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dreampiggydreampiggy
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Add blend mode to UIImage+Transform tint color API
Also works for CIFilter variant
1 parent c8f74d2 commit 0993718

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2 files changed

+162
-10
lines changed

2 files changed

+162
-10
lines changed

‎SDWebImage/Core/UIImage+Transform.h‎

Lines changed: 11 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -98,13 +98,23 @@ typedef NS_OPTIONS(NSUInteger, SDRectCorner) {
9898
#pragma mark - Image Blending
9999

100100
/**
101-
Return a tinted image with the given color. This actually use alpha blending of current image and the tint color.
101+
Return a tinted image with the given color. This actually use `sourceAtop` blend mode.
102102
103103
@param tintColor The tint color.
104104
@return The new image with the tint color.
105105
*/
106106
- (nullable UIImage *)sd_tintedImageWithColor:(nonnull UIColor *)tintColor;
107107

108+
/**
109+
Return a tinted image with the given color and blend mode.
110+
@note The blend mode treat `self` as background image (destination), treat `tintColor` as input image (source). So mostly you need `source` variant blend mode (use `sourceAtop` not `destinationAtop`).
111+
112+
@param tintColor The tint color.
113+
@param blendMode The blend mode.
114+
@return The new image with the tint color.
115+
*/
116+
- (nullable UIImage *)sd_tintedImageWithColor:(nonnull UIColor *)tintColor blendMode:(CGBlendMode)blendMode;
117+
108118
/**
109119
Return the pixel color at specify position. The point is from the top-left to the bottom-right and 0-based. The returned the color is always be RGBA format. The image must be CG-based.
110120
@note The point's x/y will be converted into integer.

‎SDWebImage/Core/UIImage+Transform.m‎

Lines changed: 151 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -536,38 +536,180 @@ - (nullable UIImage *)sd_flippedImageWithHorizontal:(BOOL)horizontal vertical:(B
536536

537537
#pragma mark - Image Blending
538538

539+
static NSString * _Nullable SDGetCIFilterNameFromBlendMode(CGBlendMode blendMode) {
540+
// CGBlendMode: https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_images/dq_images.html#//apple_ref/doc/uid/TP30001066-CH212-CJBIJEFG
541+
// CIFilter: https://developer.apple.com/library/archive/documentation/GraphicsImaging/Reference/CoreImageFilterReference/index.html#//apple_ref/doc/uid/TP30000136-SW71
542+
NSString *filterName;
543+
switch (blendMode) {
544+
case kCGBlendModeMultiply:
545+
filterName = @"CIMultiplyBlendMode";
546+
break;
547+
case kCGBlendModeScreen:
548+
filterName = @"CIScreenBlendMode";
549+
break;
550+
case kCGBlendModeOverlay:
551+
filterName = @"CIOverlayBlendMode";
552+
break;
553+
case kCGBlendModeDarken:
554+
filterName = @"CIDarkenBlendMode";
555+
break;
556+
case kCGBlendModeLighten:
557+
filterName = @"CILightenBlendMode";
558+
break;
559+
case kCGBlendModeColorDodge:
560+
filterName = @"CIColorDodgeBlendMode";
561+
break;
562+
case kCGBlendModeColorBurn:
563+
filterName = @"CIColorBurnBlendMode";
564+
break;
565+
case kCGBlendModeSoftLight:
566+
filterName = @"CISoftLightBlendMode";
567+
break;
568+
case kCGBlendModeHardLight:
569+
filterName = @"CIHardLightBlendMode";
570+
break;
571+
case kCGBlendModeDifference:
572+
filterName = @"CIDifferenceBlendMode";
573+
break;
574+
case kCGBlendModeExclusion:
575+
filterName = @"CIExclusionBlendMode";
576+
break;
577+
case kCGBlendModeHue:
578+
filterName = @"CIHueBlendMode";
579+
break;
580+
case kCGBlendModeSaturation:
581+
filterName = @"CISaturationBlendMode";
582+
break;
583+
case kCGBlendModeColor:
584+
// Color blend mode uses the luminance values of the background with the hue and saturation values of the source image.
585+
filterName = @"CIColorBlendMode";
586+
break;
587+
case kCGBlendModeLuminosity:
588+
filterName = @"CILuminosityBlendMode";
589+
break;
590+
591+
// macOS 10.5+
592+
case kCGBlendModeSourceAtop:
593+
case kCGBlendModeDestinationAtop:
594+
filterName = @"CISourceAtopCompositing";
595+
break;
596+
case kCGBlendModeSourceIn:
597+
case kCGBlendModeDestinationIn:
598+
filterName = @"CISourceInCompositing";
599+
break;
600+
case kCGBlendModeSourceOut:
601+
case kCGBlendModeDestinationOut:
602+
filterName = @"CISourceOutCompositing";
603+
break;
604+
case kCGBlendModeNormal: // SourceOver
605+
case kCGBlendModeDestinationOver:
606+
filterName = @"CISourceOverCompositing";
607+
break;
608+
609+
// need special handling
610+
case kCGBlendModeClear:
611+
// use clear color instead
612+
break;
613+
case kCGBlendModeCopy:
614+
// use input color instead
615+
break;
616+
case kCGBlendModeXOR:
617+
// unsupported
618+
break;
619+
case kCGBlendModePlusDarker:
620+
// chain filters
621+
break;
622+
case kCGBlendModePlusLighter:
623+
// chain filters
624+
break;
625+
}
626+
return filterName;
627+
}
628+
539629
- (nullable UIImage *)sd_tintedImageWithColor:(nonnull UIColor *)tintColor {
630+
return [self sd_tintedImageWithColor:tintColor blendMode:kCGBlendModeSourceAtop];
631+
}
632+
633+
- (nullable UIImage *)sd_tintedImageWithColor:(nonnull UIColor *)tintColor blendMode:(CGBlendMode)blendMode {
540634
BOOL hasTint = CGColorGetAlpha(tintColor.CGColor) > __FLT_EPSILON__;
541635
if (!hasTint) {
542636
return self;
543637
}
544638

639+
// blend mode, see https://en.wikipedia.org/wiki/Alpha_compositing
545640
#if SD_UIKIT || SD_MAC
546641
// CIImage shortcut
547-
if (self.CIImage) {
548-
CIImage *ciImage = self.CIImage;
642+
CIImage *ciImage = self.CIImage;
643+
if (ciImage) {
549644
CIImage *colorImage = [CIImage imageWithColor:[[CIColor alloc] initWithColor:tintColor]];
550645
colorImage = [colorImage imageByCroppingToRect:ciImage.extent];
551-
CIFilter *filter = [CIFilter filterWithName:@"CISourceAtopCompositing"];
552-
[filter setValue:colorImage forKey:kCIInputImageKey];
553-
[filter setValue:ciImage forKey:kCIInputBackgroundImageKey];
554-
ciImage = filter.outputImage;
646+
NSString *filterName = SDGetCIFilterNameFromBlendMode(blendMode);
647+
// Some blend mode is not nativelly supported
648+
if (filterName) {
649+
CIFilter *filter = [CIFilter filterWithName:filterName];
650+
[filter setValue:colorImage forKey:kCIInputImageKey];
651+
[filter setValue:ciImage forKey:kCIInputBackgroundImageKey];
652+
ciImage = filter.outputImage;
653+
} else {
654+
if (blendMode == kCGBlendModeClear) {
655+
// R = 0
656+
CIColor *clearColor;
657+
if (@available(iOS 10.0, macOS 10.12, tvOS 10.0, *)) {
658+
clearColor = CIColor.clearColor;
659+
} else {
660+
clearColor = [[CIColor alloc] initWithColor:UIColor.clearColor];
661+
}
662+
ciImage = [CIImage imageWithColor:clearColor];
663+
} else if (blendMode == kCGBlendModeCopy) {
664+
// R = S
665+
ciImage = colorImage;
666+
} else if (blendMode == kCGBlendModePlusLighter) {
667+
// R = MIN(1, S + D)
668+
// S + D
669+
CIFilter *filter = [CIFilter filterWithName:@"CIAdditionCompositing"];
670+
[filter setValue:colorImage forKey:kCIInputImageKey];
671+
[filter setValue:ciImage forKey:kCIInputBackgroundImageKey];
672+
ciImage = filter.outputImage;
673+
// MIN
674+
ciImage = [ciImage imageByApplyingFilter:@"CIColorClamp" withInputParameters:nil];
675+
} else if (blendMode == kCGBlendModePlusDarker) {
676+
// R = MAX(0, (1 - D) + (1 - S))
677+
// (1 - D)
678+
CIFilter *filter1 = [CIFilter filterWithName:@"CIColorInvert"];
679+
[filter1 setValue:ciImage forKey:kCIInputImageKey];
680+
ciImage = filter1.outputImage;
681+
// (1 - S)
682+
CIFilter *filter2 = [CIFilter filterWithName:@"CIColorInvert"];
683+
[filter2 setValue:colorImage forKey:kCIInputImageKey];
684+
colorImage = filter2.outputImage;
685+
// +
686+
CIFilter *filter = [CIFilter filterWithName:@"CIAdditionCompositing"];
687+
[filter setValue:colorImage forKey:kCIInputImageKey];
688+
[filter setValue:ciImage forKey:kCIInputBackgroundImageKey];
689+
ciImage = filter.outputImage;
690+
// MAX
691+
ciImage = [ciImage imageByApplyingFilter:@"CIColorClamp" withInputParameters:nil];
692+
} else {
693+
SD_LOG("UIImage+Transform error: Unsupported blend mode: %zu", blendMode);
694+
ciImage = nil;
695+
}
696+
}
697+
698+
if (ciImage) {
555699
#if SD_UIKIT
556700
UIImage *image = [UIImage imageWithCIImage:ciImage scale:self.scale orientation:self.imageOrientation];
557701
#else
558702
UIImage *image = [[UIImage alloc] initWithCIImage:ciImage scale:self.scale orientation:kCGImagePropertyOrientationUp];
559703
#endif
560704
return image;
705+
}
561706
}
562707
#endif
563708

564709
CGSize size = self.size;
565710
CGRect rect = { CGPointZero, size };
566711
CGFloat scale = self.scale;
567712

568-
// blend mode, see https://en.wikipedia.org/wiki/Alpha_compositing
569-
CGBlendMode blendMode = kCGBlendModeSourceAtop;
570-
571713
SDGraphicsImageRendererFormat *format = [[SDGraphicsImageRendererFormat alloc] init];
572714
format.scale = scale;
573715
SDGraphicsImageRenderer *renderer = [[SDGraphicsImageRenderer alloc] initWithSize:size format:format];

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