(NOTE: DO NOT TEST)

Start of planned DerivedMesh refactoring.  The mface
interfaces in DerivedMesh have been renamed to reflect
their new status as tesselated face interfaces (rather 
then the primary ones, which are now stored in mpolys).

short review: mpolys store "primary" face data, while
mfaces store the tesselated form of the mesh (generally
as triangles).  mpolys are defined by mloops, and each
mpoly defines a range of loops it "owns" in the main
mloop array.

I've also added basic read-only face iterators, which
are implemented for CDDM, ccgsubsurf, and the bmeditmesh
derivedmesh.  Since faces are now variable-length things,
trying to implement the same interface as mfaces would not
have worked well (especially since faces are stored as
an mpoly + a range of mloops).

I figure first we can evaluate these simple read-only
face iterators, then decide if a) we like using iterators
in DerivedMesh, b) how much of it should use them, and c)
if we want write-capable iterators.

I plan to write official docs on this design after I get
it more stable; I'm committing now because there's a rather
lot of changes, and I might do a merge soon.

1 files changed, 16 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_cdderivedmesh.h b/source/blender/blenkernel/BKE_cdderivedmesh.h
index d4fee61f9c6..36db9553c59 100644
--- a/source/blender/blenkernel/BKE_cdderivedmesh.h
+++ b/source/blender/blenkernel/BKE_cdderivedmesh.h
@@ -44,7 +44,8 @@ struct Mesh;
 struct Object;
 
 /* creates a new CDDerivedMesh */
-struct DerivedMesh *CDDM_new(int numVerts, int numEdges, int numFaces);
+struct DerivedMesh *CDDM_new(int numVerts, int numEdges, int numFaces,
+                             int numLoops, int numPolys);
 
 /* creates a CDDerivedMesh from the given Mesh, this will reference the
    original data in Mesh, but it is safe to apply vertex coordinates or
@@ -68,7 +69,13 @@ struct DerivedMesh *CDDM_copy(struct DerivedMesh *dm);
  * elements are initialised to all zeros
  */
 struct DerivedMesh *CDDM_from_template(struct DerivedMesh *source,
-                                  int numVerts, int numEdges, int numFaces);
+                                  int numVerts, int numEdges, int numFaces,
+                                  int numLoops, int numPolys);
+
+/*converts mfaces to mpolys.  note things may break if there are not valid
+ *medges surrounding each mface.
+ */
+void CDDM_tessfaces_to_faces(struct DerivedMesh *dm);
 
 /* applies vertex coordinates or normals to a CDDerivedMesh. if the MVert
  * layer is a referenced layer, it will be duplicate to not overwrite the
@@ -99,7 +106,9 @@ void CDDM_lower_num_faces(struct DerivedMesh *dm, int numFaces);
  */
 struct MVert *CDDM_get_vert(struct DerivedMesh *dm, int index);
 struct MEdge *CDDM_get_edge(struct DerivedMesh *dm, int index);
-struct MFace *CDDM_get_face(struct DerivedMesh *dm, int index);
+struct MFace *CDDM_get_tessface(struct DerivedMesh *dm, int index);
+struct MLoop *CDDM_get_loop(struct DerivedMesh *dm, int index);
+struct MPoly *CDDM_get_face(struct DerivedMesh *dm, int index);
 
 /* vertex/edge/face array access functions - return the array holding the
  * desired data
@@ -108,6 +117,9 @@ struct MFace *CDDM_get_face(struct DerivedMesh *dm, int index);
  */
 struct MVert *CDDM_get_verts(struct DerivedMesh *dm);
 struct MEdge *CDDM_get_edges(struct DerivedMesh *dm);
-struct MFace *CDDM_get_faces(struct DerivedMesh *dm);
+struct MFace *CDDM_get_tessfaces(struct DerivedMesh *dm);
+struct MLoop *CDDM_get_loops(struct DerivedMesh *dm);
+struct MPoly *CDDM_get_faces(struct DerivedMesh *dm);
+
 #endif