CTUIImage+Extensions

gistfile1.m

@implementation UIImage (CTUIImageExtensions)

+ (UIImage *)ct_imageWithPDFNamed:(NSString *)name size:(CGSize)size
    {
    CGFloat scale = 1;
    CGColorSpaceRef colorspace = NULL;
    CGContextRef layerContext = NULL;
    void *layerBytes = NULL;
    CGPDFDocumentRef iconDocument = NULL;
    CGImageRef cg_image = NULL;
    UIImage *image = nil;

    if ([UIScreen instancesRespondToSelector:@selector(scale)])
        {
        scale = [[UIScreen mainScreen] scale];
        }

    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        size = CGSizeMake(size.width * scale, size.height * scale);
        }
    else
        {
        scale = 1;
        }

    /* Setup */
    colorspace = CGColorSpaceCreateDeviceRGB();

    CGRect layerRect = CGRectMake(0, 0, size.width, size.height);
    layerBytes = calloc(size.width * size.height, 4);
    if (!layerBytes)
        goto END_RENDER;

    layerContext = CGBitmapContextCreate(
        layerBytes,
        size.width,
        size.height,
        8,
        4 * size.width,
        colorspace,
        kCGImageAlphaPremultipliedLast);
    if (!layerContext)
        goto END_RENDER;

    CFStringRef iconPath = (CFStringRef)[[NSBundle mainBundle] pathForResource:name ofType:@"pdf"];
    if (!iconPath)
        goto END_RENDER;
    CFURLRef iconURL = CFURLCreateWithFileSystemPath(NULL, iconPath, kCFURLPOSIXPathStyle, false);
    iconDocument = CGPDFDocumentCreateWithURL(iconURL);
    CFRelease(iconURL);
    if (!iconDocument)
        goto END_RENDER;

    CGPDFPageRef iconPage = CGPDFDocumentGetPage(iconDocument, 1);


    /* Draw */
    CGRect iconRect = CGPDFPageGetBoxRect(iconPage, kCGPDFCropBox);
    CGAffineTransform iconTransform = CGPDFPageGetDrawingTransform(iconPage, kCGPDFCropBox, iconRect, 0, true);

    CGFloat scaleFactor = MIN(layerRect.size.width/iconRect.size.width, layerRect.size.height/iconRect.size.width);
    iconTransform = CGAffineTransformTranslate(iconTransform, CGRectGetWidth(layerRect)/2., CGRectGetHeight(layerRect)/2.);
    iconTransform = CGAffineTransformScale(iconTransform, scaleFactor, scaleFactor);
    iconTransform = CGAffineTransformTranslate(iconTransform, -CGRectGetMinX(iconRect)-CGRectGetWidth(iconRect)/2., -CGRectGetMinY(iconRect)-CGRectGetHeight(iconRect)/2.);
    CGContextConcatCTM(layerContext, iconTransform);
    CGContextDrawPDFPage(layerContext, iconPage);

    /* Render */
    cg_image = CGBitmapContextCreateImage(layerContext);
    if (!cg_image)
        goto END_RENDER;

    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        image = [UIImage imageWithCGImage:cg_image scale:scale orientation:UIImageOrientationUp];
        }
    else
        {
        image = [UIImage imageWithCGImage:cg_image];
        }


END_RENDER:
    if (cg_image != NULL)
        CGImageRelease(cg_image);
    if (iconDocument != NULL)
        CGPDFDocumentRelease(iconDocument);
    if (layerContext != NULL)
        CGContextRelease(layerContext);
    if (layerBytes != NULL)
        free(layerBytes);
    if (colorspace != NULL)
        CGColorSpaceRelease(colorspace);

    return image;
    }

- (UIImage *)ct_imageWithShadowOffset:(CGSize)offset blur:(CGFloat)blur color:(UIColor *)color
    {
    CGColorSpaceRef colorspace = NULL;
    CGContextRef layerContext = NULL;
    void *layerBytes = NULL;
    CGImageRef cg_image = NULL;
    UIImage *image = nil;

    CGFloat scale = [self respondsToSelector:@selector(scale)] ? [self scale] : 1;
    CGSize size = [self size];
    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        size = CGSizeMake(size.width * scale, size.height * scale);
        offset = CGSizeMake(offset.width * scale, offset.height * scale);
        blur = blur * scale;
        }
    else
        {
        scale = 1;
        }
    blur = MAX(blur, 0);
    offset = CGSizeMake(offset.width, -offset.height);

    /* Setup */
    colorspace = CGColorSpaceCreateDeviceRGB();

    CGRect layerRect = CGRectMake(blur+fabs(offset.width), blur+fabs(offset.height), size.width, size.height);

    size = CGSizeMake(size.width+blur*2+fabsf(offset.width)*2, size.height+blur*2+fabsf(offset.height)*2);
    layerBytes = calloc(size.width * size.height, 4);
    if (!layerBytes)
        goto END_RENDER;

    layerContext = CGBitmapContextCreate(
        layerBytes,
        size.width,
        size.height,
        8,
        4 * size.width,
        colorspace,
        kCGImageAlphaPremultipliedLast);
    if (!layerContext)
        goto END_RENDER;

    /* Draw */
    CGContextSetShadowWithColor(layerContext, offset, blur, [color CGColor]);
    CGContextBeginTransparencyLayer(layerContext, NULL);
    CGContextDrawImage(layerContext, layerRect, [self CGImage]);
    CGContextEndTransparencyLayer(layerContext);

    /* Render */
    cg_image = CGBitmapContextCreateImage(layerContext);
    if (!cg_image)
        goto END_RENDER;

    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        image = [UIImage imageWithCGImage:cg_image scale:scale orientation:UIImageOrientationUp];
        }
    else
        {
        image = [UIImage imageWithCGImage:cg_image];
        }


END_RENDER:
    if (colorspace != NULL)
        CGColorSpaceRelease(colorspace);
    if (layerContext != NULL)
        CGContextRelease(layerContext);
    if (cg_image != NULL)
        CGImageRelease(cg_image);
    if (layerBytes != NULL)
        free(layerBytes);

    return image;
    }

- (UIImage *)ct_imageWithOverlayColor:(UIColor *)color
    {
    CGColorSpaceRef colorspace = NULL;
    CGContextRef layerContext = NULL;
    void *layerBytes = NULL;
    CGImageRef cg_image = NULL;
    UIImage *image = nil;

    CGFloat scale = [self respondsToSelector:@selector(scale)] ? [self scale] : 1;
    CGSize size = [self size];
    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        size = CGSizeMake(size.width * scale, size.height * scale);
        }
    else
        {
        scale = 1;
        }

    /* Setup */
    colorspace = CGColorSpaceCreateDeviceRGB();

    CGRect layerRect = CGRectMake(0, 0, size.width, size.height);
    layerBytes = calloc(size.width * size.height, 4);
    if (!layerBytes)
        goto END_RENDER;

    layerContext = CGBitmapContextCreate(
        layerBytes,
        size.width,
        size.height,
        8,
        4 * size.width,
        colorspace,
        kCGImageAlphaPremultipliedLast);
    if (!layerContext)
        goto END_RENDER;

    /* Draw */
    CGContextDrawImage(layerContext, layerRect, [self CGImage]);
    CGContextSetBlendMode(layerContext, kCGBlendModeSourceIn);
    CGContextSetFillColorWithColor(layerContext, [color CGColor]);
    CGContextFillRect(layerContext, layerRect);

    /* Render */
    cg_image = CGBitmapContextCreateImage(layerContext);
    if (!cg_image)
        goto END_RENDER;

    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        image = [UIImage imageWithCGImage:cg_image scale:scale orientation:UIImageOrientationUp];
        }
    else
        {
        image = [UIImage imageWithCGImage:cg_image];
        }


END_RENDER:
    if (colorspace != NULL)
        CGColorSpaceRelease(colorspace);
    if (layerContext != NULL)
        CGContextRelease(layerContext);
    if (cg_image != NULL)
        CGImageRelease(cg_image);
    if (layerBytes != NULL)
        free(layerBytes);

    return image;
    }

- (UIImage *)ct_imageWithInnerShadowOffset:(CGSize)offset color:(UIColor *)color
    {
    CGColorSpaceRef colorspace = NULL;
    CGContextRef layerContext = NULL;
    void *layerBytes = NULL;
    CGImageRef cg_image = NULL;
    UIImage *image = nil;

    CGFloat scale = [self respondsToSelector:@selector(scale)] ? [self scale] : 1;
    CGSize size = [self size];
    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        size = CGSizeMake(size.width * scale, size.height * scale);
        offset = CGSizeMake(offset.width * scale, offset.height * scale);
        }
    else
        {
        scale = 1;
        }
    offset = CGSizeMake(offset.width, -offset.height);

    /* Setup */
    colorspace = CGColorSpaceCreateDeviceRGB();

    CGRect layerRect = CGRectMake(0, 0, size.width, size.height);
    layerBytes = calloc(size.width * size.height, 4);
    if (!layerBytes)
        goto END_RENDER;

    layerContext = CGBitmapContextCreate(
        layerBytes,
        size.width,
        size.height,
        8,
        4 * size.width,
        colorspace,
        kCGImageAlphaPremultipliedLast);
    if (!layerContext)
        goto END_RENDER;

    /* Draw */
    CGContextDrawImage(layerContext, layerRect, [self CGImage]);

    CGLayerRef shadowLayer = CGLayerCreateWithContext(layerContext, layerRect.size, NULL);
    CGContextRef shadowContext = CGLayerGetContext(shadowLayer);
    CGContextDrawImage(shadowContext, CGRectOffset(layerRect, offset.width, offset.height), [self CGImage]);
    CGContextSetBlendMode(shadowContext, kCGBlendModeSourceOut);
    CGContextSetFillColorWithColor(shadowContext, [color CGColor]);
    CGContextFillRect(shadowContext, layerRect);
    CGContextSetBlendMode(layerContext, kCGBlendModeSourceAtop);
    CGContextDrawLayerInRect(layerContext, layerRect, shadowLayer);
    CGLayerRelease(shadowLayer);

    /* Render */
    cg_image = CGBitmapContextCreateImage(layerContext);
    if (!cg_image)
        goto END_RENDER;

    if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)])
        {
        image = [UIImage imageWithCGImage:cg_image scale:scale orientation:UIImageOrientationUp];
        }
    else
        {
        image = [UIImage imageWithCGImage:cg_image];
        }


END_RENDER:
    if (colorspace != NULL)
        CGColorSpaceRelease(colorspace);
    if (layerContext != NULL)
        CGContextRelease(layerContext);
    if (cg_image != NULL)
        CGImageRelease(cg_image);
    if (layerBytes != NULL)
        free(layerBytes);

    return image;
    }

@end