Todo item: linked curve objects behaves incorrect with modifiers

Use object's displists for storing deformed tesselated curve. Was unable to
totally get rid of curve's displist because of how texture space is calculating.

source/blender/blenkernel/intern/cdderivedmesh.c

@@ -1644,7 +1644,7 @@ DerivedMesh *CDDM_from_editmesh(EditMesh *em, Mesh *UNUSED(me))
 
 DerivedMesh *CDDM_from_curve(Object *ob)
 {
-	return CDDM_from_curve_customDB(ob, &((Curve *)ob->data)->disp);
+	return CDDM_from_curve_customDB(ob, &ob->disp);
 }
 
 DerivedMesh *CDDM_from_curve_customDB(Object *ob, ListBase *dispbase)

source/blender/blenkernel/intern/curve.c

@@ -1266,10 +1266,10 @@ void makebevelcurve(Scene *scene, Object *ob, ListBase *disp, int forRender)
 				makeDispListCurveTypes_forRender(scene, cu->bevobj, &bevdisp, NULL, 0);
 				dl= bevdisp.first;
 			} else {
-				dl= bevcu->disp.first;
+				dl= cu->bevobj->disp.first;
 				if(dl==0) {
 					makeDispListCurveTypes(scene, cu->bevobj, 0);
-					dl= bevcu->disp.first;
+					dl= cu->bevobj->disp.first;
 				}
 			}
 

source/blender/blenkernel/intern/depsgraph.c

@@ -2330,23 +2330,10 @@ static void dag_id_flush_update(Scene *sce, ID *id)
 		idtype= GS(id->name);
 
 		if(ELEM7(idtype, ID_ME, ID_CU, ID_MB, ID_LA, ID_LT, ID_CA, ID_AR)) {
-			int first_ob= 1;
 			for(obt=bmain->object.first; obt; obt= obt->id.next) {
 				if(!(ob && obt == ob) && obt->data == id) {
-
-					/* try to avoid displist recalculation for linked curves */
-					if (!first_ob && ELEM(obt->type, OB_CURVE, OB_SURF)) {
-						/* if curve object has got derivedFinal it means this
-						   object has got constructive modifiers and object
-						   should be recalculated anyhow */
-						if (!obt->derivedFinal)
-							continue;
-					}
-
 					obt->recalc |= OB_RECALC_DATA;
 					BKE_ptcache_object_reset(sce, obt, PTCACHE_RESET_DEPSGRAPH);
-
-					first_ob= 0;
 				}
 			}
 		}

source/blender/blenkernel/intern/displist.c

@@ -660,7 +660,7 @@ void shadeDispList(Scene *scene, Base *base)
 		
 			/* now we need the normals */
 			cu= ob->data;
-			dl= cu->disp.first;
+			dl= ob->disp.first;
 			
 			while(dl) {
 				extern Material defmaterial;	/* material.c */
@@ -1140,16 +1140,14 @@ static void curve_to_filledpoly(Curve *cu, ListBase *UNUSED(nurb), ListBase *dis
 */
 float calc_taper(Scene *scene, Object *taperobj, int cur, int tot)
 {
-	Curve *cu;
 	DispList *dl;
 	
 	if(taperobj==NULL || taperobj->type!=OB_CURVE) return 1.0;
 	
-	cu= taperobj->data;
-	dl= cu->disp.first;
+	dl= taperobj->disp.first;
 	if(dl==NULL) {
 		makeDispListCurveTypes(scene, taperobj, 0);
-		dl= cu->disp.first;
+		dl= taperobj->disp.first;
 	}
 	if(dl) {
 		float fac= ((float)cur)/(float)(tot-1);
@@ -1678,6 +1676,11 @@ void makeDispListSurf(Scene *scene, Object *ob, ListBase *dispbase,
 		}
 	}
 
+	/* make copy of 'undeformed" displist for texture space calculation
+	   actually, it's not totally undeformed -- pre-tesselation modifiers are
+	   already applied, thats how it worked for years, so keep for compatibility (sergey) */
+	copy_displist(&cu->disp, dispbase);
+
 	if (!forRender) {
 		tex_space_curve(cu);
 	}
@@ -1851,6 +1854,11 @@ static void do_makeDispListCurveTypes(Scene *scene, Object *ob, ListBase *dispba
 
 		if(cu->flag & CU_PATH) calc_curvepath(ob);
 
+		/* make copy of 'undeformed" displist for texture space calculation
+		   actually, it's not totally undeformed -- pre-tesselation modifiers are
+		   already applied, thats how it worked for years, so keep for compatibility (sergey) */
+		copy_displist(&cu->disp, dispbase);
+
 		 if (!forRender) {
 			 tex_space_curve(cu);
 		 }
@@ -1865,13 +1873,16 @@ static void do_makeDispListCurveTypes(Scene *scene, Object *ob, ListBase *dispba
 
 void makeDispListCurveTypes(Scene *scene, Object *ob, int forOrco)
 {
-	Curve *cu = ob->data;
+	Curve *cu= ob->data;
 	ListBase *dispbase;
 
 	freedisplist(&(ob->disp));
-	dispbase= &(cu->disp);
+	dispbase= &(ob->disp);
 	freedisplist(dispbase);
 
+	/* free displist used for textspace */
+	freedisplist(&cu->disp);
+
 	do_makeDispListCurveTypes(scene, ob, dispbase, &ob->derivedFinal, 0, forOrco);
 
 	if (ob->derivedFinal) {
@@ -1941,7 +1952,7 @@ static void boundbox_displist(Object *ob)
 		if(cu->bb==0) cu->bb= MEM_callocN(sizeof(BoundBox), "boundbox");
 		bb= cu->bb;
 		
-		dl= cu->disp.first;
+		dl= ob->disp.first;
 
 		while (dl) {
 			if(dl->type==DL_INDEX3) tot= dl->nr;

source/blender/blenkernel/intern/mesh.c

@@ -735,7 +735,7 @@ void mball_to_mesh(ListBase *lb, Mesh *me)
 int nurbs_to_mdata(Object *ob, MVert **allvert, int *totvert,
 	MEdge **alledge, int *totedge, MFace **allface, int *totface)
 {
-	return nurbs_to_mdata_customdb(ob, &((Curve *)ob->data)->disp,
+	return nurbs_to_mdata_customdb(ob, &ob->disp,
 		allvert, totvert, alledge, totedge, allface, totface);
 }
 

source/blender/editors/object/object_add.c

@@ -1036,9 +1036,7 @@ static EnumPropertyItem convert_target_items[]= {
 
 static void curvetomesh(Scene *scene, Object *ob) 
 {
-	Curve *cu= ob->data;
-	
-	if(cu->disp.first==0)
+	if(ob->disp.first==0)
 		makeDispListCurveTypes(scene, ob, 0); /* force creation */
 
 	nurbs_to_mesh(ob); /* also does users */
@@ -1188,7 +1186,7 @@ static int convert_exec(bContext *C, wmOperator *op)
 
 			cu= newob->data;
 
-			if (!cu->disp.first)
+			if (!newob->disp.first)
 				makeDispListCurveTypes(scene, newob, 0);
 
 			newob->type= OB_CURVE;
@@ -1225,8 +1223,12 @@ static int convert_exec(bContext *C, wmOperator *op)
 			for(nu=cu->nurb.first; nu; nu=nu->next)
 				nu->charidx= 0;
 
-			if(target == OB_MESH)
+			if(target == OB_MESH) {
 				curvetomesh(scene, newob);
+
+				/* meshes doesn't use displist */
+				freedisplist(&newob->disp);
+			}
 		}
 		else if(ELEM(ob->type, OB_CURVE, OB_SURF)) {
 			ob->flag |= OB_DONE;
@@ -1243,6 +1245,9 @@ static int convert_exec(bContext *C, wmOperator *op)
 					newob->data= copy_curve(ob->data);
 				} else {
 					newob= ob;
+
+					/* meshes doesn't use displist */
+					freedisplist(&newob->disp);
 				}
 
 				curvetomesh(scene, newob);

source/blender/editors/space_info/info_stats.c

@@ -91,13 +91,12 @@ static void stats_object(Object *ob, int sel, int totob, SceneStats *stats)
 	case OB_SURF:
 	case OB_CURVE:
 	case OB_FONT: {
-		Curve *cu= ob->data;
 		int tot= 0, totf= 0;
 
 		stats->totcurve += totob;
 
-		if(cu->disp.first)
-			count_displist(&cu->disp, &tot, &totf);
+		if(ob->disp.first)
+			count_displist(&ob->disp, &tot, &totf);
 
 		tot *= totob;
 		totf *= totob;

source/blender/editors/space_view3d/drawobject.c

@@ -3146,7 +3146,7 @@ static int drawDispList(Scene *scene, View3D *v3d, RegionView3D *rv3d, Base *bas
 	case OB_CURVE:
 		cu= ob->data;
 		
-		lb= &cu->disp;
+		lb= &ob->disp;
 		
 		if(solid) {
 			dl= lb->first;
@@ -3193,7 +3193,7 @@ static int drawDispList(Scene *scene, View3D *v3d, RegionView3D *rv3d, Base *bas
 		break;
 	case OB_SURF:
 
-		lb= &((Curve *)ob->data)->disp;
+		lb= &ob->disp;
 		
 		if(solid) {
 			dl= lb->first;
@@ -5436,7 +5436,7 @@ static void drawObjectSelect(Scene *scene, View3D *v3d, ARegion *ar, Base *base)
 		if (dm) {
 			hasfaces= dm->getNumFaces(dm);
 		} else {
-			hasfaces= displist_has_faces(&cu->disp);
+			hasfaces= displist_has_faces(&ob->disp);
 		}
 
 		if (hasfaces && boundbox_clip(rv3d, ob->obmat, ob->bb ? ob->bb : cu->bb)) {
@@ -5444,7 +5444,7 @@ static void drawObjectSelect(Scene *scene, View3D *v3d, ARegion *ar, Base *base)
 			if (dm) {
 				draw_mesh_object_outline(v3d, ob, dm);
 			} else {
-				drawDispListwire(&cu->disp);
+				drawDispListwire(&ob->disp);
 			}
 			draw_index_wire= 1;
 		}
@@ -5499,7 +5499,7 @@ static void drawWireExtra(Scene *scene, RegionView3D *rv3d, Object *ob)
 			if (ob->derivedFinal) {
 				drawCurveDMWired(ob);
 			} else {
-				drawDispListwire(&cu->disp);
+				drawDispListwire(&ob->disp);
 			}
 
 			if (ob->type==OB_CURVE)
@@ -5820,9 +5820,8 @@ void draw_object(Scene *scene, ARegion *ar, View3D *v3d, Base *base, int flag)
 
 	/* bad exception, solve this! otherwise outline shows too late */
 	if(ELEM3(ob->type, OB_CURVE, OB_SURF, OB_FONT)) {
-		cu= ob->data;
 		/* still needed for curves hidden in other layers. depgraph doesnt handle that yet */
-		if (cu->disp.first==NULL) makeDispListCurveTypes(scene, ob, 0);
+		if (ob->disp.first==NULL) makeDispListCurveTypes(scene, ob, 0);
 	}
 	
 	/* draw outline for selected objects, mesh does itself */

source/blender/makesdna/DNA_curve_types.h

@@ -171,7 +171,7 @@ typedef struct Curve {
 	struct BoundBox *bb;
 	
 	ListBase nurb;		/* actual data, called splines in rna */
-	ListBase disp;
+	ListBase disp;		/* undeformed display list, used mostly for texture space calculation */
 	
 	EditNurb *editnurb;	/* edited data, not in file, use pointer so we can check for it */