[cairo] [PATCH 0/6] cover glyph support

[Matthias Clasen]

On Sat, Apr 9, 2016 at 3:54 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Fri, Apr 08, 2016 at 11:22:27PM -0400, matthias.clasen at gmail.com wrote:
>> From: Matthias Clasen <mclasen at redhat.com>
>>
>> Its been almost three years since Behdad posted a quick sketch
>> of how support for colored glyphs could look in cairo
>> (https://github.com/behdad/cairo/commits/color-emoji).
>> Over the last few days, I've spent some time on turning this
>> into a more complete solution.
>>
>> The patches in this series provide fully working support for
>> colored glyphs in OpenType fonts for the image compositor and
>> the xlib compositor, and should be mergable.
>
> It's not mergeable since you break cairo_show_glyphs(), which now
> randomly operates differently based on whether the system loaded a "color"
> glyph - your implementation completely discards the source and changes
> the definition of the glyph operator.
>
> Looking at the implmentation, there is no difference between the RGBA
> color glyph and the RGBA non-color glyphs, just that you imposed a WHITE
> source.

The difference is component alpha. I couldn't use the pixman glpyh
cache since it forces component alpha on for all rgba glyphs, breaking
these color glpyhs.