// 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

void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth, float ovalHeight);
{
	float fw, fh;
	if (ovalWidth == 0 || ovalHeight == 0) {
		CGContextAddRect(context, rect);
		return;
	}
	CGContextSaveGState(context);
	CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect));
	CGContextScaleCTM (context, ovalWidth, ovalHeight);
	fw = CGRectGetWidth (rect) / ovalWidth;
	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);
}

- (UIImage *)roundCornersOfImage:(UIImage *)source;
{
	int w = source.size.width;
	int h = source.size.height;

	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
	CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

	CGContextBeginPath(context);
	CGRect rect = CGRectMake(0, 0, w, h);
	addRoundedRectToPath(context, rect, 5, 5);
	CGContextClosePath(context);
	CGContextClip(context);

	CGContextDrawImage(context, CGRectMake(0, 0, w, h), source.CGImage);

	CGImageRef imageMasked = CGBitmapContextCreateImage(context);
	CGContextRelease(context);
	CGColorSpaceRelease(colorSpace);

	return [UIImage imageWithCGImage:imageMasked];    
}