egl: Fixes transparency with EGL and X11.

This commit does this by allowing both RGB and RGBA visuals to match with
EGL configs. We also expose the `EGL_MESA_config_select_group` egl
extension, which is similar to GLX's visual select group extension, to
allow the RGBA visuals to get less priority.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67676
Fixes: 049f343e8ac "egl: Allow 24-bit visuals for 32-bit RGBA8888 configs"
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Hal Gentz <zegentzy@protonmail.com>

1 files changed, 13 insertions, 16 deletions

diff --git a/src/egl/drivers/dri2/platform_x11.c b/src/egl/drivers/dri2/platform_x11.c
index 5a1e2f31890..414d5f74c5d 100644
--- a/src/egl/drivers/dri2/platform_x11.c
+++ b/src/egl/drivers/dri2/platform_x11.c
@@ -816,28 +816,25 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
                if (dri2_conf->base.ConfigID == config_count + 1)
                   config_count++;
 
-            /* Allow a 24-bit RGB visual to match a 32-bit RGBA EGLConfig.
-             * Ditto for 30-bit RGB visuals to match a 32-bit RGBA EGLConfig.
+            /* Allows RGB visuals to match a 32-bit RGBA EGLConfig.
              * Otherwise it will only match a 32-bit RGBA visual.  On a
              * composited window manager on X11, this will make all of the
              * EGLConfigs with destination alpha get blended by the
              * compositor.  This is probably not what the application
              * wants... especially on drivers that only have 32-bit RGBA
              * EGLConfigs! */
-            if (d.data->depth == 24 || d.data->depth == 30) {
-               unsigned int rgba_mask = ~(visuals[i].red_mask |
-                                          visuals[i].green_mask |
-                                          visuals[i].blue_mask);
-               rgba_shifts[3] = ffs(rgba_mask) - 1;
-               rgba_sizes[3] = util_bitcount(rgba_mask);
-               dri2_conf = dri2_add_config(disp, config, config_count + 1,
-                                           surface_type, config_attrs,
-                                           rgba_shifts, rgba_sizes);
-               if (dri2_conf)
-                  if (dri2_conf->base.ConfigID == config_count + 1)
-                     config_count++;
-            }
-	 }
+            unsigned int rgba_mask = ~(visuals[i].red_mask |
+                                       visuals[i].green_mask |
+                                       visuals[i].blue_mask);
+            rgba_shifts[3] = ffs(rgba_mask) - 1;
+            rgba_sizes[3] = util_bitcount(rgba_mask);
+            dri2_conf = dri2_add_config(disp, config, config_count + 1,
+                                        surface_type, config_attrs,
+                                        rgba_shifts, rgba_sizes);
+            if (dri2_conf)
+               if (dri2_conf->base.ConfigID == config_count + 1)
+                  config_count++;
+         }
       }
 
       xcb_depth_next(&d);