gsk: Tie render nodes to renderers

Render nodes need access to rendering information like scaling factors.
If we keep render nodes separate from renderers until we submit a nodes
tree for rendering we're going to have to duplicate all that information
in a way that makes the API more complicated and fuzzier on its
semantics.

By having GskRenderer create GskRenderNode instances we can tie nodes
and renderers together; since higher layers will also have access to
the renderer instance, this does not add any burden to callers.

Additionally, if memory measurements indicate that we are spending too
much time in the allocation of new render nodes, we can now easily
implement a free-list or a renderer-specific allocator without breaking
the API.

gsk/gskrenderer.c

@@ -921,6 +921,7 @@ gsk_renderer_render (GskRenderer       *renderer,
   g_return_if_fail (GDK_IS_DRAWING_CONTEXT (context));
   g_return_if_fail (priv->drawing_context == NULL);
   g_return_if_fail (priv->root_node == NULL);
+  g_return_if_fail (root->renderer == renderer);
 
   priv->drawing_context = g_object_ref (context);
   priv->root_node = gsk_render_node_ref (root);
@@ -1034,6 +1035,24 @@ gsk_renderer_get_use_alpha (GskRenderer *renderer)
   return priv->use_alpha;
 }
 
+/**
+ * gsk_renderer_create_render_node:
+ * @renderer: a #GskRenderer
+ *
+ * Creates a new #GskRenderNode instance tied to the given @renderer.
+ *
+ * Returns: (transfer full): the new #GskRenderNode
+ *
+ * Since: 3.22
+ */
+GskRenderNode *
+gsk_renderer_create_render_node (GskRenderer *renderer)
+{
+  g_return_val_if_fail (GSK_IS_RENDERER (renderer), NULL);
+
+  return gsk_render_node_new (renderer);
+}
+
 /**
  * gsk_renderer_get_for_display:
  * @display: a #GdkDisplay

gsk/gskrenderer.h

@@ -96,6 +96,10 @@ GDK_AVAILABLE_IN_3_22
 gboolean                gsk_renderer_realize                    (GskRenderer             *renderer);
 GDK_AVAILABLE_IN_3_22
 void                    gsk_renderer_unrealize                  (GskRenderer             *renderer);
+
+GDK_AVAILABLE_IN_3_22
+GskRenderNode *         gsk_renderer_create_render_node         (GskRenderer             *renderer);
+
 GDK_AVAILABLE_IN_3_22
 void                    gsk_renderer_render                     (GskRenderer             *renderer,
                                                                  GskRenderNode           *root,

gsk/gskrendernode.c

@@ -233,19 +233,22 @@ gsk_render_node_get_type (void)
   return gsk_render_node_type__volatile;
 }
 
-/**
+/*< private >
  * gsk_render_node_new:
+ * @renderer: a #GskRenderer
  *
- * Creates a new #GskRenderNode, to be used with #GskRenderer.
+ * Creates a new #GskRenderNode, to be used with a #GskRenderer.
  *
  * Returns: (transfer full): the newly created #GskRenderNode
- *
- * Since: 3.22
  */
 GskRenderNode *
-gsk_render_node_new (void)
+gsk_render_node_new (GskRenderer *renderer)
 {
-  return (GskRenderNode *) g_type_create_instance (GSK_TYPE_RENDER_NODE);
+  GskRenderNode *res = (GskRenderNode *) g_type_create_instance (GSK_TYPE_RENDER_NODE);
+
+  res->renderer = renderer;
+
+  return res;
 }
 
 /**

gsk/gskrendernode.h

@@ -38,8 +38,6 @@ typedef struct _GskRenderNodeClass      GskRenderNodeClass;
 GDK_AVAILABLE_IN_3_22
 GType gsk_render_node_get_type (void) G_GNUC_CONST;
 
-GDK_AVAILABLE_IN_3_22
-GskRenderNode *         gsk_render_node_new                     (void);
 GDK_AVAILABLE_IN_3_22
 GskRenderNode *         gsk_render_node_ref                     (GskRenderNode *node);
 GDK_AVAILABLE_IN_3_22

gsk/gskrendernodeprivate.h

@@ -2,6 +2,7 @@
 #define __GSK_RENDER_NODE_PRIVATE_H__
 
 #include "gskrendernode.h"
+#include "gskrenderer.h"
 #include <cairo.h>
 
 G_BEGIN_DECLS
@@ -16,6 +17,9 @@ struct _GskRenderNode
 
   volatile int ref_count;
 
+  /* Back pointer to the renderer that created the node */
+  GskRenderer *renderer;
+
   /* The graph */
   GskRenderNode *parent;
   GskRenderNode *first_child;
@@ -68,6 +72,8 @@ struct _GskRenderNodeClass
   void (* finalize) (GskRenderNode *node);
 };
 
+GskRenderNode *gsk_render_node_new (GskRenderer *renderer);
+
 void gsk_render_node_make_immutable (GskRenderNode *node);
 
 void gsk_render_node_get_bounds (GskRenderNode   *node,

gtk/gtkwidget.c

@@ -15859,7 +15859,7 @@ gtk_widget_get_render_node (GtkWidget   *widget,
       GskRenderNode *tmp;
       cairo_t *cr;
 
-      tmp = gsk_render_node_new ();
+      tmp = gsk_renderer_create_render_node (renderer);
       gsk_render_node_set_name (tmp, "Draw Fallback");
       gsk_render_node_set_bounds (tmp, &bounds);
       gsk_render_node_set_transform (tmp, &m);
@@ -15882,7 +15882,7 @@ gtk_widget_get_render_node (GtkWidget   *widget,
           gboolean result;
           cairo_t *cr;
 
-          tmp = gsk_render_node_new ();
+          tmp = gsk_renderer_create_render_node (renderer);
           gsk_render_node_set_name (tmp, "Draw Signal Handler");
           gsk_render_node_set_bounds (tmp, &bounds);
           gsk_render_node_set_transform (tmp, &m);

gtk/gtkwindow.c

@@ -9597,7 +9597,7 @@ gtk_window_get_render_node (GtkWidget   *widget,
   graphene_rect_init (&bounds, allocation.x, allocation.y, allocation.width, allocation.height);
   graphene_matrix_init_translate (&m, graphene_point3d_init (&p, allocation.x, allocation.y, 0.));
 
-  node = gsk_render_node_new ();
+  node = gsk_renderer_create_render_node (renderer);
   gsk_render_node_set_name (node, "Window Decoration");
   gsk_render_node_set_bounds (node, &bounds);
   gsk_render_node_set_transform (node, &m);