Undo: unified undo system w/ linear history

- Use a single undo history for all operations.
- UndoType's are registered and poll the context to check if they
  should be used when performing an undo push.
- Mode switching is used to ensure the state is correct before
  undo data is restored.
- Some undo types accumulate changes (image & text editing)
  others store the state multiple times (with de-duplication).
  This is supported by checking UndoStack.mode `ACCUMULATE` / `STORE`.
- Each undo step stores ID datablocks they use with utilities to help
  manage restoring correct ID's.
  Needed since global undo is now mixed with other modes undo.
- Currently performs each undo step when going up/down history
  Previously this wasn't done, making history fail in some cases.
  This can be optimized to skip some combinations of undo steps.

grease-pencil is an exception which has not been updated
since it integrates undo into the draw-session.

See D3113

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/editors/include/ED_lattice.h b/source/blender/editors/include/ED_lattice.h
index b652fb4c00b..b30929f5307 100644
--- a/source/blender/editors/include/ED_lattice.h
+++ b/source/blender/editors/include/ED_lattice.h
@@ -31,6 +31,8 @@
 #define __ED_LATTICE_H__
 
 struct wmKeyConfig;
+struct UndoType;
+struct Object;
 
 /* lattice_ops.c */
 void ED_operatortypes_lattice(void);
@@ -41,6 +43,6 @@ void ED_lattice_flags_set(struct Object *obedit, int flag);
 bool ED_lattice_select_pick(struct bContext *C, const int mval[2], bool extend, bool deselect, bool toggle);
 
 /* editlattice_undo.c */
-void undo_push_lattice(struct bContext *C, const char *name);
+void ED_lattice_undosys_type(struct UndoType *ut);
 
 #endif  /* __ED_LATTICE_H__ */