[cairo] my recent testcase

Chris Wilson chris at chris-wilson.co.uk
Wed Nov 4 04:43:55 PST 2009

Excerpts from Benjamin Otte's message of Wed Nov 04 11:21:26 +0000 2009:
> 1) disabling the test on vector backends
> As the test is targetted at xlib in particular and causes aliasing
> artifacts, I want to disable it on backends where it's not necessary
> to run it. I used CAIRO_ANTIALIAS_NONE to get rid of the artefacts,
> but the vector backends can't honor that flag. Is there a way to
> disable the test there?

Add "raster" to the requirements line in CAIRO_TEST()

> cairo-xlib-surface.c defines these two values to -32768 / 32767 and
> then compares them to cairo_fixed_t without conversion in
> _line_exceeds_16_16. I'm 90% sure this is wrong, but I'd like Chris
> (or someone else) to say something like "yes, you need to multiply it
> with CAIRO_FIXED_ONE there" before going to fix that.
> So far it just seems to cause way a lot of unnecessary projections
> occuring (one of which triggered the original bug I fixed).

Indeed I do have a patch that fixes it as
_cairo_fixed_from_int (-32768), along with tens of thousands of other
lines. Gah.
Chris Wilson, Intel Open Source Technology Centre

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