Sanitize and cleanup a bit depsgraph relations building in some modifiers.

This commit mainly:
* Removes some uneeded dependencies to geometry of other objects (since
  we only use positions of those objects...).
* Ensures `DEG_add_modifier_to_transform_relation` is only called once
  per modifier (in one case at least it could be called twice).
* For modifiers using texture mask, only add dependencies to object used
  to generate texture coordinates when there is actually a texture set.

No behavior change expected from this commit...

1 files changed, 14 insertions, 10 deletions

diff --git a/source/blender/modifiers/intern/MOD_weightvgmix.c b/source/blender/modifiers/intern/MOD_weightvgmix.c
index e764b354ba5..f256045f53a 100644
--- a/source/blender/modifiers/intern/MOD_weightvgmix.c
+++ b/source/blender/modifiers/intern/MOD_weightvgmix.c
@@ -181,19 +181,23 @@ static void foreachTexLink(ModifierData *md, Object *ob, TexWalkFunc walk, void
 static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
 {
   WeightVGMixModifierData *wmd = (WeightVGMixModifierData *)md;
-  if (wmd->mask_tex_map_obj != NULL && wmd->mask_tex_mapping == MOD_DISP_MAP_OBJECT) {
-    MOD_depsgraph_update_object_bone_relation(
-        ctx->node, wmd->mask_tex_map_obj, wmd->mask_tex_map_bone, "WeightVGMix Modifier");
-    DEG_add_object_relation(
-        ctx->node, wmd->mask_tex_map_obj, DEG_OB_COMP_GEOMETRY, "WeightVGMix Modifier");
+  bool need_transform_relation = false;
 
-    DEG_add_modifier_to_transform_relation(ctx->node, "WeightVGMix Modifier");
-  }
-  else if (wmd->mask_tex_mapping == MOD_DISP_MAP_GLOBAL) {
-    DEG_add_modifier_to_transform_relation(ctx->node, "WeightVGMix Modifier");
-  }
   if (wmd->mask_texture != NULL) {
     DEG_add_generic_id_relation(ctx->node, &wmd->mask_texture->id, "WeightVGMix Modifier");
+
+    if (wmd->mask_tex_map_obj != NULL && wmd->mask_tex_mapping == MOD_DISP_MAP_OBJECT) {
+      MOD_depsgraph_update_object_bone_relation(
+          ctx->node, wmd->mask_tex_map_obj, wmd->mask_tex_map_bone, "WeightVGMix Modifier");
+      need_transform_relation = true;
+    }
+    else if (wmd->mask_tex_mapping == MOD_DISP_MAP_GLOBAL) {
+      need_transform_relation = true;
+    }
+  }
+
+  if (need_transform_relation) {
+    DEG_add_modifier_to_transform_relation(ctx->node, "WeightVGMix Modifier");
   }
 }