Basis Texture Loader ASTC and PVRTC alpha support and refactor

e7a9d3be · shrekshao · e8145dca · e7a9d3be · e7a9d3be · e7a9d3be
9 changed file
--- a/docs/examples/en/loaders/BasisTextureLoader.html
+++ b/docs/examples/en/loaders/BasisTextureLoader.html
@@ -34,6 +34,7 @@
 		<code>
 		var basisLoader = new THREE.BasisTextureLoader();
 		basisLoader.setTranscoderPath( 'examples/js/libs/basis/' );
+		basisLoader.useAlpha = false;
 		basisLoader.detectSupport( renderer );
 		basisLoader.load( 'diffuse.basis', function ( texture ) {


--- a/docs/examples/zh/loaders/BasisTextureLoader.html
+++ b/docs/examples/zh/loaders/BasisTextureLoader.html
@@ -34,6 +34,7 @@
 		<code>
 		var basisLoader = new THREE.BasisTextureLoader();
 		basisLoader.setTranscoderPath( 'examples/js/libs/basis/' );
+		basisLoader.useAlpha = false;
 		basisLoader.detectSupport( renderer );
 		basisLoader.load( 'diffuse.basis', function ( texture ) {


--- a/examples/js/libs/basis/README.md
+++ b/examples/js/libs/basis/README.md
@@ -19,6 +19,7 @@ Both are dependencies of `THREE.BasisTextureLoader`:
 ```js
 var basisLoader = new THREE.BasisTextureLoader();
 basisLoader.setTranscoderPath( 'examples/js/libs/basis/' );
+basisLoader.useAlpha = false;
 basisLoader.detectSupport( renderer );
 basisLoader.load( 'diffuse.basis', function ( texture ) {

@@ -36,7 +37,7 @@ basisLoader.load( 'diffuse.basis', function ( texture ) {
 ```

 For further documentation about the Basis compressor and transcoder, refer to
-the [Basis GitHub repository](https://github.com/BinomialLLC/basis_universal). The JavaScript wrapper requires one modification from the version provided in the Basis repository – the declaration on the first line is changed from `var Module` to `Module`, to accomodate lazy initialization in a Web Worker ([details](https://github.com/mrdoob/three.js/issues/16524)).
+the [Basis GitHub repository](https://github.com/BinomialLLC/basis_universal).

 ## License


--- a/examples/js/libs/basis/basis_transcoder.js
+++ b/examples/js/libs/basis/basis_transcoder.js
--- a/examples/js/libs/basis/basis_transcoder.wasm
+++ b/examples/js/libs/basis/basis_transcoder.wasm
--- a/examples/js/loaders/BasisTextureLoader.js
+++ b/examples/js/loaders/BasisTextureLoader.js
@@ -4,8 +4,6 @@
 * @author Shrek Shao / https://github.com/shrekshao
 */

-/* global Module, createBasisModule */
-
 /**
 * Loader for Basis Universal GPU Texture Codec.
 *
@@ -22,6 +20,7 @@ THREE.BasisTextureLoader = function ( manager ) {

 	THREE.Loader.call( this, manager );

+  this.useAlpha = true;
 	this.transcoderPath = '';
 	this.transcoderBinary = null;
 	this.transcoderPending = null;
@@ -31,10 +30,12 @@ THREE.BasisTextureLoader = function ( manager ) {
 	this.workerNextTaskID = 1;
 	this.workerSourceURL = '';
 	this.workerConfig = {
-		format: null,
+    format: null,
+    useAlpha: true,
+    astcSupported: false,
 		etcSupported: false,
 		dxtSupported: false,
-		pvrtcSupported: false,
+    pvrtcSupported: false,
 	};

 };
@@ -63,22 +64,27 @@ THREE.BasisTextureLoader.prototype = Object.assign( Object.create( THREE.Loader.

 		var config = this.workerConfig;

+    config.astcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_astc' );
 		config.etcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_etc1' );
 		config.dxtSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_s3tc' );
 		config.pvrtcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_pvrtc' )
-			|| !! renderer.extensions.get( 'WEBKIT_WEBGL_compressed_texture_pvrtc' );
+      || !! renderer.extensions.get( 'WEBKIT_WEBGL_compressed_texture_pvrtc' );

-		if ( config.etcSupported ) {
+    if (config.astcSupported) {

-			config.format = THREE.BasisTextureLoader.BASIS_FORMAT.cTFETC1;
+      config.format = THREE.BasisTextureLoader.BASIS_FORMAT.cTFASTC_4x4;

-		} else if ( config.dxtSupported ) {
+    } else if ( config.dxtSupported ) {

-			config.format = THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC1;
+			config.format = this.useAlpha ? THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC3 : THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC1;

 		} else if ( config.pvrtcSupported ) {

-			config.format = THREE.BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_OPAQUE_ONLY;
+			config.format = this.useAlpha ? THREE.BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGBA : THREE.BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGB;
+
+    } else if ( config.etcSupported ) {
+
+			config.format = THREE.BasisTextureLoader.BASIS_FORMAT.cTFETC1;

 		} else {

@@ -136,27 +142,30 @@ THREE.BasisTextureLoader.prototype = Object.assign( Object.create( THREE.Loader.

 				var config = this.workerConfig;

-				var { width, height, mipmaps } = message;
+				var { width, height, hasAlpha, mipmaps } = message;

 				var texture;

-				if ( config.etcSupported ) {
-
-					texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.RGB_ETC1_Format );
-
-				} else if ( config.dxtSupported ) {
-
-					texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.BasisTextureLoader.DXT_FORMAT_MAP[ config.format ], THREE.UnsignedByteType );
-
-				} else if ( config.pvrtcSupported ) {
-
-					texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.RGB_PVRTC_4BPPV1_Format );
-
-				} else {
-
-					throw new Error( 'THREE.BasisTextureLoader: No supported format available.' );
-
-				}
+        switch(config.format) {
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFASTC_4x4:
+            texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.BasisTextureLoader.COMPRESSED_RGBA_ASTC_4x4_KHR );
+            break;
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC1:
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC3:
+            texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.BasisTextureLoader.DXT_FORMAT_MAP[ config.format ], THREE.UnsignedByteType );
+            break;
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFETC1:
+            texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.RGB_ETC1_Format );
+            break;
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGB:
+            texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.RGB_PVRTC_4BPPV1_Format );
+            break;
+          case THREE.BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGBA:
+            texture = new THREE.CompressedTexture( mipmaps, width, height, THREE.RGBA_PVRTC_4BPPV1_Format );
+            break;
+          default:
+              throw new Error( 'THREE.BasisTextureLoader: No supported format available.' );
+        }

 				texture.minFilter = mipmaps.length === 1 ? THREE.LinearFilter : THREE.LinearMipmapLinearFilter;
 				texture.magFilter = THREE.LinearFilter;
@@ -214,12 +223,7 @@ THREE.BasisTextureLoader.prototype = Object.assign( Object.create( THREE.Loader.

 					var body = [
 						'/* basis_transcoder.js */',
-						'var Module;',
-						'function createBasisModule () {',
-						'  ' + jsContent,
-						'  return Module;',
-						'}',
-						'',
+						jsContent,
 						'/* worker */',
 						fn.substring( fn.indexOf( '{' ) + 1, fn.lastIndexOf( '}' ) )
 					].join( '\n' );
@@ -247,6 +251,7 @@ THREE.BasisTextureLoader.prototype = Object.assign( Object.create( THREE.Loader.
 				worker._taskCosts = {};
 				worker._taskLoad = 0;

+        this.workerConfig.useAlpha = this.useAlpha;
 				worker.postMessage( {
 					type: 'init',
 					config: this.workerConfig,
@@ -312,13 +317,22 @@ THREE.BasisTextureLoader.prototype = Object.assign( Object.create( THREE.Loader.

 THREE.BasisTextureLoader.BASIS_FORMAT = {
 	cTFETC1: 0,
-	cTFBC1: 1,
-	cTFBC4: 2,
-	cTFPVRTC1_4_OPAQUE_ONLY: 3,
-	cTFBC7_M6_OPAQUE_ONLY: 4,
-	cTFETC2: 5,
-	cTFBC3: 6,
-	cTFBC5: 7,
+	cTFETC2: 1,
+	cTFBC1: 2,
+	cTFBC3: 3,
+	cTFBC4: 4,
+	cTFBC5: 5,
+	cTFBC7_M6_OPAQUE_ONLY: 6,
+  cTFBC7_M5: 7,
+  cTFPVRTC1_4_RGB: 8,
+  cTFPVRTC1_4_RGBA: 9,
+  cTFASTC_4x4: 10,
+  cTFATC_RGB: 11,
+  cTFATC_RGBA_INTERPOLATED_ALPHA: 12,
+  cTFRGBA32: 13,
+  cTFRGB565: 14,
+  cTFBGR565: 15,
+  cTFRGBA4444: 16,
 };

 // DXT formats, from:
@@ -333,7 +347,11 @@ THREE.BasisTextureLoader.DXT_FORMAT_MAP = {};
 THREE.BasisTextureLoader.DXT_FORMAT_MAP[ THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC1 ] =
 	THREE.BasisTextureLoader.DXT_FORMAT.COMPRESSED_RGB_S3TC_DXT1_EXT;
 THREE.BasisTextureLoader.DXT_FORMAT_MAP[ THREE.BasisTextureLoader.BASIS_FORMAT.cTFBC3 ] =
-	THREE.BasisTextureLoader.DXT_FORMAT.COMPRESSED_RGBA_S3TC_DXT5_EXT;
+  THREE.BasisTextureLoader.DXT_FORMAT.COMPRESSED_RGBA_S3TC_DXT5_EXT;
+
+// ASTC formats, from:
+// https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_astc/
+THREE.BasisTextureLoader.COMPRESSED_RGBA_ASTC_4x4_KHR = 0x93B0;

 /* WEB WORKER */

@@ -359,7 +377,7 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 					try {

-						var { width, height, mipmaps } = transcode( message.buffer );
+						var { width, height, hasAlpha, mipmaps } = transcode( message.buffer );

 						var buffers = [];

@@ -369,7 +387,7 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 						}

-						self.postMessage( { type: 'transcode', id: message.id, width, height, mipmaps }, buffers );
+						self.postMessage( { type: 'transcode', id: message.id, width, height, hasAlpha, mipmaps }, buffers );

 					} catch ( error ) {

@@ -388,19 +406,15 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 	function init( wasmBinary ) {

-		transcoderPending = new Promise( ( resolve ) => {
-
-			// The 'Module' global is used by the Basis wrapper, which will check for
-			// the 'wasmBinary' property before trying to load the file itself.
+    var m;
+    transcoderPending = new Promise( ( resolve ) => {

-			// TODO(donmccurdy): This only works with a modified version of the
-			// emscripten-generated wrapper. The default seems to have a bug making it
-			// impossible to override the WASM binary.
-			Module = { wasmBinary, onRuntimeInitialized: resolve };
+      m = { wasmBinary, onRuntimeInitialized: resolve };
+			BASIS(m);

 		} ).then( () => {

-			var { BasisFile, initializeBasis } = Module;
+      var { BasisFile, initializeBasis } = m;

 			_BasisFile = BasisFile;

@@ -408,8 +422,6 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 		} );

-		createBasisModule();
-
 	}

 	function transcode( buffer ) {
@@ -418,7 +430,8 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 		var width = basisFile.getImageWidth( 0, 0 );
 		var height = basisFile.getImageHeight( 0, 0 );
-		var levels = basisFile.getNumLevels( 0 );
+    var levels = basisFile.getNumLevels( 0 );
+    var hasAlpha = basisFile.getHasAlpha();

 		function cleanup() {

@@ -441,12 +454,6 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 		}

-		if ( basisFile.getHasAlpha() ) {
-
-			console.warn( 'THREE.BasisTextureLoader: Alpha not yet implemented.' );
-
-		}
-
 		var mipmaps = [];

 		for ( var mip = 0; mip < levels; mip ++ ) {
@@ -459,8 +466,8 @@ THREE.BasisTextureLoader.BasisWorker = function () {
 				dst,
 				0,
 				mip,
-				config.format,
-				config.etcSupported ? 0 : ( config.dxtSupported ? 1 : 0 ),
+        config.format,
+        config.useAlpha,
 				0
 			);

@@ -477,8 +484,8 @@ THREE.BasisTextureLoader.BasisWorker = function () {

 		cleanup();

-		return { width, height, mipmaps };
+		return { width, height, hasAlpha, mipmaps };

 	}

-};
+};
\ No newline at end of file
--- a/examples/jsm/loaders/BasisTextureLoader.d.ts
+++ b/examples/jsm/loaders/BasisTextureLoader.d.ts
@@ -8,12 +8,15 @@ import {
 export class BasisTextureLoader extends Loader {

 	constructor( manager?: LoadingManager );
+	useAlpha: boolean;
 	transcoderBinary: ArrayBuffer | null;
 	transcoderPath: string;
 	transcoderPending: Promise<void> | null;

 	workerConfig: {
 		format: number;
+		useAlpha: boolean,
+		astcSupported: boolean,
 		etcSupported: boolean;
 		dxtSupported: boolean;
 		pvrtcSupported: boolean;

--- a/examples/jsm/loaders/BasisTextureLoader.js
+++ b/examples/jsm/loaders/BasisTextureLoader.js
@@ -10,8 +10,10 @@ import {
 	LinearFilter,
 	LinearMipmapLinearFilter,
 	Loader,
+	RGBA_ASTC_4x4_Format,
 	RGB_ETC1_Format,
 	RGB_PVRTC_4BPPV1_Format,
+	RGBA_PVRTC_4BPPV1_Format,
 	UnsignedByteType
 } from "../../../build/three.module.js";

@@ -33,6 +35,7 @@ var BasisTextureLoader = function ( manager ) {

 	Loader.call( this, manager );

+	this.useAlpha = true;
 	this.transcoderPath = '';
 	this.transcoderBinary = null;
 	this.transcoderPending = null;
@@ -43,6 +46,8 @@ var BasisTextureLoader = function ( manager ) {
 	this.workerSourceURL = '';
 	this.workerConfig = {
 		format: null,
+		useAlpha: true,
+		astcSupported: false,
 		etcSupported: false,
 		dxtSupported: false,
 		pvrtcSupported: false,
@@ -74,22 +79,27 @@ BasisTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ),

 		var config = this.workerConfig;

+    config.astcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_astc' );
 		config.etcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_etc1' );
 		config.dxtSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_s3tc' );
 		config.pvrtcSupported = !! renderer.extensions.get( 'WEBGL_compressed_texture_pvrtc' )
-			|| !! renderer.extensions.get( 'WEBKIT_WEBGL_compressed_texture_pvrtc' );
+      || !! renderer.extensions.get( 'WEBKIT_WEBGL_compressed_texture_pvrtc' );

-		if ( config.etcSupported ) {
+    if (config.astcSupported) {

-			config.format = BasisTextureLoader.BASIS_FORMAT.cTFETC1;
+      config.format = BasisTextureLoader.BASIS_FORMAT.cTFASTC_4x4;

-		} else if ( config.dxtSupported ) {
+    } else if ( config.dxtSupported ) {

-			config.format = BasisTextureLoader.BASIS_FORMAT.cTFBC1;
+			config.format = this.useAlpha ? BasisTextureLoader.BASIS_FORMAT.cTFBC3 : BasisTextureLoader.BASIS_FORMAT.cTFBC1;

 		} else if ( config.pvrtcSupported ) {

-			config.format = BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_OPAQUE_ONLY;
+			config.format = this.useAlpha ? BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGBA : BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGB;
+
+    } else if ( config.etcSupported ) {
+
+			config.format = BasisTextureLoader.BASIS_FORMAT.cTFETC1;

 		} else {

@@ -147,27 +157,30 @@ BasisTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ),

 				var config = this.workerConfig;

-				var { width, height, mipmaps } = message;
+				var { width, height, hasAlpha, mipmaps } = message;

 				var texture;

-				if ( config.etcSupported ) {
-
-					texture = new CompressedTexture( mipmaps, width, height, RGB_ETC1_Format );
-
-				} else if ( config.dxtSupported ) {
-
-					texture = new CompressedTexture( mipmaps, width, height, BasisTextureLoader.DXT_FORMAT_MAP[ config.format ], UnsignedByteType );
-
-				} else if ( config.pvrtcSupported ) {
-
-					texture = new CompressedTexture( mipmaps, width, height, RGB_PVRTC_4BPPV1_Format );
-
-				} else {
-
-					throw new Error( 'THREE.BasisTextureLoader: No supported format available.' );
-
-				}
+				switch(config.format) {
+          case BasisTextureLoader.BASIS_FORMAT.cTFASTC_4x4:
+            texture = new CompressedTexture( mipmaps, width, height, RGBA_ASTC_4x4_Format );
+            break;
+          case BasisTextureLoader.BASIS_FORMAT.cTFBC1:
+          case BasisTextureLoader.BASIS_FORMAT.cTFBC3:
+            texture = new CompressedTexture( mipmaps, width, height, BasisTextureLoader.DXT_FORMAT_MAP[ config.format ], UnsignedByteType );
+            break;
+          case BasisTextureLoader.BASIS_FORMAT.cTFETC1:
+            texture = new CompressedTexture( mipmaps, width, height, RGB_ETC1_Format );
+            break;
+          case BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGB:
+            texture = new CompressedTexture( mipmaps, width, height, RGB_PVRTC_4BPPV1_Format );
+            break;
+          case BasisTextureLoader.BASIS_FORMAT.cTFPVRTC1_4_RGBA:
+            texture = new CompressedTexture( mipmaps, width, height, RGBA_PVRTC_4BPPV1_Format );
+            break;
+          default:
+              throw new Error( 'THREE.BasisTextureLoader: No supported format available.' );
+        }

 				texture.minFilter = mipmaps.length === 1 ? LinearFilter : LinearMipmapLinearFilter;
 				texture.magFilter = LinearFilter;
@@ -225,12 +238,7 @@ BasisTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ),

 					var body = [
 						'/* basis_transcoder.js */',
-						'var Module;',
-						'function createBasisModule () {',
-						'  ' + jsContent,
-						'  return Module;',
-						'}',
-						'',
+						jsContent,
 						'/* worker */',
 						fn.substring( fn.indexOf( '{' ) + 1, fn.lastIndexOf( '}' ) )
 					].join( '\n' );
@@ -323,13 +331,22 @@ BasisTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ),

 BasisTextureLoader.BASIS_FORMAT = {
 	cTFETC1: 0,
-	cTFBC1: 1,
-	cTFBC4: 2,
-	cTFPVRTC1_4_OPAQUE_ONLY: 3,
-	cTFBC7_M6_OPAQUE_ONLY: 4,
-	cTFETC2: 5,
-	cTFBC3: 6,
-	cTFBC5: 7,
+	cTFETC2: 1,
+	cTFBC1: 2,
+	cTFBC3: 3,
+	cTFBC4: 4,
+	cTFBC5: 5,
+	cTFBC7_M6_OPAQUE_ONLY: 6,
+  cTFBC7_M5: 7,
+  cTFPVRTC1_4_RGB: 8,
+  cTFPVRTC1_4_RGBA: 9,
+  cTFASTC_4x4: 10,
+  cTFATC_RGB: 11,
+  cTFATC_RGBA_INTERPOLATED_ALPHA: 12,
+  cTFRGBA32: 13,
+  cTFRGB565: 14,
+  cTFBGR565: 15,
+  cTFRGBA4444: 16,
 };

 // DXT formats, from:
@@ -346,6 +363,10 @@ BasisTextureLoader.DXT_FORMAT_MAP[ BasisTextureLoader.BASIS_FORMAT.cTFBC1 ] =
 BasisTextureLoader.DXT_FORMAT_MAP[ BasisTextureLoader.BASIS_FORMAT.cTFBC3 ] =
 	BasisTextureLoader.DXT_FORMAT.COMPRESSED_RGBA_S3TC_DXT5_EXT;

+// ASTC formats, from:
+// https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_astc/
+BasisTextureLoader.COMPRESSED_RGBA_ASTC_4x4_KHR = 0x93B0;
+
 /* WEB WORKER */

 BasisTextureLoader.BasisWorker = function () {
@@ -370,7 +391,7 @@ BasisTextureLoader.BasisWorker = function () {

 					try {

-						var { width, height, mipmaps } = transcode( message.buffer );
+						var { width, height, hasAlpha, mipmaps } = transcode( message.buffer );

 						var buffers = [];

@@ -380,7 +401,7 @@ BasisTextureLoader.BasisWorker = function () {

 						}

-						self.postMessage( { type: 'transcode', id: message.id, width, height, mipmaps }, buffers );
+						self.postMessage( { type: 'transcode', id: message.id, width, height, hasAlpha, mipmaps }, buffers );

 					} catch ( error ) {

@@ -399,19 +420,15 @@ BasisTextureLoader.BasisWorker = function () {

 	function init( wasmBinary ) {

-		transcoderPending = new Promise( ( resolve ) => {
+		var m;
+    transcoderPending = new Promise( ( resolve ) => {

-			// The 'Module' global is used by the Basis wrapper, which will check for
-			// the 'wasmBinary' property before trying to load the file itself.
-
-			// TODO(donmccurdy): This only works with a modified version of the
-			// emscripten-generated wrapper. The default seems to have a bug making it
-			// impossible to override the WASM binary.
-			Module = { wasmBinary, onRuntimeInitialized: resolve };
+      m = { wasmBinary, onRuntimeInitialized: resolve };
+			BASIS(m);

 		} ).then( () => {

-			var { BasisFile, initializeBasis } = Module;
+      var { BasisFile, initializeBasis } = m;

 			_BasisFile = BasisFile;

@@ -419,8 +436,6 @@ BasisTextureLoader.BasisWorker = function () {

 		} );

-		createBasisModule();
-
 	}

 	function transcode( buffer ) {
@@ -430,6 +445,7 @@ BasisTextureLoader.BasisWorker = function () {
 		var width = basisFile.getImageWidth( 0, 0 );
 		var height = basisFile.getImageHeight( 0, 0 );
 		var levels = basisFile.getNumLevels( 0 );
+    var hasAlpha = basisFile.getHasAlpha();

 		function cleanup() {

@@ -471,7 +487,7 @@ BasisTextureLoader.BasisWorker = function () {
 				0,
 				mip,
 				config.format,
-				config.etcSupported ? 0 : ( config.dxtSupported ? 1 : 0 ),
+				config.useAlpha,
 				0
 			);

@@ -488,7 +504,7 @@ BasisTextureLoader.BasisWorker = function () {

 		cleanup();

-		return { width, height, mipmaps };
+		return { width, height, hasAlpha, mipmaps };

 	}


--- a/examples/webgl_loader_texture_basis.html
+++ b/examples/webgl_loader_texture_basis.html
@@ -50,8 +50,8 @@

 				var loader = new BasisTextureLoader();
 				loader.setTranscoderPath( 'js/libs/basis/' );
+				loader.useAlpha = false;
 				loader.detectSupport( renderer );
-
 				loader.load( 'textures/compressed/PavingStones.basis', function ( texture ) {

 					texture.encoding = THREE.sRGBEncoding;