[mutter/gbsneto/offscreen-paint-node: 1/8] clutter/offscreen-effect: Use paint nodes to paint target

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

commit 1135a74e3e9cb28229440345ead62112df8d6a72
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sun Jul 5 17:44:38 2020 -0300

    clutter/offscreen-effect: Use paint nodes to paint target
    
    Add a new ClutterPaintNode parameter to the paint_target() vfunc.
    For now, create a temporary ClutterEffectNode that is passed to
    paint_target() and immediately painted; next commits will move
    this to upper layers.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1355

 clutter/clutter/clutter-deform-effect.c         | 44 ++++++++++++++++++-------
 clutter/clutter/clutter-offscreen-effect.c      | 33 ++++++++++++++-----
 clutter/clutter/clutter-offscreen-effect.h      |  1 +
 clutter/clutter/clutter-shader-effect.c         |  3 +-
 src/tests/clutter/conform/actor-shader-effect.c |  6 ++--
 5 files changed, 64 insertions(+), 23 deletions(-)
---
diff --git a/clutter/clutter/clutter-deform-effect.c b/clutter/clutter/clutter-deform-effect.c
index d244761725..fbd524690c 100644
--- a/clutter/clutter/clutter-deform-effect.c
+++ b/clutter/clutter/clutter-deform-effect.c
@@ -58,9 +58,12 @@
 
 #include <cogl/cogl.h>
 
+#include "clutter-color.h"
 #include "clutter-debug.h"
 #include "clutter-enum-types.h"
 #include "clutter-offscreen-effect-private.h"
+#include "clutter-paint-node.h"
+#include "clutter-paint-nodes.h"
 #include "clutter-private.h"
 
 #define DEFAULT_N_TILES         32
@@ -166,14 +169,13 @@ clutter_deform_effect_set_actor (ClutterActorMeta *meta,
 
 static void
 clutter_deform_effect_paint_target (ClutterOffscreenEffect *effect,
+                                    ClutterPaintNode       *node,
                                     ClutterPaintContext    *paint_context)
 {
   ClutterDeformEffect *self= CLUTTER_DEFORM_EFFECT (effect);
   ClutterDeformEffectPrivate *priv = self->priv;
   CoglPipeline *pipeline;
   CoglDepthState depth_state;
-  CoglFramebuffer *fb =
-    clutter_paint_context_get_framebuffer (paint_context);
 
   if (priv->is_dirty)
     {
@@ -291,11 +293,21 @@ clutter_deform_effect_paint_target (ClutterOffscreenEffect *effect,
 
   /* draw the front */
   if (pipeline != NULL)
-    cogl_framebuffer_draw_primitive (fb, pipeline, priv->primitive);
+    {
+      ClutterPaintNode *front_node;
+
+      front_node = clutter_pipeline_node_new (pipeline);
+      clutter_paint_node_set_static_name (front_node,
+                                          "ClutterDeformEffect (front)");
+      clutter_paint_node_add_child (node, front_node);
+      clutter_paint_node_add_primitive (front_node, priv->primitive);
+      clutter_paint_node_unref (front_node);
+    }
 
   /* draw the back */
   if (priv->back_pipeline != NULL)
     {
+      ClutterPaintNode *back_node;
       CoglPipeline *back_pipeline;
 
       /* We probably shouldn't be modifying the user's material so
@@ -305,20 +317,30 @@ clutter_deform_effect_paint_target (ClutterOffscreenEffect *effect,
       cogl_pipeline_set_cull_face_mode (back_pipeline,
                                         COGL_PIPELINE_CULL_FACE_MODE_FRONT);
 
-      cogl_framebuffer_draw_primitive (fb, back_pipeline, priv->primitive);
 
+      back_node = clutter_pipeline_node_new (back_pipeline);
+      clutter_paint_node_set_static_name (back_node,
+                                          "ClutterDeformEffect (back)");
+      clutter_paint_node_add_child (node, back_node);
+      clutter_paint_node_add_primitive (back_node, priv->primitive);
+
+      clutter_paint_node_unref (back_node);
       cogl_object_unref (back_pipeline);
     }
 
   if (G_UNLIKELY (priv->lines_primitive != NULL))
     {
-      CoglContext *ctx =
-        clutter_backend_get_cogl_context (clutter_get_default_backend ());
-      CoglPipeline *lines_pipeline = cogl_pipeline_new (ctx);
-      cogl_pipeline_set_color4f (lines_pipeline, 1.0, 0, 0, 1.0);
-      cogl_framebuffer_draw_primitive (fb, lines_pipeline,
-                                       priv->lines_primitive);
-      cogl_object_unref (lines_pipeline);
+      const ClutterColor *red;
+      ClutterPaintNode *lines_node;
+
+      red = clutter_color_get_static (CLUTTER_COLOR_RED);
+
+      lines_node = clutter_color_node_new (red);
+      clutter_paint_node_set_static_name (lines_node,
+                                          "ClutterDeformEffect (lines)");
+      clutter_paint_node_add_child (node, lines_node);
+      clutter_paint_node_add_primitive (lines_node, priv->lines_primitive);
+      clutter_paint_node_unref (lines_node);
     }
 }
 
diff --git a/clutter/clutter/clutter-offscreen-effect.c b/clutter/clutter/clutter-offscreen-effect.c
index f209e9ca61..f583c5aaa0 100644
--- a/clutter/clutter/clutter-offscreen-effect.c
+++ b/clutter/clutter/clutter-offscreen-effect.c
@@ -75,6 +75,8 @@
 #include "clutter-private.h"
 #include "clutter-stage-private.h"
 #include "clutter-paint-context-private.h"
+#include "clutter-paint-node-private.h"
+#include "clutter-paint-nodes.h"
 #include "clutter-paint-volume-private.h"
 #include "clutter-actor-box-private.h"
 
@@ -381,11 +383,11 @@ fail:
 
 static void
 clutter_offscreen_effect_real_paint_target (ClutterOffscreenEffect *effect,
+                                            ClutterPaintNode       *node,
                                             ClutterPaintContext    *paint_context)
 {
   ClutterOffscreenEffectPrivate *priv = effect->priv;
-  CoglFramebuffer *framebuffer =
-    clutter_paint_context_get_framebuffer (paint_context);
+  ClutterPaintNode *pipeline_node;
   guint8 paint_opacity;
 
   paint_opacity = clutter_actor_get_paint_opacity (priv->actor);
@@ -396,18 +398,24 @@ clutter_offscreen_effect_real_paint_target (ClutterOffscreenEffect *effect,
                               paint_opacity,
                               paint_opacity);
 
+  pipeline_node = clutter_pipeline_node_new (priv->pipeline);
+  clutter_paint_node_set_static_name (pipeline_node,
+                                      "ClutterOffscreenEffect (pipeline)");
+  clutter_paint_node_add_child (node, pipeline_node);
+
   /* At this point we are in stage coordinates translated so if
    * we draw our texture using a textured quad the size of the paint
    * box then we will overlay where the actor would have drawn if it
    * hadn't been redirected offscreen.
    */
-  cogl_framebuffer_draw_textured_rectangle (framebuffer,
-                                            priv->pipeline,
-                                            0, 0,
-                                            cogl_texture_get_width (priv->texture),
-                                            cogl_texture_get_height (priv->texture),
-                                            0.0, 0.0,
-                                            1.0, 1.0);
+  clutter_paint_node_add_rectangle (pipeline_node,
+                                    &(ClutterActorBox) {
+                                        0.f, 0.f,
+                                        cogl_texture_get_width (priv->texture),
+                                        cogl_texture_get_height (priv->texture),
+                                    });
+
+  clutter_paint_node_unref (pipeline_node);
 }
 
 static void
@@ -625,10 +633,17 @@ void
 clutter_offscreen_effect_paint_target (ClutterOffscreenEffect *effect,
                                        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);
 }
 
 /**
diff --git a/clutter/clutter/clutter-offscreen-effect.h b/clutter/clutter/clutter-offscreen-effect.h
index 6a91f3f126..69ed65ebd4 100644
--- a/clutter/clutter/clutter-offscreen-effect.h
+++ b/clutter/clutter/clutter-offscreen-effect.h
@@ -82,6 +82,7 @@ struct _ClutterOffscreenEffectClass
   CoglPipeline* (* create_pipeline) (ClutterOffscreenEffect *effect,
                                      CoglTexture            *texture);
   void       (* paint_target)   (ClutterOffscreenEffect *effect,
+                                 ClutterPaintNode       *node,
                                  ClutterPaintContext    *paint_context);
 
   /*< private >*/
diff --git a/clutter/clutter/clutter-shader-effect.c b/clutter/clutter/clutter-shader-effect.c
index 87a866fdf4..02103f17ec 100644
--- a/clutter/clutter/clutter-shader-effect.c
+++ b/clutter/clutter/clutter-shader-effect.c
@@ -384,6 +384,7 @@ clutter_shader_effect_try_static_source (ClutterShaderEffect *self)
 
 static void
 clutter_shader_effect_paint_target (ClutterOffscreenEffect *effect,
+                                    ClutterPaintNode       *node,
                                     ClutterPaintContext    *paint_context)
 {
   ClutterShaderEffect *self = CLUTTER_SHADER_EFFECT (effect);
@@ -414,7 +415,7 @@ clutter_shader_effect_paint_target (ClutterOffscreenEffect *effect,
 out:
   /* paint the offscreen buffer */
   parent = CLUTTER_OFFSCREEN_EFFECT_CLASS (clutter_shader_effect_parent_class);
-  parent->paint_target (effect, paint_context);
+  parent->paint_target (effect, node, paint_context);
 
 }
 
diff --git a/src/tests/clutter/conform/actor-shader-effect.c b/src/tests/clutter/conform/actor-shader-effect.c
index 4a663403ca..5772538727 100644
--- a/src/tests/clutter/conform/actor-shader-effect.c
+++ b/src/tests/clutter/conform/actor-shader-effect.c
@@ -37,6 +37,7 @@ G_DEFINE_TYPE (FooOldShaderEffect,
 
 static void
 foo_old_shader_effect_paint_target (ClutterOffscreenEffect *effect,
+                                    ClutterPaintNode       *node,
                                     ClutterPaintContext    *paint_context)
 {
   clutter_shader_effect_set_shader_source (CLUTTER_SHADER_EFFECT (effect),
@@ -47,7 +48,7 @@ foo_old_shader_effect_paint_target (ClutterOffscreenEffect *effect,
                                      1.0f, 0.0f, 0.0f);
 
   CLUTTER_OFFSCREEN_EFFECT_CLASS (foo_old_shader_effect_parent_class)->
-    paint_target (effect, paint_context);
+    paint_target (effect, node, paint_context);
 }
 
 static void
@@ -112,6 +113,7 @@ foo_new_shader_effect_get_static_source (ClutterShaderEffect *effect)
 
 static void
 foo_new_shader_effect_paint_target (ClutterOffscreenEffect *effect,
+                                    ClutterPaintNode       *node,
                                     ClutterPaintContext    *paint_context)
 {
   clutter_shader_effect_set_uniform (CLUTTER_SHADER_EFFECT (effect),
@@ -120,7 +122,7 @@ foo_new_shader_effect_paint_target (ClutterOffscreenEffect *effect,
                                      0.0f, 1.0f, 0.0f);
 
   CLUTTER_OFFSCREEN_EFFECT_CLASS (foo_new_shader_effect_parent_class)->
-    paint_target (effect, paint_context);
+    paint_target (effect, node, paint_context);
 }
 
 static void