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

2 files changed, 11 insertions, 8 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 82ef725ef37..e34382dc752 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -6640,7 +6640,9 @@ static void direct_link_scene(FileData *fd, Scene *sce)
 
 	sce->depsgraph_hash = NULL;
 	sce->fps_info = NULL;
-	sce->customdata_mask_modal = 0;
+
+	memset(&sce->customdata_mask, 0, sizeof(sce->customdata_mask));
+	memset(&sce->customdata_mask_modal, 0, sizeof(sce->customdata_mask_modal));
 
 	BKE_sound_create_scene(sce);
 
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 6694e050695..4226b111d16 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -2101,14 +2101,15 @@ static void write_grid_paint_mask(WriteData *wd, int count, GridPaintMask *grid_
 }
 
 static void write_customdata(
-        WriteData *wd, ID *id, int count, CustomData *data, CustomDataLayer *layers,
+        WriteData *wd, ID *id,
+        int count, CustomData *data, CustomDataLayer *layers, CustomDataMask cddata_mask,
         int partial_type, int partial_count)
 {
 	int i;
 
 	/* write external customdata (not for undo) */
 	if (data->external && (wd->use_memfile == false)) {
-		CustomData_external_write(data, id, CD_MASK_MESH, count, 0);
+		CustomData_external_write(data, id, cddata_mask, count, 0);
 	}
 
 	writestruct_at_address(wd, DATA, CustomDataLayer, data->totlayer, data->layers, layers);
@@ -2209,12 +2210,12 @@ static void write_mesh(WriteData *wd, Mesh *mesh)
 			writedata(wd, DATA, sizeof(void *) * mesh->totcol, mesh->mat);
 			writedata(wd, DATA, sizeof(MSelect) * mesh->totselect, mesh->mselect);
 
-			write_customdata(wd, &mesh->id, mesh->totvert, &mesh->vdata, vlayers, -1, 0);
-			write_customdata(wd, &mesh->id, mesh->totedge, &mesh->edata, elayers, -1, 0);
+			write_customdata(wd, &mesh->id, mesh->totvert, &mesh->vdata, vlayers, CD_MASK_MESH.vmask, -1, 0);
+			write_customdata(wd, &mesh->id, mesh->totedge, &mesh->edata, elayers, CD_MASK_MESH.emask, -1, 0);
 			/* fdata is really a dummy - written so slots align */
-			write_customdata(wd, &mesh->id, mesh->totface, &mesh->fdata, flayers, -1, 0);
-			write_customdata(wd, &mesh->id, mesh->totloop, &mesh->ldata, llayers, -1, 0);
-			write_customdata(wd, &mesh->id, mesh->totpoly, &mesh->pdata, players, -1, 0);
+			write_customdata(wd, &mesh->id, mesh->totface, &mesh->fdata, flayers, CD_MASK_MESH.fmask, -1, 0);
+			write_customdata(wd, &mesh->id, mesh->totloop, &mesh->ldata, llayers, CD_MASK_MESH.lmask, -1, 0);
+			write_customdata(wd, &mesh->id, mesh->totpoly, &mesh->pdata, players, CD_MASK_MESH.pmask, -1, 0);
 
 			/* restore pointer */
 			mesh = old_mesh;