From 57c1ed35faaa82829e18690bfca1a8e09567d66b Mon Sep 17 00:00:00 2001
From: Don McCurdy <don.r.mccurdy@gmail.com>
Date: Wed, 15 Jul 2020 20:21:36 -0700
Subject: [PATCH] KTX2Loader: Fix transcode target choices for UASTC on iOS.
 Add BC7 option.

---
 examples/jsm/loaders/KTX2Loader.js      | 42 +++++++++++++++++++------
 examples/webgl_loader_texture_ktx2.html |  2 ++
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/examples/jsm/loaders/KTX2Loader.js b/examples/jsm/loaders/KTX2Loader.js
index 0ddc6786c47256..a39789f801efc1 100644
--- a/examples/jsm/loaders/KTX2Loader.js
+++ b/examples/jsm/loaders/KTX2Loader.js
@@ -25,16 +25,18 @@ import {
 	LinearEncoding,
 	LinearFilter,
 	LinearMipmapLinearFilter,
+	RGBAFormat,
+	RGBA_ASTC_4x4_Format,
+	RGBA_BPTC_Format,
+	RGBA_ETC2_EAC_Format,
+	RGBA_PVRTC_4BPPV1_Format,
+	RGBA_S3TC_DXT5_Format,
 	RGB_ETC1_Format,
 	RGB_ETC2_Format,
-	RGBA_ETC2_EAC_Format,
 	RGB_PVRTC_4BPPV1_Format,
 	RGB_S3TC_DXT1_Format,
-	RGBA_ASTC_4x4_Format,
-	RGBA_PVRTC_4BPPV1_Format,
-	RGBA_S3TC_DXT5_Format,
-	sRGBEncoding,
 	UnsignedByteType,
+	sRGBEncoding,
 } from '../../../build/three.module.js';
 
 // Data Format Descriptor (DFD) constants.
@@ -81,10 +83,21 @@ class KTX2Loader extends CompressedTextureLoader {
 			etc1Supported: renderer.extensions.has( 'WEBGL_compressed_texture_etc1' ),
 			etc2Supported: renderer.extensions.has( 'WEBGL_compressed_texture_etc' ),
 			dxtSupported: renderer.extensions.has( 'WEBGL_compressed_texture_s3tc' ),
+			bptcSupported: renderer.extensions.has( 'EXT_texture_compression_bptc' ),
 			pvrtcSupported: renderer.extensions.has( 'WEBGL_compressed_texture_pvrtc' )
 				|| renderer.extensions.has( 'WEBKIT_WEBGL_compressed_texture_pvrtc' )
 		};
 
+		alert( JSON.stringify( {
+			WEBGL_compressed_texture_astc: !! renderer.extensions.has( 'WEBGL_compressed_texture_astc' ),
+			WEBGL_compressed_texture_etc1: !! renderer.extensions.has( 'WEBGL_compressed_texture_etc1' ),
+			WEBGL_compressed_texture_etc: !! renderer.extensions.has( 'WEBGL_compressed_texture_etc' ),
+			WEBGL_compressed_texture_s3tc: !! renderer.extensions.has( 'WEBGL_compressed_texture_s3tc' ),
+			EXT_texture_compression_bptc: !! renderer.extensions.has( 'EXT_texture_compression_bptc' ),
+			WEBGL_compressed_texture_pvrtc: !! renderer.extensions.has( 'WEBGL_compressed_texture_pvrtc' )
+				|| !! renderer.extensions.has( 'WEBKIT_WEBGL_compressed_texture_pvrtc' )
+		}, null, 2 ) );
+
 		return this;
 
 	}
@@ -458,32 +471,43 @@ class KTX2Container {
 			targetFormat = TranscodeTarget.ASTC_4x4_RGBA;
 			this.transcodedFormat = RGBA_ASTC_4x4_Format;
 
+		} else if ( config.bptcSupported && texFormat === TextureFormat.UASTC4x4 ) {
+
+			targetFormat = hasAlpha ? TranscodeTarget.BC7_M5_RGBA : BC7_M6_RGB;
+			this.transcodedFormat = RGBA_BPTC_Format;
+
 		} else if ( config.dxtSupported ) {
 
 			targetFormat = hasAlpha ? TranscodeTarget.BC3_RGBA : TranscodeTarget.BC1_RGB;
 			this.transcodedFormat = hasAlpha ? RGBA_S3TC_DXT5_Format : RGB_S3TC_DXT1_Format;
 
-		} else if ( config.pvrtcSupported ) {
+		} else if ( config.pvrtcSupported && texFormat === TextureFormat.ETC1S ) {
 
 			targetFormat = hasAlpha ? TranscodeTarget.PVRTC1_4_RGBA : TranscodeTarget.PVRTC1_4_RGB;
 			this.transcodedFormat = hasAlpha ? RGBA_PVRTC_4BPPV1_Format : RGB_PVRTC_4BPPV1_Format;
 
-		} else if ( config.etc2Supported ) {
+		} else if ( config.etc2Supported && texFormat === TextureFormat.ETC1S ) {
 
 			targetFormat = hasAlpha ? TranscodeTarget.ETC2_RGBA : TranscodeTarget.ETC1_RGB /* subset of ETC2 */;
 			this.transcodedFormat = hasAlpha ? RGBA_ETC2_EAC_Format : RGB_ETC2_Format;
 
-		} else if ( config.etc1Supported ) {
+		} else if ( config.etc1Supported && texFormat === TextureFormat.ETC1S ) {
 
 			targetFormat = TranscodeTarget.ETC1_RGB;
 			this.transcodedFormat = RGB_ETC1_Format;
 
 		} else {
 
-			throw new Error( 'THREE.KTX2Loader: No suitable compressed texture format found.' );
+			console.warn( 'THREE.KTX2Loader: No suitable compressed texture format found. Decoding to RGBA32.' );
+
+			targetFormat = TranscodeTarget.RGBA32;
+			this.transcodedFormat = RGBAFormat;
 
 		}
 
+		// DO NOT SUBMIT
+		alert( targetFormat.constructor.name );
+
 		if ( ! this.basisModule.isFormatSupported( targetFormat, texFormat ) ) {
 
 			throw new Error( 'THREE.KTX2Loader: Selected texture format not supported by current transcoder build.' );
diff --git a/examples/webgl_loader_texture_ktx2.html b/examples/webgl_loader_texture_ktx2.html
index 1fd45059e43d4c..549a9b6cd06af9 100644
--- a/examples/webgl_loader_texture_ktx2.html
+++ b/examples/webgl_loader_texture_ktx2.html
@@ -52,6 +52,7 @@
 			scene.add( mesh );
 
 			var formatStrings = {
+				[ THREE.RGBAFormat ]: "RGBA32",
 				[ THREE.RGBA_ASTC_4x4_Format ]: "RGBA_ASTC_4x4",
 				[ THREE.RGB_S3TC_DXT1_Format ]: "RGB_S3TC_DXT1",
 				[ THREE.RGBA_S3TC_DXT5_Format ]: "RGBA_S3TC_DXT5",
@@ -70,6 +71,7 @@
 					console.info( `transcoded to ${formatStrings[ texture.format ]}` );
 
 					material.map = texture;
+					material.transparent = true;
 
 					material.needsUpdate = true;