[mutter/wayland] shaped-texture: Simplify pipeline creation

[Jasper St. Pierre <jstpierre src gnome org>]

commit 69f038f7c799ad7a7e8309a47ee05c0095e4ed72
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Aug 27 16:03:42 2013 -0400

    shaped-texture: Simplify pipeline creation
    
    Split out pipeline creation to a separate function so that we don't
    have so much dense code in the paint function itself, and remove some
    indentation levels.
    
    Also, don't use our own template for the unmasked pipeline, since it
    has nothing different from the default pipeline template.
    
    We also don't store the pipelines anymore since their creation isn't
    really helping us; we set the mask texture and paint texture on every
    paint anyway.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=707019

 src/compositor/meta-shaped-texture.c |   72 ++++++++++++++--------------------
 1 files changed, 30 insertions(+), 42 deletions(-)
---
diff --git a/src/compositor/meta-shaped-texture.c b/src/compositor/meta-shaped-texture.c
index 856f284..142a3e9 100644
--- a/src/compositor/meta-shaped-texture.c
+++ b/src/compositor/meta-shaped-texture.c
@@ -91,8 +91,6 @@ struct _MetaShapedTexturePrivate
   CoglTexture *texture;
 
   CoglTexture *mask_texture;
-  CoglPipeline *pipeline;
-  CoglPipeline *pipeline_unshaped;
 
   cairo_region_t *clip_region;
   cairo_region_t *input_shape_region;
@@ -145,8 +143,6 @@ meta_shaped_texture_dispose (GObject *object)
     meta_texture_tower_free (priv->paint_tower);
   priv->paint_tower = NULL;
 
-  g_clear_pointer (&priv->pipeline, cogl_object_unref);
-  g_clear_pointer (&priv->pipeline_unshaped, cogl_object_unref);
   g_clear_pointer (&priv->texture, cogl_object_unref);
 
   meta_shaped_texture_set_mask_texture (self, NULL);
@@ -155,6 +151,27 @@ meta_shaped_texture_dispose (GObject *object)
   G_OBJECT_CLASS (meta_shaped_texture_parent_class)->dispose (object);
 }
 
+static CoglPipeline *
+get_unmasked_pipeline (CoglContext *ctx)
+{
+  return cogl_pipeline_new (ctx);
+}
+
+static CoglPipeline *
+get_masked_pipeline (CoglContext *ctx)
+{
+  static CoglPipeline *template = NULL;
+  if (G_UNLIKELY (template == NULL))
+    {
+      template = cogl_pipeline_new (ctx);
+      cogl_pipeline_set_layer_combine (template, 1,
+                                       "RGBA = MODULATE (PREVIOUS, TEXTURE[A])",
+                                       NULL);
+    }
+
+  return cogl_pipeline_copy (template);
+}
+
 static void
 set_cogl_texture (MetaShapedTexture *stex,
                   CoglTexture       *cogl_tex)
@@ -171,12 +188,6 @@ set_cogl_texture (MetaShapedTexture *stex,
 
   priv->texture = cogl_tex;
 
-  if (priv->pipeline != NULL)
-    cogl_pipeline_set_layer_texture (priv->pipeline, 0, COGL_TEXTURE (cogl_tex));
-
-  if (priv->pipeline_unshaped != NULL)
-    cogl_pipeline_set_layer_texture (priv->pipeline_unshaped, 0, COGL_TEXTURE (cogl_tex));
-
   if (cogl_tex != NULL)
     {
       width = cogl_texture_get_width (COGL_TEXTURE (cogl_tex));
@@ -213,10 +224,7 @@ meta_shaped_texture_paint (ClutterActor *actor)
   CoglTexture *paint_tex;
   guint tex_width, tex_height;
   ClutterActorBox alloc;
-
-  static CoglPipeline *pipeline_template = NULL;
-  static CoglPipeline *pipeline_unshaped_template = NULL;
-
+  CoglContext *ctx;
   CoglPipeline *pipeline;
 
   if (priv->clip_region && cairo_region_is_empty (priv->clip_region))
@@ -254,38 +262,15 @@ meta_shaped_texture_paint (ClutterActor *actor)
   if (tex_width == 0 || tex_height == 0) /* no contents yet */
     return;
 
+  ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
+
   if (priv->mask_texture == NULL)
     {
-      /* Use a single-layer texture if we don't have a mask. */
-
-      if (priv->pipeline_unshaped == NULL)
-        {
-          if (G_UNLIKELY (pipeline_unshaped_template == NULL))
-            {
-              CoglContext *ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
-              pipeline_unshaped_template = cogl_pipeline_new (ctx);
-            }
-
-          priv->pipeline_unshaped = cogl_pipeline_copy (pipeline_unshaped_template);
-        }
-        pipeline = priv->pipeline_unshaped;
+      pipeline = get_unmasked_pipeline (ctx);
     }
   else
     {
-      if (priv->pipeline == NULL)
-       {
-          if (G_UNLIKELY (pipeline_template == NULL))
-           {
-              CoglContext *ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
-             pipeline_template =  cogl_pipeline_new (ctx);
-             cogl_pipeline_set_layer_combine (pipeline_template, 1,
-                                          "RGBA = MODULATE (PREVIOUS, TEXTURE[A])",
-                                          NULL);
-           }
-         priv->pipeline = cogl_pipeline_copy (pipeline_template);
-       }
-      pipeline = priv->pipeline;
-
+      pipeline = get_masked_pipeline (ctx);
       cogl_pipeline_set_layer_texture (pipeline, 1, priv->mask_texture);
     }
 
@@ -346,13 +331,16 @@ meta_shaped_texture_paint (ClutterActor *actor)
                                                        &coords[0], 8);
             }
 
-         return;
+          goto out;
        }
     }
 
   cogl_rectangle (0, 0,
                  alloc.x2 - alloc.x1,
                  alloc.y2 - alloc.y1);
+
+ out:
+  cogl_object_unref (pipeline);
 }
 
 static void