Re: [hackers] Announcing libschrift (a TrueType font rendering library)

From: Michael Forney <mforney_AT_mforney.org>
Date: Thu, 23 Apr 2020 01:24:03 -0700

On 2020-04-23, Silvan Jegen <s.jegen_AT_gmail.com> wrote:
> I had a quick look and currently it looks like it's mostly useful for
> rendering of fonts in X. I wonder how an interface would look like that
> could also be used for text rendering for a Wayland client. I assume the
> library would instead just render to some graphics memory to be rendered
> by the compositor, but I am not completely sure.

I think the interface would look the same for Wayland, but the missing
piece is something to composite the glyphs into the application's
window buffer, which is handled by XRender in the demo.

If you are rendering to shared memory, pixman (which is essentially
XRender in a library) can be used similarly. You can create a glyph
cache, load the glyph images produced by libschrift into it, and then
use pixman_composite_glyphs to render them onto your frame.

For OpenGL/Vulkan, it's the same on X11 and Wayland, since the client
is doing direct rendering in both cases. I believe it's generally done
by creating an "atlas" texture containing a bunch of glyphs at
different positions, and then rendering subregions of it onto your
frame. Most code using freetype directly could probably be adapted to
libschrift fairly easily.
Received on Thu Apr 23 2020 - 10:24:03 CEST