hytgbn

어젯밤 UIImage Rotation 을 구글링하다
마땅히 찾지 못해서;;

일단 급하게 만들어봄..

Rotation하면 크기가 커지기 마련인데;;

그냥 UIImageView transform하듯이 하려면

중간에 주석을 제거하면 된다.

/**
 * UIImage + Rotation
 * angle in radian
 * @hytgbn
 */
- (UIImage *)rotateImage:(UIImage *)image angle:(CGFloat)rad{
	
	CGImageRef imageRef = [image CGImage];
	CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
	CGColorSpaceRef colorSpaceInfo = CGColorSpaceCreateDeviceRGB();
	
	if (alphaInfo == kCGImageAlphaNone)
		alphaInfo = kCGImageAlphaNoneSkipLast;
	
// original image size
	CGFloat width, height;
	
	width = [image size].width;
	height = [image size].height;
	
// this kind of a dull stuff, looking for better looking-good code..

	CGFloat newWidthMax = max( 0.f*cos(rad)+0.f*sin(rad) ,
							  max( width*cos(rad)+height*sin(rad) ,
								  max( 0.f*cos(rad)+height*sin(rad) ,
									  width*cos(rad)+0.f*sin(rad) )));
	CGFloat newWidthMin = min( 0.f*cos(rad)+0.f*sin(rad) ,
							  min( width*cos(rad)+height*sin(rad) ,
								  min( 0.f*cos(rad)+height*sin(rad) ,
									  width*cos(rad)+0.f*sin(rad) )));
	CGFloat newHeightMax = max( -0.f*sin(rad)+0.f*cos(rad) ,
							   max( -width*sin(rad)+height*cos(rad) ,
								   max( -0.f*sin(rad)+height*cos(rad) ,
									   -width*sin(rad)+0.f*cos(rad) )));
	CGFloat newHeightMin = min( -0.f*sin(rad)+0.f*cos(rad) ,
							   min( -width*sin(rad)+height*cos(rad) ,
								   min( -0.f*sin(rad)+height*cos(rad) ,
									   -width*sin(rad)+0.f*cos(rad) )));
	
	CGFloat newWidth = newWidthMax - newWidthMin;
	CGFloat newHeight = newHeightMax - newHeightMin;
// and if you want to rotate into same size, uncomment 2 lines
//    newWidth = width;
//    newHeight = height;
	
	DLog(@"original : %f, %f", width, height);
	DLog(@"new : %f, %f", newWidth, newHeight);
	
	CGContextRef bitmap;
	
	bitmap = CGBitmapContextCreate(NULL, (int)newWidth, (int)newHeight, 
								   CGImageGetBitsPerComponent(imageRef),0, colorSpaceInfo, alphaInfo);
	
	CGContextTranslateCTM (bitmap, newWidth/2.f,newHeight/2.f);
	CGContextRotateCTM (bitmap, rad);		
	CGContextTranslateCTM (bitmap, -width/2.f,-height/2.f);
	
	CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
	CGImageRef ref = CGBitmapContextCreateImage(bitmap);
	UIImage *result = [UIImage imageWithCGImage:ref];
	
	CGContextRelease(bitmap);
	CGImageRelease(ref);
	
	return result;
	
}