import Cartesian3 from "../Core/Cartesian3.js";
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import ComponentDatatype from "../Core/ComponentDatatype.js";
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import defined from "../Core/defined.js";
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import destroyObject from "../Core/destroyObject.js";
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import IndexDatatype from "../Core/IndexDatatype.js";
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import loadKTX2 from "../Core/loadKTX2.js";
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import PixelFormat from "../Core/PixelFormat.js";
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import Buffer from "../Renderer/Buffer.js";
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import BufferUsage from "../Renderer/BufferUsage.js";
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import ComputeCommand from "../Renderer/ComputeCommand.js";
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import CubeMap from "../Renderer/CubeMap.js";
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import PixelDatatype from "../Renderer/PixelDatatype.js";
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import ShaderProgram from "../Renderer/ShaderProgram.js";
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import ShaderSource from "../Renderer/ShaderSource.js";
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import Texture from "../Renderer/Texture.js";
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import VertexArray from "../Renderer/VertexArray.js";
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import OctahedralProjectionAtlasFS from "../Shaders/OctahedralProjectionAtlasFS.js";
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import OctahedralProjectionFS from "../Shaders/OctahedralProjectionFS.js";
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import OctahedralProjectionVS from "../Shaders/OctahedralProjectionVS.js";
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import when from "../ThirdParty/when.js";
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/**
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* Packs all mip levels of a cube map into a 2D texture atlas.
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*
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* Octahedral projection is a way of putting the cube maps onto a 2D texture
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* with minimal distortion and easy look up.
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* See Chapter 16 of WebGL Insights "HDR Image-Based Lighting on the Web" by Jeff Russell
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* and "Octahedron Environment Maps" for reference.
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*
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* @private
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*/
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function OctahedralProjectedCubeMap(url) {
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this._url = url;
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this._cubeMapBuffers = undefined;
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this._cubeMaps = undefined;
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this._texture = undefined;
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this._mipTextures = undefined;
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this._va = undefined;
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this._sp = undefined;
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this._maximumMipmapLevel = undefined;
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this._loading = false;
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this._ready = false;
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this._readyPromise = when.defer();
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}
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Object.defineProperties(OctahedralProjectedCubeMap.prototype, {
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/**
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* The url to the KTX2 file containing the specular environment map and convoluted mipmaps.
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* @memberof OctahedralProjectedCubeMap.prototype
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* @type {String}
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* @readonly
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*/
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url: {
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get: function () {
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return this._url;
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},
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},
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/**
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* A texture containing all the packed convolutions.
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* @memberof OctahedralProjectedCubeMap.prototype
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* @type {Texture}
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* @readonly
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*/
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texture: {
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get: function () {
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return this._texture;
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},
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},
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/**
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* The maximum number of mip levels.
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* @memberOf OctahedralProjectedCubeMap.prototype
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* @type {Number}
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* @readonly
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*/
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maximumMipmapLevel: {
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get: function () {
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return this._maximumMipmapLevel;
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},
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},
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/**
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* Determines if the texture atlas is complete and ready to use.
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* @memberof OctahedralProjectedCubeMap.prototype
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* @type {Boolean}
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* @readonly
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*/
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ready: {
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get: function () {
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return this._ready;
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},
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},
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/**
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* Gets a promise that resolves when the texture atlas is ready to use.
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* @memberof OctahedralProjectedCubeMap.prototype
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* @type {Promise<void>}
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* @readonly
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*/
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readyPromise: {
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get: function () {
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return this._readyPromise.promise;
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},
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},
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});
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OctahedralProjectedCubeMap.isSupported = function (context) {
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return (
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(context.colorBufferHalfFloat && context.halfFloatingPointTexture) ||
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(context.floatingPointTexture && context.colorBufferFloat)
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);
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};
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// These vertices are based on figure 1 from "Octahedron Environment Maps".
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var v1 = new Cartesian3(1.0, 0.0, 0.0);
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var v2 = new Cartesian3(0.0, 0.0, 1.0);
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var v3 = new Cartesian3(-1.0, 0.0, 0.0);
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var v4 = new Cartesian3(0.0, 0.0, -1.0);
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var v5 = new Cartesian3(0.0, 1.0, 0.0);
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var v6 = new Cartesian3(0.0, -1.0, 0.0);
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// top left, left, top, center, right, top right, bottom, bottom left, bottom right
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var cubeMapCoordinates = [v5, v3, v2, v6, v1, v5, v4, v5, v5];
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var length = cubeMapCoordinates.length;
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var flatCubeMapCoordinates = new Float32Array(length * 3);
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var offset = 0;
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for (var i = 0; i < length; ++i, offset += 3) {
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Cartesian3.pack(cubeMapCoordinates[i], flatCubeMapCoordinates, offset);
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}
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var flatPositions = new Float32Array([
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-1.0,
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1.0, // top left
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-1.0,
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0.0, // left
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0.0,
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1.0, // top
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0.0,
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0.0, // center
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1.0,
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0.0, // right
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1.0,
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1.0, // top right
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0.0,
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-1.0, // bottom
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-1.0,
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-1.0, // bottom left
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1.0,
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-1.0, // bottom right
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]);
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var indices = new Uint16Array([
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0,
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1,
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2, // top left, left, top,
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2,
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3,
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1, // top, center, left,
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7,
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6,
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1, // bottom left, bottom, left,
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3,
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6,
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1, // center, bottom, left,
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2,
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5,
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4, // top, top right, right,
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3,
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4,
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2, // center, right, top,
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4,
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8,
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6, // right, bottom right, bottom,
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3,
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4,
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6, //center, right, bottom
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]);
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function createVertexArray(context) {
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var positionBuffer = Buffer.createVertexBuffer({
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context: context,
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typedArray: flatPositions,
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usage: BufferUsage.STATIC_DRAW,
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});
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var cubeMapCoordinatesBuffer = Buffer.createVertexBuffer({
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context: context,
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typedArray: flatCubeMapCoordinates,
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usage: BufferUsage.STATIC_DRAW,
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});
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var indexBuffer = Buffer.createIndexBuffer({
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context: context,
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typedArray: indices,
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usage: BufferUsage.STATIC_DRAW,
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indexDatatype: IndexDatatype.UNSIGNED_SHORT,
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});
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var attributes = [
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{
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index: 0,
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vertexBuffer: positionBuffer,
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componentsPerAttribute: 2,
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componentDatatype: ComponentDatatype.FLOAT,
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},
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{
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index: 1,
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vertexBuffer: cubeMapCoordinatesBuffer,
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componentsPerAttribute: 3,
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componentDatatype: ComponentDatatype.FLOAT,
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},
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];
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return new VertexArray({
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context: context,
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attributes: attributes,
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indexBuffer: indexBuffer,
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});
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}
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function createUniformTexture(texture) {
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return function () {
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return texture;
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};
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}
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function cleanupResources(map) {
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map._va = map._va && map._va.destroy();
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map._sp = map._sp && map._sp.destroy();
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var i;
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var length;
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var cubeMaps = map._cubeMaps;
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if (defined(cubeMaps)) {
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length = cubeMaps.length;
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for (i = 0; i < length; ++i) {
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cubeMaps[i].destroy();
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}
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}
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var mipTextures = map._mipTextures;
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if (defined(mipTextures)) {
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length = mipTextures.length;
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for (i = 0; i < length; ++i) {
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mipTextures[i].destroy();
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}
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}
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map._va = undefined;
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map._sp = undefined;
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map._cubeMaps = undefined;
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map._cubeMapBuffers = undefined;
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map._mipTextures = undefined;
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}
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/**
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* Creates compute commands to generate octahedral projections of each cube map
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* and then renders them to an atlas.
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* <p>
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* Only needs to be called twice. The first call queues the compute commands to generate the atlas.
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* The second call cleans up unused resources. Every call afterwards is a no-op.
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* </p>
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*
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* @param {FrameState} frameState The frame state.
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*
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* @private
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*/
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OctahedralProjectedCubeMap.prototype.update = function (frameState) {
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var context = frameState.context;
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if (!OctahedralProjectedCubeMap.isSupported(context)) {
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return;
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}
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if (defined(this._texture) && defined(this._va)) {
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cleanupResources(this);
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}
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if (defined(this._texture)) {
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return;
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}
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if (!defined(this._texture) && !this._loading) {
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var cachedTexture = context.textureCache.getTexture(this._url);
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if (defined(cachedTexture)) {
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cleanupResources(this);
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this._texture = cachedTexture;
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this._maximumMipmapLevel = this._texture.maximumMipmapLevel;
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this._ready = true;
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this._readyPromise.resolve();
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return;
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}
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}
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var cubeMapBuffers = this._cubeMapBuffers;
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if (!defined(cubeMapBuffers) && !this._loading) {
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var that = this;
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loadKTX2(this._url)
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.then(function (buffers) {
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that._cubeMapBuffers = buffers;
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that._loading = false;
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})
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.otherwise(this._readyPromise.reject);
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this._loading = true;
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}
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if (!defined(this._cubeMapBuffers)) {
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return;
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}
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var defines = [];
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// Datatype is defined if it is a normalized type (i.e. ..._UNORM, ..._SFLOAT)
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var pixelDatatype = cubeMapBuffers[0].positiveX.pixelDatatype;
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if (!defined(pixelDatatype)) {
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pixelDatatype = context.halfFloatingPointTexture
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? PixelDatatype.HALF_FLOAT
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: PixelDatatype.FLOAT;
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} else {
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defines.push("RGBA_NORMALIZED");
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}
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var pixelFormat = PixelFormat.RGBA;
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var fs = new ShaderSource({
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defines: defines,
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sources: [OctahedralProjectionFS],
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});
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this._va = createVertexArray(context);
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this._sp = ShaderProgram.fromCache({
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context: context,
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vertexShaderSource: OctahedralProjectionVS,
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fragmentShaderSource: fs,
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attributeLocations: {
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position: 0,
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cubeMapCoordinates: 1,
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},
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});
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// We only need up to 6 mip levels to avoid artifacts.
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var length = Math.min(cubeMapBuffers.length, 6);
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this._maximumMipmapLevel = length - 1;
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var cubeMaps = (this._cubeMaps = new Array(length));
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var mipTextures = (this._mipTextures = new Array(length));
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var originalSize = cubeMapBuffers[0].positiveX.width * 2.0;
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var uniformMap = {
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originalSize: function () {
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return originalSize;
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},
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};
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// First we project each cubemap onto a flat octahedron, and write that to a texture.
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for (var i = 0; i < length; ++i) {
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// Swap +Y/-Y faces since the octahedral projection expects this order.
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var positiveY = cubeMapBuffers[i].positiveY;
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cubeMapBuffers[i].positiveY = cubeMapBuffers[i].negativeY;
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cubeMapBuffers[i].negativeY = positiveY;
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var cubeMap = (cubeMaps[i] = new CubeMap({
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context: context,
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source: cubeMapBuffers[i],
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pixelDatatype: pixelDatatype,
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}));
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var size = cubeMaps[i].width * 2;
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var mipTexture = (mipTextures[i] = new Texture({
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context: context,
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width: size,
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height: size,
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pixelDatatype: pixelDatatype,
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pixelFormat: pixelFormat,
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}));
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var command = new ComputeCommand({
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vertexArray: this._va,
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shaderProgram: this._sp,
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uniformMap: {
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cubeMap: createUniformTexture(cubeMap),
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},
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outputTexture: mipTexture,
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persists: true,
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owner: this,
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});
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frameState.commandList.push(command);
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uniformMap["texture" + i] = createUniformTexture(mipTexture);
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}
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this._texture = new Texture({
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context: context,
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width: originalSize * 1.5 + 2.0, // We add a 1 pixel border to avoid linear sampling artifacts.
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height: originalSize,
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pixelDatatype: pixelDatatype,
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pixelFormat: pixelFormat,
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});
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this._texture.maximumMipmapLevel = this._maximumMipmapLevel;
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context.textureCache.addTexture(this._url, this._texture);
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var atlasCommand = new ComputeCommand({
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fragmentShaderSource: OctahedralProjectionAtlasFS,
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uniformMap: uniformMap,
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outputTexture: this._texture,
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persists: false,
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owner: this,
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});
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frameState.commandList.push(atlasCommand);
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this._ready = true;
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this._readyPromise.resolve();
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};
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/**
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* Returns true if this object was destroyed; otherwise, false.
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* <p>
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* If this object was destroyed, it should not be used; calling any function other than
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* <code>isDestroyed</code> will result in a {@link DeveloperError} exception.
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* </p>
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*
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* @returns {Boolean} <code>true</code> if this object was destroyed; otherwise, <code>false</code>.
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*
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* @see OctahedralProjectedCubeMap#destroy
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*/
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OctahedralProjectedCubeMap.prototype.isDestroyed = function () {
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return false;
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};
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/**
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* Destroys the WebGL resources held by this object. Destroying an object allows for deterministic
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* release of WebGL resources, instead of relying on the garbage collector to destroy this object.
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* <p>
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* Once an object is destroyed, it should not be used; calling any function other than
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* <code>isDestroyed</code> will result in a {@link DeveloperError} exception. Therefore,
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* assign the return value (<code>undefined</code>) to the object as done in the example.
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* </p>
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*
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* @exception {DeveloperError} This object was destroyed, i.e., destroy() was called.
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*
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* @see OctahedralProjectedCubeMap#isDestroyed
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*/
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OctahedralProjectedCubeMap.prototype.destroy = function () {
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cleanupResources(this);
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this._texture = this._texture && this._texture.destroy();
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return destroyObject(this);
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};
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export default OctahedralProjectedCubeMap;
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