// luma.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
// Feature detection for WebGL
// Provides a function that enables simple checking of which WebGL features are
import { DeviceFeatures } from '@luma.gl/core';
import { getWebGLExtension } from "../../context/helpers/webgl-extensions.js";
import { isTextureFeature, checkTextureFeature } from "../converters/texture-formats.js";
import { TEXTURE_FEATURES } from "../converters/texture-formats.js";
/**
 * Defines luma.gl "feature" names and semantics
 * when value is 'string' it is the name of the extension that enables this feature
 */
const WEBGL_FEATURES = {
    // optional WebGPU features
    'depth-clip-control': 'EXT_depth_clamp', // TODO these seem subtly different
    // 'timestamp-query' // GPUQueryType "timestamp-query"
    // "indirect-first-instance"
    // Textures are handled by getTextureFeatures()
    // 'depth24unorm-stencil8' // GPUTextureFormat 'depth24unorm-stencil8'
    // 'depth32float-stencil8' // GPUTextureFormat 'depth32float-stencil8'
    // optional WebGL features
    'timer-query-webgl': 'EXT_disjoint_timer_query_webgl2',
    'compilation-status-async-webgl': 'KHR_parallel_shader_compile',
    'polygon-mode-webgl': 'WEBGL_polygon_mode',
    'provoking-vertex-webgl': 'WEBGL_provoking_vertex',
    'shader-clip-cull-distance-webgl': 'WEBGL_clip_cull_distance',
    'shader-noperspective-interpolation-webgl': 'NV_shader_noperspective_interpolation',
    'shader-conservative-depth-webgl': 'EXT_conservative_depth'
    // Textures are handled by getTextureFeatures()
};
/**
 * WebGL extensions exposed as luma.gl features
 * To minimize GL log noise and improve performance, this class ensures that
 * - WebGL extensions are not queried until the corresponding feature is checked.
 * - WebGL extensions are only queried once.
 */
export class WebGLDeviceFeatures extends DeviceFeatures {
    gl;
    extensions;
    testedFeatures = new Set();
    constructor(gl, extensions, disabledFeatures) {
        super([], disabledFeatures);
        this.gl = gl;
        this.extensions = extensions;
        // TODO - is this really needed?
        // Enable EXT_float_blend first: https://developer.mozilla.org/en-US/docs/Web/API/EXT_float_blend
        getWebGLExtension(gl, 'EXT_color_buffer_float', extensions);
    }
    *[Symbol.iterator]() {
        const features = this.getFeatures();
        for (const feature of features) {
            if (this.has(feature)) {
                yield feature;
            }
        }
        return [];
    }
    has(feature) {
        if (this.disabledFeatures[feature]) {
            return false;
        }
        // We have already tested this feature
        if (!this.testedFeatures.has(feature)) {
            this.testedFeatures.add(feature);
            // Check the feature once
            if (isTextureFeature(feature) && checkTextureFeature(this.gl, feature, this.extensions)) {
                this.features.add(feature);
            }
            if (this.getWebGLFeature(feature)) {
                this.features.add(feature);
            }
        }
        return this.features.has(feature);
    }
    // FOR DEVICE
    initializeFeatures() {
        // Initialize all features by checking them.
        // Except WEBGL_polygon_mode since Chrome logs ugly console warnings
        const features = this.getFeatures().filter(feature => feature !== 'polygon-mode-webgl');
        for (const feature of features) {
            this.has(feature);
        }
    }
    // IMPLEMENTATION
    getFeatures() {
        return [...Object.keys(WEBGL_FEATURES), ...Object.keys(TEXTURE_FEATURES)];
    }
    /** Extract all WebGL features */
    getWebGLFeature(feature) {
        const featureInfo = WEBGL_FEATURES[feature];
        // string value requires checking the corresponding WebGL extension
        const isSupported = typeof featureInfo === 'string'
            ? Boolean(getWebGLExtension(this.gl, featureInfo, this.extensions))
            : Boolean(featureInfo);
        return isSupported;
    }
}