weston/libweston/renderer-gl
Pekka Paalanen 6234cb98d1 gl-renderer: fix performance regression in frag
When color management is disabled, the fragment shader was still first
ensuring straight alpha and then immediately just going back to
pre-multiplied. This is near-impossible for a shader compiler to
optimize out, I guess because of the if-statement to handle division by
zero. Having view alpha applied in between certainly didn't make it
easier.

That causes extra fragment computations that are unnecessary. In the
issue report this was found to cause a notable performance regression.

Fix the performance regression by introducing special-case paths for
when straight alpha is not needed. This skips the unnecessary
computations.

Fixes: https://gitlab.freedesktop.org/wayland/weston/-/issues/623
Fixes: 9a6a4e7032

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
2022-06-03 09:38:10 +00:00
..
egl-glue.c gl_renderer: log EGL features 2022-05-18 14:18:53 +03:00
fragment.glsl gl-renderer: fix performance regression in frag 2022-06-03 09:38:10 +00:00
gl-renderer-internal.h gl-renderer: move extension lists away from log 2022-05-18 13:45:53 +03:00
gl-renderer.c gl-renderer: fix double-alloc of gl_buffer_state 2022-05-31 13:08:01 +03:00
gl-renderer.h gl-renderer: Replace pbuffer-create args with struct 2020-03-20 15:25:24 +00:00
gl-shader-config-color-transformation.c gl-renderer: shaders implementation of color mapping function 2022-02-09 20:42:50 -05:00
gl-shaders.c gl-renderer: shaders implementation of color mapping function 2022-02-09 20:42:50 -05:00
meson.build gl-renderer: implement 3 x 1D LUT color pre-curve 2021-06-21 14:36:33 +00:00
vertex.glsl gl-renderer: move vertex shader into new file 2021-02-25 13:16:02 +02:00