[Xr] Clipping problems

Carl Worth cworth at east.isi.edu
Wed Jun 4 06:23:04 PDT 2003

On Jun 2, Soorya Kuloor wrote:
 > While using clipping stuff I found that it is very slow (you had told me
 > so before too). Here is a sample application that draws stuff and uses
 > clipping. Without clipping the painting takes approx. 20-40msecs. With
 > clipping it takes approx 1500 msecs, that is approx. 50-80 times
 > slowdown. Are there any plans to fix this pretty soon?


I notice that your example happens to use a clipping path that is a
rectangle aligned with the device pixel grid. That's one case that
should be quite easy to make ridiculously faster than what currently

Both of the two current backends support setting a clip region,
(consisting of whole pixels), on the destination surface. It shouldn't
be too hard to hook up XrClip to use that when possible.

As always, anyone is welcome to attempt to fix this before I get
around to it. :)


Carl Worth                                        
USC Information Sciences Institute                      cworth at isi.edu

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