Fix T42257: Curve vertex parent not working with animation

Vertex parent was using original non-modified nurbs list, simply because
it didn't have something else to operate with.

Now we've got deformed by pre-tessellation modifiers nurbs in the curve
cache which might be used y the vertex parent.

3 files changed, 19 insertions, 15 deletions

diff --git a/source/blender/blenkernel/BKE_curve.h b/source/blender/blenkernel/BKE_curve.h
index 5de7d9936e6..253d9edc3b5 100644
--- a/source/blender/blenkernel/BKE_curve.h
+++ b/source/blender/blenkernel/BKE_curve.h
@@ -49,6 +49,7 @@ struct rctf;
 typedef struct CurveCache {
 	ListBase disp;
 	ListBase bev;
+	ListBase deformed_nurbs;
 	struct Path *path;
 } CurveCache;
 
diff --git a/source/blender/blenkernel/intern/displist.c b/source/blender/blenkernel/intern/displist.c
index 98f0025921d..893c69741cd 100644
--- a/source/blender/blenkernel/intern/displist.c
+++ b/source/blender/blenkernel/intern/displist.c
@@ -1271,6 +1271,7 @@ void BKE_displist_make_surf(Scene *scene, Object *ob, ListBase *dispbase,
 	}
 
 	if (!for_orco) {
+		BKE_nurbList_duplicate(&ob->curve_cache->deformed_nurbs, &nubase);
 		curve_calc_modifiers_post(scene, ob, &nubase, dispbase, r_dm_final,
 		                          for_render, use_render_resolution);
 	}
@@ -1729,8 +1730,10 @@ static void do_makeDispListCurveTypes(Scene *scene, Object *ob, ListBase *dispba
 			}
 		}
 
-		if (!for_orco)
+		if (!for_orco) {
+			BKE_nurbList_duplicate(&ob->curve_cache->deformed_nurbs, &nubase);
 			curve_calc_modifiers_post(scene, ob, &nubase, dispbase, r_dm_final, for_render, use_render_resolution);
+		}
 
 		if (cu->flag & CU_DEFORM_FILL && !ob->derivedFinal) {
 			curve_to_filledpoly(cu, &nubase, dispbase);
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index 7a8843f3308..53b0e0cf4a1 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -185,6 +185,7 @@ void BKE_object_free_curve_cache(Object *ob)
 		if (ob->curve_cache->path) {
 			free_path(ob->curve_cache->path);
 		}
+		BKE_nurbList_free(&ob->curve_cache->deformed_nurbs);
 		MEM_freeN(ob->curve_cache);
 		ob->curve_cache = NULL;
 	}
@@ -321,18 +322,7 @@ void BKE_object_free_derived_caches(Object *ob)
 		ob->derivedDeform = NULL;
 	}
 	
-	if (ob->curve_cache) {
-		BKE_displist_free(&ob->curve_cache->disp);
-		BKE_curve_bevelList_free(&ob->curve_cache->bev);
-		if (ob->curve_cache->path) {
-			free_path(ob->curve_cache->path);
-			ob->curve_cache->path = NULL;
-		}
-
-		/* Signal for viewport to run DAG workarounds. */
-		MEM_freeN(ob->curve_cache);
-		ob->curve_cache = NULL;
-	}
+	BKE_object_free_curve_cache(ob);
 }
 
 /* do not free object itself */
@@ -2219,8 +2209,18 @@ static void give_parvert(Object *par, int nr, float vec[3])
 		}
 	}
 	else if (ELEM(par->type, OB_CURVE, OB_SURF)) {
-		Curve *cu       = par->data;
-		ListBase *nurb  = BKE_curve_nurbs_get(cu);
+		ListBase *nurb;
+
+		/* Unless there's some weird depsgraph failure the cache should exist. */
+		BLI_assert(par->curve_cache != NULL);
+
+		if (par->curve_cache->deformed_nurbs.first != NULL) {
+			nurb = &par->curve_cache->deformed_nurbs;
+		}
+		else {
+			Curve *cu = par->data;
+			nurb = BKE_curve_nurbs_get(cu);
+		}
 
 		BKE_nurbList_index_get_co(nurb, nr, vec);
 	}