import { lerp } from '@math.gl/core';
const DEFAULT_INDICES = new Uint32Array([0, 2, 1, 0, 3, 2]);
const DEFAULT_TEX_COORDS = new Float32Array([0, 1, 0, 0, 1, 0, 1, 1]);
/*
  1 ---- 2
  |      |
  |      |
  0 ---- 3
*/
/* eslint-disable max-statements */
export default function createMesh(bounds, resolution) {
    if (!resolution) {
        return createQuad(bounds);
    }
    const maxXSpan = Math.max(Math.abs(bounds[0][0] - bounds[3][0]), Math.abs(bounds[1][0] - bounds[2][0]));
    const maxYSpan = Math.max(Math.abs(bounds[1][1] - bounds[0][1]), Math.abs(bounds[2][1] - bounds[3][1]));
    const uCount = Math.ceil(maxXSpan / resolution) + 1;
    const vCount = Math.ceil(maxYSpan / resolution) + 1;
    const vertexCount = (uCount - 1) * (vCount - 1) * 6;
    const indices = new Uint32Array(vertexCount);
    const texCoords = new Float32Array(uCount * vCount * 2);
    const positions = new Float64Array(uCount * vCount * 3);
    // Tesselate
    let vertex = 0;
    let index = 0;
    for (let u = 0; u < uCount; u++) {
        const ut = u / (uCount - 1);
        for (let v = 0; v < vCount; v++) {
            const vt = v / (vCount - 1);
            const p = interpolateQuad(bounds, ut, vt);
            positions[vertex * 3 + 0] = p[0];
            positions[vertex * 3 + 1] = p[1];
            positions[vertex * 3 + 2] = p[2] || 0;
            texCoords[vertex * 2 + 0] = ut;
            texCoords[vertex * 2 + 1] = 1 - vt;
            if (u > 0 && v > 0) {
                indices[index++] = vertex - vCount;
                indices[index++] = vertex - vCount - 1;
                indices[index++] = vertex - 1;
                indices[index++] = vertex - vCount;
                indices[index++] = vertex - 1;
                indices[index++] = vertex;
            }
            vertex++;
        }
    }
    return {
        vertexCount,
        positions,
        indices,
        texCoords
    };
}
function createQuad(bounds) {
    const positions = new Float64Array(12);
    // [[minX, minY], [minX, maxY], [maxX, maxY], [maxX, minY]]
    for (let i = 0; i < bounds.length; i++) {
        positions[i * 3 + 0] = bounds[i][0];
        positions[i * 3 + 1] = bounds[i][1];
        positions[i * 3 + 2] = bounds[i][2] || 0;
    }
    return {
        vertexCount: 6,
        positions,
        indices: DEFAULT_INDICES,
        texCoords: DEFAULT_TEX_COORDS
    };
}
function interpolateQuad(quad, ut, vt) {
    return lerp(lerp(quad[0], quad[1], vt), lerp(quad[3], quad[2], vt), ut);
}