Implemented parsing of data URLs for images

warrenm · Apr 20, 2022 · 5f75e5d · 5f75e5d
1 parent 589ef13
commit 5f75e5d
Show file tree

Hide file tree

Showing 2 changed files with 32 additions and 4 deletions.
diff --git a/GLTFKit2/GLTFKit2/GLTFAsset.m b/GLTFKit2/GLTFKit2/GLTFAsset.m
@@ -69,6 +69,25 @@ int GLTFComponentCountForDimension(GLTFValueDimension dim) {
     return 0;
 }
 
+NSData *GLTFCreateImageDataFromDataURI(NSString *uriData) {
+    NSString *prefix = @"data:";
+    if ([uriData hasPrefix:prefix]) {
+        NSInteger prefixEnd = prefix.length;
+        NSInteger firstComma = [uriData rangeOfString:@","].location;
+        if (firstComma != NSNotFound) {
+            NSString *mediaTypeAndTokenString = [uriData substringWithRange:NSMakeRange(prefixEnd, firstComma - prefixEnd)];
+            NSArray *mediaTypeAndToken = [mediaTypeAndTokenString componentsSeparatedByString:@";"];
+            if (mediaTypeAndToken.count > 0) {
+                NSString *encodedImageData = [uriData substringFromIndex:firstComma + 1];
+                NSData *imageData = [[NSData alloc] initWithBase64EncodedString:encodedImageData
+                                                                        options:NSDataBase64DecodingIgnoreUnknownCharacters];
+                return imageData;
+            }
+        }
+    }
+    return nil;
+}
+
 @implementation GLTFObject
 
 - (instancetype)init {
@@ -377,7 +396,12 @@ - (CGImageRef)newCGImage {
         imageSource = CGImageSourceCreateWithData(sourceData, NULL);
         CFRelease(sourceData);
     } else if (self.uri) {
-        imageSource = CGImageSourceCreateWithURL((__bridge CFURLRef)_uri, NULL);
+        if ([self.uri.scheme isEqualTo:@"data"]) {
+            NSData *imageData = GLTFCreateImageDataFromDataURI(self.uri.absoluteString);
+            imageSource = CGImageSourceCreateWithData((__bridge CFDataRef)imageData, NULL);
+        } else {
+            imageSource = CGImageSourceCreateWithURL((__bridge CFURLRef)_uri, NULL);
+        }
     }
     if (imageSource) {
         CGImageRef image = CGImageSourceCreateImageAtIndex(imageSource, 0, NULL);

diff --git a/GLTFKit2/GLTFKit2/impl/GLTFAssetReader.m b/GLTFKit2/GLTFKit2/impl/GLTFAssetReader.m
@@ -410,9 +410,13 @@ - (NSArray *)convertImages
             image = [[GLTFImage alloc] initWithBufferView:bufferView mimeType:mime];
         } else {
             assert(img->uri);
-            NSURL *baseURI = [self.asset.url URLByDeletingLastPathComponent];
-            NSURL *imageURI = [baseURI URLByAppendingPathComponent:[NSString stringWithUTF8String:img->uri]];
-            image = [[GLTFImage alloc] initWithURI:imageURI];
+            if (strncmp(img->uri, "data:", 5) == 0) {
+                image = [[GLTFImage alloc] initWithURI:[NSURL URLWithString:[NSString stringWithUTF8String:img->uri]]];
+            } else {
+                NSURL *baseURI = [self.asset.url URLByDeletingLastPathComponent];
+                NSURL *imageURI = [baseURI URLByAppendingPathComponent:[NSString stringWithUTF8String:img->uri]];
+                image = [[GLTFImage alloc] initWithURI:imageURI];
+            }
         }
         image.name = img->name ? [NSString stringWithUTF8String:img->name]
                                : [self.nameGenerator nextUniqueNameWithPrefix:@"Image"];