Improvement: --glx-swap-method & --fade-exclude

- GLX backend: Add --glx-swap-method, to reduce painting region if the
  driver uses exchange or copy buffer swaps. Untested.

- Add --fade-exclude, to disable fading on specific windows based on
  some conditions. Untested.

- Expose GLX backend options through configuration file. Add fetching of
  GLX backend options through D-Bus.

- Use NULL pointer instead of element count to delimit string arrays in
  parse_vsync()/parse_backend()/parse_glx_swap_method().

- Add documentation about "wintypes" section in configuration file.

1 files changed, 13 insertions, 1 deletions

diff --git a/opengl.c b/opengl.c
index 6560afe55..2ea8a8c15 100644
--- a/opengl.c
+++ b/opengl.c
@@ -545,10 +545,20 @@ glx_paint_pre(session_t *ps, XserverRegion *preg) {
   ps->glx_z = 0.0;
   // glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
+  // Exchange swap is interested in the raw damaged region only
+  XserverRegion all_damage_last = ps->all_damage_last;
+  ps->all_damage_last = None;
+  if (SWAPM_EXCHANGE == ps->o.glx_swap_method && *preg)
+    ps->all_damage_last = copy_region(ps, *preg);
+
   // OpenGL doesn't support partial repaint without GLX_MESA_copy_sub_buffer,
   // we could redraw the whole screen or copy unmodified pixels from
   // front buffer with --glx-copy-from-front.
-  if (ps->o.glx_use_copysubbuffermesa || !*preg) {
+  if (ps->o.glx_use_copysubbuffermesa || SWAPM_COPY == ps->o.glx_swap_method
+      || !*preg) {
+  }
+  else if (SWAPM_EXCHANGE == ps->o.glx_swap_method && all_damage_last) {
+    XFixesUnionRegion(ps->dpy, *preg, *preg, all_damage_last);
   }
   else if (!ps->o.glx_copy_from_front) {
     free_region(ps, preg);
@@ -572,6 +582,8 @@ glx_paint_pre(session_t *ps, XserverRegion *preg) {
     }
   }
 
+  free_region(ps, &all_damage_last);
+
   glx_set_clip(ps, *preg, NULL);
 }