=true;')
    }

    scope('a1(', env.shared.context, ',a0,', env.batchId, ');')
  }

  function isDynamicObject (object) {
    if (typeof object !== 'object' || isArrayLike(object)) {
      return
    }
    var props = Object.keys(object)
    for (var i = 0; i < props.length; ++i) {
      if (dynamic.isDynamic(object[props[i]])) {
        return true
      }
    }
    return false
  }

  function splatObject (env, options, name) {
    var object = options.static[name]
    if (!object || !isDynamicObject(object)) {
      return
    }

    var globals = env.global
    var keys = Object.keys(object)
    var thisDep = false
    var contextDep = false
    var propDep = false
    var objectRef = env.global.def('{}')
    keys.forEach(function (key) {
      var value = object[key]
      if (dynamic.isDynamic(value)) {
        if (typeof value === 'function') {
          value = object[key] = dynamic.unbox(value)
        }
        var deps = createDynamicDecl(value, null)
        thisDep = thisDep || deps.thisDep
        propDep = propDep || deps.propDep
        contextDep = contextDep || deps.contextDep
      } else {
        globals(objectRef, '.', key, '=')
        switch (typeof value) {
          case 'number':
            globals(value)
            break
          case 'string':
            globals('"', value, '"')
            break
          case 'object':
            if (Array.isArray(value)) {
              globals('[', value.join(), ']')
            }
            break
          default:
            globals(env.link(value))
            break
        }
        globals(';')
      }
    })

    function appendBlock (env, block) {
      keys.forEach(function (key) {
        var value = object[key]
        if (!dynamic.isDynamic(value)) {
          return
        }
        var ref = env.invoke(block, value)
        block(objectRef, '.', key, '=', ref, ';')
      })
    }

    options.dynamic[name] = new dynamic.DynamicVariable(DYN_THUNK, {
      thisDep: thisDep,
      contextDep: contextDep,
      propDep: propDep,
      ref: objectRef,
      append: appendBlock
    })
    delete options.static[name]
  }

  // ===========================================================================
  // ===========================================================================
  // MAIN DRAW COMMAND
  // ===========================================================================
  // ===========================================================================
  function compileCommand (options, attributes, uniforms, context, stats) {
    var env = createREGLEnvironment()

    // link stats, so that we can easily access it in the program.
    env.stats = env.link(stats)

    // splat options and attributes to allow for dynamic nested properties
    Object.keys(attributes.static).forEach(function (key) {
      splatObject(env, attributes, key)
    })
    NESTED_OPTIONS.forEach(function (name) {
      splatObject(env, options, name)
    })

    var args = parseArguments(options, attributes, uniforms, context, env)

    if (args.shader.program) {
      args.shader.program.attributes.sort(function (a, b) {
        return a.name < b.name ? -1 : 1
      })
      args.shader.program.uniforms.sort(function (a, b) {
        return a.name < b.name ? -1 : 1
      })
    }

    emitDrawProc(env, args)
    emitScopeProc(env, args)
    emitBatchProc(env, args)

    return extend(env.compile(), {
      destroy: function () {
        args.shader.program.destroy()
      }
    })
  }

  // ===========================================================================
  // ===========================================================================
  // POLL / REFRESH
  // ===========================================================================
  // ===========================================================================
  return {
    next: nextState,
    current: currentState,
    procs: (function () {
      var env = createREGLEnvironment()
      var poll = env.proc('poll')
      var refresh = env.proc('refresh')
      var common = env.block()
      poll(common)
      refresh(common)

      var shared = env.shared
      var GL = shared.gl
      var NEXT_STATE = shared.next
      var CURRENT_STATE = shared.current

      common(CURRENT_STATE, '.dirty=false;')

      emitPollFramebuffer(env, poll)
      emitPollFramebuffer(env, refresh, null, true)

      // Refresh updates all attribute state changes
      var INSTANCING
      if (extInstancing) {
        INSTANCING = env.link(extInstancing)
      }

      // update vertex array bindings
      if (extensions.oes_vertex_array_object) {
        refresh(env.link(extensions.oes_vertex_array_object), '.bindVertexArrayOES(null);')
      }
      var BINDING = refresh.def(shared.attributes)
      var TEMP_BINDING = refresh.def(0)

      var ifte = env.cond(TEMP_BINDING, '.buffer')
      ifte.then(
        GL, '.enableVertexAttribArray(i);',
        GL, '.bindBuffer(',
        GL_ARRAY_BUFFER$2, ',',
        TEMP_BINDING, '.buffer.buffer);',
        GL, '.vertexAttribPointer(i,',
        TEMP_BINDING, '.size,',
        TEMP_BINDING, '.type,',
        TEMP_BINDING, '.normalized,',
        TEMP_BINDING, '.stride,',
        TEMP_BINDING, '.offset);'
      ).else(
        GL, '.disableVertexAttribArray(i);',
        GL, '.vertexAttrib4f(i,',
        TEMP_BINDING, '.x,',
        TEMP_BINDING, '.y,',
        TEMP_BINDING, '.z,',
        TEMP_BINDING, '.w);',
        TEMP_BINDING, '.buffer=null;')
      var MAX_ATTRIBUTES = env.link(limits.maxAttributes, {stable: true})
      refresh(
        'for(var i=0;i<', MAX_ATTRIBUTES, ';++i){',
        TEMP_BINDING, '=', BINDING, '[i];',
        ifte,
        '}'
      )

      if (extInstancing) {
        refresh(
          'for(var i=0;i<', MAX_ATTRIBUTES, ';++i){',
          INSTANCING, '.vertexAttribDivisorANGLE(i,',
          BINDING, '[i].divisor);',
          '}')
      }
      refresh(
        env.shared.vao, '.currentVAO=null;',
        env.shared.vao, '.setVAO(', env.shared.vao, '.targetVAO);')

      Object.keys(GL_FLAGS).forEach(function (flag) {
        var cap = GL_FLAGS[flag]
        var NEXT = common.def(NEXT_STATE, '.', flag)
        var block = env.block()
        block('if(', NEXT, '){',
          GL, '.enable(', cap, ')}else{',
          GL, '.disable(', cap, ')}',
          CURRENT_STATE, '.', flag, '=', NEXT, ';')
        refresh(block)
        poll(
          'if(', NEXT, '!==', CURRENT_STATE, '.', flag, '){',
          block,
          '}')
      })

      Object.keys(GL_VARIABLES).forEach(function (name) {
        var func = GL_VARIABLES[name]
        var init = currentState[name]
        var NEXT, CURRENT
        var block = env.block()
        block(GL, '.', func, '(')
        if (isArrayLike(init)) {
          var n = init.length
          NEXT = env.global.def(NEXT_STATE, '.', name)
          CURRENT = env.global.def(CURRENT_STATE, '.', name)
          block(
            loop(n, function (i) {
              return NEXT + '[' + i + ']'
            }), ');',
            loop(n, function (i) {
              return CURRENT + '[' + i + ']=' + NEXT + '[' + i + '];'
            }).join(''))
          poll(
            'if(', loop(n, function (i) {
              return NEXT + '[' + i + ']!==' + CURRENT + '[' + i + ']'
            }).join('||'), '){',
            block,
            '}')
        } else {
          NEXT = common.def(NEXT_STATE, '.', name)
          CURRENT = common.def(CURRENT_STATE, '.', name)
          block(
            NEXT, ');',
            CURRENT_STATE, '.', name, '=', NEXT, ';')
          poll(
            'if(', NEXT, '!==', CURRENT, '){',
            block,
            '}')
        }
        refresh(block)
      })

      return env.compile()
    })(),
    compile: compileCommand
  }
}

function stats () {
  return {
    vaoCount: 0,
    bufferCount: 0,
    elementsCount: 0,
    framebufferCount: 0,
    shaderCount: 0,
    textureCount: 0,
    cubeCount: 0,
    renderbufferCount: 0,
    maxTextureUnits: 0
  }
}

var GL_QUERY_RESULT_EXT = 0x8866
var GL_QUERY_RESULT_AVAILABLE_EXT = 0x8867
var GL_TIME_ELAPSED_EXT = 0x88BF

var createTimer = function (gl, extensions) {
  if (!extensions.ext_disjoint_timer_query) {
    return null
  }

  // QUERY POOL BEGIN
  var queryPool = []
  function allocQuery () {
    return queryPool.pop() || extensions.ext_disjoint_timer_query.createQueryEXT()
  }
  function freeQuery (query) {
    queryPool.push(query)
  }
  // QUERY POOL END

  var pendingQueries = []
  function beginQuery (stats) {
    var query = allocQuery()
    extensions.ext_disjoint_timer_query.beginQueryEXT(GL_TIME_ELAPSED_EXT, query)
    pendingQueries.push(query)
    pushScopeStats(pendingQueries.length - 1, pendingQueries.length, stats)
  }

  function endQuery () {
    extensions.ext_disjoint_timer_query.endQueryEXT(GL_TIME_ELAPSED_EXT)
  }

  //
  // Pending stats pool.
  //
  function PendingStats () {
    this.startQueryIndex = -1
    this.endQueryIndex = -1
    this.sum = 0
    this.stats = null
  }
  var pendingStatsPool = []
  function allocPendingStats () {
    return pendingStatsPool.pop() || new PendingStats()
  }
  function freePendingStats (pendingStats) {
    pendingStatsPool.push(pendingStats)
  }
  // Pending stats pool end

  var pendingStats = []
  function pushScopeStats (start, end, stats) {
    var ps = allocPendingStats()
    ps.startQueryIndex = start
    ps.endQueryIndex = end
    ps.sum = 0
    ps.stats = stats
    pendingStats.push(ps)
  }

  // we should call this at the beginning of the frame,
  // in order to update gpuTime
  var timeSum = []
  var queryPtr = []
  function update () {
    var ptr, i

    var n = pendingQueries.length
    if (n === 0) {
      return
    }

    // Reserve space
    queryPtr.length = Math.max(queryPtr.length, n + 1)
    timeSum.length = Math.max(timeSum.length, n + 1)
    timeSum[0] = 0
    queryPtr[0] = 0

    // Update all pending timer queries
    var queryTime = 0
    ptr = 0
    for (i = 0; i < pendingQueries.length; ++i) {
      var query = pendingQueries[i]
      if (extensions.ext_disjoint_timer_query.getQueryObjectEXT(query, GL_QUERY_RESULT_AVAILABLE_EXT)) {
        queryTime += extensions.ext_disjoint_timer_query.getQueryObjectEXT(query, GL_QUERY_RESULT_EXT)
        freeQuery(query)
      } else {
        pendingQueries[ptr++] = query
      }
      timeSum[i + 1] = queryTime
      queryPtr[i + 1] = ptr
    }
    pendingQueries.length = ptr

    // Update all pending stat queries
    ptr = 0
    for (i = 0; i < pendingStats.length; ++i) {
      var stats = pendingStats[i]
      var start = stats.startQueryIndex
      var end = stats.endQueryIndex
      stats.sum += timeSum[end] - timeSum[start]
      var startPtr = queryPtr[start]
      var endPtr = queryPtr[end]
      if (endPtr === startPtr) {
        stats.stats.gpuTime += stats.sum / 1e6
        freePendingStats(stats)
      } else {
        stats.startQueryIndex = startPtr
        stats.endQueryIndex = endPtr
        pendingStats[ptr++] = stats
      }
    }
    pendingStats.length = ptr
  }

  return {
    beginQuery: beginQuery,
    endQuery: endQuery,
    pushScopeStats: pushScopeStats,
    update: update,
    getNumPendingQueries: function () {
      return pendingQueries.length
    },
    clear: function () {
      queryPool.push.apply(queryPool, pendingQueries)
      for (var i = 0; i < queryPool.length; i++) {
        extensions.ext_disjoint_timer_query.deleteQueryEXT(queryPool[i])
      }
      pendingQueries.length = 0
      queryPool.length = 0
    },
    restore: function () {
      pendingQueries.length = 0
      queryPool.length = 0
    }
  }
}

var GL_COLOR_BUFFER_BIT = 16384
var GL_DEPTH_BUFFER_BIT = 256
var GL_STENCIL_BUFFER_BIT = 1024

var GL_ARRAY_BUFFER = 34962

var CONTEXT_LOST_EVENT = 'webglcontextlost'
var CONTEXT_RESTORED_EVENT = 'webglcontextrestored'

var DYN_PROP = 1
var DYN_CONTEXT = 2
var DYN_STATE = 3

function find (haystack, needle) {
  for (var i = 0; i < haystack.length; ++i) {
    if (haystack[i] === needle) {
      return i
    }
  }
  return -1
}

function wrapREGL (args) {
  var config = parseArgs(args)
  if (!config) {
    return null
  }

  var gl = config.gl
  var glAttributes = gl.getContextAttributes()
  var contextLost = gl.isContextLost()

  var extensionState = createExtensionCache(gl, config)
  if (!extensionState) {
    return null
  }

  var stringStore = createStringStore()
  var stats$$1 = stats()
  var cachedCode = config.cachedCode || {};
  var extensions = extensionState.extensions
  var timer = createTimer(gl, extensions)

  var START_TIME = clock()
  var WIDTH = gl.drawingBufferWidth
  var HEIGHT = gl.drawingBufferHeight

  var contextState = {
    tick: 0,
    time: 0,
    viewportWidth: WIDTH,
    viewportHeight: HEIGHT,
    framebufferWidth: WIDTH,
    framebufferHeight: HEIGHT,
    drawingBufferWidth: WIDTH,
    drawingBufferHeight: HEIGHT,
    pixelRatio: config.pixelRatio
  }
  var uniformState = {}
  var drawState = {
    elements: null,
    primitive: 4, // GL_TRIANGLES
    count: -1,
    offset: 0,
    instances: -1
  }

  var limits = wrapLimits(gl, extensions)
  var bufferState = wrapBufferState(
    gl,
    stats$$1,
    config,
    destroyBuffer)
  var elementState = wrapElementsState(gl, extensions, bufferState, stats$$1)
  var attributeState = wrapAttributeState(
    gl,
    extensions,
    limits,
    stats$$1,
    bufferState,
    elementState,
    drawState)
  function destroyBuffer (buffer) {
    return attributeState.destroyBuffer(buffer)
  }
  var shaderState = wrapShaderState(gl, stringStore, stats$$1, config)
  var textureState = createTextureSet(
    gl,
    extensions,
    limits,
    function () { core.procs.poll() },
    contextState,
    stats$$1,
    config)
  var renderbufferState = wrapRenderbuffers(gl, extensions, limits, stats$$1, config)
  var framebufferState = wrapFBOState(
    gl,
    extensions,
    limits,
    textureState,
    renderbufferState,
    stats$$1)
  var core = reglCore(
    gl,
    stringStore,
    extensions,
    limits,
    bufferState,
    elementState,
    textureState,
    framebufferState,
    uniformState,
    attributeState,
    shaderState,
    drawState,
    contextState,
    timer,
    cachedCode,
    config)
  var readPixels = wrapReadPixels(
    gl,
    framebufferState,
    core.procs.poll,
    contextState,
    glAttributes, extensions, limits)

  var nextState = core.next
  var canvas = gl.canvas

  var rafCallbacks = []
  var lossCallbacks = []
  var restoreCallbacks = []
  var destroyCallbacks = [config.onDestroy]

  var activeRAF = null
  function handleRAF () {
    if (rafCallbacks.length === 0) {
      if (timer) {
        timer.update()
      }
      activeRAF = null
      return
    }

    // schedule next animation frame
    activeRAF = raf.next(handleRAF)

    // poll for changes
    poll()

    // fire a callback for all pending rafs
    for (var i = rafCallbacks.length - 1; i >= 0; --i) {
      var cb = rafCallbacks[i]
      if (cb) {
        cb(contextState, null, 0)
      }
    }

    // flush all pending webgl calls
    gl.flush()

    // poll GPU timers *after* gl.flush so we don't delay command dispatch
    if (timer) {
      timer.update()
    }
  }

  function startRAF () {
    if (!activeRAF && rafCallbacks.length > 0) {
      activeRAF = raf.next(handleRAF)
    }
  }

  function stopRAF () {
    if (activeRAF) {
      raf.cancel(handleRAF)
      activeRAF = null
    }
  }

  function handleContextLoss (event) {
    event.preventDefault()

    // set context lost flag
    contextLost = true

    // pause request animation frame
    stopRAF()

    // lose context
    lossCallbacks.forEach(function (cb) {
      cb()
    })
  }

  function handleContextRestored (event) {
    // clear error code
    gl.getError()

    // clear context lost flag
    contextLost = false

    // refresh state
    extensionState.restore()
    shaderState.restore()
    bufferState.restore()
    textureState.restore()
    renderbufferState.restore()
    framebufferState.restore()
    attributeState.restore()
    if (timer) {
      timer.restore()
    }

    // refresh state
    core.procs.refresh()

    // restart RAF
    startRAF()

    // restore context
    restoreCallbacks.forEach(function (cb) {
      cb()
    })
  }

  if (canvas) {
    canvas.addEventListener(CONTEXT_LOST_EVENT, handleContextLoss, false)
    canvas.addEventListener(CONTEXT_RESTORED_EVENT, handleContextRestored, false)
  }

  function destroy () {
    rafCallbacks.length = 0
    stopRAF()

    if (canvas) {
      canvas.removeEventListener(CONTEXT_LOST_EVENT, handleContextLoss)
      canvas.removeEventListener(CONTEXT_RESTORED_EVENT, handleContextRestored)
    }

    shaderState.clear()
    framebufferState.clear()
    renderbufferState.clear()
    attributeState.clear()
    textureState.clear()
    elementState.clear()
    bufferState.clear()

    if (timer) {
      timer.clear()
    }

    destroyCallbacks.forEach(function (cb) {
      cb()
    })
  }

  function compileProcedure (options) {
    
    

    function flattenNestedOptions (options) {
      var result = extend({}, options)
      delete result.uniforms
      delete result.attributes
      delete result.context
      delete result.vao

      if ('stencil' in result && result.stencil.op) {
        result.stencil.opBack = result.stencil.opFront = result.stencil.op
        delete result.stencil.op
      }

      function merge (name) {
        if (name in result) {
          var child = result[name]
          delete result[name]
          Object.keys(child).forEach(function (prop) {
            result[name + '.' + prop] = child[prop]
          })
        }
      }
      merge('blend')
      merge('depth')
      merge('cull')
      merge('stencil')
      merge('polygonOffset')
      merge('scissor')
      merge('sample')

      if ('vao' in options) {
        result.vao = options.vao
      }

      return result
    }

    function separateDynamic (object, useArrays) {
      var staticItems = {}
      var dynamicItems = {}
      Object.keys(object).forEach(function (option) {
        var value = object[option]
        if (dynamic.isDynamic(value)) {
          dynamicItems[option] = dynamic.unbox(value, option)
          return
        } else if (useArrays && Array.isArray(value)) {
          for (var i = 0; i < value.length; ++i) {
            if (dynamic.isDynamic(value[i])) {
              dynamicItems[option] = dynamic.unbox(value, option)
              return
            }
          }
        }
        staticItems[option] = value
      })
      return {
        dynamic: dynamicItems,
        static: staticItems
      }
    }

    // Treat context variables separate from other dynamic variables
    var context = separateDynamic(options.context || {}, true)
    var uniforms = separateDynamic(options.uniforms || {}, true)
    var attributes = separateDynamic(options.attributes || {}, false)
    var opts = separateDynamic(flattenNestedOptions(options), false)

    var stats$$1 = {
      gpuTime: 0.0,
      cpuTime: 0.0,
      count: 0
    }

    var compiled = core.compile(opts, attributes, uniforms, context, stats$$1)

    var draw = compiled.draw
    var batch = compiled.batch
    var scope = compiled.scope

    // FIXME: we should modify code generation for batch commands so this
    // isn't necessary
    var EMPTY_ARRAY = []
    function reserve (count) {
      while (EMPTY_ARRAY.length < count) {
        EMPTY_ARRAY.push(null)
      }
      return EMPTY_ARRAY
    }

    function REGLCommand (args, body) {
      var i
      if (contextLost) {
        
      }
      if (typeof args === 'function') {
        return scope.call(this, null, args, 0)
      } else if (typeof body === 'function') {
        if (typeof args === 'number') {
          for (i = 0; i < args; ++i) {
            scope.call(this, null, body, i)
          }
        } else if (Array.isArray(args)) {
          for (i = 0; i < args.length; ++i) {
            scope.call(this, args[i], body, i)
          }
        } else {
          return scope.call(this, args, body, 0)
        }
      } else if (typeof args === 'number') {
        if (args > 0) {
          return batch.call(this, reserve(args | 0), args | 0)
        }
      } else if (Array.isArray(args)) {
        if (args.length) {
          return batch.call(this, args, args.length)
        }
      } else {
        return draw.call(this, args)
      }
    }

    return extend(REGLCommand, {
      stats: stats$$1,
      destroy: function () {
        compiled.destroy()
      }
    })
  }

  var setFBO = framebufferState.setFBO = compileProcedure({
    framebuffer: dynamic.define.call(null, DYN_PROP, 'framebuffer')
  })

  function clearImpl (_, options) {
    var clearFlags = 0
    core.procs.poll()

    var c = options.color
    if (c) {
      gl.clearColor(+c[0] || 0, +c[1] || 0, +c[2] || 0, +c[3] || 0)
      clearFlags |= GL_COLOR_BUFFER_BIT
    }
    if ('depth' in options) {
      gl.clearDepth(+options.depth)
      clearFlags |= GL_DEPTH_BUFFER_BIT
    }
    if ('stencil' in options) {
      gl.clearStencil(options.stencil | 0)
      clearFlags |= GL_STENCIL_BUFFER_BIT
    }

    
    gl.clear(clearFlags)
  }

  function clear (options) {
    
    if ('framebuffer' in options) {
      if (options.framebuffer &&
          options.framebuffer_reglType === 'framebufferCube') {
        for (var i = 0; i < 6; ++i) {
          setFBO(extend({
            framebuffer: options.framebuffer.faces[i]
          }, options), clearImpl)
        }
      } else {
        setFBO(options, clearImpl)
      }
    } else {
      clearImpl(null, options)
    }
  }

  function frame (cb) {
    
    rafCallbacks.push(cb)

    function cancel () {
      // FIXME:  should we check something other than equals cb here?
      // what if a user calls frame twice with the same callback...
      //
      var i = find(rafCallbacks, cb)
      
      function pendingCancel () {
        var index = find(rafCallbacks, pendingCancel)
        rafCallbacks[index] = rafCallbacks[rafCallbacks.length - 1]
        rafCallbacks.length -= 1
        if (rafCallbacks.length <= 0) {
          stopRAF()
        }
      }
      rafCallbacks[i] = pendingCancel
    }

    startRAF()

    return {
      cancel: cancel
    }
  }

  // poll viewport
  function pollViewport () {
    var viewport = nextState.viewport
    var scissorBox = nextState.scissor_box
    viewport[0] = viewport[1] = scissorBox[0] = scissorBox[1] = 0
    contextState.viewportWidth =
      contextState.framebufferWidth =
      contextState.drawingBufferWidth =
      viewport[2] =
      scissorBox[2] = gl.drawingBufferWidth
    contextState.viewportHeight =
      contextState.framebufferHeight =
      contextState.drawingBufferHeight =
      viewport[3] =
      scissorBox[3] = gl.drawingBufferHeight
  }

  function poll () {
    contextState.tick += 1
    contextState.time = now()
    pollViewport()
    core.procs.poll()
  }

  function refresh () {
    textureState.refresh()
    pollViewport()
    core.procs.refresh()
    if (timer) {
      timer.update()
    }
  }

  function now () {
    return (clock() - START_TIME) / 1000.0
  }

  refresh()

  function addListener (event, callback) {
    

    var callbacks
    switch (event) {
      case 'frame':
        return frame(callback)
      case 'lost':
        callbacks = lossCallbacks
        break
      case 'restore':
        callbacks = restoreCallbacks
        break
      case 'destroy':
        callbacks = destroyCallbacks
        break
      default:
        
    }

    callbacks.push(callback)
    return {
      cancel: function () {
        for (var i = 0; i < callbacks.length; ++i) {
          if (callbacks[i] === callback) {
            callbacks[i] = callbacks[callbacks.length - 1]
            callbacks.pop()
            return
          }
        }
      }
    }
  }

  function getCachedCode() {
    return cachedCode
  }

  function preloadCachedCode(moreCache) {
    Object.entries(moreCache).forEach(function (kv) {
      cachedCode[kv[0]] = kv[1]
    })
  }

  var regl = extend(compileProcedure, {
    // Clear current FBO
    clear: clear,

    // Short cuts for dynamic variables
    prop: dynamic.define.bind(null, DYN_PROP),
    context: dynamic.define.bind(null, DYN_CONTEXT),
    this: dynamic.define.bind(null, DYN_STATE),

    // executes an empty draw command
    draw: compileProcedure({}),

    // Resources
    buffer: function (options) {
      return bufferState.create(options, GL_ARRAY_BUFFER, false, false)
    },
    elements: function (options) {
      return elementState.create(options, false)
    },
    texture: textureState.create2D,
    cube: textureState.createCube,
    renderbuffer: renderbufferState.create,
    framebuffer: framebufferState.create,
    framebufferCube: framebufferState.createCube,
    vao: attributeState.createVAO,

    // Expose context attributes
    attributes: glAttributes,

    // Frame rendering
    frame: frame,
    on: addListener,

    // System limits
    limits: limits,
    hasExtension: function (name) {
      return limits.extensions.indexOf(name.toLowerCase()) >= 0
    },

    // Read pixels
    read: readPixels,

    // Destroy regl and all associated resources
    destroy: destroy,

    // Direct GL state manipulation
    _gl: gl,
    _refresh: refresh,

    poll: function () {
      poll()
      if (timer) {
        timer.update()
      }
    },

    // Current time
    now: now,

    // regl Statistics Information
    stats: stats$$1,

    // cache generated code
    getCachedCode: getCachedCode,
    preloadCachedCode: preloadCachedCode
  })

  config.onDone(null, regl)

  return regl
}

return wrapREGL;

})));