[mutter] clutter/paint-node: Have caller of .._get_framebuffer() handle fallback

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit f11170fecb33da52ab1e9be6c1839f214025f55f
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Nov 22 10:19:09 2019 +0100

    clutter/paint-node: Have caller of .._get_framebuffer() handle fallback
    
    clutter_paint_node_get_framebuffer() fell back on
    cogl_get_draw_framebuffer() when the root node didn't have a custom
    get_framebuffer vfunc. As this relies on deprecated implicit Cogl stack
    API, it needs to go away, so handle this in the caller that knows more
    about the context.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/935

 clutter/clutter/clutter-paint-node.c  |  9 +++++----
 clutter/clutter/clutter-paint-nodes.c | 18 +++++++++++++++---
 src/compositor/meta-shaped-texture.c  |  6 +++++-
 3 files changed, 25 insertions(+), 8 deletions(-)
---
diff --git a/clutter/clutter/clutter-paint-node.c b/clutter/clutter/clutter-paint-node.c
index efdaef0e6..877ec1784 100644
--- a/clutter/clutter/clutter-paint-node.c
+++ b/clutter/clutter/clutter-paint-node.c
@@ -1203,9 +1203,10 @@ clutter_paint_node_get_root (ClutterPaintNode *node)
  * @node: a #ClutterPaintNode
  *
  * Retrieves the #CoglFramebuffer that @node will draw
- * into.
+ * into, if it the root node has a custom framebuffer set.
  *
- * Returns: (transfer none): a #CoglFramebuffer
+ * Returns: (transfer none): a #CoglFramebuffer or %NULL if no custom one is
+ * set.
  */
 CoglFramebuffer *
 clutter_paint_node_get_framebuffer (ClutterPaintNode *node)
@@ -1216,6 +1217,6 @@ clutter_paint_node_get_framebuffer (ClutterPaintNode *node)
   klass = CLUTTER_PAINT_NODE_GET_CLASS (root);
   if (klass->get_framebuffer != NULL)
     return klass->get_framebuffer (root);
-
-  return cogl_get_draw_framebuffer ();
+  else
+    return NULL;
 }
diff --git a/clutter/clutter/clutter-paint-nodes.c b/clutter/clutter/clutter-paint-nodes.c
index 964ef3ea6..e9282431f 100644
--- a/clutter/clutter/clutter-paint-nodes.c
+++ b/clutter/clutter/clutter-paint-nodes.c
@@ -413,6 +413,18 @@ clutter_pipeline_node_pre_draw (ClutterPaintNode    *node,
   return FALSE;
 }
 
+static CoglFramebuffer *
+get_target_framebuffer (ClutterPaintNode *node)
+{
+  CoglFramebuffer *framebuffer;
+
+  framebuffer = clutter_paint_node_get_framebuffer (node);
+  if (framebuffer)
+    return framebuffer;
+
+  return cogl_get_draw_framebuffer ();
+}
+
 static void
 clutter_pipeline_node_draw (ClutterPaintNode    *node,
                             ClutterPaintContext *paint_context)
@@ -818,7 +830,7 @@ clutter_text_node_draw (ClutterPaintNode    *node,
   if (node->operations == NULL)
     return;
 
-  fb = clutter_paint_node_get_framebuffer (node);
+  fb = get_target_framebuffer (node);
 
   pango_layout_get_pixel_extents (tnode->layout, NULL, &extents);
 
@@ -1004,7 +1016,7 @@ clutter_clip_node_pre_draw (ClutterPaintNode    *node,
   if (node->operations == NULL)
     return FALSE;
 
-  fb = clutter_paint_node_get_framebuffer (node);
+  fb = get_target_framebuffer (node);
 
   for (i = 0; i < node->operations->len; i++)
     {
@@ -1048,7 +1060,7 @@ clutter_clip_node_post_draw (ClutterPaintNode    *node,
   if (node->operations == NULL)
     return;
 
-  fb = clutter_paint_node_get_framebuffer (node);
+  fb = get_target_framebuffer (node);
 
   for (i = 0; i < node->operations->len; i++)
     {
diff --git a/src/compositor/meta-shaped-texture.c b/src/compositor/meta-shaped-texture.c
index ec02667ac..7a1a91df5 100644
--- a/src/compositor/meta-shaped-texture.c
+++ b/src/compositor/meta-shaped-texture.c
@@ -525,6 +525,7 @@ do_paint_content (MetaShapedTexture *stex,
   cairo_region_t *blended_tex_region;
   CoglContext *ctx;
   CoglPipelineFilter filter;
+  CoglFramebuffer *framebuffer;
 
   ensure_size_valid (stex);
 
@@ -547,7 +548,10 @@ do_paint_content (MetaShapedTexture *stex,
 
   filter = COGL_PIPELINE_FILTER_LINEAR;
 
-  if (meta_actor_painting_untransformed (clutter_paint_node_get_framebuffer (root_node),
+  framebuffer = clutter_paint_node_get_framebuffer (root_node);
+  if (!framebuffer)
+    framebuffer = cogl_get_draw_framebuffer ();
+  if (meta_actor_painting_untransformed (framebuffer,
                                          dst_width, dst_height,
                                          NULL, NULL))
     filter = COGL_PIPELINE_FILTER_NEAREST;