[cairo] [PATCH 2/2] gl: Remove GL fixed-function matrix usage.

[Alexandros Frantzis]

On Wed, Feb 02, 2011 at 09:07:56AM +0000, Chris Wilson wrote:
> On Wed, 2 Feb 2011 04:00:01 +0200, Alexandros Frantzis <alexandros.frantzis at linaro.org> wrote:
> > in order to get a better view of the situation, I added some simple
> > instrumentation to cairo-gl. The results for sufficiently long runs of
> > various benchmark are:
> > 
> >                                                           vertices/update 
> >                      Vertices  CPU xforms Uniform updates (xforms/update)
> > firefox-talos-gfx    365825262 121941756  2262973         160 (53)        
> > gnome-system-monitor 126700506 42233504   47897           2645 (881)
> > evolution            7236340   2412114    86182           83 (28)
> > poppler              15121080  5040360    253440          60 (20)
> > 
> > Where:
> >     Vertices: How many vertices where emitted
> >     CPU xforms: the number of point transforms on the CPU with Eric's patch
> > 	            (always ~3xVertices)

By the way, this is a typo... it should be xforms = vertices / 3

> > 	Uniform updates: the number of ModelViewProjection uniform updates
> > 	                 with my branch
> > 	vertices/update: Ratio of vertices per uniform update
> > 	xforms/update: Ratio of CPU transforms per uniform update
> 
> Before I dive in, does your MVP branch include the matrix uniform updates
> for computing the src/mask tcoords from the single dst vertex?

To get the ModelViewProjection "uniform updates" count, I just tracked
how many times _cairo_gl_composite_bind_to_shader() is called (because
that is where I added the ModelViewProjection uniform upload). I would
guess that any additional uniform updates would also be performed from
within that function.

Thanks,
Alexandros