1616
1717#pragma mark WebP includes
1818
19+ // TODO: remove this pushed diagnostic "ignored" when the modular closure of libwebp framework headers is completely fixed
20+ #pragma clang diagnostic push
21+ #pragma clang diagnostic ignored "-Wquoted-include-in-framework-header"
22+
1923#if TARGET_OS_MACCATALYST
2024#import < webp/webp.h>
2125#if TIPX_WEBP_ANIMATION_DECODING_ENABLED
3034#endif
3135#endif
3236
37+ #pragma clang diagnostic pop
38+
39+
3340NS_ASSUME_NONNULL_BEGIN
3441
3542#pragma mark - Declarations
3643
3744static UIImage * __nullable TIPXWebPRenderImage (NSData *dataBuffer,
3845 CGSize sourceDimensions,
3946 CGSize targetDimensions,
40- UIViewContentMode targetContentMode);
47+ UIViewContentMode targetContentMode,
48+ CGRect framingRect,
49+ CGContextRef __nullable canvas);
4150static UIImage * __nullable TIPXWebPConstructImage (CGDataProviderRef dataProvider,
4251 const size_t width,
4352 const size_t height,
@@ -84,20 +93,14 @@ @implementation TIPXWebPCodec
8493- (instancetype )init
8594{
8695 // Shouldn't be called, but will permit in case of type erasure
87- return [self initPreservingDefaultCodecsIfPresent: NO ];
96+ return [self initWithPreferredCodec: nil ];
8897}
8998
90- - (instancetype )initPreservingDefaultCodecsIfPresent : ( BOOL ) preserve
99+ - (instancetype )initWithPreferredCodec : (nullable id <TIPImageCodec>) preferredCodec
91100{
92101 if (self = [super init ]) {
93- if (preserve) {
94- id <TIPImageCodec> webpCodec = [TIPImageCodecCatalogue defaultCodecs ][TIPImageTypeWEBP];
95- _tip_decoder = webpCodec.tip_decoder ?: [[TIPXWebPDecoder alloc ] init ];
96- _tip_encoder = webpCodec.tip_encoder ?: [[TIPXWebPEncoder alloc ] init ];
97- } else {
98- _tip_decoder = [[TIPXWebPDecoder alloc ] init ];
99- _tip_encoder = [[TIPXWebPEncoder alloc ] init ];
100- }
102+ _tip_decoder = preferredCodec.tip_decoder ?: [[TIPXWebPDecoder alloc ] init ];
103+ _tip_encoder = preferredCodec.tip_encoder ?: [[TIPXWebPEncoder alloc ] init ];
101104 }
102105 return self;
103106}
@@ -392,7 +395,9 @@ - (nullable TIPImageContainer *)_renderStaticImage:(TIPImageDecoderRenderMode)re
392395 UIImage *image = TIPXWebPRenderImage (_dataBuffer,
393396 _tip_dimensions,
394397 targetDimensions,
395- targetContentMode);
398+ targetContentMode,
399+ CGRectZero,
400+ NULL );
396401 if (image) {
397402 _cachedImageContainer = [[TIPImageContainer alloc ] initWithImage: image];
398403 [self _cleanup ];
@@ -463,17 +468,57 @@ - (nullable TIPImageContainer *)_renderAnimatedImage:(TIPImageDecoderRenderMode)
463468 // Go through the animation and pull out the frames (stopping after the first frame if `justFirstFrame` is `YES`)
464469 NSTimeInterval totalDuration = 0 ;
465470 const NSUInteger loopCount = (NSUInteger )WebPDemuxGetI (demuxer, WEBP_FF_LOOP_COUNT);
471+ #if DEBUG
472+ const CGSize canvasDimensions = CGSizeMake (WebPDemuxGetI (demuxer, WEBP_FF_CANVAS_WIDTH), WebPDemuxGetI (demuxer, WEBP_FF_CANVAS_HEIGHT));
473+ NSCParameterAssert (canvasDimensions.width == _tip_dimensions.width);
474+ NSCParameterAssert (canvasDimensions.height == _tip_dimensions.height);
475+ #endif
476+ const CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedLast ;
477+ CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB ();
478+ TIPXDeferRelease (colorSpace);
479+ CGContextRef canvas = CGBitmapContextCreate (NULL /* data*/
480+ (size_t )_tip_dimensions.width ,
481+ (size_t )_tip_dimensions.height ,
482+ 8 ,
483+ 4 * (size_t )_tip_dimensions.width ,
484+ colorSpace,
485+ bitmapInfo);
486+ TIPXDeferRelease (canvas);
487+ CGContextClearRect (canvas, (CGRect){ .origin = CGPointZero, .size = _tip_dimensions });
466488 NSMutableArray <UIImage *> *frames = [[NSMutableArray alloc ] initWithCapacity: (NSUInteger )iter->num_frames];
467489 NSMutableArray <NSNumber *> *frameDurations = [[NSMutableArray alloc ] initWithCapacity: (NSUInteger )iter->num_frames];
468490 do {
469491
470492 NSData *fragment = [[NSData alloc ] initWithBytesNoCopy: (void *)iter->fragment.bytes
471493 length: iter->fragment.size
472494 freeWhenDone: NO ];
495+ const CGRect framingRect = CGRectMake (iter->x_offset ,
496+ iter->y_offset ,
497+ iter->width ,
498+ iter->height );
499+ // CGBitmapContext is bottem-left aligned instead of top-left aligned, so adjust the origin for that use case
500+ const CGRect canvasFramingRect = CGRectMake (framingRect.origin .x ,
501+ _tip_dimensions.height - framingRect.size .height - framingRect.origin .y ,
502+ framingRect.size .width ,
503+ framingRect.size .height );
504+
505+ const BOOL isSizedToCanvas = CGSizeEqualToSize (framingRect.size , _tip_dimensions) && CGPointEqualToPoint (framingRect.origin , CGPointZero);
506+
507+ if (iter->blend_method == WEBP_MUX_NO_BLEND) {
508+ // clear the area we are about to draw to
509+ CGContextClearRect (canvas, canvasFramingRect);
510+ }
473511 UIImage *frame = TIPXWebPRenderImage (fragment,
474512 _tip_dimensions,
475- justFirstFrame ? targetDimensions : CGSizeZero,
476- targetContentMode);
513+ (justFirstFrame && isSizedToCanvas) ? targetDimensions : CGSizeZero,
514+ targetContentMode,
515+ framingRect,
516+ canvas);
517+ if (iter->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
518+ // clear the area we just finished drawing to
519+ CGContextClearRect (canvas, canvasFramingRect);
520+ }
521+
477522 if (!frame) {
478523 return nil ;
479524 }
@@ -546,7 +591,9 @@ - (void)_cleanup TIPX_OBJC_DIRECT
546591static UIImage *TIPXWebPRenderImage (NSData *dataBuffer,
547592 CGSize sourceDimensions,
548593 CGSize targetDimensions,
549- UIViewContentMode targetContentMode)
594+ UIViewContentMode targetContentMode,
595+ CGRect framingRect,
596+ CGContextRef __nullable canvas)
550597{
551598 __block WebPDecoderConfig* config = (WebPDecoderConfig*)WebPMalloc (sizeof (WebPDecoderConfig));
552599 tipx_defer (^{
@@ -558,15 +605,32 @@ - (void)_cleanup TIPX_OBJC_DIRECT
558605 return nil ;
559606 }
560607
561- const CGSize scaledDimensions = TIPDimensionsScaledToTargetSizing (sourceDimensions,
562- targetDimensions,
563- targetContentMode);
564- if (!CGSizeEqualToSize (scaledDimensions, sourceDimensions)) {
565- config->options .scaled_width = (int )scaledDimensions.width ;
566- config->options .scaled_height = (int )scaledDimensions.height ;
567- config->options .use_scaling = 1 ;
568- // should we stop fancy upscaling? config.options.no_fancy_upsampling = 1;
608+ BOOL isAligned = canvas != NULL ; // having a canvas indicates an animation, always treat fragment as being "aligned"
609+ if (!isAligned) {
610+ // is aligned if the origin is offset
611+ isAligned = !CGPointEqualToPoint (framingRect.origin , CGPointZero);
612+ if (!isAligned) {
613+ // is aligned if the size is not the canvas size (nor zero size)
614+ isAligned = !CGSizeEqualToSize (framingRect.size , sourceDimensions)
615+ && !CGSizeEqualToSize (framingRect.size , CGSizeZero);
616+ }
569617 }
618+
619+ if (!isAligned) {
620+ const CGSize scaledDimensions = TIPDimensionsScaledToTargetSizing (sourceDimensions,
621+ targetDimensions,
622+ targetContentMode);
623+ if (!CGSizeEqualToSize (scaledDimensions, sourceDimensions)) {
624+ config->options .scaled_width = (int )scaledDimensions.width ;
625+ config->options .scaled_height = (int )scaledDimensions.height ;
626+ config->options .use_scaling = 1 ;
627+ // should we stop fancy upscaling? config.options.no_fancy_upsampling = 1;
628+ }
629+ framingRect.origin = CGPointZero;
630+ framingRect.size = scaledDimensions;
631+ }
632+
633+ // Set the output colorspace as RGB (TODO: there might be a device optimization using BGRA or ABGR...)
570634 config->output .colorspace = MODE_RGBA;
571635
572636 if (VP8_STATUS_OK != WebPDecode (dataBuffer.bytes , dataBuffer.length , config)) {
@@ -593,11 +657,31 @@ - (void)_cleanup TIPX_OBJC_DIRECT
593657 return nil ;
594658 }
595659
596- return TIPXWebPConstructImage (provider,
597- (size_t )configLongLived->output .width ,
598- (size_t )configLongLived->output .height ,
599- componentsPerPixel,
600- bytesPerPixel);
660+ UIImage *image = TIPXWebPConstructImage (provider,
661+ (size_t )configLongLived->output .width ,
662+ (size_t )configLongLived->output .height ,
663+ componentsPerPixel,
664+ bytesPerPixel);
665+ if (image && isAligned) {
666+
667+ if (canvas) {
668+ framingRect.origin .y = sourceDimensions.height - framingRect.size .height - framingRect.origin .y ;
669+ CGContextDrawImage (canvas, framingRect, image.CGImage );
670+ CGImageRef imageRef = CGBitmapContextCreateImage (canvas);
671+ TIPXDeferRelease (imageRef);
672+ image = [UIImage imageWithCGImage: imageRef];
673+ } else {
674+ UIGraphicsBeginImageContextWithOptions (sourceDimensions, !configLongLived->input .has_alpha , 1.0 );
675+ tipx_defer (^{
676+ UIGraphicsEndImageContext ();
677+ });
678+ CGContextClearRect (UIGraphicsGetCurrentContext (), (CGRect){ .origin = CGPointZero, .size = sourceDimensions });
679+ [image drawInRect: framingRect];
680+ image = UIGraphicsGetImageFromCurrentImageContext ();
681+ }
682+
683+ }
684+ return image;
601685}
602686
603687@end
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