GLTFLoader: Add EXT_texture_avif support.

examples/jsm/loaders/GLTFLoader.js

@@ -471,6 +471,7 @@ const EXTENSIONS = {
 	KHR_MESH_QUANTIZATION: 'KHR_mesh_quantization',
 	KHR_MATERIALS_EMISSIVE_STRENGTH: 'KHR_materials_emissive_strength',
 	EXT_TEXTURE_WEBP: 'EXT_texture_webp',
+	EXT_TEXTURE_AVIF: 'EXT_texture_avif',
 	EXT_MESHOPT_COMPRESSION: 'EXT_meshopt_compression',
 	EXT_MESH_GPU_INSTANCING: 'EXT_mesh_gpu_instancing'
 };
@@ -1314,6 +1315,89 @@ class GLTFTextureWebPExtension {
 
 }
 
+/**
+ * AVIF Texture Extension
+ *
+ * Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/EXT_texture_avif
+ */
+class GLTFTextureAVIFExtension {
+
+	constructor( parser ) {
+
+		this.parser = parser;
+		this.name = EXTENSIONS.EXT_TEXTURE_AVIF;
+		this.isSupported = null;
+
+	}
+
+	loadTexture( textureIndex ) {
+
+		const name = this.name;
+		const parser = this.parser;
+		const json = parser.json;
+
+		const textureDef = json.textures[ textureIndex ];
+
+		if ( ! textureDef.extensions || ! textureDef.extensions[ name ] ) {
+
+			return null;
+
+		}
+
+		const extension = textureDef.extensions[ name ];
+		const source = json.images[ extension.source ];
+
+		let loader = parser.textureLoader;
+		if ( source.uri ) {
+
+			const handler = parser.options.manager.getHandler( source.uri );
+			if ( handler !== null ) loader = handler;
+
+		}
+
+		return this.detectSupport().then( function ( isSupported ) {
+
+			if ( isSupported ) return parser.loadTextureImage( textureIndex, extension.source, loader );
+
+			if ( json.extensionsRequired && json.extensionsRequired.indexOf( name ) >= 0 ) {
+
+				throw new Error( 'THREE.GLTFLoader: AVIF required by asset but unsupported.' );
+
+			}
+
+			// Fall back to PNG or JPEG.
+			return parser.loadTexture( textureIndex );
+
+		} );
+
+	}
+
+	detectSupport() {
+
+		if ( ! this.isSupported ) {
+
+			this.isSupported = new Promise( function ( resolve ) {
+
+				const image = new Image();
+
+				// Lossy test image.
+				image.src = 'data:image/avif;base64,AAAAIGZ0eXBhdmlmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAAAAAAcGljdAAAAAAAAAAAAAAAAGxpYmF2aWYAAAAADnBpdG0AAAAAAAEAAAAeaWxvYwAAAABEAAABAAEAAAABAAABGgAAABcAAAAoaWluZgAAAAAAAQAAABppbmZlAgAAAAABAABhdjAxQ29sb3IAAAAAamlwcnAAAABLaXBjbwAAABRpc3BlAAAAAAAAAAEAAAABAAAAEHBpeGkAAAAAAwgICAAAAAxhdjFDgQAMAAAAABNjb2xybmNseAACAAIABoAAAAAXaXBtYQAAAAAAAAABAAEEAQKDBAAAAB9tZGF0EgAKCBgABogQEDQgMgkQAAAAB8dSLfI=';
+				image.onload = image.onerror = function () {
+
+					resolve( image.height === 1 );
+
+				};
+
+			} );
+
+		}
+
+		return this.isSupported;
+
+	}
+
+}
+
 /**
  * meshopt BufferView Compression Extension
  *