[cairo] API Shakeup: cairo_<device>_surface_mark_dirty

Mike Emmel mike.emmel at gmail.com
Sat Jul 30 06:35:40 PDT 2005


On 7/30/05, Owen Taylor <otaylor at redhat.com> wrote:
> On Fri, 2005-07-29 at 20:21 -0400, Mike Emmel wrote:
> > Good this should also handle the problematic case of a native surface
> > format unsupported by cairo. I create a supported secondary format
> > internally for the directfb backend.  In general should the backend
> > specific create function do this or fail with a unsupported format
> > error ?
> 
> I don't understand the relationship. These functions are for an
> application to use when mixing (say) X drawing with cairo drawing.
> 
> Regards,
>                                                 Owen
> 

Using a intermediate buffer was also very slow without this.

Technically if your using a intermediate buffer because the target
surface is not supported by cairo you should ask cairo to blit its
buffers before marking a region dirty.

So its slightly different case. Which brought up my question.  If the
target surface is not supported by cairo but you can create a internal
buffer that is supported should the backend do this ? Cairo supports a
very limited number of surface formats so dealing with a source format
not supported by cairo is prob common.
YUV,16 bit etc etc.

Mike

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