Question

I have an UIView with a layermask (smaller than its frame) that can receive touches.
Now the thing is that i want to restrict those touches within the layer mask.

The mask is a rendered shape and not always a rectangle.

Do i have to do this with:

pointInside:withEvent:

or

hitTest:withEvent:

Or is there a better solution?

Answer 1

Solved it by creating a method that checks if there a solid or transparant pixel in the layer at a specific position:

- (BOOL)isSolidPixel:(CGImageRef)image withXPosition:(int)xPos andYPosition:(int)yPos {
    if(xPos > CGImageGetWidth(image) || yPos > CGImageGetHeight(image))
        return NO;

    CFDataRef pixelData = CGDataProviderCopyData(CGImageGetDataProvider(image));
    const UInt8* data = CFDataGetBytePtr(pixelData);

    int pixelInfo = yPos * CGImageGetBytesPerRow(image) + xPos * 4;

    UInt8 alpha = data[pixelInfo];

    CFRelease(pixelData);

    if (alpha) 
        return YES;

    return NO;
}