Fix T47038: Particles in Particle Edit Mode get added in completely wrong location.

It also fixes another issue (crash) related to symmetric editing.

Quite involved, we (try to!) fix complete broken logic of parts of particle code, which would use poly index
as tessface one (or vice-versa). Issue most probably goes back to BMesh integration time...

This patch mostly fixes particle editing mode:
  - Adding/removing particles when using generative modifiers (like subsurf) should now work.
  - Adding/removing particles with a non-tessellated mesh (i.e. one having ngons) should also mostly work.
  - X-axis-mirror-editing particles over ngons does not really work, not sure why currently.
  - All this in both 'modes' (with or without using modifier stack for particles).

Tech side:
  - Store a deformed-only DM in particle modifier data.
  - Rename existing DM to make it clear it's a final one.
  - Use deformed-only DM's tessface2poly mapping to 'solve' poly/tessface mismatches.
  - Make (part of) mirror-editing code able to use a DM instead of raw mesh, so that we can mirror based on final DM
    when editing particles using modifier stack (mandatory, since there is no way currently to find orig tessface
    from an final DM tessface index).

Note that this patch is not really nice and clean (current particles are beyond hope on this side anyway),
it's more like some urgency bandage. Whole crap needs complete rewrite anyway,
BMesh's polygons make it really hard to work with current system (and looptri would not help much here).

Also, did not test everything possibly affected by those changes, so it needs some users' testing & validation too.

Reviewers: psy-fi

Subscribers: dfelinto, eyecandy

Maniphest Tasks: T47038

Differential Revision: https://developer.blender.org/D1685

1 files changed, 7 insertions, 6 deletions

diff --git a/source/blender/editors/include/ED_mesh.h b/source/blender/editors/include/ED_mesh.h
index c509aeb4ac2..f072e707d00 100644
--- a/source/blender/editors/include/ED_mesh.h
+++ b/source/blender/editors/include/ED_mesh.h
@@ -218,8 +218,8 @@ typedef struct MirrTopoStore_t {
 	int prev_ob_mode;
 } MirrTopoStore_t;
 
-bool ED_mesh_mirrtopo_recalc_check(struct Mesh *me, const int ob_mode, MirrTopoStore_t *mesh_topo_store);
-void ED_mesh_mirrtopo_init(struct Mesh *me, const int ob_mode, MirrTopoStore_t *mesh_topo_store,
+bool ED_mesh_mirrtopo_recalc_check(struct Mesh *me, struct DerivedMesh *dm, const int ob_mode, MirrTopoStore_t *mesh_topo_store);
+void ED_mesh_mirrtopo_init(struct Mesh *me, struct DerivedMesh *dm, const int ob_mode, MirrTopoStore_t *mesh_topo_store,
                            const bool skip_em_vert_array_init);
 void ED_mesh_mirrtopo_free(MirrTopoStore_t *mesh_topo_store);
 
@@ -308,17 +308,18 @@ int         join_mesh_exec(struct bContext *C, struct wmOperator *op);
 int         join_mesh_shapes_exec(struct bContext *C, struct wmOperator *op);
 
 /* mirror lookup api */
-int         ED_mesh_mirror_spatial_table(struct Object *ob, struct BMEditMesh *em, const float co[3], char mode);
-int         ED_mesh_mirror_topo_table(struct Object *ob, char mode);
+int ED_mesh_mirror_spatial_table(
+        struct Object *ob, struct BMEditMesh *em, struct DerivedMesh *dm, const float co[3], char mode);
+int  ED_mesh_mirror_topo_table(struct Object *ob, struct DerivedMesh *dm, char mode);
 
 /* retrieves mirrored cache vert, or NULL if there isn't one.
  * note: calling this without ensuring the mirror cache state
  * is bad.*/
-int            mesh_get_x_mirror_vert(struct Object *ob, int index, const bool use_topology);
+int            mesh_get_x_mirror_vert(struct Object *ob, struct DerivedMesh *dm, int index, const bool use_topology);
 struct BMVert *editbmesh_get_x_mirror_vert(struct Object *ob, struct BMEditMesh *em,
                                            struct BMVert *eve, const float co[3],
                                            int index, const bool use_topology);
-int           *mesh_get_x_mirror_faces(struct Object *ob, struct BMEditMesh *em);
+int           *mesh_get_x_mirror_faces(struct Object *ob, struct BMEditMesh *em, struct DerivedMesh *dm);
 
 int ED_mesh_mirror_get_vert(struct Object *ob, int index);