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, 4 insertions, 6 deletions

diff --git a/source/blender/modifiers/intern/MOD_simpledeform.c b/source/blender/modifiers/intern/MOD_simpledeform.c
index f53f320d93f..cc36cfbf9eb 100644
--- a/source/blender/modifiers/intern/MOD_simpledeform.c
+++ b/source/blender/modifiers/intern/MOD_simpledeform.c
@@ -344,16 +344,14 @@ static void initData(ModifierData *md)
 	smd->limit[1] =  1.0f;
 }
 
-static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *md)
+static void requiredDataMask(Object *UNUSED(ob), ModifierData *md, CustomData_MeshMasks *r_cddata_masks)
 {
 	SimpleDeformModifierData *smd = (SimpleDeformModifierData *)md;
-	CustomDataMask dataMask = 0;
 
 	/* ask for vertexgroups if we need them */
-	if (smd->vgroup_name[0])
-		dataMask |= CD_MASK_MDEFORMVERT;
-
-	return dataMask;
+	if (smd->vgroup_name[0] != '\0') {
+		r_cddata_masks->vmask |= CD_MASK_MDEFORMVERT;
+	}
 }
 
 static void foreachObjectLink(