// Create the CIContext to draw into
CIContext* ciContext = [self CIContextWithInfo:renderInfo];
// Create a CIImage from the input image's OpenGL texture
CGSize texSize = CGSizeMake ([inputImage width], [inputImage height]);
CIImage* inputCIImage = [CIImage imageWithTexture:[inTex textureId]
size:texSize
flipped:NO
colorSpace:CGColorSpaceCreateDeviceRGB()];
// Apply the filter to the input image
[_hueAdjust setDefaults];
[_hueAdjust setValue:inputCIImage forKey:@"inputImage"];
[_hueAdjust setValue:[NSNumber numberWithFloat:angle] forKey:@"inputAngle"];
// Create the output image
CIImage* outputCIImage = [_hueAdjust valueForKey:@"outputImage"];
// Draw the output image
CGRect outRect = CGRectMake(left, bottom, right - left, top - bottom);
CGRect inRect = CGRectMake(tLeft, tBottom, tRight - tLeft, tTop - tBottom);
[ciContext drawImage:outputCIImage
inRect:outRect
fromRect:inRect];