Fix T37225: UV map for closed curves incorrectly generated

Summary:
Curve ORCO was not calculating properly for cyclic 2D curves.

- Needed to split vertices for blender internal renderer.
  Otherwise it's not possible to map last face to a proper
  texture location.

- Needed to tweak curve->mesh conversion to respect cyclic
  flag along U direction.

- Removed check for orcodm in curve.c:add_orco_dm since
  this code is only called if there're enabled constructive
  modifiers on the curve.

Reviewers: brecht

Maniphest Tasks: T37225

Differential Revision: http://developer.blender.org/D45

source/blender/blenkernel/intern/curve.c

@@ -1518,6 +1518,9 @@ float *BKE_curve_make_orco(Scene *scene, Object *ob, int *r_numVerts)
 				else
 					numVerts += dl->parts * (dl->nr + 1);
 			}
+			else if (dl->flag & DL_CYCL_V) {
+				numVerts += (dl->parts + 1) * dl->nr;
+			}
 			else
 				numVerts += dl->parts * dl->nr;
 		}
@@ -1553,6 +1556,9 @@ float *BKE_curve_make_orco(Scene *scene, Object *ob, int *r_numVerts)
 				if (dl->flag & DL_CYCL_V)
 					sizev++;
 			}
+			else  if (dl->flag & DL_CYCL_V) {
+				sizev++;
+			}
 
 			for (u = 0; u < sizev; u++) {
 				for (v = 0; v < sizeu; v++, fp += 3) {

source/blender/blenkernel/intern/displist.c

@@ -1086,7 +1086,7 @@ static DerivedMesh *create_orco_dm(Scene *scene, Object *ob)
 	return dm;
 }
 
-static void add_orco_dm(Scene *scene, Object *ob, DerivedMesh *dm, DerivedMesh *orcodm)
+static void add_orco_dm(Object *ob, DerivedMesh *dm, DerivedMesh *orcodm)
 {
 	float (*orco)[3], (*layerorco)[3];
 	int totvert, a;
@@ -1094,23 +1094,12 @@ static void add_orco_dm(Scene *scene, Object *ob, DerivedMesh *dm, DerivedMesh *
 
 	totvert = dm->getNumVerts(dm);
 
-	if (orcodm) {
-		orco = MEM_callocN(sizeof(float) * 3 * totvert, "dm orco");
+	orco = MEM_callocN(sizeof(float) * 3 * totvert, "dm orco");
 
-		if (orcodm->getNumVerts(orcodm) == totvert)
-			orcodm->getVertCos(orcodm, orco);
-		else
-			dm->getVertCos(dm, orco);
-	}
-	else {
-		int totvert_curve;
-		orco = (float(*)[3])BKE_curve_make_orco(scene, ob, &totvert_curve);
-		if (totvert != totvert_curve) {
-			MEM_freeN(orco);
-			orco = MEM_callocN(sizeof(float) * 3 * totvert, "dm orco");
-			dm->getVertCos(dm, orco);
-		}
-	}
+	if (orcodm->getNumVerts(orcodm) == totvert)
+		orcodm->getVertCos(orcodm, orco);
+	else
+		dm->getVertCos(dm, orco);
 
 	for (a = 0; a < totvert; a++) {
 		float *co = orco[a];
@@ -1157,6 +1146,15 @@ static void curve_calc_orcodm(Scene *scene, Object *ob, DerivedMesh *derivedFina
 		md = pretessellatePoint->next;
 	}
 
+	/* If modifiers are disabled, we wouldn't be here because
+	 * this function is only called if there're enabled constructive
+	 * modifiers applied on the curve.
+	 *
+	 * This means we can create ORCO DM in advance and assume it's
+	 * never NULL.
+	 */
+	orcodm = create_orco_dm(scene, ob);
+
 	for (; md; md = md->next) {
 		ModifierTypeInfo *mti = modifierType_getInfo(md->type);
 
@@ -1167,9 +1165,6 @@ static void curve_calc_orcodm(Scene *scene, Object *ob, DerivedMesh *derivedFina
 		if (mti->type != eModifierTypeType_Constructive)
 			continue;
 
-		if (!orcodm)
-			orcodm = create_orco_dm(scene, ob);
-
 		ndm = modwrap_applyModifier(md, ob, orcodm, app_flag);
 
 		if (ndm) {
@@ -1182,7 +1177,7 @@ static void curve_calc_orcodm(Scene *scene, Object *ob, DerivedMesh *derivedFina
 	}
 
 	/* add an orco layer if needed */
-	add_orco_dm(scene, ob, derivedFinal, orcodm);
+	add_orco_dm(ob, derivedFinal, orcodm);
 
 	if (orcodm)
 		orcodm->release(orcodm);

source/blender/blenkernel/intern/mesh.c

@@ -1342,6 +1342,9 @@ int BKE_mesh_nurbs_displist_to_mdata(Object *ob, ListBase *dispbase,
 							if (dl->flag & DL_CYCL_V)
 								orco_sizev++;
 						}
+						else if (dl->flag & DL_CYCL_V) {
+							orco_sizev++;
+						}
 
 						for (i = 0; i < 4; i++, mloopuv++) {
 							/* find uv based on vertex index into grid array */

source/blender/render/intern/source/convertblender.c

@@ -2819,6 +2819,19 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 						}
 					}
 
+					if (dl->flag & DL_CYCL_V && orco) {
+						fp = dl->verts;
+						nr = dl->nr;
+						while (nr--) {
+							ver = RE_findOrAddVert(obr, obr->totvert++);
+							copy_v3_v3(ver->co, fp);
+							mul_m4_v3(mat, ver->co);
+							ver->orco = orco;
+							fp += 3;
+							orco += 3;
+						}
+					}
+
 					if (dl->bevelSplitFlag || timeoffset==0) {
 						const int startvlak= obr->totvlak;
 
@@ -2832,6 +2845,11 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 							p3+= startvert;
 							p4+= startvert;
 
+							if (dl->flag & DL_CYCL_V && orco && a == dl->parts - 1) {
+								p3 = p1 + dl->nr;
+								p4 = p2 + dl->nr;
+							}
+
 							for (; b<dl->nr; b++) {
 								vlr= RE_findOrAddVlak(obr, obr->totvlak++);
 								/* important 1 offset in order is kept [#24913] */