egl: implement EGL_MESA_transparent_alpha for x11 and waylandegl-transparency

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67676

6 files changed, 55 insertions, 17 deletions

diff --git a/include/EGL/eglmesaext.h b/include/EGL/eglmesaext.h
index 917a2043c7..866be76688 100644
--- a/include/EGL/eglmesaext.h
+++ b/include/EGL/eglmesaext.h
@@ -95,6 +95,11 @@ typedef EGLBoolean (EGLAPIENTRYP PFNEGLSWAPBUFFERSREGIONNOK) (EGLDisplay dpy, EG
 #define EGL_NO_CONFIG_MESA			((EGLConfig)0)
 #endif
 
+#ifndef EGL_MESA_transparent_alpha
+#define EGL_MESA_transparent_alpha 1
+#define EGL_TRANSPARENT_ALPHA_MESA		0x31D9
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index 1e127607cd..64fd51cb12 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -144,7 +144,7 @@ dri2_wl_create_surface(_EGLDriver *drv, _EGLDisplay *disp,
 
    if (conf->RedSize == 5)
       dri2_surf->format = WL_DRM_FORMAT_RGB565;
-   else if (conf->AlphaSize == 0)
+   else if (conf->AlphaSize == 0 || conf->TransparentType == EGL_NONE)
       dri2_surf->format = WL_DRM_FORMAT_XRGB8888;
    else
       dri2_surf->format = WL_DRM_FORMAT_ARGB8888;
@@ -1054,11 +1054,15 @@ dri2_initialize_wayland_drm(_EGLDriver *drv, _EGLDisplay *disp)
    struct dri2_egl_display *dri2_dpy;
    const __DRIconfig *config;
    uint32_t types;
-   int i;
+   int i, j;
    static const unsigned int argb_masks[4] =
       { 0xff0000, 0xff00, 0xff, 0xff000000 };
    static const unsigned int rgb_masks[4] = { 0xff0000, 0xff00, 0xff, 0 };
    static const unsigned int rgb565_masks[4] = { 0xf800, 0x07e0, 0x001f, 0 };
+   static const EGLint argb_attrs[] = {
+       EGL_TRANSPARENT_TYPE, EGL_TRANSPARENT_ALPHA_MESA,
+       EGL_NONE
+   };
 
    loader_set_logger(_eglLog);
 
@@ -1175,14 +1179,16 @@ dri2_initialize_wayland_drm(_EGLDriver *drv, _EGLDisplay *disp)
    }
 
    types = EGL_WINDOW_BIT;
-   for (i = 0; dri2_dpy->driver_configs[i]; i++) {
+   for (i = 0, j = 1; dri2_dpy->driver_configs[i]; i++) {
       config = dri2_dpy->driver_configs[i];
       if (dri2_dpy->formats & HAS_XRGB8888)
-	 dri2_add_config(disp, config, i + 1, types, NULL, rgb_masks);
-      if (dri2_dpy->formats & HAS_ARGB8888)
-	 dri2_add_config(disp, config, i + 1, types, NULL, argb_masks);
+	 dri2_add_config(disp, config, j++, types, NULL, rgb_masks);
+      if (dri2_dpy->formats & HAS_ARGB8888) {
+	 dri2_add_config(disp, config, j++, types, argb_attrs, argb_masks);
+	 dri2_add_config(disp, config, j++, types, NULL, argb_masks);
+      }
       if (dri2_dpy->formats & HAS_RGB565)
-        dri2_add_config(disp, config, i + 1, types, NULL, rgb565_masks);
+        dri2_add_config(disp, config, j++, types, NULL, rgb565_masks);
    }
 
    disp->Extensions.WL_bind_wayland_display = EGL_TRUE;
@@ -1197,6 +1203,7 @@ dri2_initialize_wayland_drm(_EGLDriver *drv, _EGLDisplay *disp)
          dri2_fallback_create_wayland_buffer_from_image;
    }
    disp->Extensions.EXT_buffer_age = EGL_TRUE;
+   disp->Extensions.MESA_transparent_alpha = EGL_TRUE;
 
    disp->Extensions.EXT_swap_buffers_with_damage = EGL_TRUE;
 
diff --git a/src/egl/drivers/dri2/platform_x11.c b/src/egl/drivers/dri2/platform_x11.c
index ad40bd57aa..e7f332849e 100644
--- a/src/egl/drivers/dri2/platform_x11.c
+++ b/src/egl/drivers/dri2/platform_x11.c
@@ -698,18 +698,22 @@ dri2_x11_add_configs_for_visuals(struct dri2_egl_display *dri2_dpy,
 	    dri2_add_config(disp, dri2_dpy->driver_configs[j], id++,
 			    surface_type, config_attrs, rgba_masks);
 
-            /* Allow a 24-bit RGB visual 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! */
+            rgba_masks[3] =
+               ~(rgba_masks[0] | rgba_masks[1] | rgba_masks[2]);
+
             if (d.data->depth == 24) {
-               rgba_masks[3] =
-                  ~(rgba_masks[0] | rgba_masks[1] | rgba_masks[2]);
                dri2_add_config(disp, dri2_dpy->driver_configs[j], id++,
                                surface_type, config_attrs, rgba_masks);
+            } else if (d.data->depth == 32) {
+                EGLint rgba_attrs[] = {
+                        EGL_NATIVE_VISUAL_ID,   config_attrs[1],
+                        EGL_NATIVE_VISUAL_TYPE, config_attrs[3],
+                        EGL_TRANSPARENT_TYPE,   EGL_TRANSPARENT_ALPHA_MESA,
+                        EGL_NONE
+                };
+
+               dri2_add_config(disp, dri2_dpy->driver_configs[j], id++,
+                               surface_type, rgba_attrs, rgba_masks);
             }
 	 }
       }
@@ -1280,6 +1284,7 @@ dri2_initialize_x11_dri2(_EGLDriver *drv, _EGLDisplay *disp)
    disp->Extensions.NOK_texture_from_pixmap = EGL_TRUE;
    disp->Extensions.NV_post_sub_buffer = EGL_TRUE;
    disp->Extensions.CHROMIUM_sync_control = EGL_TRUE;
+   disp->Extensions.MESA_transparent_alpha = EGL_TRUE;
 
 #ifdef HAVE_WAYLAND_PLATFORM
    disp->Extensions.WL_bind_wayland_display = EGL_TRUE;
diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index 824e51ea55..896f69e3dd 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -809,6 +809,10 @@ _eglCreatePixmapSurfaceCommon(_EGLDisplay *disp, EGLConfig config,
    EGLSurface ret;
 
    _EGL_CHECK_CONFIG(disp, conf, EGL_NO_SURFACE, drv);
+
+   if (conf->TransparentType == EGL_TRANSPARENT_ALPHA_MESA)
+      RETURN_EGL_ERROR(disp, EGL_BAD_MATCH, EGL_NO_SURFACE);
+
    surf = drv->API.CreatePixmapSurface(drv, disp, conf, native_pixmap,
                                        attrib_list);
    ret = (surf) ? _eglLinkSurface(surf) : EGL_NO_SURFACE;
@@ -882,6 +886,9 @@ eglCreatePbufferSurface(EGLDisplay dpy, EGLConfig config,
 
    _EGL_CHECK_CONFIG(disp, conf, EGL_NO_SURFACE, drv);
 
+   if (conf->TransparentType == EGL_TRANSPARENT_ALPHA_MESA)
+      RETURN_EGL_ERROR(disp, EGL_BAD_MATCH, EGL_NO_SURFACE);
+
    surf = drv->API.CreatePbufferSurface(drv, disp, conf, attrib_list);
    ret = (surf) ? _eglLinkSurface(surf) : EGL_NO_SURFACE;
 
@@ -1275,6 +1282,9 @@ eglCreatePbufferFromClientBuffer(EGLDisplay dpy, EGLenum buftype,
 
    _EGL_CHECK_CONFIG(disp, conf, EGL_NO_SURFACE, drv);
 
+   if (conf->TransparentType == EGL_TRANSPARENT_ALPHA_MESA)
+      RETURN_EGL_ERROR(disp, EGL_BAD_MATCH, EGL_NO_SURFACE);
+
    surf = drv->API.CreatePbufferFromClientBuffer(drv, disp, buftype, buffer,
                                                  conf, attrib_list);
    ret = (surf) ? _eglLinkSurface(surf) : EGL_NO_SURFACE;
diff --git a/src/egl/main/eglconfig.c b/src/egl/main/eglconfig.c
index cf65c69b7b..c7830fb743 100644
--- a/src/egl/main/eglconfig.c
+++ b/src/egl/main/eglconfig.c
@@ -301,7 +301,8 @@ _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
                valid = EGL_FALSE;
             break;
          case EGL_TRANSPARENT_TYPE:
-            if (val != EGL_NONE && val != EGL_TRANSPARENT_RGB)
+            if (val != EGL_NONE && val != EGL_TRANSPARENT_RGB &&
+                val != EGL_TRANSPARENT_ALPHA_MESA)
                valid = EGL_FALSE;
             break;
          case EGL_COLOR_BUFFER_TYPE:
@@ -367,6 +368,15 @@ _eglValidateConfig(const _EGLConfig *conf, EGLBoolean for_matching)
       }
    }
 
+   /* an initial check for conflicting attribute values, required when
+    * for_matching is true */
+
+   if (conf->TransparentType == EGL_TRANSPARENT_ALPHA_MESA &&
+       conf->AlphaSize == 0) {
+      _eglLog(_EGL_DEBUG, "conflicting transparent type and alpha size values");
+      return EGL_FALSE;
+   }
+
    /* any invalid attribute value should have been catched */
    if (!valid || for_matching)
       return valid;
diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
index 8d3393564b..5ddf3fb5f6 100644
--- a/src/egl/main/egldisplay.h
+++ b/src/egl/main/egldisplay.h
@@ -121,6 +121,7 @@ struct _egl_extensions
    EGLBoolean MESA_drm_display;
    EGLBoolean MESA_drm_image;
    EGLBoolean MESA_image_dma_buf_export;
+   EGLBoolean MESA_transparent_alpha;
 
    EGLBoolean NOK_swap_region;
    EGLBoolean NOK_texture_from_pixmap;