[cairo] Pixman performace

[Chris Wilson]

On Fri, Oct 18, 2013 at 11:40:33AM +0200, Carlos López González wrote:
>    Hi!
>    I would like to know if when rendering to image surface there is
>    noticeable performance increment when changing from default
>    CAIRO_ANTIALIAS_DEFAULT to CAIRO_ANTIALIAS_NONE

In theory, for equivalent output, no. That is the optimisations we make
at the pixman level are based on the geometry, so if the rendering was
already pixel-aligned with CAIRO_ANTIALIAS_DEFAULT then you should hit
exactly the same paths as CAIRO_ANTIALIAS_NONE. Where ANTIALIAS_NONE can
have a big impact is in the generation of geometry, either using a
faster scanline rasteriser or in simplifying the input geometry to
bypass rasterisation altogether.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre