Add dynamic topology support to sculpt mode

* User documentation:
  wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.66/Dynamic_Topology_Sculpting

* Code review for this and the other dynamic-topology commits:
  https://codereview.appspot.com/6947064/
  Thanks to Sergey for doing code review!

* Add SCULPT_OT_dynamic_topology_toggle operator to enable or disable
  dynamic topology mode

* Most brushes need little modification for dynamic topology, but for
  some it won't work well and is disabled. This decision is made in
  sculpt_stroke_dynamic_topology().

* For brushes that need original data (e.g. grab brush) the topology
  is not updated during the stroke, but some changes to original
  vertex data is accessed were made since BMesh works a little
  differently from mesh/multires. This is abstracted with
  SculptOrigVertData and associated functions.

* Smooth brush gets yet another set of functions, for mesh and
  multires and dynamic topology and, separetely, masking

* For most brushes, the topology is updated during the stroke right
  before the regular brush action takes place. This is handled in
  sculpt_topology_update().

* Exiting sculpt mode also disables dynamic topology

* Sculpt undo works differently with BMesh. Since the contents of
  nodes in the PBVH do not remain static during a sculpt session, the
  SculptUndoNodes do not correspond with PBVHNodes if dynamic topology
  is enabled. Rather, each SculptUndoNode is associated with a
  BMLogEntry.

* Sculpt undo gets a few new cases: entering and exiting dynamic
  topology does an undo push of all mesh data. Symmetrize will
  similarly push a full copy of BMesh data, although it does so
  through the BMLog API.

* Undo and redo in dynamic-topology mode will do a full recalculation
  of the PBVH.

* Add some documentation to doc/sculpt.org. This could stand to be
  expanded a lot more, for now it mostly contains test cases for the
  undo system.

* Add SCULPT_OT_optimize operator to recalculate the BVH. The BVH gets
  less optimal more quickly with dynamic topology than regular
  sculpting. There is no doubt more clever stuff we can do to optimize
  it on the fly, but for now this gives the user a nicer way to
  recalculate it than toggling modes.

1 files changed, 24 insertions, 1 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt_intern.h b/source/blender/editors/sculpt_paint/sculpt_intern.h
index cfc908bf453..e56962a3964 100644
--- a/source/blender/editors/sculpt_paint/sculpt_intern.h
+++ b/source/blender/editors/sculpt_paint/sculpt_intern.h
@@ -49,6 +49,7 @@ struct Object;
 struct Scene;
 struct Sculpt;
 struct SculptStroke;
+struct SculptUndoNode;
 
 /* Interface */
 struct MultiresModifierData *sculpt_multires_active(struct Scene *scene, struct Object *ob);
@@ -67,12 +68,22 @@ void free_sculptsession_deformMats(struct SculptSession *ss);
 /* Stroke */
 int sculpt_stroke_get_location(bContext *C, float out[3], const float mouse[2]);
 
+/* Dynamic topology */
+void sculpt_pbvh_clear(Object *ob);
+void sculpt_update_after_dynamic_topology_toggle(bContext *C);
+void sculpt_dynamic_topology_enable(struct bContext *C);
+void sculpt_dynamic_topology_disable(struct bContext *C,
+									 struct SculptUndoNode *unode);
+
 /* Undo */
 
 typedef enum {
 	SCULPT_UNDO_COORDS,
 	SCULPT_UNDO_HIDDEN,
-	SCULPT_UNDO_MASK
+	SCULPT_UNDO_MASK,
+	SCULPT_UNDO_DYNTOPO_BEGIN,
+	SCULPT_UNDO_DYNTOPO_END,
+	SCULPT_UNDO_DYNTOPO_SYMMETRIZE,
 } SculptUndoType;
 
 typedef struct SculptUndoNode {
@@ -101,6 +112,18 @@ typedef struct SculptUndoNode {
 	int *grids;                 /* to restore into right location */
 	BLI_bitmap *grid_hidden;
 
+	/* bmesh */
+	struct BMLogEntry *bm_entry;
+	int applied;
+	CustomData bm_enter_vdata;
+	CustomData bm_enter_edata;
+	CustomData bm_enter_ldata;
+	CustomData bm_enter_pdata;
+	int bm_enter_totvert;
+	int bm_enter_totedge;
+	int bm_enter_totloop;
+	int bm_enter_totpoly;
+
 	/* shape keys */
 	char shapeName[sizeof(((KeyBlock *)0))->name];
 } SculptUndoNode;