[Pixman] Pixman on iOS

cu cairouser at yahoo.com
Sun Jul 10 17:56:05 PDT 2011

I am lifting an old thread here, since there is a bit of data that may
be related.

I have been testing Quartz surface vs. image surface performance - on an
Intel Mac.
The results are somewhat surprising to me. A certain image that's a
pretty good mix of polygons, lines, icons (copied from another surface)
and text gets the following drawing times (seconds):

Pixman with SSE - 0.122
Pixman, no SSE or MMX: 0.140
Quartz (using fonts through Freetype backend): 0.145
Quartz (using fonts through Quartz font backend): 0.165

A few conclusions:
- Pixman is quite a bit faster than Quartz when used by cairo. Assuming
this extrapolates to iOS/arm - having a proper optimized Pixman build on
iOS is quite crucial.
- Even unoptimized, it is still somewhat preferable to use pixman over
- Quartz is slower with its own fonts - this one I just don't get

As an aside, even if I use exactly the same fonts (selected by name in
Quartz vs. loaded as file in Freetype), they render differently in both
image and quartz surface, with Freetype fonts quite a bit "crisper".

All of the above based on cairo 1.9.8.

Andrea Canciani wrote:
> Cairo should already provide the needed support for iOS in the
> Quartz backend. If that is the main backend used by the application,
> Pixman should already be quite usable without NEON optimization,
> as it will only be used for fallbacks. Of course it would be nice to get
> NEON fast paths, if they can actually be used on that architecture.

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