cogl/pipeline-layer: Inherit from GObject directly

Instead of inheriting from CoglNode, inherit from GObject and manually
manage children.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4155>

cogl/cogl/cogl-pipeline-debug.c

@@ -49,10 +49,10 @@ typedef struct
   int indent;
 } PrintDebugState;
 
-static gboolean
-dump_layer_cb (CoglNode *node, void *user_data)
+static void
+dump_layer_cb (CoglPipelineLayer *layer,
+               gpointer           user_data)
 {
-  CoglPipelineLayer *layer = COGL_PIPELINE_LAYER (node);
   PrintDebugState *state = user_data;
   int layer_id = *state->node_id_ptr;
   PrintDebugState state_out;
@@ -62,7 +62,7 @@ dump_layer_cb (CoglNode *node, void *user_data)
   if (state->parent_id >= 0)
     g_string_append_printf (state->graph, "%*slayer%p -> layer%p;\n",
                             state->indent, "",
-                            layer->parent_instance.parent,
+                            layer->parent,
                             layer);
 
   g_string_append_printf (state->graph,
@@ -116,11 +116,12 @@ dump_layer_cb (CoglNode *node, void *user_data)
   state_out.graph = state->graph;
   state_out.indent = state->indent + 2;
 
-  _cogl_pipeline_node_foreach_child (COGL_NODE (layer),
-                                     dump_layer_cb,
-                                     &state_out);
-
-  return TRUE;
+  for (CoglPipelineLayer *child = layer->first_child;
+       child != NULL;
+       child = child->next_sibling)
+    {
+      dump_layer_cb (child, &state_out);
+    }
 }
 
 static gboolean
@@ -264,7 +265,7 @@ _cogl_debug_dump_pipelines_dot_file (const char  *filename,
   layer_state.parent_id = -1;
   layer_state.node_id_ptr = &layer_id;
   layer_state.indent = 0;
-  dump_layer_cb ((CoglNode *)ctx->default_layer_0, &layer_state);
+  dump_layer_cb (ctx->default_layer_0, &layer_state);
 
   pipeline_state.graph = graph;
   pipeline_state.parent_id = -1;

cogl/cogl/cogl-pipeline-layer-private.h

@@ -35,7 +35,6 @@
 
 #include "cogl/cogl-private.h"
 #include "cogl/cogl-pipeline.h"
-#include "cogl/cogl-node-private.h"
 #include "cogl/cogl-texture.h"
 #include "cogl/cogl-pipeline-layer-state.h"
 #include "cogl/cogl-pipeline-snippet-private.h"
@@ -218,7 +217,13 @@ struct _CoglPipelineLayer
    * the state relating to a given pipeline or layer may actually be
    * owned by one if is ancestors in the tree. We have a common data
    * type to track the tree hierarchy so we can share code... */
-  CoglNode parent_instance;
+  GObject parent_instance;
+
+  CoglPipelineLayer *parent;
+  CoglPipelineLayer *prev_sibling;
+  CoglPipelineLayer *next_sibling;
+  CoglPipelineLayer *first_child;
+  CoglPipelineLayer *last_child;
 
   /* Some layers have a pipeline owner, which is to say that the layer
    * is referenced in that pipelines->layer_differences list.  A layer
@@ -264,7 +269,7 @@ struct _CoglPipelineLayer
 
 struct _CoglPipelineLayerClass
 {
-   CoglNodeClass parent_class;
+   GObjectClass parent_class;
 };
 
 
@@ -280,8 +285,7 @@ _cogl_pipeline_init_default_layers (CoglContext *ctx);
 static inline CoglPipelineLayer *
 _cogl_pipeline_layer_get_parent (CoglPipelineLayer *layer)
 {
-  CoglNode *parent_node = COGL_NODE (layer)->parent;
-  return COGL_PIPELINE_LAYER (parent_node);
+  return layer->parent;
 }
 
 CoglPipelineLayer *

cogl/cogl/cogl-pipeline-layer.c

@@ -41,20 +41,42 @@
 #include "cogl/cogl-pipeline-layer-private.h"
 #include "cogl/cogl-pipeline-layer-state-private.h"
 #include "cogl/cogl-pipeline-layer-state.h"
-#include "cogl/cogl-node-private.h"
 #include "cogl/cogl-context-private.h"
 #include "cogl/cogl-texture-private.h"
 
 #include <string.h>
 
-G_DEFINE_FINAL_TYPE (CoglPipelineLayer, cogl_pipeline_layer, COGL_TYPE_NODE)
+G_DEFINE_FINAL_TYPE (CoglPipelineLayer, cogl_pipeline_layer, G_TYPE_OBJECT)
+
+static void
+cogl_pipeline_layer_unparent (CoglPipelineLayer *layer)
+{
+  g_autoptr (CoglPipelineLayer) parent = g_steal_pointer (&layer->parent);
+
+  if (parent)
+    {
+      if (parent->first_child == layer)
+        parent->first_child = layer->next_sibling;
+
+      if (parent->last_child == layer)
+        parent->last_child = layer->prev_sibling;
+
+      if (layer->prev_sibling)
+        layer->prev_sibling->next_sibling = layer->next_sibling;
+      if (layer->next_sibling)
+        layer->next_sibling->prev_sibling = layer->prev_sibling;
+    }
+
+  layer->prev_sibling = NULL;
+  layer->next_sibling = NULL;
+}
 
 static void
 cogl_pipeline_layer_dispose (GObject *object)
 {
   CoglPipelineLayer *layer = COGL_PIPELINE_LAYER (object);
 
-  _cogl_pipeline_node_unparent (COGL_NODE (layer));
+  cogl_pipeline_layer_unparent (layer);
 
   if (layer->differences & COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA &&
       layer->texture != NULL)
@@ -371,8 +393,7 @@ _cogl_pipeline_layer_pre_change_notify (CoglPipeline *required_owner,
 {
   /* Identify the case where the layer is new with no owner or
    * dependants and so we don't need to do anything. */
-  if (_cogl_list_empty (&COGL_NODE (layer)->children) &&
-      layer->owner == NULL)
+  if (layer->first_child == NULL && layer->owner == NULL)
     goto init_layer_state;
 
   /* We only allow a NULL required_owner for new layers */
@@ -393,8 +414,7 @@ _cogl_pipeline_layer_pre_change_notify (CoglPipeline *required_owner,
    * they have dependants - either direct children, or another
    * pipeline as an owner.
    */
-  if (!_cogl_list_empty (&COGL_NODE (layer)->children) ||
-      layer->owner != required_owner)
+  if (layer->first_child != NULL || layer->owner != required_owner)
     {
       CoglPipelineLayer *new = _cogl_pipeline_layer_copy (layer);
       if (layer->owner == required_owner)
@@ -468,10 +488,32 @@ static void
 _cogl_pipeline_layer_set_parent (CoglPipelineLayer *layer,
                                  CoglPipelineLayer *parent)
 {
-  /* Chain up */
-  _cogl_pipeline_node_set_parent (COGL_NODE (layer),
-                                  COGL_NODE (parent),
-                                  TRUE);
+  g_autoptr (CoglPipelineLayer) owned_parent = NULL;
+
+  g_assert (COGL_IS_PIPELINE_LAYER (layer));
+  g_assert (COGL_IS_PIPELINE_LAYER (parent));
+
+  if (layer->parent == parent)
+    return;
+
+  if (layer->parent)
+    {
+      owned_parent = g_object_ref (layer->parent);
+      cogl_pipeline_layer_unparent (layer);
+    }
+
+  layer->parent = g_object_ref (parent);
+
+  if (parent->first_child)
+    {
+      parent->first_child->prev_sibling = layer;
+      layer->next_sibling = parent->first_child;
+    }
+  else
+    {
+      parent->last_child = layer;
+    }
+  parent->first_child = layer;
 }
 
 CoglPipelineLayer *

cogl/cogl/cogl-pipeline.c

@@ -2558,7 +2558,7 @@ deep_copy_layer_cb (CoglPipelineLayer *src_layer,
           differences ^= to_copy;
         }
 
-      src_layer = COGL_PIPELINE_LAYER (COGL_NODE (src_layer)->parent);
+      src_layer = src_layer->parent;
     }
 
   return TRUE;