Updated processImage function to take image type with export params.

This locks the function down to process one specific image and prevents use of texture properties after cache retrieval that would violate the cache scheme.

examples/js/exporters/GLTFExporter.js

@@ -599,14 +599,16 @@ THREE.GLTFExporter.prototype = {
 
 		/**
 		 * Process image
-		 * @param  {Texture} map Texture to process
+		 * @param  {Image} image to process
+		 * @param  {String} mimeType to use for writing out
+		 * @param  {Boolean} flip the image in the Y before writing out
 		 * @return {Integer}     Index of the processed texture in the "images" array
 		 */
-		function processImage( map ) {
+		function processImage( image, mimeType, flipY ) {
 
-			if ( cachedData.images.has( map.image ) ) {
+			if ( cachedData.images.has( image ) ) {
 
-				return cachedData.images.get( map.image );
+				return cachedData.images.get( image );
 
 			}
 
@@ -616,19 +618,18 @@ THREE.GLTFExporter.prototype = {
 
 			}
 
-			var mimeType = map.format === THREE.RGBAFormat ? 'image/png' : 'image/jpeg';
 			var gltfImage = { mimeType: mimeType };
 
 			if ( options.embedImages ) {
 
 				var canvas = cachedCanvas = cachedCanvas || document.createElement( 'canvas' );
 
-				canvas.width = map.image.width;
-				canvas.height = map.image.height;
+				canvas.width = image.width;
+				canvas.height = image.height;
 
-				if ( options.forcePowerOfTwoTextures && ! isPowerOfTwo( map.image ) ) {
+				if ( options.forcePowerOfTwoTextures && ! isPowerOfTwo( image ) ) {
 
-					console.warn( 'GLTFExporter: Resized non-power-of-two image.', map.image );
+					console.warn( 'GLTFExporter: Resized non-power-of-two image.', image );
 
 					canvas.width = THREE.Math.floorPowerOfTwo( canvas.width );
 					canvas.height = THREE.Math.floorPowerOfTwo( canvas.height );
@@ -637,14 +638,14 @@ THREE.GLTFExporter.prototype = {
 
 				var ctx = canvas.getContext( '2d' );
 
-				if ( map.flipY === true ) {
+				if ( flipY === true ) {
 
 					ctx.translate( 0, canvas.height );
 					ctx.scale( 1, - 1 );
 
 				}
 
-				ctx.drawImage( map.image, 0, 0, canvas.width, canvas.height );
+				ctx.drawImage( image, 0, 0, canvas.width, canvas.height );
 
 				if ( options.binary === true ) {
 
@@ -672,16 +673,17 @@ THREE.GLTFExporter.prototype = {
 
 			} else {
 
-				gltfImage.uri = map.image.src;
+				gltfImage.uri = image.src;
 
 			}
 
 			outputJSON.images.push( gltfImage );
 
 			var index = outputJSON.images.length - 1;
-			cachedData.images.set( map.image, index );
+			cachedData.images.set( image, index );
 
 			return index;
+
 		}
 
 		/**
@@ -731,10 +733,11 @@ THREE.GLTFExporter.prototype = {
 
 			}
 
+			var mimeType = map.format === THREE.RGBAFormat ? 'image/png' : 'image/jpeg';
 			var gltfTexture = {
 
 				sampler: processSampler( map ),
-				source: processImage( map )
+				source: processImage( map.image, mimeType, map.flipY  )
 
 			};