[mutter] clutter/stage-view: Always use cogl_blit_framebuffer() from shadowfb

[verdre <jonasd src gnome org>]

commit 4e27a4ea1d59d2ae60e85e124d21e35b6a72b18f
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue May 5 18:55:03 2020 +0200

    clutter/stage-view: Always use cogl_blit_framebuffer() from shadowfb
    
    It should only be used when direct blitting is supported, so there is no
    reason we should have to deal with pipelines etc when blitting from the
    shadow buffer to the onscreen.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1237

 clutter/clutter/clutter-stage-view.c | 36 +++++++++++++++---------------------
 1 file changed, 15 insertions(+), 21 deletions(-)
---
diff --git a/clutter/clutter/clutter-stage-view.c b/clutter/clutter/clutter-stage-view.c
index 48d8b35773..a9b202f8cd 100644
--- a/clutter/clutter/clutter-stage-view.c
+++ b/clutter/clutter/clutter-stage-view.c
@@ -57,7 +57,6 @@ typedef struct _ClutterStageViewPrivate
   gboolean use_shadowfb;
   struct {
     CoglOffscreen *framebuffer;
-    CoglPipeline *pipeline;
   } shadow;
 
   CoglScanout *next_scanout;
@@ -158,19 +157,6 @@ clutter_stage_view_ensure_offscreen_blit_pipeline (ClutterStageView *view)
     view_class->setup_offscreen_blit_pipeline (view, priv->offscreen_pipeline);
 }
 
-static void
-clutter_stage_view_ensure_shadowfb_blit_pipeline (ClutterStageView *view)
-{
-  ClutterStageViewPrivate *priv =
-    clutter_stage_view_get_instance_private (view);
-
-  if (priv->shadow.pipeline)
-    return;
-
-  priv->shadow.pipeline =
-    clutter_stage_view_create_framebuffer_pipeline (priv->shadow.framebuffer);
-}
-
 void
 clutter_stage_view_invalidate_offscreen_blit_pipeline (ClutterStageView *view)
 {
@@ -326,12 +312,21 @@ clutter_stage_view_after_paint (ClutterStageView *view)
 
   if (priv->shadow.framebuffer)
     {
-      clutter_stage_view_ensure_shadowfb_blit_pipeline (view);
-      clutter_stage_view_copy_to_framebuffer (view,
-                                              priv->shadow.pipeline,
-                                              priv->shadow.framebuffer,
-                                              priv->framebuffer,
-                                              TRUE);
+      int width, height;
+      g_autoptr (GError) error = NULL;
+
+      width = cogl_framebuffer_get_width (priv->framebuffer);
+      height = cogl_framebuffer_get_height (priv->framebuffer);
+      if (!cogl_blit_framebuffer (priv->shadow.framebuffer,
+                                  priv->framebuffer,
+                                  0, 0,
+                                  0, 0,
+                                  width, height,
+                                  &error))
+        {
+          g_warning ("Failed to blit shadow buffer: %s", error->message);
+          return;
+        }
     }
 }
 
@@ -646,7 +641,6 @@ clutter_stage_view_dispose (GObject *object)
   g_clear_pointer (&priv->name, g_free);
   g_clear_pointer (&priv->framebuffer, cogl_object_unref);
   g_clear_pointer (&priv->shadow.framebuffer, cogl_object_unref);
-  g_clear_pointer (&priv->shadow.pipeline, cogl_object_unref);
   g_clear_pointer (&priv->offscreen, cogl_object_unref);
   g_clear_pointer (&priv->offscreen_pipeline, cogl_object_unref);
   g_clear_pointer (&priv->redraw_clip, cairo_region_destroy);