Add DNA/RNA/BKE infrastructure for dynamic-topology sculpt mode

* Add a detail_size field to the Sculpt struct, two new sculpt flags,
  and a Mesh flag for dynamic-topology mode; that's it for file-level
  changes needed by dynamic topology

* Add RNA for the new DNA field and flags

* Add a new icon for dynamic-topology created by Julio Iglesias. TODO:
  update the icon for the new SVG icon format

* Add a SculptSession function for converting from BMesh to Mesh,
  handles reordering mesh elements and setting face shading

7 files changed, 85 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_paint.h b/source/blender/blenkernel/BKE_paint.h
index c452c177143..0a4a7f75e25 100644
--- a/source/blender/blenkernel/BKE_paint.h
+++ b/source/blender/blenkernel/BKE_paint.h
@@ -33,6 +33,7 @@
  */
 
 struct bContext;
+struct BMesh;
 struct Brush;
 struct MDisps;
 struct MeshElemMap;
@@ -92,6 +93,12 @@ typedef struct SculptSession {
 	/* Mesh connectivity */
 	const struct MeshElemMap *pmap;
 
+	/* BMesh for dynamic topology sculpting */
+	struct BMesh *bm;
+	int bm_smooth_shading;
+	/* Undo/redo log for dynamic topology sculpting */
+	struct BMLog *bm_log;
+
 	/* PBVH acceleration structure */
 	struct PBVH *pbvh;
 	int show_diffuse_color;
@@ -121,5 +128,6 @@ typedef struct SculptSession {
 
 void free_sculptsession(struct Object *ob);
 void free_sculptsession_deformMats(struct SculptSession *ss);
+void sculptsession_bm_to_me(struct Object *ob, int reorder);
 
 #endif
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index 99b163ce45b..92b2c8231d3 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -264,14 +264,44 @@ void free_sculptsession_deformMats(SculptSession *ss)
 	ss->deform_imats = NULL;
 }
 
+/* Write out the sculpt dynamic-topology BMesh to the Mesh */
+void sculptsession_bm_to_me(struct Object *ob, int reorder)
+{
+	if (ob && ob->sculpt) {
+		SculptSession *ss = ob->sculpt;
+
+		if (ss->bm) {
+			if (ob->data) {
+				BMIter iter;
+				BMFace *efa;
+				BM_ITER_MESH (efa, &iter, ss->bm, BM_FACES_OF_MESH) {
+					BM_elem_flag_set(efa, BM_ELEM_SMOOTH,
+									 ss->bm_smooth_shading);
+				}
+				if (reorder)
+					BM_log_mesh_elems_reorder(ss->bm, ss->bm_log);
+				BM_mesh_bm_to_me(ss->bm, ob->data, FALSE);
+			}
+		}
+	}
+}
+
 void free_sculptsession(Object *ob)
 {
 	if (ob && ob->sculpt) {
 		SculptSession *ss = ob->sculpt;
 		DerivedMesh *dm = ob->derivedFinal;
 
+		if (ss->bm) {
+			sculptsession_bm_to_me(ob, TRUE);
+			BM_mesh_free(ss->bm);
+		}
+
 		if (ss->pbvh)
 			BLI_pbvh_free(ss->pbvh);
+		if (ss->bm_log)
+ 			BM_log_free(ss->bm_log);
+
 		if (dm && dm->getPBVH)
 			dm->getPBVH(NULL, dm);  /* signal to clear */
 
diff --git a/source/blender/editors/include/UI_icons.h b/source/blender/editors/include/UI_icons.h
index 99f7f0856b3..0a794040692 100644
--- a/source/blender/editors/include/UI_icons.h
+++ b/source/blender/editors/include/UI_icons.h
@@ -699,9 +699,7 @@ DEF_ICON(RNDCURVE)
 DEF_ICON(PROP_OFF)
 DEF_ICON(PROP_ON)
 DEF_ICON(PROP_CON)
-#ifndef DEF_ICON_BLANK_SKIP
-	DEF_ICON(BLANK212)
-#endif
+DEF_ICON(SCULPT_DYNTOPO)
 DEF_ICON(PARTICLE_POINT)
 DEF_ICON(PARTICLE_TIP)
 DEF_ICON(PARTICLE_PATH)
diff --git a/source/blender/makesdna/DNA_mesh_types.h b/source/blender/makesdna/DNA_mesh_types.h
index 05f8d2645ad..4c9f6014445 100644
--- a/source/blender/makesdna/DNA_mesh_types.h
+++ b/source/blender/makesdna/DNA_mesh_types.h
@@ -170,6 +170,7 @@ typedef struct TFace {
 #define ME_SUBSURF		128
 #define ME_OPT_EDGES	256
 #define ME_DS_EXPAND	512
+#define ME_SCULPT_DYNAMIC_TOPOLOGY 1024
 
 /* me->drawflag, short */
 #define ME_DRAWEDGES	(1 << 0)
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 5af116df772..0d1ef7af591 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -830,7 +830,8 @@ typedef struct Sculpt {
 
 	float special_rotation;
 
-	int pad;
+	/* Maximum edge length for dynamic topology sculpting (in pixels) */
+	int detail_size;
 } Sculpt;
 
 typedef struct UvSculpt {
@@ -1479,6 +1480,14 @@ typedef enum SculptFlags {
 	SCULPT_USE_OPENMP = (1<<7),
 	SCULPT_ONLY_DEFORM = (1<<8),
 	SCULPT_SHOW_DIFFUSE = (1<<9),
+
+	/* If set, the mesh will be drawn with smooth-shading in
+	   dynamic-topology mode */
+	SCULPT_DYNTOPO_SMOOTH_SHADING = (1<<10),
+
+	/* If set, dynamic-topology brushes will collapse short edges in
+	   addition to subdividing long ones */
+	SCULPT_DYNTOPO_COLLAPSE = (1<<11)
 } SculptFlags;
 
 /* ImagePaintSettings.flag */
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 4918aabdb1f..6e81e866118 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -48,6 +48,7 @@
 
 #include "BLI_utildefines.h"
 
+#include "BKE_paint.h"
 #include "BKE_tessmesh.h"
 #include "BKE_group.h" /* needed for object_in_group() */
 
@@ -1436,6 +1437,12 @@ int rna_DupliObject_index_get(PointerRNA *ptr)
 	return dob->persistent_id[0];
 }
 
+int rna_Object_use_dynamic_topology_sculpting_get(PointerRNA *ptr)
+{
+	SculptSession *ss = ((Object*)ptr->id.data)->sculpt;
+	return (ss && ss->bm);
+}
+
 #else
 
 static int rna_matrix_dimsize_4x4[] = {4, 4};
@@ -2629,6 +2636,12 @@ static void rna_def_object(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Active Shape Key Index", "Current shape key index");
 	RNA_def_property_update(prop, 0, "rna_Object_active_shape_update");
 
+	/* sculpt */
+	prop = RNA_def_property(srna, "use_dynamic_topology_sculpting", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_funcs(prop, "rna_Object_use_dynamic_topology_sculpting_get", NULL);
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Dynamic Topology Sculpting", NULL);
+
 	RNA_api_object(srna);
 }
 
diff --git a/source/blender/makesrna/intern/rna_sculpt_paint.c b/source/blender/makesrna/intern/rna_sculpt_paint.c
index f717c83075a..e3b41222a38 100644
--- a/source/blender/makesrna/intern/rna_sculpt_paint.c
+++ b/source/blender/makesrna/intern/rna_sculpt_paint.c
@@ -204,6 +204,11 @@ static void rna_Sculpt_update(Main *UNUSED(bmain), Scene *scene, PointerRNA *UNU
 	if (ob) {
 		DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
 		WM_main_add_notifier(NC_OBJECT | ND_MODIFIER, ob);
+
+		if (ob->sculpt) {
+			ob->sculpt->bm_smooth_shading = (scene->toolsettings->sculpt->flags &
+											 SCULPT_DYNTOPO_SMOOTH_SHADING);
+		}
 	}
 }
 
@@ -319,6 +324,23 @@ static void rna_def_sculpt(BlenderRNA  *brna)
 	RNA_def_property_ui_text(prop, "Show Diffuse Color",
 	                         "Show diffuse color of object and overlay sculpt mask on top of it");
 	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_Sculpt_ShowDiffuseColor_update");
+
+	prop = RNA_def_property(srna, "detail_size", PROP_INT, PROP_DISTANCE);
+	RNA_def_property_ui_range(prop, 2, 100, 0, 0);
+	RNA_def_property_ui_text(prop, "Detail Size", "Maximum edge length for dynamic topology sculpting (in pixels)");
+
+	prop = RNA_def_property(srna, "use_smooth_shading", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flags", SCULPT_DYNTOPO_SMOOTH_SHADING);
+	RNA_def_property_ui_text(prop, "Smooth Shading",
+							 "Show faces in dynamic-topology mode with smooth "
+							 "shading rather than flat shaded");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_Sculpt_update");
+
+	prop = RNA_def_property(srna, "use_edge_collapse", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flags", SCULPT_DYNTOPO_COLLAPSE);
+	RNA_def_property_ui_text(prop, "Collapse Short Edges",
+							 "In dynamic-topology mode, collapse short edges "
+							 "in addition to subdividing long ones");
 }