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iOS Dev: UIImage Orientaion Code

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// method for swipe
static CGRect swapWidthAndHeight(CGRect rect)
{
CGFloat swap = rect.size.width;
rect.size.width = rect.size.height;
rect.size.height = swap;
return rect;
}
#pragma mark - rotateImage captured
-(UIImage*)rotateImageOrien:(UIImageOrientation)orient andImage:(UIImage *)img
{
CGRect bnds = CGRectZero;
UIImage* copy = nil;
CGContextRef ctxt = nil;
CGImageRef imag = img.CGImage;
CGRect rect = CGRectZero;
CGAffineTransform tran = CGAffineTransformIdentity;
rect.size.width = CGImageGetWidth(imag);
rect.size.height = CGImageGetHeight(imag);
bnds = rect;
switch (orient)
{
case UIImageOrientationUp:
// would get you an exact copy of the original
//assert(false);
return nil;
case UIImageOrientationUpMirrored:
tran = CGAffineTransformMakeTranslation(rect.size.width, 0.0);
tran = CGAffineTransformScale(tran, -1.0, 1.0);
break;
case UIImageOrientationDown:
tran = CGAffineTransformMakeTranslation(rect.size.width,
rect.size.height);
tran = CGAffineTransformRotate(tran, M_PI);
break;
case UIImageOrientationDownMirrored:
tran = CGAffineTransformMakeTranslation(0.0, rect.size.height);
tran = CGAffineTransformScale(tran, 1.0, -1.0);
break;
case UIImageOrientationLeft:
bnds = swapWidthAndHeight(bnds);
tran = CGAffineTransformMakeTranslation(0.0, rect.size.width);
tran = CGAffineTransformRotate(tran, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeftMirrored:
bnds = swapWidthAndHeight(bnds);
tran = CGAffineTransformMakeTranslation(rect.size.height,
rect.size.width);
tran = CGAffineTransformScale(tran, -1.0, 1.0);
tran = CGAffineTransformRotate(tran, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRight:
bnds = swapWidthAndHeight(bnds);
tran = CGAffineTransformMakeTranslation(rect.size.height, 0.0);
tran = CGAffineTransformRotate(tran, M_PI / 2.0);
break;
case UIImageOrientationRightMirrored:
bnds = swapWidthAndHeight(bnds);
tran = CGAffineTransformMakeScale(-1.0, 1.0);
tran = CGAffineTransformRotate(tran, M_PI / 2.0);
break;
default:
// orientation value supplied is invalid
assert(false);
return nil;
}
UIGraphicsBeginImageContext(bnds.size);
ctxt = UIGraphicsGetCurrentContext();
switch (orient)
{
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
CGContextScaleCTM(ctxt, -1.0, 1.0);
CGContextTranslateCTM(ctxt, -rect.size.height, 0.0);
break;
default:
CGContextScaleCTM(ctxt, 1.0, -1.0);
CGContextTranslateCTM(ctxt, 0.0, -rect.size.height);
break;
}
CGContextConcatCTM(ctxt, tran);
CGContextDrawImage(UIGraphicsGetCurrentContext(), rect, imag);
copy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return copy;
}
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