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Fix the wrong roration when the CGImage's width is not equal to its height

This commit is contained in:
DreamPiggy 2019-04-25 18:14:23 +08:00
parent 9c6c4927fb
commit 628e172047
1 changed files with 21 additions and 17 deletions
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38
SDWebImage/SDImageCoderHelper.m
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@ -239,36 +239,40 @@ static const CGFloat kDestSeemOverlap = 2.0f; // the numbers of pixels to over
size_t width = CGImageGetWidth(cgImage);
size_t height = CGImageGetHeight(cgImage);
if (width == 0 || height == 0) return NULL;
BOOL hasAlpha = [self CGImageContainsAlpha:cgImage];
// iOS prefer BGRA8888 (premultiplied) or BGRX8888 bitmapInfo for screen rendering, which is same as `UIGraphicsBeginImageContext()` or `- [CALayer drawInContext:]`
// Though you can use any supported bitmapInfo (see: https://developer.apple.com/library/content/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_context/dq_context.html#//apple_ref/doc/uid/TP30001066-CH203-BCIBHHBB ) and let Core Graphics reorder it when you call `CGContextDrawImage`
// But since our build-in coders use this bitmapInfo, this can have a little performance benefit
CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Host;
bitmapInfo |= hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst;
CGContextRef context = CGBitmapContextCreate(NULL, width, height, 8, 0, [self colorSpaceGetDeviceRGB], bitmapInfo);
if (!context) {
return NULL;
}
// Apply transform
CGAffineTransform transform = SDCGContextTransformFromOrientation(orientation, CGSizeMake(width, height));
CGRect rect;
size_t newWidth;
size_t newHeight;
switch (orientation) {
case kCGImagePropertyOrientationLeft:
case kCGImagePropertyOrientationLeftMirrored:
case kCGImagePropertyOrientationRight:
case kCGImagePropertyOrientationRightMirrored: {
// These orientation should swap width & height
rect = CGRectMake(0, 0, height, width);
newWidth = height;
newHeight = width;
}
break;
default: {
rect = CGRectMake(0, 0, width, height);
newWidth = width;
newHeight = height;
}
break;
}
BOOL hasAlpha = [self CGImageContainsAlpha:cgImage];
// iOS prefer BGRA8888 (premultiplied) or BGRX8888 bitmapInfo for screen rendering, which is same as `UIGraphicsBeginImageContext()` or `- [CALayer drawInContext:]`
// Though you can use any supported bitmapInfo (see: https://developer.apple.com/library/content/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_context/dq_context.html#//apple_ref/doc/uid/TP30001066-CH203-BCIBHHBB ) and let Core Graphics reorder it when you call `CGContextDrawImage`
// But since our build-in coders use this bitmapInfo, this can have a little performance benefit
CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Host;
bitmapInfo |= hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst;
CGContextRef context = CGBitmapContextCreate(NULL, newWidth, newHeight, 8, 0, [self colorSpaceGetDeviceRGB], bitmapInfo);
if (!context) {
return NULL;
}
// Apply transform
CGAffineTransform transform = SDCGContextTransformFromOrientation(orientation, CGSizeMake(newWidth, newHeight));
CGContextConcatCTM(context, transform);
CGContextDrawImage(context, rect, cgImage);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), cgImage); // The rect is bounding box of CGImage, don't swap width & height
CGImageRef newImageRef = CGBitmapContextCreateImage(context);
CGContextRelease(context);