[cairo] Color fonts

[Adrian Johnson]

Does it work with user fonts?

On 30/07/17 01:00, Behdad Esfahbod wrote:
> On Sat, Jul 29, 2017 at 11:58 AM, Uli Schlachter <psychon at znc.in
> <mailto:psychon at znc.in>> wrote:
> 
>     Hi Behdad
> 
>     I don't think that is my decision to make. When thinking about "fonts in
>     cairo", I'm thinking "Behdad". I'm just asking weird questions from the
>     sideline. :-)
> 
> 
> Thanks. :-)  Pushed!!!!  At least ten people already asked me "what's up
> with emoji" at GUADEC...
>  
> 
>     Uli
> 
>     P.S.: How relevant and up to date is the CC list here? I always get a
>     "your message to gtk-devel-list awaits moderator approval"-mail when
>     replying to this thread...
> 
> 
> My messages go through, yours probably don't because you are not a
> member.  It's valuable still.
> 
> Cheers,
> b
>  
> 
>     On 28.07.2017 16:38, Behdad Esfahbod 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 <mailto: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 <mailto:matthias.clasen at gmail.com>> wrote:
>     >>
>     >>> On Sat, Jul 15, 2017 at 4:05 AM, Uli Schlachter <psychon at znc.in
>     <mailto: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
>     <mailto: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 <mailto: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/
>     >>
>     >
>     >
>     >
> 
> 
>     --
>     "Why make things difficult, when it is possible to make them cryptic
>     and totally illogical, with just a little bit more effort?" -- A. P. J.
> 
> 
> 
> 
> -- 
> behdad
> http://behdad.org/
> 
>