CGImageRef旋转扭曲图像

Question

具有以下旋转代码：

CGFloat angleInRadians = angle * M_PI/180.0; 
    CGFloat width = CGImageGetWidth(imgRef); 
    CGFloat height = CGImageGetHeight(imgRef); 

    CGRect imgRect = CGRectMake(width, height, width, height); 
    CGAffineTransform transform = CGAffineTransformMakeRotation(angleInRadians); 
    CGRect rotatedRect = CGRectApplyAffineTransform(imgRect, transform); 

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 
    CGContextRef bmContext = CGBitmapContextCreate(NULL, 
                rotatedRect.size.width, 
                rotatedRect.size.height, 
                8, 
                0, 
                colorSpace, 
                (CGBitmapInfo)kCGImageAlphaPremultipliedFirst); 
    CGContextSetAllowsAntialiasing(bmContext, true); 
    CGContextSetShouldAntialias(bmContext, true); 
    CGContextSetInterpolationQuality(bmContext, kCGInterpolationHigh); 
    CGColorSpaceRelease(colorSpace); 
    CGContextTranslateCTM(
          bmContext, 
          +(rotatedRect.size.width/2), 
          +(rotatedRect.size.height/2)); 
    CGContextRotateCTM(bmContext, angleInRadians); 
    CGContextTranslateCTM(
          bmContext, 
          -(rotatedRect.size.width/2), 
          -(rotatedRect.size.height/2)); 
    CGContextDrawImage(bmContext, CGRectMake(0, 0, rotatedRect.size.width, rotatedRect.size.height), imgRef); 

    CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext); 
    return rotatedImage; 

因此，我越来越扭曲的图像。我在这里做错了什么？

Answer 1

. 
. 
. 
CGRect imgRect = CGRectMake(0., 0., width, height); // origin at {0, 0}; not {width, height} 
. 
. 
. 
CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext); 
CGImageRelease(bmContext); // don't need this anymore 
. 
. 
. 

作为评论的，原点在0.0, 0.0不width或height。