iphone - How to set up a clipping rectangle or area -


How to set up, modify, and clear a clipping rectangle inside an iOS draw, pictures, etc. .

Is it possible to use a more complex clipping area that is a composite of a group of rectangles and boards? You can set a clipping area with arbitrary routes, not limited to rectangles.

Followers are a few ways to do this:

  1. You can attract an arbitrary route and set a clipping area with it. For example: 

      CGContextBeginPath (reference); // Drag a route here CGContextClosePath (reference); CGContextClip (reference); // The following drawing will be deducted on the reference    
  2.  
     If you want to use a mask image to set a clipping area, then use the CGContextClipToMask method.    
     See Apple's 'Quartzdmo' sample project for more uses.

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