#import "UIImageExtra.h"

@implementation UIImage (extra)

-(UIImage *)scaleToSize:(CGSize) size {

    DLog(@"warning - this is a very expensive operation, you should avoid using it");

    // Create a bitmap graphics context; this will also set it as the current context

    UIGraphicsBeginImageContext(size);

    // Draw the scaled image in the current context

    [self drawInRect:CGRectMake(0, 0, size.width, size.height)];

    // Create a new image from current context

    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();

    // Pop the current context from the stack

    UIGraphicsEndImageContext();

    // Return our new scaled image (autoreleased)

    return scaledImage;

}

-(UIImage *)mergeWith:(UIImage *)secondImage atPoint:(CGPoint) secondImagePoint {

    // create a contex of size of the background image

    return [self mergeWith:secondImage atPoint:secondImagePoint atSize:self.size];

}

-(UIImage *)mergeWith:(UIImage *)secondImage atPoint:(CGPoint) secondImagePoint atSize:(CGSize) resultingSize {

    if (secondImage == nil) {

        DLog(@"Warning, secondImage == nil");

        return self;

    }

    // Create a bitmap graphics context; this will also set it as the current context

    UIGraphicsBeginImageContext(resultingSize);

    // draw the background image in the current context

    [self drawAtPoint:CGPointMake(0,0)];

    // draw the image on top of the first image (because the context is the same)

    [secondImage drawAtPoint:secondImagePoint];

    // create an image from the current contex (not thread safe)

    UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();

    // free drawing contex

    UIGraphicsEndImageContext();

    // return the resulting autoreleased image

    return resultImage;

}

-(id) initWithContentsOfFile:(NSString *)path andCutAt:(CGRect) rect {

    // load image from path

    UIImage *image = [[UIImage alloc] initWithContentsOfFile: path];

    if (nil != image) {

        // get its CGImage representation with a give size

        CGImageRef cgImage = CGImageCreateWithImageInRect([image CGImage], rect);

        // clean memory

        [image release];

        // create a UIImage from the CGImage (memory must be allocated already)

        UIImage *sprite = [self initWithCGImage:cgImage];

        // clean memory

        CGImageRelease(cgImage);

        // return resulting image

        return sprite;

    } else {

        DLog(@"error - image == nil");

        return nil;

    }

}

-(UIImage *)cutAt:(CGRect) rect {

    CGImageRef cgImage = CGImageCreateWithImageInRect([self CGImage], rect);

    UIImage *res = [UIImage imageWithCGImage:cgImage];

    CGImageRelease(cgImage);

    return res;

}

-(UIImage *)convertToGrayScale {

    // Create image rectangle with current image width/height

    CGRect imageRect = CGRectMake(0, 0, self.size.width, self.size.height);

    // Grayscale color space

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();

    // Create bitmap content with current image size and grayscale colorspace

    CGContextRef context = CGBitmapContextCreate(nil, self.size.width, self.size.height, 8, 0, colorSpace, kCGImageAlphaNone);

    // Draw image into current context, with specified rectangle

    // using previously defined context (with grayscale colorspace)

    CGContextDrawImage(context, imageRect, [self CGImage]);

    // Create bitmap image info from pixel data in current context

    CGImageRef imageRef = CGBitmapContextCreateImage(context);

    // Create a new UIImage object

    UIImage *newImage = [UIImage imageWithCGImage:imageRef];

    // Release colorspace, context and bitmap information

    CGColorSpaceRelease(colorSpace);

    CGContextRelease(context);

    CFRelease(imageRef);

    // Return the new grayscale image

    return newImage;

}

// by http://iphonedevelopertips.com/cocoa/how-to-mask-an-image.html turned into a category by koda

-(UIImage*) maskImageWith:(UIImage *)maskImage {

    // prepare the reference image

    CGImageRef maskRef = [maskImage CGImage];

    // create the mask using parameters of the mask reference

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),

                                        CGImageGetHeight(maskRef),

                                        CGImageGetBitsPerComponent(maskRef),

                                        CGImageGetBitsPerPixel(maskRef),

                                        CGImageGetBytesPerRow(maskRef),

                                        CGImageGetDataProvider(maskRef), NULL, false);

    // create an image in the current context

    CGImageRef masked = CGImageCreateWithMask([self CGImage], mask);

    CGImageRelease(mask);

    UIImage* retImage = [UIImage imageWithCGImage:masked];

    CGImageRelease(masked);

    return retImage;

}

// by http://blog.sallarp.com/iphone-uiimage-round-corners/ turned into a category by koda

void addRoundedRectToPath(CGContextRef context, CGRect rect, CGFloat ovalWidth, CGFloat ovalHeight) {

    CGFloat 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 *)makeRoundCornersOfSize:(CGSize) sizewh {

    CGFloat cornerWidth = sizewh.width;

    CGFloat cornerHeight = sizewh.height;

    CGFloat w = self.size.width;

    CGFloat h = self.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, cornerWidth, cornerHeight);

    CGContextClosePath(context);

    CGContextClip(context);

    CGContextDrawImage(context, CGRectMake(0, 0, w, h), [self CGImage]);

    CGImageRef imageMasked = CGBitmapContextCreateImage(context);

    CGContextRelease(context);

    CGColorSpaceRelease(colorSpace);

    UIImage *newImage = [UIImage imageWithCGImage:imageMasked];

    CGImageRelease(imageMasked);

    return newImage;

}

@end