Port multires_topology_changed to new bmesh api

This call is still needed when loading editmesh because some operations
are not creating CD layer for new loops (like crating new face) and
to prevent loosing all sculpted data when running disps correct
displacement maps should be allocated on loading edit mesh.

source/blender/blenkernel/BKE_multires.h

@@ -99,7 +99,7 @@ void multiresModifier_prepare_join(struct Scene *scene, struct Object *ob, struc
 int multires_mdisp_corners(struct MDisps *s);
 
 /* update multires data after topology changing */
-void multires_topology_changed(struct Scene *scene, struct Object *ob);
+void multires_topology_changed(struct Mesh *me);
 
 /**** interpolation stuff ****/
 void old_mdisps_bilinear(float out[3], float (*disps)[3], const int st, float u, float v);

source/blender/blenkernel/intern/multires.c

@@ -2166,58 +2166,38 @@ void multiresModifier_prepare_join(Scene *scene, Object *ob, Object *to_ob)
 }
 
 /* update multires data after topology changing */
-#if 0 // BMESH_TODO
-void multires_topology_changed(Scene *scene, Object *ob)
+void multires_topology_changed(Mesh *me)
 {
-	Mesh *me= (Mesh*)ob->data;
-	MDisps *mdisp= NULL, *cur= NULL;
-	int i, grid= 0, corners;
-	MultiresModifierData *mmd= get_multires_modifier(scene, ob, 1);
+	MDisps *mdisp = NULL, *cur = NULL;
+	int i, grid = 0;
 
-	if (mmd)
-		multires_set_tot_mdisps(me, mmd->totlvl);
+	CustomData_external_read(&me->ldata, &me->id, CD_MASK_MDISPS, me->totface);
+	mdisp = CustomData_get_layer(&me->ldata, CD_MDISPS);
 
-	CustomData_external_read(&me->fdata, &me->id, CD_MASK_MDISPS, me->totface);
-	mdisp= CustomData_get_layer(&me->fdata, CD_MDISPS);
+	if (!mdisp)
+		return;
 
-	if (!mdisp) return;
-
-	cur= mdisp;
-	for (i = 0; i < me->totface; i++, cur++) {
-		if (mdisp->totdisp) {
-			corners= multires_mdisp_corners(mdisp);
-			grid= mdisp->totdisp / corners;
+	cur = mdisp;
+	for (i = 0; i < me->totloop; i++, cur++) {
+		if (cur->totdisp) {
+			grid = mdisp->totdisp;
 
 			break;
 		}
 	}
 
-	for (i = 0; i < me->totface; i++, mdisp++) {
-		int nvert= me->mface[i].v4 ? 4 : 3;
-
+	for (i = 0; i < me->totloop; i++, mdisp++) {
 		/* allocate memory for mdisp, the whole disp layer would be erased otherwise */
 		if (!mdisp->totdisp || !mdisp->disps) {
 			if (grid) {
-				mdisp->totdisp= nvert*grid;
-				mdisp->disps= MEM_callocN(mdisp->totdisp*sizeof(float)*3, "mdisp topology");
+				mdisp->totdisp = grid;
+				mdisp->disps = MEM_callocN(3 * mdisp->totdisp * sizeof(float), "mdisp topology");
 			}
 
 			continue;
 		}
-
-		corners= multires_mdisp_corners(mdisp);
-
-		if (corners!=nvert) {
-			mdisp->totdisp= (mdisp->totdisp/corners)*nvert;
-
-			if (mdisp->disps)
-				MEM_freeN(mdisp->disps);
-
-			mdisp->disps= MEM_callocN(mdisp->totdisp*sizeof(float)*3, "mdisp topology");
-		}
 	}
 }
-#endif // BMESH_TODO
 
 /***************** Multires interpolation stuff *****************/
 

source/blender/bmesh/intern/bmesh_mesh_conv.c

@@ -89,6 +89,7 @@
 
 #include "BKE_mesh.h"
 #include "BKE_customdata.h"
+#include "BKE_multires.h"
 
 #include "BKE_global.h" /* ugh - for looping over all objects */
 #include "BKE_main.h"
@@ -854,4 +855,7 @@ void BM_mesh_bm_to_me(BMesh *bm, Mesh *me, int dotess)
 	}
 
 	if (oldverts) MEM_freeN(oldverts);
+
+	/* topology could be changed, ensure mdisps are ok */
+	multires_topology_changed(me);
 }

source/blender/editors/mesh/editmesh_utils.c

@@ -313,7 +313,6 @@ void EDBM_mesh_load(Object *ob)
 #ifdef USE_TESSFACE_DEFAULT
 	BKE_mesh_tessface_calc(me);
 #endif
-
 }
 
 void EDBM_mesh_free(BMEditMesh *tm)