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Use UIGraphicsImageRenderer in GTMUIImage+Resize. (#541) #572

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Merged
thomasvl merged 1 commit into from
Nov 6, 2025
Merged

Use UIGraphicsImageRenderer in GTMUIImage+Resize. (#541) #572

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61 changes: 33 additions & 28 deletions iPhone/GTMUIImage+Resize.m
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Original file line number Diff line number Diff line change
Expand Up @@ -87,10 +87,14 @@ - (UIImage *)gtm_imageByResizingToSize:(CGSize)targetSize

// Resize photo. Use UIImage drawing methods because they respect
// UIImageOrientation as opposed to CGContextDrawImage().
UIGraphicsBeginImageContext(targetSize);
[self drawInRect:projectTo];
UIImage* resizedPhoto = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsImageRendererFormat *rendererFormat = [[UIGraphicsImageRendererFormat alloc] init];
rendererFormat.scale = self.scale;
UIGraphicsImageRenderer *renderer = [[UIGraphicsImageRenderer alloc] initWithSize:targetSize
format:rendererFormat];
UIImage *resizedPhoto =
[renderer imageWithActions:^(UIGraphicsImageRendererContext *_Nonnull rendererContext) {
[self drawInRect:projectTo];
}];
return resizedPhoto;
}

Expand Down Expand Up @@ -156,30 +160,31 @@ - (UIImage *)gtm_imageByRotating:(UIImageOrientation)orientation {
return nil;
}

UIGraphicsBeginImageContextWithOptions(bounds.size, NO, self.scale);
CGContextRef context = UIGraphicsGetCurrentContext();

switch (orientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
CGContextScaleCTM(context, -1.0, 1.0);
CGContextTranslateCTM(context, -rect.size.height, 0.0);
break;

default:
CGContextScaleCTM(context, 1.0, -1.0);
CGContextTranslateCTM(context, 0.0, -rect.size.height);
break;
}

CGContextConcatCTM(context, transform);
CGContextDrawImage(context, rect, [self CGImage]);

UIImage *rotatedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIGraphicsImageRendererFormat *rendererFormat = [[UIGraphicsImageRendererFormat alloc] init];
rendererFormat.scale = self.scale;
UIGraphicsImageRenderer *renderer = [[UIGraphicsImageRenderer alloc] initWithSize:bounds.size
format:rendererFormat];
UIImage *rotatedImage =
[renderer imageWithActions:^(UIGraphicsImageRendererContext *_Nonnull rendererContext) {
CGContextRef context = rendererContext.CGContext;
switch (orientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
CGContextScaleCTM(context, -1.0, 1.0);
CGContextTranslateCTM(context, -rect.size.height, 0.0);
break;

default:
CGContextScaleCTM(context, 1.0, -1.0);
CGContextTranslateCTM(context, 0.0, -rect.size.height);
break;
}

CGContextConcatCTM(context, transform);
CGContextDrawImage(context, rect, [self CGImage]);
}];
return rotatedImage;
}

Expand Down
118 changes: 118 additions & 0 deletions iPhone/GTMUIImage+ResizeTest.m
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Original file line number Diff line number Diff line change
Expand Up @@ -68,13 +68,20 @@ - (void)testImageByResizingWithoutPreservingAspectRatio {

// Resize with same aspect ratio.
CGSize size50x50 = CGSizeMake(50, 50);
CGFloat expectedScale = [originalImage scale];
actual = [originalImage gtm_imageByResizingToSize:size50x50
preserveAspectRatio:NO
trimToFit:NO];
XCTAssertTrue(CGSizeEqualToSize([actual size], size50x50),
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size50x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Resize with different aspect ratio
CGSize size60x40 = CGSizeMake(60, 40);
Expand All @@ -85,6 +92,12 @@ - (void)testImageByResizingWithoutPreservingAspectRatio {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size60x40),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

CGSize size40x60 = CGSizeMake(40, 60);
actual = [originalImage gtm_imageByResizingToSize:size40x60
Expand All @@ -94,6 +107,12 @@ - (void)testImageByResizingWithoutPreservingAspectRatio {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size40x60),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);
}

- (void)testImageByResizingPreservingAspectRatioWithoutClip {
Expand All @@ -104,13 +123,20 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
// Landscape resize to 50x50, but clipped to 50x25.
CGSize size50x50 = CGSizeMake(50, 50);
CGSize expected50x25 = CGSizeMake(50, 25);
CGFloat expectedScale = [landscapeImage scale];
actual = [landscapeImage gtm_imageByResizingToSize:size50x50
preserveAspectRatio:YES
trimToFit:NO];
XCTAssertTrue(CGSizeEqualToSize([actual size], expected50x25),
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected50x25),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Landscape resize to 60x40, but clipped to 60x30.
CGSize size60x40 = CGSizeMake(60, 40);
Expand All @@ -123,6 +149,12 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected60x30),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Landscape resize to 40x60, but clipped to 40x20.
CGSize expected40x20 = CGSizeMake(40, 20);
Expand All @@ -134,6 +166,12 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected40x20),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait Image
UIImage *portraitImage = [self testImageNamed:@"GTMUIImage+Resize_50x100"];
Expand All @@ -147,6 +185,12 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected25x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait resize to 60x40, but clipped to 20x40.
CGSize expected20x40 = CGSizeMake(20, 40);
Expand All @@ -157,6 +201,12 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected20x40),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait resize to 40x60, but clipped to 30x60.
CGSize expected30x60 = CGSizeMake(30, 60);
Expand All @@ -167,6 +217,12 @@ - (void)testImageByResizingPreservingAspectRatioWithoutClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(expected30x60),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);
}

- (void)testImageByResizingPreservingAspectRatioWithClip {
Expand All @@ -176,13 +232,20 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {

// Landscape resize to 50x50
CGSize size50x50 = CGSizeMake(50, 50);
CGFloat expectedScale = [landscapeImage scale];
actual = [landscapeImage gtm_imageByResizingToSize:size50x50
preserveAspectRatio:YES
trimToFit:YES];
XCTAssertTrue(CGSizeEqualToSize([actual size], size50x50),
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size50x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Landscape resize to 60x40
CGSize size60x40 = CGSizeMake(60, 40);
Expand All @@ -193,6 +256,12 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size60x40),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Landscape resize to 40x60
CGSize size40x60 = CGSizeMake(40, 60);
Expand All @@ -203,6 +272,12 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size40x60),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait Image.
UIImage *portraitImage = [self testImageNamed:@"GTMUIImage+Resize_50x100"];
Expand All @@ -215,6 +290,12 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size50x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait resize to 60x40
actual = [portraitImage gtm_imageByResizingToSize:size60x40
Expand All @@ -224,6 +305,12 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size60x40),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Portrait resize to 40x60.
actual = [portraitImage gtm_imageByResizingToSize:size40x60
Expand All @@ -233,6 +320,12 @@ - (void)testImageByResizingPreservingAspectRatioWithClip {
@"Resized image should equal size: %@ actual: %@",
NSStringFromCGSize(size40x60),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);
}

- (void)testImageByRotating {
Expand All @@ -241,34 +334,59 @@ - (void)testImageByRotating {

CGSize size50x100 = CGSizeMake(50, 100);
CGSize size100x50 = CGSizeMake(100, 50);
CGFloat expectedScale = [landscapeImage scale];

// Rotate 90 degrees.
UIImage *actual = [landscapeImage gtm_imageByRotating:UIImageOrientationRight];
XCTAssertNotNil(actual);
XCTAssertTrue(CGSizeEqualToSize([actual size], size50x100),
@"Resized image should equal size: %@ actual: %@", NSStringFromCGSize(size50x100),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Rotate 180 degrees.
actual = [landscapeImage gtm_imageByRotating:UIImageOrientationDown];
XCTAssertNotNil(actual);
XCTAssertTrue(CGSizeEqualToSize([actual size], size100x50),
@"Resized image should equal size: %@ actual: %@", NSStringFromCGSize(size100x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Rotate 270 degrees.
actual = [landscapeImage gtm_imageByRotating:UIImageOrientationLeft];
XCTAssertNotNil(actual);
XCTAssertTrue(CGSizeEqualToSize([actual size], size50x100),
@"Resized image should equal size: %@ actual: %@", NSStringFromCGSize(size50x100),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);

// Rotate 360 degrees.
actual = [landscapeImage gtm_imageByRotating:UIImageOrientationUp];
XCTAssertNotNil(actual);
XCTAssertTrue(CGSizeEqualToSize([actual size], size100x50),
@"Resized image should equal size: %@ actual: %@", NSStringFromCGSize(size100x50),
NSStringFromCGSize([actual size]));
XCTAssertEqualWithAccuracy([actual scale],
expectedScale,
0.000000001,
@"Resized image should have scale: %f actual: %f",
expectedScale,
[actual scale]);
}

@end