[cairo] [patch] gl: when using a surface as source/mask in drawing operation on GL surface target, we can avoid map_to_image()

[Henry (Yu) Song - SISA]

Hi, Chris

Got your idea.  I will look into using PBO instead of creating image surface from system memory.

Thanks

Henry

-----Original Message-----
From: Chris Wilson [mailto:chris at chris-wilson.co.uk] 
Sent: Friday, March 30, 2012 8:32 AM
To: Henry (Yu) Song - SISA; cairo at cairographics.org
Subject: RE: [cairo] [patch] gl: when using a surface as source/mask in drawing operation on GL surface target, we can avoid map_to_image()

On Fri, 30 Mar 2012 15:16:59 +0000, "Henry (Yu) Song - SISA" <hsong at sisa.samsung.com> wrote:
> Hi, Chris
> 
> Is cairo_surface_map_to_image() calls _cairo_gl_surface_map_to_image() in which a new image surface is allocated and use glReadPixels() to read pixels from gl surface to image surface?  I could not see where PBO is allocated.

Patches welcome. :)

The reason for introducing map-to-image and create-similar-image was for the express purpose of being able to do PBO (or SHM transport for X), and exposing that ability to the user as well.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre