[cairo] [PATCH] don't wipe out quartz data with memset

T Rowley tor at cs.brown.edu
Wed Sep 14 08:21:58 PDT 2005

On 9/14/05 3:48 AM, Josh Aas wrote:
> Right now, the quartz backend draws into a buffer and dumps that buffer 
> down the CGContextRef pipe when it is ready (release_dest_image). 
> Problem is, right now we memset that whole buffer to zero after dumping 
> it each time. Thus, if you use an operator like 
> CAIRO_OPERATOR_DEST_OVER, it won't be aware of any existing dest data. 
> Here is a patch that drops the memset, and makes quartz drawing much 
> more correct.

Actually this makes normal use of OVER incorrect, as each primitive 
being drawn will cause the entire image to be accumulated on the 
destination Quartz surface.

Yes, the memset is a hack, but needed until aquire_dest_image is 
properly implemented in the Quartz backend.


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