Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Branch: master
Fetching contributors…

Cannot retrieve contributors at this time

80 lines (66 sloc) 3.569 kB
// UIImage+RoundedCorner.m
// Created by Trevor Harmon on 9/20/09.
// Free for personal or commercial use, with or without modification.
// No warranty is expressed or implied.
#import "UIImage+RoundedCorner.h"
#import "UIImage+Alpha.h"
// Private helper methods
@interface UIImage ()
- (void)addRoundedRectToPath:(CGRect)rect context:(CGContextRef)context ovalWidth:(CGFloat)ovalWidth ovalHeight:(CGFloat)ovalHeight;
@end
@implementation UIImage (RoundedCorner)
// Creates a copy of this image with rounded corners
// If borderSize is non-zero, a transparent border of the given size will also be added
// Original author: Björn Sållarp. Used with permission. See: http://blog.sallarp.com/iphone-uiimage-round-corners/
- (UIImage *)roundedCornerImage:(NSInteger)cornerSize borderSize:(NSInteger)borderSize {
// If the image does not have an alpha layer, add one
UIImage *image = [self imageWithAlpha];
// Build a context that's the same dimensions as the new size
CGContextRef context = CGBitmapContextCreate(NULL,
image.size.width,
image.size.height,
CGImageGetBitsPerComponent(image.CGImage),
0,
CGImageGetColorSpace(image.CGImage),
CGImageGetBitmapInfo(image.CGImage));
// Create a clipping path with rounded corners
CGContextBeginPath(context);
[self addRoundedRectToPath:CGRectMake(borderSize, borderSize, image.size.width - borderSize * 2, image.size.height - borderSize * 2)
context:context
ovalWidth:cornerSize
ovalHeight:cornerSize];
CGContextClosePath(context);
CGContextClip(context);
// Draw the image to the context; the clipping path will make anything outside the rounded rect transparent
CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
// Create a CGImage from the context
CGImageRef clippedImage = CGBitmapContextCreateImage(context);
CGContextRelease(context);
// Create a UIImage from the CGImage
UIImage *roundedImage = [UIImage imageWithCGImage:clippedImage];
CGImageRelease(clippedImage);
return roundedImage;
}
#pragma mark -
#pragma mark Private helper methods
// Adds a rectangular path to the given context and rounds its corners by the given extents
// Original author: Björn Sållarp. Used with permission. See: http://blog.sallarp.com/iphone-uiimage-round-corners/
- (void)addRoundedRectToPath:(CGRect)rect context:(CGContextRef)context ovalWidth:(CGFloat)ovalWidth ovalHeight:(CGFloat)ovalHeight {
if (ovalWidth == 0 || ovalHeight == 0) {
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);
CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM(context, ovalWidth, ovalHeight);
CGFloat fw = CGRectGetWidth(rect) / ovalWidth;
CGFloat fh = CGRectGetHeight(rect) / ovalHeight;
CGContextMoveToPoint(context, fw, fh/2);
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1);
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1);
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1);
CGContextClosePath(context);
CGContextRestoreGState(context);
}
@end
Jump to Line
Something went wrong with that request. Please try again.