UIImage from MASKED CALayer - uiimage

Question

I'm in need of an UIImage from a Masked CALayer. This is the function I use:
- (UIImage *)imageFromLayer:(CALayer *)layer
{
UIGraphicsBeginImageContext([layer frame].size);
[layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return outputImage;
}
The problem is that the mask isn't maintained.
This is the completed code:
CAShapeLayer * layerRight= [CAShapeLayer layer];
layerRight.path = elasticoRight;
im2.layer.mask = layerRight;
CAShapeLayer * layerLeft= [CAShapeLayer layer];
layerLeft.path = elasticoLeft;
im3.layer.mask = layerLeft;
[viewImage.layer addSublayer:im2.layer];
[viewImage.layer addSublayer:im3.layer];
UIImage *image_result = [self imageFromLayer:viewImage.layer];
If I visualize the viewImage, the result is correct, but if I try to obtain the image relative to the layer, the masks are lost.

Answer 1

I've solved.
Now i obtaining the image mask and use CGContextClipToMask.
CGRect rect = CGRectMake(0, 0, 1024, 768);
UIGraphicsBeginImageContextWithOptions(rect.size, YES, 0.0);
{
[[UIColor blackColor] setFill];
UIRectFill(rect);
[[UIColor whiteColor] setFill];
UIBezierPath *leftPath = [UIBezierPath bezierPath];
// Set the starting point of the shape.
CGPoint p1 = [(NSValue *)[leftPoints objectAtIndex:0] CGPointValue];
[leftPath moveToPoint:CGPointMake(p1.x, p1.y)];
for (uint i=1; i<leftPoints.count; i++)
{
CGPoint p = [(NSValue *)[leftPoints objectAtIndex:i] CGPointValue];
[leftPath addLineToPoint:CGPointMake(p.x, p.y)];
}
[leftPath closePath];
[leftPath fill];
}
UIImage *mask = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
{
CGContextClipToMask(UIGraphicsGetCurrentContext(), rect, mask.CGImage);
[im_senza drawAtPoint:CGPointZero];
}
UIImage *maskedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();