clutter/effect: Add paint nodes to all paint vfuncs

In the purely paint node based rendering future, ClutterEffects
simply add more paint nodes to the tree when painting the actor.

This is the leap to achieve that future.

Add paint nodes to pre_paint, paint, and post_paint, and move the
ClutterEffectNode creation to _clutter_effect_paint().

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1355>

clutter/clutter/clutter-blur-effect.c

@@ -126,6 +126,7 @@ clutter_blur_effect_create_pipeline (ClutterOffscreenEffect *effect,
 
 static gboolean
 clutter_blur_effect_pre_paint (ClutterEffect       *effect,
+                               ClutterPaintNode    *node,
                                ClutterPaintContext *paint_context)
 {
   ClutterEffectClass *parent_class;
@@ -143,7 +144,7 @@ clutter_blur_effect_pre_paint (ClutterEffect       *effect,
     }
 
   parent_class = CLUTTER_EFFECT_CLASS (clutter_blur_effect_parent_class);
-  return parent_class->pre_paint (effect, paint_context);
+  return parent_class->pre_paint (effect, node, paint_context);
 }
 
 static gboolean

clutter/clutter/clutter-brightness-contrast-effect.c

@@ -140,6 +140,7 @@ clutter_brightness_contrast_effect_create_pipeline (ClutterOffscreenEffect *effe
 
 static gboolean
 clutter_brightness_contrast_effect_pre_paint (ClutterEffect       *effect,
+                                              ClutterPaintNode    *node,
                                               ClutterPaintContext *paint_context)
 {
   ClutterBrightnessContrastEffect *self = CLUTTER_BRIGHTNESS_CONTRAST_EFFECT (effect);
@@ -164,7 +165,7 @@ clutter_brightness_contrast_effect_pre_paint (ClutterEffect       *effect,
   parent_class =
     CLUTTER_EFFECT_CLASS (clutter_brightness_contrast_effect_parent_class);
 
-  return parent_class->pre_paint (effect, paint_context);
+  return parent_class->pre_paint (effect, node, paint_context);
 }
 
 static void

clutter/clutter/clutter-colorize-effect.c

@@ -114,6 +114,7 @@ clutter_colorize_effect_create_pipeline (ClutterOffscreenEffect *effect,
 
 static gboolean
 clutter_colorize_effect_pre_paint (ClutterEffect       *effect,
+                                   ClutterPaintNode    *node,
                                    ClutterPaintContext *paint_context)
 {
   ClutterEffectClass *parent_class;
@@ -131,7 +132,7 @@ clutter_colorize_effect_pre_paint (ClutterEffect       *effect,
     }
 
   parent_class = CLUTTER_EFFECT_CLASS (clutter_colorize_effect_parent_class);
-  return parent_class->pre_paint (effect, paint_context);
+  return parent_class->pre_paint (effect, node, paint_context);
 }
 
 static void

clutter/clutter/clutter-desaturate-effect.c

@@ -125,6 +125,7 @@ clutter_desaturate_effect_create_pipeline (ClutterOffscreenEffect *effect,
 
 static gboolean
 clutter_desaturate_effect_pre_paint (ClutterEffect       *effect,
+                                     ClutterPaintNode    *node,
                                      ClutterPaintContext *paint_context)
 {
   ClutterEffectClass *parent_class;
@@ -142,7 +143,7 @@ clutter_desaturate_effect_pre_paint (ClutterEffect       *effect,
     }
 
   parent_class = CLUTTER_EFFECT_CLASS (clutter_desaturate_effect_parent_class);
-  return parent_class->pre_paint (effect, paint_context);
+  return parent_class->pre_paint (effect, node, paint_context);
 }
 
 static void

clutter/clutter/clutter-effect.c

@@ -180,6 +180,7 @@ G_DEFINE_ABSTRACT_TYPE (ClutterEffect,
 
 static gboolean
 clutter_effect_real_pre_paint (ClutterEffect       *effect,
+                               ClutterPaintNode    *node,
                                ClutterPaintContext *paint_context)
 {
   return TRUE;
@@ -187,6 +188,7 @@ clutter_effect_real_pre_paint (ClutterEffect       *effect,
 
 static void
 clutter_effect_real_post_paint (ClutterEffect       *effect,
+                                ClutterPaintNode    *node,
                                 ClutterPaintContext *paint_context)
 {
 }
@@ -216,28 +218,23 @@ clutter_effect_real_paint_node (ClutterEffect           *effect,
 
 static void
 clutter_effect_real_paint (ClutterEffect           *effect,
+                           ClutterPaintNode        *node,
                            ClutterPaintContext     *paint_context,
                            ClutterEffectPaintFlags  flags)
 {
   ClutterEffectClass *effect_class = CLUTTER_EFFECT_GET_CLASS (effect);
-  ClutterPaintNode *node;
   gboolean pre_paint_succeeded;
 
   /* The default implementation provides a compatibility wrapper for
      effects that haven't migrated to use the 'paint' virtual yet. This
      just calls the old pre and post virtuals before chaining on */
 
-  pre_paint_succeeded = effect_class->pre_paint (effect, paint_context);
+  pre_paint_succeeded = effect_class->pre_paint (effect, node,paint_context);
-
-  node = clutter_effect_node_new (effect);
 
   effect_class->paint_node (effect, node, paint_context, flags);
-  clutter_paint_node_paint (node, paint_context);
 
   if (pre_paint_succeeded)
-    effect_class->post_paint (effect, paint_context);
+    effect_class->post_paint (effect, node, paint_context);
-
-  clutter_paint_node_unref (node);
 }
 
 static void
@@ -291,9 +288,19 @@ _clutter_effect_paint (ClutterEffect           *effect,
                        ClutterPaintContext     *paint_context,
                        ClutterEffectPaintFlags  flags)
 {
+  ClutterPaintNode *node;
+
   g_return_if_fail (CLUTTER_IS_EFFECT (effect));
 
-  CLUTTER_EFFECT_GET_CLASS (effect)->paint (effect, paint_context, flags);
+  node = clutter_effect_node_new (effect);
+
+  CLUTTER_EFFECT_GET_CLASS (effect)->paint (effect,
+                                            node,
+                                            paint_context,
+                                            flags);
+
+  clutter_paint_node_paint (node, paint_context);
+  clutter_paint_node_unref (node);
 }
 
 void

clutter/clutter/clutter-effect.h

@@ -77,14 +77,17 @@ struct _ClutterEffectClass
 
   /*< public >*/
   gboolean (* pre_paint)           (ClutterEffect           *effect,
+                                    ClutterPaintNode        *node,
                                     ClutterPaintContext     *paint_context);
   void     (* post_paint)          (ClutterEffect           *effect,
+                                    ClutterPaintNode        *node,
                                     ClutterPaintContext     *paint_context);
 
   gboolean (* modify_paint_volume) (ClutterEffect           *effect,
                                     ClutterPaintVolume      *volume);
 
   void     (* paint)               (ClutterEffect           *effect,
+                                    ClutterPaintNode        *node,
                                     ClutterPaintContext     *paint_context,
                                     ClutterEffectPaintFlags  flags);
   void     (* paint_node)          (ClutterEffect           *effect,

clutter/clutter/clutter-offscreen-effect.c

@@ -99,8 +99,6 @@ struct _ClutterOffscreenEffectPrivate
   int target_width;
   int target_height;
 
-  gint old_opacity_override;
-
   gulong purge_handler_id;
 };
 
@@ -270,6 +268,7 @@ update_fbo (ClutterEffect *effect,
 
 static gboolean
 clutter_offscreen_effect_pre_paint (ClutterEffect       *effect,
+                                    ClutterPaintNode    *node,
                                     ClutterPaintContext *paint_context)
 {
   ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
@@ -279,7 +278,6 @@ clutter_offscreen_effect_pre_paint (ClutterEffect       *effect,
   ClutterActor *stage;
   graphene_matrix_t projection, modelview;
   const ClutterPaintVolume *volume;
-  CoglColor transparent;
   gfloat stage_width, stage_height;
   gfloat target_width = -1, target_height = -1;
   float resource_scale;
@@ -336,7 +334,6 @@ clutter_offscreen_effect_pre_paint (ClutterEffect       *effect,
     goto disable_effect;
 
   offscreen = COGL_FRAMEBUFFER (priv->offscreen);
-  clutter_paint_context_push_framebuffer (paint_context, offscreen);
 
   /* We don't want the FBO contents to be transformed. That could waste memory
    * (e.g. during zoom), or result in something that's not rectangular (clipped
@@ -363,22 +360,6 @@ clutter_offscreen_effect_pre_paint (ClutterEffect       *effect,
 
   cogl_framebuffer_set_projection_matrix (offscreen, &projection);
 
-  cogl_color_init_from_4ub (&transparent, 0, 0, 0, 0);
-  cogl_framebuffer_clear (offscreen,
-                          COGL_BUFFER_BIT_COLOR |
-                          COGL_BUFFER_BIT_DEPTH,
-                          &transparent);
-
-  cogl_framebuffer_push_matrix (offscreen);
-
-  /* Override the actor's opacity to fully opaque - we paint the offscreen
-   * texture with the actor's paint opacity, so we need to do this to avoid
-   * multiplying the opacity twice.
-   */
-  priv->old_opacity_override =
-    clutter_actor_get_opacity_override (priv->actor);
-  clutter_actor_set_opacity_override (priv->actor, 0xff);
-
   return TRUE;
 
 disable_effect:
@@ -425,63 +406,57 @@ clutter_offscreen_effect_real_paint_target (ClutterOffscreenEffect *effect,
 
 static void
 clutter_offscreen_effect_paint_texture (ClutterOffscreenEffect *effect,
+                                        ClutterPaintNode       *node,
                                         ClutterPaintContext    *paint_context)
 {
   ClutterOffscreenEffectPrivate *priv = effect->priv;
-  CoglFramebuffer *framebuffer =
+  graphene_matrix_t transform;
-    clutter_paint_context_get_framebuffer (paint_context);
   float resource_scale;
 
-  cogl_framebuffer_push_matrix (framebuffer);
+  graphene_matrix_init_translate (&transform,
+                                  &GRAPHENE_POINT3D_INIT (priv->fbo_offset_x,
+                                                          priv->fbo_offset_y,
+                                                          0.0f));
 
-  /* The current modelview matrix is *almost* perfect already. It's only
-   * missing a correction for the expanded FBO and offset rendering within...
-   */
   resource_scale = clutter_actor_get_resource_scale (priv->actor);
-
   if (resource_scale != 1.0f)
     {
       float paint_scale = 1.0f / resource_scale;
-      cogl_framebuffer_scale (framebuffer, paint_scale, paint_scale, 1.f);
+      graphene_matrix_scale (&transform, paint_scale, paint_scale, 1.f);
     }
 
-  cogl_framebuffer_translate (framebuffer,
+  if (!graphene_matrix_is_identity (&transform))
-                              priv->fbo_offset_x,
+    {
-                              priv->fbo_offset_y,
+      ClutterPaintNode *transform_node;
-                              0.0f);
+
+      transform_node = clutter_transform_node_new (&transform);
+      clutter_paint_node_set_static_name (transform_node,
+                                          "ClutterOffscreenEffect (transform)");
+      clutter_paint_node_add_child (node, transform_node);
+      clutter_paint_node_unref (transform_node);
+
+      node = transform_node;
+    }
 
   /* paint the target material; this is virtualized for
    * sub-classes that require special hand-holding
    */
-  clutter_offscreen_effect_paint_target (effect, paint_context);
+  clutter_offscreen_effect_paint_target (effect, node, paint_context);
-
-  cogl_framebuffer_pop_matrix (framebuffer);
 }
 
 static void
 clutter_offscreen_effect_post_paint (ClutterEffect       *effect,
+                                     ClutterPaintNode    *node,
                                      ClutterPaintContext *paint_context)
 {
   ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
   ClutterOffscreenEffectPrivate *priv = self->priv;
-  CoglFramebuffer *framebuffer;
 
   g_warn_if_fail (priv->offscreen);
   g_warn_if_fail (priv->pipeline);
   g_warn_if_fail (priv->actor);
 
-  /* Restore the previous opacity override */
+  clutter_offscreen_effect_paint_texture (self, node, paint_context);
-  if (priv->actor)
-    {
-      clutter_actor_set_opacity_override (priv->actor,
-                                          priv->old_opacity_override);
-    }
-
-  framebuffer = clutter_paint_context_get_framebuffer (paint_context);
-  cogl_framebuffer_pop_matrix (framebuffer);
-  clutter_paint_context_pop_framebuffer (paint_context);
-
-  clutter_offscreen_effect_paint_texture (self, paint_context);
 }
 
 static void
@@ -520,15 +495,18 @@ clutter_offscreen_effect_paint_node (ClutterEffect           *effect,
 
 static void
 clutter_offscreen_effect_paint (ClutterEffect           *effect,
+                                ClutterPaintNode        *node,
                                 ClutterPaintContext     *paint_context,
                                 ClutterEffectPaintFlags  flags)
 {
   ClutterOffscreenEffect *self = CLUTTER_OFFSCREEN_EFFECT (effect);
   ClutterOffscreenEffectPrivate *priv = self->priv;
+  ClutterEffectClass *parent_class =
+    CLUTTER_EFFECT_CLASS (clutter_offscreen_effect_parent_class);
 
   if (flags & CLUTTER_EFFECT_PAINT_BYPASS_EFFECT)
     {
-      clutter_actor_continue_paint (priv->actor, paint_context);
+      add_actor_node (self, node, -1);
       g_clear_object (&priv->offscreen);
       return;
     }
@@ -537,14 +515,9 @@ clutter_offscreen_effect_paint (ClutterEffect           *effect,
    * then we can just use the cached image in the FBO.
    */
   if (priv->offscreen == NULL || (flags & CLUTTER_EFFECT_PAINT_ACTOR_DIRTY))
-    {
+    parent_class->paint (effect, node, paint_context, flags);
-      ClutterEffectClass *parent_class =
-        CLUTTER_EFFECT_CLASS (clutter_offscreen_effect_parent_class);
-
-      parent_class->paint (effect, paint_context, flags);
-    }
   else
-    clutter_offscreen_effect_paint_texture (self, paint_context);
+    clutter_offscreen_effect_paint_texture (self, node, paint_context);
 }
 
 static void
@@ -659,6 +632,7 @@ clutter_offscreen_effect_get_pipeline (ClutterOffscreenEffect *effect)
 /**
  * clutter_offscreen_effect_paint_target:
  * @effect: a #ClutterOffscreenEffect
+ * @node: a #ClutterPaintNode
  * @paint_context: a #ClutterPaintContext
  *
  * Calls the paint_target() virtual function of the @effect
@@ -667,19 +641,14 @@ clutter_offscreen_effect_get_pipeline (ClutterOffscreenEffect *effect)
  */
 void
 clutter_offscreen_effect_paint_target (ClutterOffscreenEffect *effect,
+                                       ClutterPaintNode       *node,
                                        ClutterPaintContext    *paint_context)
 {
-  ClutterPaintNode *node;
-
   g_return_if_fail (CLUTTER_IS_OFFSCREEN_EFFECT (effect));
 
-  node = clutter_effect_node_new (CLUTTER_EFFECT (effect));
-
   CLUTTER_OFFSCREEN_EFFECT_GET_CLASS (effect)->paint_target (effect,
                                                              node,
                                                              paint_context);
-  clutter_paint_node_paint (node, paint_context);
-  clutter_paint_node_unref (node);
 }
 
 /**

clutter/clutter/clutter-offscreen-effect.h

@@ -106,6 +106,7 @@ CoglHandle      clutter_offscreen_effect_get_texture            (ClutterOffscree
 
 CLUTTER_EXPORT
 void            clutter_offscreen_effect_paint_target           (ClutterOffscreenEffect *effect,
+                                                                 ClutterPaintNode       *node,
                                                                  ClutterPaintContext    *paint_context);
 CLUTTER_EXPORT
 CoglHandle      clutter_offscreen_effect_create_texture         (ClutterOffscreenEffect *effect,