[cairo] Color fonts

[Behdad Esfahbod]

On Fri, Jul 28, 2017 at 6:00 PM, Bill Spitzak <spitzak at gmail.com> wrote:

> I think the stacking order of glyphs can remain undefined for
> cairo_show_glyphs. This seems more like something pango would be in
> charge of.
>

We are talking about order of glyphs drawn in one cairo_show_glyphs(), so I
don't see how this is pango's job.


>
> On Fri, Jul 28, 2017 at 7:38 AM, Behdad Esfahbod <behdad at behdad.org>
> wrote:
> > Uli,
> >
> > Can we commit this?  I don't think waiting another few years will result
> in
> > a superior patchset. :)
> >
> > Cheers,
> >
> > behdad
> >
> > On Wed, Jul 19, 2017 at 1:53 AM, Behdad Esfahbod <behdad at behdad.org>
> wrote:
> >>
> >> Right.  In the future we would want to make it show glyphs in the input
> >> order, ie. not separate color vs non-color.  That's the order required
> by
> >> CSS for example.  In a show-text-glyphs call with
> >> CAIRO_TEXT_CLUSTER_FLAG_BACKWARD, it might be desirable to show
> >> back-to-front.
> >>
> >> On Tue, Jul 18, 2017 at 1:59 PM, Matthias Clasen
> >> <matthias.clasen at gmail.com> wrote:
> >>>
> >>> On Sat, Jul 15, 2017 at 4:05 AM, Uli Schlachter <psychon at znc.in>
> wrote:
> >>>>
> >>>> On 07.07.2017 15:23, Matthias Clasen wrote:
> >>>> > On Sat, Jul 1, 2017 at 2:25 AM, Uli Schlachter <psychon at znc.in>
> wrote:
> >>>> >> On 30.06.2017 17:29, Behdad Esfahbod wrote:
> >>>> >>> On Jun 30, 2017 7:51 PM, "Matthias Clasen" <mclasen at redhat.com>
> >>>> >>> wrote:
> >>>> >>> On Fri, 2017-06-30 at 17:02 +0200, Uli Schlachter wrote:
> >>>> >>>> On 28.06.2017 14:23, Behdad Esfahbod wrote:
> >>>> >>>>> All of you have asked me about the status of color fonts in
> >>>> >>>>> cairo.  There's
> >>>> >>>>> some discussion here:
> >>>> >>>>
> >>>> >>>> what was the solution to make this fit into cairo's drawing
> model?
> >>>> >>>> Text
> >>>> >>>> / glyphs are used as a mask and a mask does not have colors.
> >>>> >>>>
> >>>> >>>
> >>>> >>> There is no solution to that. The assumption in cairo's drawing
> >>>> >>> model
> >>>> >>> about glyphs/fonts has simply been invalidated by reality.
> >>>> >>>
> >>>> >>>
> >>>> >>> Correct.
> >>>> >>
> >>>> >> Okay... so what is the new model? What happens when I draw a color
> >>>> >> glyph
> >>>> >> with operator XOR and a red source?
> >>>> >
> >>>> >
> >>>> > The red source is ignored for color glyphs because they are used as
> >>>> > the
> >>>> > source.
> >>>>
> >>>> Hi again,
> >>>>
> >>>> I just came up with another question: How are overlapping glyphs
> >>>> handled?
> >>>>
> >>>> Let's say I have a red glyph and a blue glyph and I draw them in such
> a
> >>>> way that they overlap. Let's say this additionally overlaps with a
> >>>> non-colored glyph in the same position and I use a green source with
> 50%
> >>>> alpha (cairo_set_source_rgba(cr, 0, 1, 0, 0.5)).
> >>>>
> >>>> What's the visible result?
> >>>>
> >>>
> >>> Here is what my implementation does: It renders the color glyphs, in
> >>> order, followed by the non-color glyphs.
> >>>
> >>> In practice, I don't think the case of mixed color and non-color glyphs
> >>> in the same call will be all that common.
> >>> Most apps will explicitly set a color font just for the emoji and they
> >>> won't render regular text with an emoji font,
> >>> with the result that runs of color glyphs and non-color glyphs will
> >>> typically be in separate calls.
> >>
> >>
> >>
> >>
> >> --
> >> behdad
> >> http://behdad.org/
> >
> >
> >
> >
> > --
> > behdad
> > http://behdad.org/
> >
> > --
> > cairo mailing list
> > cairo at cairographics.org
> > https://lists.cairographics.org/mailman/listinfo/cairo
>



-- 
behdad
http://behdad.org/
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