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- //
- // UIImage-Extensions.m
- //
- // Created by Hardy Macia on 7/1/09.
- // Copyright 2009 Catamount Software. All rights reserved.
- //
- #import "UIImage-Extensions.h"
- CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
- CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};
- @implementation UIImage (CS_Extensions)
- -(UIImage *)imageAtRect:(CGRect)rect
- {
- CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect);
- UIImage* subImage = [UIImage imageWithCGImage: imageRef];
- CGImageRelease(imageRef);
- return subImage;
- }
- - (UIImage *)imageByScalingProportionallyToMinimumSize:(CGSize)targetSize {
- UIImage *sourceImage = self;
- UIImage *newImage = nil;
- CGSize imageSize = sourceImage.size;
- CGFloat width = imageSize.width;
- CGFloat height = imageSize.height;
- CGFloat targetWidth = targetSize.width;
- CGFloat targetHeight = targetSize.height;
- CGFloat scaleFactor = 0.0;
- CGFloat scaledWidth = targetWidth;
- CGFloat scaledHeight = targetHeight;
- CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
- if (CGSizeEqualToSize(imageSize, targetSize) == NO) {
- CGFloat widthFactor = targetWidth / width;
- CGFloat heightFactor = targetHeight / height;
- if (widthFactor > heightFactor)
- scaleFactor = widthFactor;
- else
- scaleFactor = heightFactor;
- scaledWidth = width * scaleFactor;
- scaledHeight = height * scaleFactor;
- // center the image
- if (widthFactor > heightFactor) {
- thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
- } else if (widthFactor < heightFactor) {
- thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
- }
- }
- // this is actually the interesting part:
- UIGraphicsBeginImageContext(targetSize);
- CGRect thumbnailRect = CGRectZero;
- thumbnailRect.origin = thumbnailPoint;
- thumbnailRect.size.width = scaledWidth;
- thumbnailRect.size.height = scaledHeight;
- [sourceImage drawInRect:thumbnailRect];
- newImage = UIGraphicsGetImageFromCurrentImageContext();
- UIGraphicsEndImageContext();
- if(newImage == nil) NSLog(@"could not scale image");
- return newImage ;
- }
- - (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize {
- UIImage *sourceImage = self;
- UIImage *newImage = nil;
- CGSize imageSize = sourceImage.size;
- CGFloat width = imageSize.width;
- CGFloat height = imageSize.height;
- CGFloat targetWidth = targetSize.width;
- CGFloat targetHeight = targetSize.height;
- CGFloat scaleFactor = 0.0;
- CGFloat scaledWidth = targetWidth;
- CGFloat scaledHeight = targetHeight;
- CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
- if (CGSizeEqualToSize(imageSize, targetSize) == NO) {
- CGFloat widthFactor = targetWidth / width;
- CGFloat heightFactor = targetHeight / height;
- if (widthFactor < heightFactor)
- scaleFactor = widthFactor;
- else
- scaleFactor = heightFactor;
- scaledWidth = width * scaleFactor;
- scaledHeight = height * scaleFactor;
- // center the image
- if (widthFactor < heightFactor) {
- thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
- } else if (widthFactor > heightFactor) {
- thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
- }
- }
- // this is actually the interesting part:
- UIGraphicsBeginImageContext(targetSize);
- CGRect thumbnailRect = CGRectZero;
- thumbnailRect.origin = thumbnailPoint;
- thumbnailRect.size.width = scaledWidth;
- thumbnailRect.size.height = scaledHeight;
- [sourceImage drawInRect:thumbnailRect];
- newImage = UIGraphicsGetImageFromCurrentImageContext();
- UIGraphicsEndImageContext();
- if(newImage == nil) NSLog(@"could not scale image");
- return newImage ;
- }
- - (UIImage *)imageByScalingToSize:(CGSize)targetSize {
- UIImage *sourceImage = self;
- UIImage *newImage = nil;
- // CGSize imageSize = sourceImage.size;
- // CGFloat width = imageSize.width;
- // CGFloat height = imageSize.height;
- CGFloat targetWidth = targetSize.width;
- CGFloat targetHeight = targetSize.height;
- // CGFloat scaleFactor = 0.0;
- CGFloat scaledWidth = targetWidth;
- CGFloat scaledHeight = targetHeight;
- CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
- // this is actually the interesting part:
- UIGraphicsBeginImageContext(targetSize);
- CGRect thumbnailRect = CGRectZero;
- thumbnailRect.origin = thumbnailPoint;
- thumbnailRect.size.width = scaledWidth;
- thumbnailRect.size.height = scaledHeight;
- [sourceImage drawInRect:thumbnailRect];
- newImage = UIGraphicsGetImageFromCurrentImageContext();
- UIGraphicsEndImageContext();
- if(newImage == nil) NSLog(@"could not scale image");
- return newImage ;
- }
- - (UIImage *)imageRotatedByRadians:(CGFloat)radians
- {
- return [self imageRotatedByDegrees:RadiansToDegrees(radians)];
- }
- - (UIImage *)imageRotatedByDegrees:(CGFloat)degrees
- {
- // calculate the size of the rotated view's containing box for our drawing space
- UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
- CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
- rotatedViewBox.transform = t;
- CGSize rotatedSize = rotatedViewBox.frame.size;
- [rotatedViewBox release];
- // Create the bitmap context
- UIGraphicsBeginImageContext(rotatedSize);
- CGContextRef bitmap = UIGraphicsGetCurrentContext();
- // Move the origin to the middle of the image so we will rotate and scale around the center.
- CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
- // // Rotate the image context
- CGContextRotateCTM(bitmap, DegreesToRadians(degrees));
- // Now, draw the rotated/scaled image into the context
- CGContextScaleCTM(bitmap, 1.0, -1.0);
- CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
- UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
- UIGraphicsEndImageContext();
- return newImage;
- }
- @end;
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