[Bf-blender-cvs] [411adadf675] master: Depsgraph: Ensure it's fully evaluated after POST callbacks

[Sergey Sharybin]

Commit: 411adadf6753715b2c84e41707383f145842a36c
Author: Sergey Sharybin
Date:   Thu Sep 5 12:57:41 2019 +0200
Branches: master
https://developer.blender.org/rB411adadf6753715b2c84e41707383f145842a36c

Depsgraph: Ensure it's fully evaluated after POST callbacks

It is possible that POST callbacks will modify objects or relations.
This change makes it so an extra update pass is done if needed.

Reviewers: brecht

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D5690

===================================================================

M	source/blender/blenkernel/intern/scene.c

===================================================================

diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 36d0cfe9ac4..6f8d14252f0 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -1557,29 +1557,37 @@ static void scene_graph_update_tagged(Depsgraph *depsgraph, Main *bmain, bool on
     BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_DEPSGRAPH_UPDATE_PRE);
   }
 
-  /* TODO(sergey): Some functions here are changing global state,
-   * for example, clearing update tags from bmain.
-   */
-  /* (Re-)build dependency graph if needed. */
-  DEG_graph_relations_update(depsgraph, bmain, scene, view_layer);
-  /* Uncomment this to check if graph was properly tagged for update. */
-  // DEG_debug_graph_relations_validate(depsgraph, bmain, scene);
-  /* Flush editing data if needed. */
-  prepare_mesh_for_viewport_render(bmain, view_layer);
-  /* Update all objects: drivers, matrices, displists, etc. flags set
-   * by depgraph or manual, no layer check here, gets correct flushed.
-   */
-  DEG_evaluate_on_refresh(bmain, depsgraph);
-  /* Update sound system. */
-  BKE_scene_update_sound(depsgraph, bmain);
-  /* Notify python about depsgraph update. */
-  if (run_callbacks) {
-    BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_DEPSGRAPH_UPDATE_POST);
+  for (int pass = 0; pass < 2; ++pass) {
+    /* (Re-)build dependency graph if needed. */
+    DEG_graph_relations_update(depsgraph, bmain, scene, view_layer);
+    /* Uncomment this to check if graph was properly tagged for update. */
+    // DEG_debug_graph_relations_validate(depsgraph, bmain, scene);
+    /* Flush editing data if needed. */
+    prepare_mesh_for_viewport_render(bmain, view_layer);
+    /* Update all objects: drivers, matrices, displists, etc. flags set
+     * by depgraph or manual, no layer check here, gets correct flushed.
+     */
+    DEG_evaluate_on_refresh(bmain, depsgraph);
+    /* Update sound system. */
+    BKE_scene_update_sound(depsgraph, bmain);
+    /* Notify python about depsgraph update. */
+    if (run_callbacks) {
+      BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_DEPSGRAPH_UPDATE_POST);
+    }
+    /* Inform editors about possible changes. */
+    DEG_ids_check_recalc(bmain, depsgraph, scene, view_layer, false);
+    /* Clear recalc flags. */
+    DEG_ids_clear_recalc(bmain, depsgraph);
+
+    /* If user callback did not tag anything for update we can skip second iteration.
+     * Otherwise we update scene once again, but without running callbacks to bring
+     * scene to a fully evaluated state with user modifications taken into account. */
+    if (DEG_is_fully_evaluated(depsgraph)) {
+      break;
+    }
+
+    run_callbacks = false;
   }
-  /* Inform editors about possible changes. */
-  DEG_ids_check_recalc(bmain, depsgraph, scene, view_layer, false);
-  /* Clear recalc flags. */
-  DEG_ids_clear_recalc(bmain, depsgraph);
 }
 
 void BKE_scene_graph_update_tagged(Depsgraph *depsgraph, Main *bmain)
@@ -1598,33 +1606,44 @@ void BKE_scene_graph_update_for_newframe(Depsgraph *depsgraph, Main *bmain)
   Scene *scene = DEG_get_input_scene(depsgraph);
   ViewLayer *view_layer = DEG_get_input_view_layer(depsgraph);
 
-  /* TODO(sergey): Some functions here are changing global state,
-   * for example, clearing update tags from bmain.
-   */
-  const float ctime = BKE_scene_frame_get(scene);
   /* Keep this first. */
   BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_FRAME_CHANGE_PRE);
-  /* Update animated image textures for particles, modifiers, gpu, etc,
-   * call this at the start so modifiers with textures don't lag 1 frame.
-   */
-  BKE_image_editors_update_frame(bmain, scene->r.cfra);
-  BKE_sound_set_cfra(scene->r.cfra);
-  DEG_graph_relations_update(depsgraph, bmain, scene, view_layer);
+
+  for (int pass = 0; pass < 2; ++pass) {
+    /* Update animated image textures for particles, modifiers, gpu, etc,
+     * call this at the start so modifiers with textures don't lag 1 frame.
+     */
+    BKE_image_editors_update_frame(bmain, scene->r.cfra);
+    BKE_sound_set_cfra(scene->r.cfra);
+    DEG_graph_relations_update(depsgraph, bmain, scene, view_layer);
 #ifdef POSE_ANIMATION_WORKAROUND
-  scene_armature_depsgraph_workaround(bmain, depsgraph);
+    scene_armature_depsgraph_workaround(bmain, depsgraph);
 #endif
-  /* Update all objects: drivers, matrices, displists, etc. flags set
-   * by depgraph or manual, no layer check here, gets correct flushed.
-   */
-  DEG_evaluate_on_framechange(bmain, depsgraph, ctime);
-  /* Update sound system animation. */
-  BKE_scene_update_sound(depsgraph, bmain);
-  /* Notify editors and python about recalc. */
-  BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_FRAME_CHANGE_POST);
-  /* Inform editors about possible changes. */
-  DEG_ids_check_recalc(bmain, depsgraph, scene, view_layer, true);
-  /* clear recalc flags */
-  DEG_ids_clear_recalc(bmain, depsgraph);
+    /* Update all objects: drivers, matrices, displists, etc. flags set
+     * by depgraph or manual, no layer check here, gets correct flushed.
+     */
+    const float ctime = BKE_scene_frame_get(scene);
+    DEG_evaluate_on_framechange(bmain, depsgraph, ctime);
+    /* Update sound system animation. */
+    BKE_scene_update_sound(depsgraph, bmain);
+
+    /* Notify editors and python about recalc. */
+    if (pass == 0) {
+      BLI_callback_exec(bmain, &scene->id, BLI_CB_EVT_FRAME_CHANGE_POST);
+    }
+
+    /* Inform editors about possible changes. */
+    DEG_ids_check_recalc(bmain, depsgraph, scene, view_layer, true);
+    /* clear recalc flags */
+    DEG_ids_clear_recalc(bmain, depsgraph);
+
+    /* If user callback did not tag anything for update we can skip second iteration.
+     * Otherwise we update scene once again, but without running callbacks to bring
+     * scene to a fully evaluated state with user modifications taken into account. */
+    if (DEG_is_fully_evaluated(depsgraph)) {
+      break;
+    }
+  }
 }
 
 /** Ensures given scene/view_layer pair has a valid, up-to-date depsgraph.