Add RGTC support (#25180)

src/constants.js

@@ -122,6 +122,10 @@ export const RGBA_ASTC_10x10_Format = 37819;
 export const RGBA_ASTC_12x10_Format = 37820;
 export const RGBA_ASTC_12x12_Format = 37821;
 export const RGBA_BPTC_Format = 36492;
+export const RED_RGTC1_Format = 36283;
+export const SIGNED_RED_RGTC1_Format = 36284;
+export const RED_GREEN_RGTC2_Format = 36285;
+export const SIGNED_RED_GREEN_RGTC2_Format = 36286;
 export const LoopOnce = 2200;
 export const LoopRepeat = 2201;
 export const LoopPingPong = 2202;

src/renderers/webgl/WebGLUtils.js

@@ -1,4 +1,4 @@
-import { RGBA_ASTC_4x4_Format, RGBA_ASTC_5x4_Format, RGBA_ASTC_5x5_Format, RGBA_ASTC_6x5_Format, RGBA_ASTC_6x6_Format, RGBA_ASTC_8x5_Format, RGBA_ASTC_8x6_Format, RGBA_ASTC_8x8_Format, RGBA_ASTC_10x5_Format, RGBA_ASTC_10x6_Format, RGBA_ASTC_10x8_Format, RGBA_ASTC_10x10_Format, RGBA_ASTC_12x10_Format, RGBA_ASTC_12x12_Format, RGB_ETC1_Format, RGB_ETC2_Format, RGBA_ETC2_EAC_Format, RGBA_PVRTC_2BPPV1_Format, RGBA_PVRTC_4BPPV1_Format, RGB_PVRTC_2BPPV1_Format, RGB_PVRTC_4BPPV1_Format, RGBA_S3TC_DXT5_Format, RGBA_S3TC_DXT3_Format, RGBA_S3TC_DXT1_Format, RGB_S3TC_DXT1_Format, DepthFormat, DepthStencilFormat, LuminanceAlphaFormat, LuminanceFormat, RedFormat, RGBFormat, RGBAFormat, AlphaFormat, RedIntegerFormat, RGFormat, RGIntegerFormat, RGBAIntegerFormat, HalfFloatType, FloatType, UnsignedIntType, IntType, UnsignedShortType, ShortType, ByteType, UnsignedInt248Type, UnsignedShort5551Type, UnsignedShort4444Type, UnsignedByteType, RGBA_BPTC_Format, sRGBEncoding, _SRGBAFormat } from '../../constants.js';
+import { RGBA_ASTC_4x4_Format, RGBA_ASTC_5x4_Format, RGBA_ASTC_5x5_Format, RGBA_ASTC_6x5_Format, RGBA_ASTC_6x6_Format, RGBA_ASTC_8x5_Format, RGBA_ASTC_8x6_Format, RGBA_ASTC_8x8_Format, RGBA_ASTC_10x5_Format, RGBA_ASTC_10x6_Format, RGBA_ASTC_10x8_Format, RGBA_ASTC_10x10_Format, RGBA_ASTC_12x10_Format, RGBA_ASTC_12x12_Format, RGB_ETC1_Format, RGB_ETC2_Format, RGBA_ETC2_EAC_Format, RGBA_PVRTC_2BPPV1_Format, RGBA_PVRTC_4BPPV1_Format, RGB_PVRTC_2BPPV1_Format, RGB_PVRTC_4BPPV1_Format, RGBA_S3TC_DXT5_Format, RGBA_S3TC_DXT3_Format, RGBA_S3TC_DXT1_Format, RGB_S3TC_DXT1_Format, DepthFormat, DepthStencilFormat, LuminanceAlphaFormat, LuminanceFormat, RedFormat, RGBFormat, RGBAFormat, AlphaFormat, RedIntegerFormat, RGFormat, RGIntegerFormat, RGBAIntegerFormat, HalfFloatType, FloatType, UnsignedIntType, IntType, UnsignedShortType, ShortType, ByteType, UnsignedInt248Type, UnsignedShort5551Type, UnsignedShort4444Type, UnsignedByteType, RGBA_BPTC_Format, sRGBEncoding, _SRGBAFormat, RED_RGTC1_Format, SIGNED_RED_RGTC1_Format, RED_GREEN_RGTC2_Format, SIGNED_RED_GREEN_RGTC2_Format } from '../../constants.js';
 
 function WebGLUtils( gl, extensions, capabilities ) {
 
@@ -232,6 +232,27 @@ function WebGLUtils( gl, extensions, capabilities ) {
 
 		}
 
+		// RGTC
+
+		if ( p === RED_RGTC1_Format || p === SIGNED_RED_RGTC1_Format || p === RED_GREEN_RGTC2_Format || p === SIGNED_RED_GREEN_RGTC2_Format ) {
+
+			extension = extensions.get( 'EXT_texture_compression_rgtc' );
+
+			if ( extension !== null ) {
+
+				if ( p === RGBA_BPTC_Format ) return extension.COMPRESSED_RED_RGTC1_EXT;
+				if ( p === SIGNED_RED_RGTC1_Format ) return extension.COMPRESSED_SIGNED_RED_RGTC1_EXT;
+				if ( p === RED_GREEN_RGTC2_Format ) return extension.COMPRESSED_RED_GREEN_RGTC2_EXT;
+				if ( p === SIGNED_RED_GREEN_RGTC2_Format ) return extension.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT;
+
+			} else {
+
+				return null;
+
+			}
+
+		}
+
 		//
 
 		if ( p === UnsignedInt248Type ) {