Depsgraph/Python: callbacks and properties to detect datablock changes

* Adds two new python handlers: scene_update_pre() and scene_update_post()
  These run before and after Blender does a scene update on making modifications
  to the scene.
* Datablocks now have an is_updated property. This will be set to true in the
  above callbacks if the datablock was tagged to be updated. This works for the
  most common datablocks used for rendering: object, material, world, lamsp,
  texture, mesh, curve.
* Datablock collections also have an is_updated property. If this is set, it
  means one datablock of this type was added, removed or modified. It's also
  useful as a quick check to avoid looping over all datablocks.
* RenderEngine.view_update() can also check these properties, for interactive
  viewport rendering.

http://wiki.blender.org/index.php/Dev:2.6/Source/Render/UpdateAPI

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index c902bee80a8..b25120c0fff 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -992,6 +992,8 @@ void scene_update_tagged(Main *bmain, Scene *scene)
 {
 	DAG_ids_flush_tagged(bmain);
 
+	BLI_exec_cb(bmain, &scene->id, BLI_CB_EVT_SCENE_UPDATE_PRE);
+
 	scene->physics_settings.quick_cache_step= 0;
 
 	/* update all objects: drivers, matrices, displists, etc. flags set
@@ -1011,10 +1013,19 @@ void scene_update_tagged(Main *bmain, Scene *scene)
 	if (scene->physics_settings.quick_cache_step)
 		BKE_ptcache_quick_cache_all(bmain, scene);
 
+	DAG_ids_check_recalc(bmain);
+
+	BLI_exec_cb(bmain, &scene->id, BLI_CB_EVT_SCENE_UPDATE_POST);
+
 	/* in the future this should handle updates for all datablocks, not
 	   only objects and scenes. - brecht */
 }
 
+void scene_clear_tagged(Main *bmain, Scene *UNUSED(scene))
+{
+	DAG_ids_clear_recalc(bmain);
+}
+
 /* applies changes right away, does all sets too */
 void scene_update_for_newframe(Main *bmain, Scene *sce, unsigned int lay)
 {
@@ -1039,6 +1050,8 @@ void scene_update_for_newframe(Main *bmain, Scene *sce, unsigned int lay)
 	 * so dont call within 'scene_update_tagged_recursive' */
 	DAG_scene_update_flags(bmain, sce, lay, TRUE);   // only stuff that moves or needs display still
 
+	BLI_exec_cb(bmain, (ID *)sce, BLI_CB_EVT_SCENE_UPDATE_PRE);
+
 	/* All 'standard' (i.e. without any dependencies) animation is handled here,
 	 * with an 'local' to 'macro' order of evaluation. This should ensure that
 	 * settings stored nestled within a hierarchy (i.e. settings in a Texture block
@@ -1052,6 +1065,7 @@ void scene_update_for_newframe(Main *bmain, Scene *sce, unsigned int lay)
 	scene_update_tagged_recursive(bmain, sce, sce);
 
 	/* keep this last */
+	BLI_exec_cb(bmain, (ID *)sce, BLI_CB_EVT_SCENE_UPDATE_POST);
 	BLI_exec_cb(bmain, (ID *)sce, BLI_CB_EVT_FRAME_CHANGE_POST);
 }