How to detect whether user have touched an area of an image?

Question

I have an image with transparent background. I would like to find out whether use have touched the non-transparent area of the image with CoreGraphics framework. Is this possible? Is there any resources that I can read about this?

Thanks heaps for the guidance

score 2 · Accepted Answer · edited May 23 '17 at 12:04

2

You will have to implement the logic yourself here. You will need to intercept the touches to get the coordinates in the image, get the pixel data of the image and determine the alpha value, then determine if that satisfies your definition of transparent.

edited May 23 '17 at 12:04

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answered May 06 '11 at 15:49

coneybeare

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How to detect whether user have touched an area of an image?

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