Added basis_loader.js for WebGL
diff --git a/webgl/transcoder/.gitignore b/webgl/transcoder/.gitignore
index 707a2b1..324ab6c 100644
--- a/webgl/transcoder/.gitignore
+++ b/webgl/transcoder/.gitignore
@@ -1,3 +1,4 @@
build/*
+!build/basis_loader.js
!build/basis_transcoder.js
!build/basis_transcoder.wasm
diff --git a/webgl/transcoder/build/basis_loader.js b/webgl/transcoder/build/basis_loader.js
new file mode 100644
index 0000000..3fef5ec
--- /dev/null
+++ b/webgl/transcoder/build/basis_loader.js
@@ -0,0 +1,493 @@
+/*
+ * Basis Loader
+ *
+ * Usage:
+ * // basis_loader.js should be loaded from the same directory as
+ * // basis_transcoder.js and basis_transcoder.wasm
+ *
+ * // Create the texture loader and set the WebGL context it should use. Spawns
+ * // a worker which handles all of the transcoding.
+ * let basisLoader = new BasisLoader();
+ * basisLoader.setWebGLContext(gl);
+ *
+ * // To allow separate color and alpha textures to be returned in cases where
+ * // it would provide higher quality:
+ * basisLoader.allowSeparateAlpha = true;
+ *
+ * // loadFromUrl() returns a promise which resolves to a completed WebGL
+ * // texture or rejects if there's an error loading.
+ * basisBasics.loadFromUrl(fullPathToTexture).then((result) => {
+ * // WebGL color+alpha texture;
+ * result.texture;
+ *
+ * // WebGL alpha texture, only if basisLoader.allowSeparateAlpha is true.
+ * // null if alpha is encoded in result.texture or result.alpha is false.
+ * result.alphaTexture;
+ *
+ * // True if the texture contained an alpha channel.
+ * result.alpha;
+ *
+ * // Number of mip levels in texture/alphaTexture
+ * result.mipLevels;
+ *
+ * // Dimensions of the base mip level.
+ * result.width;
+ * result.height;
+ * });
+ */
+
+// This file contains the code both for the main thread interface and the
+// worker that does the transcoding.
+const IN_WORKER = typeof importScripts === "function";
+const SCRIPT_PATH = typeof document !== 'undefined' && document.currentScript ? document.currentScript.src : undefined;
+
+if (!IN_WORKER) {
+ //
+ // Main Thread
+ //
+ class PendingTextureRequest {
+ constructor(gl, url) {
+ this.gl = gl;
+ this.url = url;
+ this.texture = null;
+ this.alphaTexture = null;
+ this.promise = new Promise((resolve, reject) => {
+ this.resolve = resolve;
+ this.reject = reject;
+ });
+ }
+
+ uploadImageData(webglFormat, buffer, mipLevels) {
+ let gl = this.gl;
+ let texture = gl.createTexture();
+ gl.bindTexture(gl.TEXTURE_2D, texture);
+ gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+ gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, mipLevels.length > 1 || webglFormat.uncompressed ? gl.LINEAR_MIPMAP_LINEAR : gl.LINEAR);
+
+ let levelData = null;
+
+ for (let mipLevel of mipLevels) {
+ if (!webglFormat.uncompressed) {
+ levelData = new Uint8Array(buffer, mipLevel.offset, mipLevel.size);
+ gl.compressedTexImage2D(
+ gl.TEXTURE_2D,
+ mipLevel.level,
+ webglFormat.format,
+ mipLevel.width,
+ mipLevel.height,
+ 0,
+ levelData);
+ } else {
+ switch (webglFormat.type) {
+ case WebGLRenderingContext.UNSIGNED_SHORT_4_4_4_4:
+ case WebGLRenderingContext.UNSIGNED_SHORT_5_5_5_1:
+ case WebGLRenderingContext.UNSIGNED_SHORT_5_6_5:
+ levelData = new Uint16Array(buffer, mipLevel.offset, mipLevel.size / 2);
+ break;
+ default:
+ levelData = new Uint8Array(buffer, mipLevel.offset, mipLevel.size);
+ break;
+ }
+ gl.texImage2D(
+ gl.TEXTURE_2D,
+ mipLevel.level,
+ webglFormat.format,
+ mipLevel.width,
+ mipLevel.height,
+ 0,
+ webglFormat.format,
+ webglFormat.type,
+ levelData);
+ }
+ }
+
+ if (webglFormat.uncompressed && mipLevels.length == 1) {
+ gl.generateMipmap(gl.TEXTURE_2D);
+ }
+
+ return texture;
+ }
+ };
+
+ class BasisLoader {
+ constructor() {
+ this.gl = null;
+ this.supportedFormats = {};
+ this.pendingTextures = {};
+ this.nextPendingTextureId = 1;
+ this.allowSeparateAlpha = false;
+
+ // Reload the current script as a worker
+ this.worker = new Worker(SCRIPT_PATH);
+ this.worker.onmessage = (msg) => {
+ // Find the pending texture associated with the data we just received
+ // from the worker.
+ let pendingTexture = this.pendingTextures[msg.data.id];
+ if (!pendingTexture) {
+ if (msg.data.error) {
+ console.error(`Basis transcode failed: ${msg.data.error}`);
+ }
+ console.error(`Invalid pending texture ID: ${msg.data.id}`);
+ return;
+ }
+
+ // Remove the pending texture from the waiting list.
+ delete this.pendingTextures[msg.data.id];
+
+ // If the worker indicated an error has occured handle it now.
+ if (msg.data.error) {
+ console.error(`Basis transcode failed: ${msg.data.error}`);
+ pendingTexture.reject(`${msg.data.error}`);
+ return;
+ }
+
+ // Upload the image data returned by the worker.
+ pendingTexture.texture = pendingTexture.uploadImageData(
+ msg.data.webglFormat,
+ msg.data.buffer,
+ msg.data.mipLevels);
+
+ if (msg.data.alphaBuffer) {
+ pendingTexture.alphaTexture = pendingTexture.uploadImageData(
+ msg.data.webglFormat,
+ msg.data.alphaBuffer,
+ msg.data.mipLevels);
+ }
+
+ pendingTexture.resolve({
+ mipLevels: msg.data.mipLevels.length,
+ width: msg.data.mipLevels[0].width,
+ height: msg.data.mipLevels[0].height,
+ alpha: msg.data.hasAlpha,
+ texture: pendingTexture.texture,
+ alphaTexture: pendingTexture.alphaTexture,
+ });
+ };
+ }
+
+ setWebGLContext(gl) {
+ if (this.gl != gl) {
+ this.gl = gl;
+ if (gl) {
+ this.supportedFormats = {
+ s3tc: !!gl.getExtension('WEBGL_compressed_texture_s3tc'),
+ etc1: !!gl.getExtension('WEBGL_compressed_texture_etc1'),
+ etc2: !!gl.getExtension('WEBGL_compressed_texture_etc'),
+ pvrtc: !!gl.getExtension('WEBGL_compressed_texture_pvrtc'),
+ astc: !!gl.getExtension('WEBGL_compressed_texture_astc'),
+ bptc: !!gl.getExtension('EXT_texture_compression_bptc')
+ };
+ } else {
+ this.supportedFormats = {};
+ }
+ }
+ }
+
+ // This method changes the active texture unit's TEXTURE_2D binding
+ // immediately prior to resolving the returned promise.
+ loadFromUrl(url) {
+ let pendingTexture = new PendingTextureRequest(this.gl, url);
+ this.pendingTextures[this.nextPendingTextureId] = pendingTexture;
+
+ this.worker.postMessage({
+ id: this.nextPendingTextureId,
+ url: url,
+ allowSeparateAlpha: this.allowSeparateAlpha,
+ supportedFormats: this.supportedFormats
+ });
+
+ this.nextPendingTextureId++;
+ return pendingTexture.promise;
+ }
+ }
+
+ window.BasisLoader = BasisLoader;
+
+} else {
+ //
+ // Worker
+ //
+ importScripts('basis_transcoder.js');
+
+ let BasisFile = null;
+
+ const BASIS_INITIALIZED = BASIS().then((module) => {
+ BasisFile = module.BasisFile;
+ module.initializeBasis();
+ });
+
+ // Copied from enum class transcoder_texture_format in basisu_transcoder.h with minor javascript-ification
+ const BASIS_FORMAT = {
+ // Compressed formats
+
+ // ETC1-2
+ cTFETC1_RGB: 0, // Opaque only, returns RGB or alpha data if cDecodeFlagsTranscodeAlphaDataToOpaqueFormats flag is specified
+ cTFETC2_RGBA: 1, // Opaque+alpha, ETC2_EAC_A8 block followed by a ETC1 block, alpha channel will be opaque for opaque .basis files
+
+ // BC1-5, BC7 (desktop, some mobile devices)
+ cTFBC1_RGB: 2, // Opaque only, no punchthrough alpha support yet, transcodes alpha slice if cDecodeFlagsTranscodeAlphaDataToOpaqueFormats flag is specified
+ cTFBC3_RGBA: 3, // Opaque+alpha, BC4 followed by a BC1 block, alpha channel will be opaque for opaque .basis files
+ cTFBC4_R: 4, // Red only, alpha slice is transcoded to output if cDecodeFlagsTranscodeAlphaDataToOpaqueFormats flag is specified
+ cTFBC5_RG: 5, // XY: Two BC4 blocks, X=R and Y=Alpha, .basis file should have alpha data (if not Y will be all 255's)
+ cTFBC7_RGBA: 6, // RGB or RGBA, mode 5 for ETC1S, modes (1,2,3,5,6,7) for UASTC
+
+ // PVRTC1 4bpp (mobile, PowerVR devices)
+ cTFPVRTC1_4_RGB: 8, // Opaque only, RGB or alpha if cDecodeFlagsTranscodeAlphaDataToOpaqueFormats flag is specified, nearly lowest quality of any texture format.
+ cTFPVRTC1_4_RGBA: 9, // Opaque+alpha, most useful for simple opacity maps. If .basis file doesn't have alpha cTFPVRTC1_4_RGB will be used instead. Lowest quality of any supported texture format.
+
+ // ASTC (mobile, Intel devices, hopefully all desktop GPU's one day)
+ cTFASTC_4x4_RGBA: 10, // Opaque+alpha, ASTC 4x4, alpha channel will be opaque for opaque .basis files. Transcoder uses RGB/RGBA/L/LA modes, void extent, and up to two ([0,47] and [0,255]) endpoint precisions.
+
+ // Uncompressed (raw pixel) formats
+ cTFRGBA32: 13, // 32bpp RGBA image stored in raster (not block) order in memory, R is first byte, A is last byte.
+ cTFRGB565: 14, // 166pp RGB image stored in raster (not block) order in memory, R at bit position 11
+ cTFBGR565: 15, // 16bpp RGB image stored in raster (not block) order in memory, R at bit position 0
+ cTFRGBA4444: 16, // 16bpp RGBA image stored in raster (not block) order in memory, R at bit position 12, A at bit position 0
+
+ cTFTotalTextureFormats: 22,
+ };
+
+ // WebGL compressed formats types, from:
+ // http://www.khronos.org/registry/webgl/extensions/
+
+ // https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_s3tc/
+ const COMPRESSED_RGB_S3TC_DXT1_EXT = 0x83F0;
+ const COMPRESSED_RGBA_S3TC_DXT1_EXT = 0x83F1;
+ const COMPRESSED_RGBA_S3TC_DXT3_EXT = 0x83F2;
+ const COMPRESSED_RGBA_S3TC_DXT5_EXT = 0x83F3;
+
+ // https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_etc1/
+ const COMPRESSED_RGB_ETC1_WEBGL = 0x8D64
+
+ // https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_etc/
+ const COMPRESSED_R11_EAC = 0x9270;
+ const COMPRESSED_SIGNED_R11_EAC = 0x9271;
+ const COMPRESSED_RG11_EAC = 0x9272;
+ const COMPRESSED_SIGNED_RG11_EAC = 0x9273;
+ const COMPRESSED_RGB8_ETC2 = 0x9274;
+ const COMPRESSED_SRGB8_ETC2 = 0x9275;
+ const COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2 = 0x9276;
+ const COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2 = 0x9277;
+ const COMPRESSED_RGBA8_ETC2_EAC = 0x9278;
+ const COMPRESSED_SRGB8_ALPHA8_ETC2_EAC = 0x9279;
+
+ // https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_astc/
+ const COMPRESSED_RGBA_ASTC_4x4_KHR = 0x93B0;
+
+ // https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_pvrtc/
+ const COMPRESSED_RGB_PVRTC_4BPPV1_IMG = 0x8C00;
+ const COMPRESSED_RGB_PVRTC_2BPPV1_IMG = 0x8C01;
+ const COMPRESSED_RGBA_PVRTC_4BPPV1_IMG = 0x8C02;
+ const COMPRESSED_RGBA_PVRTC_2BPPV1_IMG = 0x8C03;
+
+ // https://www.khronos.org/registry/webgl/extensions/EXT_texture_compression_bptc/
+ const COMPRESSED_RGBA_BPTC_UNORM_EXT = 0x8E8C;
+ const COMPRESSED_SRGB_ALPHA_BPTC_UNORM_EXT = 0x8E8D;
+ const COMPRESSED_RGB_BPTC_SIGNED_FLOAT_EXT = 0x8E8E;
+ const COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_EXT = 0x8E8F;
+
+ const BASIS_WEBGL_FORMAT_MAP = {};
+ // Compressed formats
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFBC1_RGB] = { format: COMPRESSED_RGB_S3TC_DXT1_EXT };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFBC3_RGBA] = { format: COMPRESSED_RGBA_S3TC_DXT5_EXT };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFBC7_RGBA] = { format: COMPRESSED_RGBA_BPTC_UNORM_EXT };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFETC1_RGB] = { format: COMPRESSED_RGB_ETC1_WEBGL };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFETC2_RGBA] = { format: COMPRESSED_RGBA8_ETC2_EAC };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFASTC_4x4_RGBA] = { format: COMPRESSED_RGBA_ASTC_4x4_KHR };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFPVRTC1_4_RGB] = { format: COMPRESSED_RGB_PVRTC_4BPPV1_IMG };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFPVRTC1_4_RGBA] = { format: COMPRESSED_RGBA_PVRTC_4BPPV1_IMG };
+
+ // Uncompressed formats
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFRGBA32] = { uncompressed: true, format: WebGLRenderingContext.RGBA, type: WebGLRenderingContext.UNSIGNED_BYTE };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFRGB565] = { uncompressed: true, format: WebGLRenderingContext.RGB, type: WebGLRenderingContext.UNSIGNED_SHORT_5_6_5 };
+ BASIS_WEBGL_FORMAT_MAP[BASIS_FORMAT.cTFRGBA4444] = { uncompressed: true, format: WebGLRenderingContext.RGBA, type: WebGLRenderingContext.UNSIGNED_SHORT_4_4_4_4 };
+
+ // Notifies the main thread when a texture has failed to load for any reason.
+ function fail(id, errorMsg) {
+ postMessage({
+ id: id,
+ error: errorMsg
+ });
+ }
+
+ function basisFileFail(id, basisFile, errorMsg) {
+ fail(id, errorMsg);
+ basisFile.close();
+ basisFile.delete();
+ }
+
+ // This utility currently only transcodes the first image in the file.
+ const IMAGE_INDEX = 0;
+ const TOP_LEVEL_MIP = 0;
+
+ function transcode(id, arrayBuffer, supportedFormats, allowSeparateAlpha) {
+ let basisData = new Uint8Array(arrayBuffer);
+
+ let basisFile = new BasisFile(basisData);
+ let images = basisFile.getNumImages();
+ let levels = basisFile.getNumLevels(IMAGE_INDEX);
+ let hasAlpha = basisFile.getHasAlpha();
+ if (!images || !levels) {
+ basisFileFail(id, basisFile, 'Invalid Basis data');
+ return;
+ }
+
+ if (!basisFile.startTranscoding()) {
+ basisFileFail(id, basisFile, 'startTranscoding failed');
+ return;
+ }
+
+ let basisFormat = undefined;
+ let needsSecondaryAlpha = false;
+ if (hasAlpha) {
+ if (supportedFormats.etc2) {
+ basisFormat = BASIS_FORMAT.cTFETC2_RGBA;
+ } else if (supportedFormats.bptc) {
+ basisFormat = BASIS_FORMAT.cTFBC7_RGBA;
+ } else if (supportedFormats.s3tc) {
+ basisFormat = BASIS_FORMAT.cTFBC3_RGBA;
+ } else if (supportedFormats.astc) {
+ basisFormat = BASIS_FORMAT.cTFASTC_4x4_RGBA;
+ } else if (supportedFormats.pvrtc) {
+ if (allowSeparateAlpha) {
+ basisFormat = BASIS_FORMAT.cTFPVRTC1_4_RGB;
+ } else {
+ basisFormat = BASIS_FORMAT.cTFPVRTC1_4_RGBA;
+ }
+ } else if (supportedFormats.etc1 && allowSeparateAlpha) {
+ basisFormat = BASIS_FORMAT.cTFETC1_RGB;
+ needsSecondaryAlpha = true;
+ } else {
+ // If we don't support any appropriate compressed formats transcode to
+ // raw pixels. This is something of a last resort, because the GPU
+ // upload will be significantly slower and take a lot more memory, but
+ // at least it prevents you from needing to store a fallback JPG/PNG and
+ // the download size will still likely be smaller.
+ basisFormat = BASIS_FORMAT.RGBA32;
+ }
+ } else {
+ if (supportedFormats.etc1) {
+ // Should be the highest quality, so use when available.
+ // http://richg42.blogspot.com/2018/05/basis-universal-gpu-texture-format.html
+ basisFormat = BASIS_FORMAT.cTFETC1_RGB;
+ } else if (supportedFormats.bptc) {
+ basisFormat = BASIS_FORMAT.cTFBC7_RGBA;
+ } else if (supportedFormats.s3tc) {
+ basisFormat = BASIS_FORMAT.cTFBC1_RGB;
+ } else if (supportedFormats.etc2) {
+ basisFormat = BASIS_FORMAT.cTFETC2_RGBA;
+ } else if (supportedFormats.astc) {
+ basisFormat = BASIS_FORMAT.cTFASTC_4x4_RGBA;
+ } else if (supportedFormats.pvrtc) {
+ basisFormat = BASIS_FORMAT.cTFPVRTC1_4_RGB;
+ } else {
+ // See note on uncompressed transcode above.
+ basisFormat = BASIS_FORMAT.cTFRGB565;
+ }
+ }
+
+ if (basisFormat === undefined) {
+ basisFileFail(id, basisFile, 'No supported transcode formats');
+ return;
+ }
+
+ let webglFormat = BASIS_WEBGL_FORMAT_MAP[basisFormat];
+
+ // If we're not using compressed textures it'll be cheaper to generate
+ // mipmaps on the fly, so only transcode a single level.
+ if (webglFormat.uncompressed) {
+ levels = 1;
+ }
+
+ // Gather information about each mip level to be transcoded.
+ let mipLevels = [];
+ let totalTranscodeSize = 0;
+
+ for (let mipLevel = 0; mipLevel < levels; ++mipLevel) {
+ let transcodeSize = basisFile.getImageTranscodedSizeInBytes(IMAGE_INDEX, mipLevel, basisFormat);
+ mipLevels.push({
+ level: mipLevel,
+ offset: totalTranscodeSize,
+ size: transcodeSize,
+ width: basisFile.getImageWidth(IMAGE_INDEX, mipLevel),
+ height: basisFile.getImageHeight(IMAGE_INDEX, mipLevel),
+ });
+ totalTranscodeSize += transcodeSize;
+ }
+
+ // Allocate a buffer large enough to hold all of the transcoded mip levels at once.
+ let transcodeData = new Uint8Array(totalTranscodeSize);
+ let alphaTranscodeData = needsSecondaryAlpha ? new Uint8Array(totalTranscodeSize) : null;
+
+ // Transcode each mip level into the appropriate section of the overall buffer.
+ for (let mipLevel of mipLevels) {
+ let levelData = new Uint8Array(transcodeData.buffer, mipLevel.offset, mipLevel.size);
+ if (!basisFile.transcodeImage(levelData, IMAGE_INDEX, mipLevel.level, basisFormat, 1, 0)) {
+ basisFileFail(id, basisFile, 'transcodeImage failed');
+ return;
+ }
+ if (needsSecondaryAlpha) {
+ let alphaLevelData = new Uint8Array(alphaTranscodeData.buffer, mipLevel.offset, mipLevel.size);
+ if (!basisFile.transcodeImage(alphaLevelData, IMAGE_INDEX, mipLevel.level, basisFormat, 1, 1)) {
+ basisFileFail(id, basisFile, 'alpha transcodeImage failed');
+ return;
+ }
+ }
+ }
+
+ basisFile.close();
+ basisFile.delete();
+
+ // Post the transcoded results back to the main thread.
+ let transferList = [transcodeData.buffer];
+ if (needsSecondaryAlpha) {
+ transferList.push(alphaTranscodeData.buffer);
+ }
+ postMessage({
+ id: id,
+ buffer: transcodeData.buffer,
+ alphaBuffer: needsSecondaryAlpha ? alphaTranscodeData.buffer : null,
+ webglFormat: webglFormat,
+ mipLevels: mipLevels,
+ hasAlpha: hasAlpha,
+ }, transferList);
+ }
+
+ onmessage = (msg) => {
+ // Each call to the worker must contain:
+ let url = msg.data.url; // The URL of the basis image OR
+ let buffer = msg.data.buffer; // An array buffer with the basis image data
+ let allowSeparateAlpha = msg.data.allowSeparateAlpha;
+ let supportedFormats = msg.data.supportedFormats; // The formats this device supports
+ let id = msg.data.id; // A unique ID for the texture
+
+ if (url) {
+ // Make the call to fetch the basis texture data
+ fetch(`../../${url}`).then(function(response) {
+ if (response.ok) {
+ response.arrayBuffer().then((arrayBuffer) => {
+ if (BasisFile) {
+ transcode(id, arrayBuffer, supportedFormats, allowSeparateAlpha);
+ } else {
+ BASIS_INITIALIZED.then(() => {
+ transcode(id, arrayBuffer, supportedFormats, allowSeparateAlpha);
+ });
+ }
+ });
+ } else {
+ fail(id, `Fetch failed: ${response.status}, ${response.statusText}`);
+ }
+ });
+ } else if (buffer) {
+ if (BasisFile) {
+ transcode(id, buffer, supportedFormats, allowSeparateAlpha);
+ } else {
+ BASIS_INITIALIZED.then(() => {
+ transcode(id, buffer, supportedFormats, allowSeparateAlpha);
+ });
+ }
+ } else {
+ fail(id, `No url or buffer specified`);
+ }
+ };
+}
\ No newline at end of file
