Refactor CDData masks, to have one mask per mesh elem type.

We already have different storages for cddata of verts, edges etc.,
'simply' do the same for the mask flags we use all around Blender code
to request some data, or limit some operation to some layers, etc.

Reason we need this is that some cddata types (like Normals) are
actually shared between verts/polys/loops, and we don’t want to generate
clnors everytime we request vnors!

As a side note, this also does final fix to T59338, which was the
trigger for this patch (need to request computed loop normals for
another mesh than evaluated one).

Reviewers: brecht, campbellbarton, sergey

Differential Revision: https://developer.blender.org/D4407

1 files changed, 22 insertions, 19 deletions

diff --git a/source/blender/blenkernel/intern/cdderivedmesh.c b/source/blender/blenkernel/intern/cdderivedmesh.c
index cb4118b6abb..859c5534183 100644
--- a/source/blender/blenkernel/intern/cdderivedmesh.c
+++ b/source/blender/blenkernel/intern/cdderivedmesh.c
@@ -582,15 +582,16 @@ DerivedMesh *CDDM_new(int numVerts, int numEdges, int numTessFaces, int numLoops
 
 DerivedMesh *CDDM_from_mesh(Mesh *mesh)
 {
-	return CDDM_from_mesh_ex(mesh, CD_REFERENCE, CD_MASK_MESH);
+	return CDDM_from_mesh_ex(mesh, CD_REFERENCE, &CD_MASK_MESH);
 }
 
-DerivedMesh *CDDM_from_mesh_ex(Mesh *mesh, eCDAllocType alloctype, CustomDataMask mask)
+DerivedMesh *CDDM_from_mesh_ex(Mesh *mesh, eCDAllocType alloctype, const CustomData_MeshMasks *mask)
 {
 	CDDerivedMesh *cddm = cdDM_create(__func__);
 	DerivedMesh *dm = &cddm->dm;
+	CustomData_MeshMasks cddata_masks = *mask;
 
-	mask &= ~CD_MASK_MDISPS;
+	cddata_masks.lmask &= ~CD_MASK_MDISPS;
 
 	/* this does a referenced copy, with an exception for fluidsim */
 
@@ -608,15 +609,15 @@ DerivedMesh *CDDM_from_mesh_ex(Mesh *mesh, eCDAllocType alloctype, CustomDataMas
 	}
 	/* TODO DM_DIRTY_TESS_CDLAYERS ? Maybe not though, since we probably want to switch to looptris ? */
 
-	CustomData_merge(&mesh->vdata, &dm->vertData, mask, alloctype,
+	CustomData_merge(&mesh->vdata, &dm->vertData, cddata_masks.vmask, alloctype,
 	                 mesh->totvert);
-	CustomData_merge(&mesh->edata, &dm->edgeData, mask, alloctype,
+	CustomData_merge(&mesh->edata, &dm->edgeData, cddata_masks.emask, alloctype,
 	                 mesh->totedge);
-	CustomData_merge(&mesh->fdata, &dm->faceData, mask | CD_MASK_ORIGINDEX, alloctype,
+	CustomData_merge(&mesh->fdata, &dm->faceData, cddata_masks.fmask | CD_MASK_ORIGINDEX, alloctype,
 	                 0 /* mesh->totface */);
-	CustomData_merge(&mesh->ldata, &dm->loopData, mask, alloctype,
+	CustomData_merge(&mesh->ldata, &dm->loopData, cddata_masks.lmask, alloctype,
 	                 mesh->totloop);
-	CustomData_merge(&mesh->pdata, &dm->polyData, mask, alloctype,
+	CustomData_merge(&mesh->pdata, &dm->polyData, cddata_masks.pmask, alloctype,
 	                 mesh->totpoly);
 
 	cddm->mvert = CustomData_get_layer(&dm->vertData, CD_MVERT);
@@ -767,7 +768,7 @@ static DerivedMesh *cddm_from_bmesh_ex(
 	int numCol = CustomData_number_of_layers(&bm->ldata, CD_MLOOPCOL);
 	int numUV  = CustomData_number_of_layers(&bm->ldata, CD_MLOOPUV);
 	int *index, add_orig;
-	CustomDataMask mask;
+	CustomData_MeshMasks mask = {0};
 	unsigned int i, j;
 
 	const int cd_vert_bweight_offset = CustomData_get_offset(&bm->vdata, CD_BWEIGHT);
@@ -779,18 +780,21 @@ static DerivedMesh *cddm_from_bmesh_ex(
 	/* don't add origindex layer if one already exists */
 	add_orig = !CustomData_has_layer(&bm->pdata, CD_ORIGINDEX);
 
-	mask = use_mdisps ? CD_MASK_DERIVEDMESH | CD_MASK_MDISPS : CD_MASK_DERIVEDMESH;
+	mask = CD_MASK_DERIVEDMESH;
+	if (use_mdisps) {
+		mask.lmask |= CD_MASK_MDISPS;
+	}
 
 	/* don't process shapekeys, we only feed them through the modifier stack as needed,
 	 * e.g. for applying modifiers or the like*/
-	mask &= ~CD_MASK_SHAPEKEY;
-	CustomData_merge(&bm->vdata, &dm->vertData, mask,
+	mask.vmask &= ~CD_MASK_SHAPEKEY;
+	CustomData_merge(&bm->vdata, &dm->vertData, mask.vmask,
 	                 CD_CALLOC, dm->numVertData);
-	CustomData_merge(&bm->edata, &dm->edgeData, mask,
+	CustomData_merge(&bm->edata, &dm->edgeData, mask.emask,
 	                 CD_CALLOC, dm->numEdgeData);
-	CustomData_merge(&bm->ldata, &dm->loopData, mask,
+	CustomData_merge(&bm->ldata, &dm->loopData, mask.lmask,
 	                 CD_CALLOC, dm->numLoopData);
-	CustomData_merge(&bm->pdata, &dm->polyData, mask,
+	CustomData_merge(&bm->pdata, &dm->polyData, mask.pmask,
 	                 CD_CALLOC, dm->numPolyData);
 
 	/* add tessellation mface layers */
@@ -974,11 +978,10 @@ DerivedMesh *CDDM_copy(DerivedMesh *source)
 
 /* note, the CD_ORIGINDEX layers are all 0, so if there is a direct
  * relationship between mesh data this needs to be set by the caller. */
-DerivedMesh *CDDM_from_template_ex(
-        DerivedMesh *source,
+DerivedMesh *CDDM_from_template_ex(DerivedMesh *source,
         int numVerts, int numEdges, int numTessFaces,
         int numLoops, int numPolys,
-        CustomDataMask mask)
+        const CustomData_MeshMasks *mask)
 {
 	CDDerivedMesh *cddm = cdDM_create("CDDM_from_template dest");
 	DerivedMesh *dm = &cddm->dm;
@@ -1026,7 +1029,7 @@ DerivedMesh *CDDM_from_template(
 	return CDDM_from_template_ex(
 	        source, numVerts, numEdges, numTessFaces,
 	        numLoops, numPolys,
-	        CD_MASK_DERIVEDMESH);
+	        &CD_MASK_DERIVEDMESH);
 }
 
 void CDDM_apply_vert_coords(DerivedMesh *dm, float (*vertCoords)[3])