Cleanup: split `BKE_scene_get_depsgraph()` into two functions

Split the depsgraph allocation into a separate function
`BKE_scene_ensure_depsgraph()`. Parameters are only passed to those
functions that actually need them. This removes the the "if that boolean
is `false` this pointer is allowed to be `NULL`" logic and more cleanly
decouples code.

No functional changes.

source/blender/blenkernel/BKE_scene.h

@@ -219,10 +219,12 @@ void BKE_scene_ensure_depsgraph_hash(struct Scene *scene);
 void BKE_scene_free_depsgraph_hash(struct Scene *scene);
 void BKE_scene_free_view_layer_depsgraph(struct Scene *scene, struct ViewLayer *view_layer);
 
-struct Depsgraph *BKE_scene_get_depsgraph(struct Main *bmain,
-                                          struct Scene *scene,
-                                          struct ViewLayer *view_layer,
-                                          bool allocate);
+/* Do not allocate new depsgraph. */
+struct Depsgraph *BKE_scene_get_depsgraph(struct Scene *scene, struct ViewLayer *view_layer);
+/* Allocate new depsgraph if necessary. */
+struct Depsgraph *BKE_scene_ensure_depsgraph(struct Main *bmain,
+                                             struct Scene *scene,
+                                             struct ViewLayer *view_layer);
 
 struct GHash *BKE_scene_undo_depsgraphs_extract(struct Main *bmain);
 void BKE_scene_undo_depsgraphs_restore(struct Main *bmain, struct GHash *depsgraph_extract);

source/blender/blenkernel/intern/context.c

@@ -1349,7 +1349,7 @@ Depsgraph *CTX_data_depsgraph_pointer(const bContext *C)
   Main *bmain = CTX_data_main(C);
   Scene *scene = CTX_data_scene(C);
   ViewLayer *view_layer = CTX_data_view_layer(C);
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   /* Dependency graph might have been just allocated, and hence it will not be marked.
    * This confuses redo system due to the lack of flushing changes back to the original data.
    * In the future we would need to check whether the CTX_wm_window(C)  is in editing mode (as an
@@ -1377,8 +1377,7 @@ Depsgraph *CTX_data_ensure_evaluated_depsgraph(const bContext *C)
 
 Depsgraph *CTX_data_depsgraph_on_load(const bContext *C)
 {
-  Main *bmain = CTX_data_main(C);
   Scene *scene = CTX_data_scene(C);
   ViewLayer *view_layer = CTX_data_view_layer(C);
-  return BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+  return BKE_scene_get_depsgraph(scene, view_layer);
 }

source/blender/blenkernel/intern/scene.c

@@ -1609,7 +1609,7 @@ void BKE_scene_graph_update_for_newframe(Depsgraph *depsgraph)
  */
 void BKE_scene_view_layer_graph_evaluated_ensure(Main *bmain, Scene *scene, ViewLayer *view_layer)
 {
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   DEG_make_active(depsgraph);
   BKE_scene_graph_update_tagged(depsgraph, bmain);
 }
@@ -2243,11 +2243,9 @@ void BKE_scene_free_view_layer_depsgraph(Scene *scene, ViewLayer *view_layer)
 
 /* Query depsgraph for a specific contexts. */
 
-static Depsgraph **scene_get_depsgraph_p(Main *bmain,
-                                         Scene *scene,
+static Depsgraph **scene_get_depsgraph_p(Scene *scene,
                                          ViewLayer *view_layer,
-                                         const bool allocate_ghash_entry,
-                                         const bool allocate_depsgraph)
+                                         const bool allocate_ghash_entry)
 {
   /* bmain may be NULL here! */
   BLI_assert(scene != NULL);
@@ -2261,9 +2259,7 @@ static Depsgraph **scene_get_depsgraph_p(Main *bmain,
   if (scene->depsgraph_hash == NULL) {
     return NULL;
   }
-  /* Either ensure item is in the hash or simply return NULL if it's not,
-   * depending on whether caller wants us to create depsgraph or not.
-   */
+
   DepsgraphKey key;
   key.view_layer = view_layer;
 
@@ -2276,20 +2272,35 @@ static Depsgraph **scene_get_depsgraph_p(Main *bmain,
   DepsgraphKey **key_ptr;
   if (BLI_ghash_ensure_p_ex(
           scene->depsgraph_hash, &key, (void ***)&key_ptr, (void ***)&depsgraph_ptr)) {
-    /* Depsgraph was found in the ghash. */
-    return depsgraph_ptr;
-  }
-
-  if (!allocate_depsgraph) {
-    /* Not found and not allowed to allocate. */
-    *depsgraph_ptr = NULL;
     return depsgraph_ptr;
   }
 
+  /* Depsgraph was not found in the ghash, but the key still needs allocating. */
   *key_ptr = MEM_mallocN(sizeof(DepsgraphKey), __func__);
   **key_ptr = key;
 
+  *depsgraph_ptr = NULL;
+  return depsgraph_ptr;
+}
+
+static Depsgraph **scene_ensure_depsgraph_p(Main *bmain, Scene *scene, ViewLayer *view_layer)
+{
+  BLI_assert(bmain != NULL);
+
+  Depsgraph **depsgraph_ptr = scene_get_depsgraph_p(scene, view_layer, true);
+  if (depsgraph_ptr == NULL) {
+    /* The scene has no depsgraph hash. */
+    return NULL;
+  }
+  if (*depsgraph_ptr != NULL) {
+    /* The depsgraph was found, no need to allocate. */
+    return depsgraph_ptr;
+  }
+
+  /* Allocate a new depsgraph. scene_get_depsgraph_p() already ensured that the pointer is stored
+   * in the scene's depsgraph hash. */
   *depsgraph_ptr = DEG_graph_new(bmain, scene, view_layer, DAG_EVAL_VIEWPORT);
+
   /* TODO(sergey): Would be cool to avoid string format print,
    * but is a bit tricky because we can't know in advance whether
    * we will ever enable debug messages for this depsgraph.
@@ -2301,9 +2312,15 @@ static Depsgraph **scene_get_depsgraph_p(Main *bmain,
   return depsgraph_ptr;
 }
 
-Depsgraph *BKE_scene_get_depsgraph(Main *bmain, Scene *scene, ViewLayer *view_layer, bool allocate)
+Depsgraph *BKE_scene_get_depsgraph(Scene *scene, ViewLayer *view_layer)
 {
-  Depsgraph **depsgraph_ptr = scene_get_depsgraph_p(bmain, scene, view_layer, allocate, allocate);
+  Depsgraph **depsgraph_ptr = scene_get_depsgraph_p(scene, view_layer, false);
+  return (depsgraph_ptr != NULL) ? *depsgraph_ptr : NULL;
+}
+
+Depsgraph *BKE_scene_ensure_depsgraph(Main *bmain, Scene *scene, ViewLayer *view_layer)
+{
+  Depsgraph **depsgraph_ptr = scene_ensure_depsgraph_p(bmain, scene, view_layer);
   return (depsgraph_ptr != NULL) ? *depsgraph_ptr : NULL;
 }
 
@@ -2369,8 +2386,7 @@ void BKE_scene_undo_depsgraphs_restore(Main *bmain, GHash *depsgraph_extract)
       }
       BLI_assert(*depsgraph_extract_ptr != NULL);
 
-      Depsgraph **depsgraph_scene_ptr = scene_get_depsgraph_p(
-          bmain, scene, view_layer, true, false);
+      Depsgraph **depsgraph_scene_ptr = scene_get_depsgraph_p(scene, view_layer, true);
       BLI_assert(depsgraph_scene_ptr != NULL);
       BLI_assert(*depsgraph_scene_ptr == NULL);
 

source/blender/blenkernel/intern/sequencer.c

@@ -3592,7 +3592,7 @@ static ImBuf *seq_render_scene_strip(const SeqRenderData *context,
     }
 
     /* opengl offscreen render */
-    depsgraph = BKE_scene_get_depsgraph(context->bmain, scene, view_layer, true);
+    depsgraph = BKE_scene_ensure_depsgraph(context->bmain, scene, view_layer);
     BKE_scene_graph_update_for_newframe(depsgraph);
     ibuf = sequencer_view3d_fn(
         /* set for OpenGL render (NULL when scrubbing) */

source/blender/draw/intern/draw_manager.c

@@ -909,7 +909,7 @@ void DRW_cache_free_old_batches(Main *bmain)
 
   for (scene = bmain->scenes.first; scene; scene = scene->id.next) {
     for (view_layer = scene->view_layers.first; view_layer; view_layer = view_layer->next) {
-      Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+      Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
       if (depsgraph == NULL) {
         continue;
       }

source/blender/editors/render/render_update.c

@@ -194,7 +194,7 @@ void ED_render_engine_changed(Main *bmain, const bool update_scene_data)
     update_ctx.scene = scene;
     LISTBASE_FOREACH (ViewLayer *, view_layer, &scene->view_layers) {
       /* TDODO(sergey): Iterate over depsgraphs instead? */
-      update_ctx.depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+      update_ctx.depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
       update_ctx.view_layer = view_layer;
       ED_render_id_flush_update(&update_ctx, &scene->id);
     }

source/blender/editors/scene/scene_edit.c

@@ -116,7 +116,7 @@ bool ED_scene_delete(bContext *C, Main *bmain, Scene *scene)
 /* Depsgraph updates after scene becomes active in a window. */
 void ED_scene_change_update(Main *bmain, Scene *scene, ViewLayer *layer)
 {
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, layer);
 
   BKE_scene_set_background(bmain, scene);
   DEG_graph_relations_update(depsgraph);

source/blender/editors/screen/screen_ops.c

@@ -4432,7 +4432,7 @@ static int screen_animation_step(bContext *C, wmOperator *UNUSED(op), const wmEv
     Main *bmain = CTX_data_main(C);
     Scene *scene = CTX_data_scene(C);
     ViewLayer *view_layer = WM_window_get_active_view_layer(win);
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+    Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
     Scene *scene_eval = (depsgraph != NULL) ? DEG_get_evaluated_scene(depsgraph) : NULL;
     wmTimer *wt = screen->animtimer;
     ScreenAnimData *sad = wt->customdata;

source/blender/editors/space_info/info_stats.c

@@ -426,7 +426,7 @@ static bool format_stats(Main *bmain,
     if (wm->is_interface_locked) {
       return false;
     }
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+    Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
     stats_update(depsgraph, view_layer);
   }
 

source/blender/editors/transform/transform_convert_object.c

@@ -346,7 +346,7 @@ static void set_trans_object_base_flags(TransInfo *t)
   ViewLayer *view_layer = t->view_layer;
   View3D *v3d = t->view;
   Scene *scene = t->scene;
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   /* NOTE: if Base selected and has parent selected:
    *   base->flag_legacy = BA_WAS_SEL
    */
@@ -421,7 +421,7 @@ static int count_proportional_objects(TransInfo *t)
   View3D *v3d = t->view;
   struct Main *bmain = CTX_data_main(t->context);
   Scene *scene = t->scene;
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   /* Clear all flags we need. It will be used to detect dependencies. */
   trans_object_base_deps_flag_prepare(view_layer);
   /* Rotations around local centers are allowed to propagate, so we take all objects. */

source/blender/io/collada/BlenderContext.cpp

@@ -123,7 +123,7 @@ bContext *BlenderContext::get_context()
 Depsgraph *BlenderContext::get_depsgraph()
 {
   if (!depsgraph) {
-    depsgraph = BKE_scene_get_depsgraph(main, scene, view_layer, true);
+    depsgraph = BKE_scene_ensure_depsgraph(main, scene, view_layer);
   }
   return depsgraph;
 }

source/blender/makesrna/intern/rna_layer.c

@@ -184,10 +184,7 @@ static PointerRNA rna_ViewLayer_depsgraph_get(PointerRNA *ptr)
   if (GS(id->name) == ID_SCE) {
     Scene *scene = (Scene *)id;
     ViewLayer *view_layer = (ViewLayer *)ptr->data;
-    // NOTE: We don't allocate new depsgraph here, so the bmain is ignored. So it's easier to pass
-    // NULL.
-    // Still weak though.
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(NULL, scene, view_layer, false);
+    Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
     return rna_pointer_inherit_refine(ptr, &RNA_Depsgraph, depsgraph);
   }
   return PointerRNA_NULL;
@@ -206,7 +203,7 @@ static void rna_ViewLayer_update_tagged(ID *id_ptr,
                                         ReportList *reports)
 {
   Scene *scene = (Scene *)id_ptr;
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
 
   if (DEG_is_evaluating(depsgraph)) {
     BKE_report(reports, RPT_ERROR, "Dependency graph update requested during evaluation");

source/blender/makesrna/intern/rna_scene_api.c

@@ -72,7 +72,7 @@ static void rna_Scene_frame_set(Scene *scene, Main *bmain, int frame, float subf
 
   for (ViewLayer *view_layer = scene->view_layers.first; view_layer != NULL;
        view_layer = view_layer->next) {
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+    Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
     BKE_scene_graph_update_for_newframe(depsgraph);
   }
 

source/blender/makesrna/intern/rna_space_api.c

@@ -49,7 +49,7 @@ static void rna_RegionView3D_update(ID *id, RegionView3D *rv3d, bContext *C)
       if (WM_window_get_active_screen(win) == screen) {
         Scene *scene = WM_window_get_active_scene(win);
         ViewLayer *view_layer = WM_window_get_active_view_layer(win);
-        Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+        Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
 
         ED_view3d_update_viewmat(depsgraph, scene, v3d, region, NULL, NULL, NULL, false);
         break;

source/blender/python/gpu/gpu_py_offscreen.c

@@ -246,7 +246,7 @@ static PyObject *bpygpu_offscreen_draw_view3d(BPyGPUOffScreen *self,
 
   BLI_assert(BKE_id_is_in_global_main(&scene->id));
 
-  depsgraph = BKE_scene_get_depsgraph(G_MAIN, scene, view_layer, true);
+  depsgraph = BKE_scene_ensure_depsgraph(G_MAIN, scene, view_layer);
 
   rv3d_mats = ED_view3d_mats_rv3d_backup(region->regiondata);
 

source/blender/render/intern/source/pipeline.c

@@ -1857,7 +1857,7 @@ static void update_physics_cache(Render *re,
   baker.bmain = re->main;
   baker.scene = scene;
   baker.view_layer = view_layer;
-  baker.depsgraph = BKE_scene_get_depsgraph(re->main, scene, view_layer, true);
+  baker.depsgraph = BKE_scene_ensure_depsgraph(re->main, scene, view_layer);
   baker.bake = 0;
   baker.render = 1;
   baker.anim_init = 1;

source/blender/windowmanager/intern/wm_draw.c

@@ -910,7 +910,7 @@ static bool wm_draw_update_test_window(Main *bmain, bContext *C, wmWindow *win)
   const wmWindowManager *wm = CTX_wm_manager(C);
   Scene *scene = WM_window_get_active_scene(win);
   ViewLayer *view_layer = WM_window_get_active_view_layer(win);
-  struct Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+  struct Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   bScreen *screen = WM_window_get_active_screen(win);
   ARegion *region;
   bool do_draw = false;

source/blender/windowmanager/intern/wm_event_system.c

@@ -350,7 +350,7 @@ void wm_event_do_depsgraph(bContext *C, bool is_after_open_file)
      * and for until then we have to accept ambiguities when object is shared
      * across visible view layers and has overrides on it.
      */
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, true);
+    Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
     if (is_after_open_file) {
       DEG_graph_relations_update(depsgraph);
       DEG_graph_on_visible_update(bmain, depsgraph, true);
@@ -3189,10 +3189,9 @@ void wm_event_do_handlers(bContext *C)
       wm_event_free_all(win);
     }
     else {
-      Main *bmain = CTX_data_main(C);
       Scene *scene = WM_window_get_active_scene(win);
       ViewLayer *view_layer = WM_window_get_active_view_layer(win);
-      Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+      Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
       Scene *scene_eval = (depsgraph != NULL) ? DEG_get_evaluated_scene(depsgraph) : NULL;
 
       if (scene_eval != NULL) {

source/blender/windowmanager/intern/wm_init_exit.c

@@ -210,7 +210,7 @@ static void sound_jack_sync_callback(Main *bmain, int mode, double time)
       continue;
     }
     ViewLayer *view_layer = WM_window_get_active_view_layer(window);
-    Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+    Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
     if (depsgraph == NULL) {
       continue;
     }

source/blender/windowmanager/xr/intern/wm_xr_session.c

@@ -195,7 +195,7 @@ static void wm_xr_session_scene_and_evaluated_depsgraph_get(Main *bmain,
   Scene *scene = WM_window_get_active_scene(root_win);
   ViewLayer *view_layer = WM_window_get_active_view_layer(root_win);
 
-  Depsgraph *depsgraph = BKE_scene_get_depsgraph(bmain, scene, view_layer, false);
+  Depsgraph *depsgraph = BKE_scene_get_depsgraph(scene, view_layer);
   BLI_assert(scene && view_layer && depsgraph);
   BKE_scene_graph_evaluated_ensure(depsgraph, bmain);
   *r_scene = scene;