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: [email protected]
Reviewed-by: Adam Jackson <[email protected]>
Signed-off-by: Hal Gentz <[email protected]>

3 files changed, 13 insertions, 1 deletions

diff --git a/src/egl/main/eglconfig.c b/src/egl/main/eglconfig.c
index 0a95e8ee05d..b3362363664 100644
--- a/src/egl/main/eglconfig.c
+++ b/src/egl/main/eglconfig.c
@@ -258,6 +258,9 @@ static const struct {
    { EGL_COLOR_COMPONENT_TYPE_EXT,  ATTRIB_TYPE_ENUM,
                                     ATTRIB_CRITERION_EXACT,
                                     EGL_COLOR_COMPONENT_TYPE_FIXED_EXT },
+   { EGL_CONFIG_SELECT_GROUP_MESA,  ATTRIB_TYPE_INTEGER,
+                                    ATTRIB_CRITERION_IGNORE,
+                                    0 },
 };
 
 
@@ -296,6 +299,8 @@ _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
             if (val > 1 || val < 0)
                valid = EGL_FALSE;
             break;
+         case EGL_CONFIG_SELECT_GROUP_MESA:
+            break;
          default:
             if (val < 0)
                valid = EGL_FALSE;
@@ -608,6 +613,10 @@ _eglCompareConfigs(const _EGLConfig *conf1, const _EGLConfig *conf2,
    if (conf1 == conf2)
       return 0;
 
+   val1 = conf1->ConfigSelectGroup - conf2->ConfigSelectGroup;
+   if (val1)
+      return val1;
+
    /* the enum values have the desired ordering */
    STATIC_ASSERT(EGL_NONE < EGL_SLOW_CONFIG);
    STATIC_ASSERT(EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
diff --git a/src/egl/main/eglconfig.h b/src/egl/main/eglconfig.h
index 605289de536..064187ff1dd 100644
--- a/src/egl/main/eglconfig.h
+++ b/src/egl/main/eglconfig.h
@@ -89,6 +89,7 @@ struct _egl_config
    EGLint FramebufferTargetAndroid;
    EGLint RecordableAndroid;
    EGLint ComponentType;
+   EGLint ConfigSelectGroup;
 };
 
 
@@ -139,6 +140,7 @@ _eglOffsetOfConfig(EGLint attr)
    ATTRIB_MAP(EGL_FRAMEBUFFER_TARGET_ANDROID, FramebufferTargetAndroid);
    ATTRIB_MAP(EGL_RECORDABLE_ANDROID,        RecordableAndroid);
    ATTRIB_MAP(EGL_COLOR_COMPONENT_TYPE_EXT,  ComponentType);
+   ATTRIB_MAP(EGL_CONFIG_SELECT_GROUP_MESA,  ConfigSelectGroup);
 #undef ATTRIB_MAP
    default:
       return -1;
diff --git a/src/egl/main/eglglobals.c b/src/egl/main/eglglobals.c
index 0d7270333ec..71d1fccf75f 100644
--- a/src/egl/main/eglglobals.c
+++ b/src/egl/main/eglglobals.c
@@ -70,7 +70,8 @@ struct _egl_global _eglGlobal =
    " EGL_EXT_device_query"
    " EGL_EXT_platform_base"
    " EGL_KHR_client_get_all_proc_addresses"
-   " EGL_KHR_debug",
+   " EGL_KHR_debug"
+   " EGL_MESA_config_select_group",
 
    .PlatformExtensionString =
 #ifdef HAVE_WAYLAND_PLATFORM