Add symmetrize operator for dynamic-topology sculpt mode

source/blender/bmesh/operators/bmo_symmetrize.c

@@ -361,6 +361,12 @@ static BMFace *symm_face_create_v(BMesh *bm, BMFace *example,
 	BMFace *f_new;
 	int i;
 
+	/* TODO: calling symmetrize in dynamic-topology sculpt mode
+	 * frequently tries to create faces of length less than two,
+	 * should investigate further */
+	if (len < 3)
+		return NULL;
+
 	for (i = 0; i < len; i++) {
 		int j = (i + 1) % len;
 		fe[i] = BM_edge_exists(fv[i], fv[j]);
@@ -374,6 +380,7 @@ static BMFace *symm_face_create_v(BMesh *bm, BMFace *example,
 		BM_elem_attrs_copy(bm, bm, example, f_new);
 	BM_face_select_set(bm, f_new, TRUE);
 	BMO_elem_flag_enable(bm, f_new, SYMM_OUTPUT_GEOM);
+
 	return f_new;
 }
 

source/blender/editors/mesh/editmesh_tools.c

@@ -5734,18 +5734,6 @@ static int mesh_symmetrize_exec(bContext *C, wmOperator *op)
 
 void MESH_OT_symmetrize(struct wmOperatorType *ot)
 {
-	static EnumPropertyItem axis_direction_items[] = {
-		{BMO_SYMMETRIZE_NEGATIVE_X, "NEGATIVE_X", 0, "-X to +X", ""},
-		{BMO_SYMMETRIZE_POSITIVE_X, "POSITIVE_X", 0, "+X to -X", ""},
-
-		{BMO_SYMMETRIZE_NEGATIVE_Y, "NEGATIVE_Y", 0, "-Y to +Y", ""},
-		{BMO_SYMMETRIZE_POSITIVE_Y, "POSITIVE_Y", 0, "+Y to -Y", ""},
-
-		{BMO_SYMMETRIZE_NEGATIVE_Z, "NEGATIVE_Z", 0, "-Z to +Z", ""},
-		{BMO_SYMMETRIZE_POSITIVE_Z, "POSITIVE_Z", 0, "+Z to -Z", ""},
-		{0, NULL, 0, NULL, NULL},
-	};
-
 	/* identifiers */
 	ot->name = "Symmetrize";
 	ot->description = "Enforce symmetry (both form and topological) across an axis";
@@ -5758,7 +5746,7 @@ void MESH_OT_symmetrize(struct wmOperatorType *ot)
 	/* flags */
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
-	ot->prop = RNA_def_enum(ot->srna, "direction", axis_direction_items,
+	ot->prop = RNA_def_enum(ot->srna, "direction", symmetrize_direction_items,
 							BMO_SYMMETRIZE_NEGATIVE_X,
 							"Direction", "Which sides to copy from and to");
 }

source/blender/editors/sculpt_paint/sculpt.c

@@ -4712,6 +4712,50 @@ static void SCULPT_OT_optimize(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
 
+/********************* Dynamic topology symmetrize ********************/
+
+static int sculpt_symmetrize_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	Object *ob = CTX_data_active_object(C);
+	const Sculpt *sd = CTX_data_tool_settings(C)->sculpt;
+	SculptSession *ss = ob->sculpt;
+
+	/* To simplify undo for symmetrize, all BMesh elements are logged
+	 * as deleted, then after symmetrize operation all BMesh elements
+	 * are logged as added (as opposed to attempting to store just the
+	 * parts that symmetrize modifies) */
+	sculpt_undo_push_begin("Dynamic topology symmetrize");
+	sculpt_undo_push_node(ob, NULL, SCULPT_UNDO_DYNTOPO_SYMMETRIZE);
+	BM_log_before_all_removed(ss->bm, ss->bm_log);
+
+	/* Symmetrize and re-triangulate */
+	BMO_op_callf(ss->bm, BMO_FLAG_DEFAULTS,
+				 "symmetrize input=%avef direction=%i",
+				 sd->symmetrize_direction);
+	sculpt_dynamic_topology_triangulate(ss->bm);
+
+	/* Finish undo */
+	BM_log_all_added(ss->bm, ss->bm_log);
+	sculpt_undo_push_end();
+
+	/* Redraw */
+	sculpt_pbvh_clear(ob);
+	WM_event_add_notifier(C, NC_OBJECT | ND_DRAW, ob);
+
+	return OPERATOR_FINISHED;
+}
+
+static void SCULPT_OT_symmetrize(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Symmetrize";
+	ot->idname = "SCULPT_OT_symmetrize";
+	
+	/* api callbacks */
+	ot->exec = sculpt_symmetrize_exec;
+	ot->poll = sculpt_and_dynamic_topology_poll;
+}
+
 /**** Toggle operator for turning sculpt mode on or off ****/
 
 static void sculpt_init_session(Scene *scene, Object *ob)
@@ -4887,4 +4931,5 @@ void ED_operatortypes_sculpt(void)
 	WM_operatortype_append(SCULPT_OT_set_persistent_base);
 	WM_operatortype_append(SCULPT_OT_dynamic_topology_toggle);
 	WM_operatortype_append(SCULPT_OT_optimize);
+	WM_operatortype_append(SCULPT_OT_symmetrize);
 }

source/blender/makesdna/DNA_scene_types.h

@@ -832,6 +832,11 @@ typedef struct Sculpt {
 
 	/* Maximum edge length for dynamic topology sculpting (in pixels) */
 	int detail_size;
+
+	/* Direction used for SCULPT_OT_symmetrize operator */
+	int symmetrize_direction;
+
+	int pad;
 } Sculpt;
 
 typedef struct UvSculpt {

source/blender/makesrna/RNA_enum_types.h

@@ -90,6 +90,8 @@ extern EnumPropertyItem brush_sculpt_tool_items[];
 extern EnumPropertyItem brush_vertex_tool_items[];
 extern EnumPropertyItem brush_image_tool_items[];
 
+extern EnumPropertyItem symmetrize_direction_items[];
+
 extern EnumPropertyItem texture_type_items[];
 
 extern EnumPropertyItem lamp_type_items[];

source/blender/makesrna/intern/rna_sculpt_paint.c

@@ -40,6 +40,9 @@
 #include "WM_api.h"
 #include "WM_types.h"
 
+#include "BLI_utildefines.h"
+#include "bmesh.h"
+
 static EnumPropertyItem particle_edit_hair_brush_items[] = {
 	{PE_BRUSH_NONE, "NONE", 0, "None", "Don't use any brush"},
 	{PE_BRUSH_COMB, "COMB", 0, "Comb", "Comb hairs"},
@@ -52,6 +55,18 @@ static EnumPropertyItem particle_edit_hair_brush_items[] = {
 	{0, NULL, 0, NULL, NULL}
 };
 
+EnumPropertyItem symmetrize_direction_items[] = {
+	{BMO_SYMMETRIZE_NEGATIVE_X, "NEGATIVE_X", 0, "-X to +X", ""},
+	{BMO_SYMMETRIZE_POSITIVE_X, "POSITIVE_X", 0, "+X to -X", ""},
+
+	{BMO_SYMMETRIZE_NEGATIVE_Y, "NEGATIVE_Y", 0, "-Y to +Y", ""},
+	{BMO_SYMMETRIZE_POSITIVE_Y, "POSITIVE_Y", 0, "+Y to -Y", ""},
+
+	{BMO_SYMMETRIZE_NEGATIVE_Z, "NEGATIVE_Z", 0, "-Z to +Z", ""},
+	{BMO_SYMMETRIZE_POSITIVE_Z, "POSITIVE_Z", 0, "+Z to -Z", ""},
+	{0, NULL, 0, NULL, NULL},
+};
+
 #ifdef RNA_RUNTIME
 #include "MEM_guardedalloc.h"
 
@@ -341,6 +356,10 @@ static void rna_def_sculpt(BlenderRNA  *brna)
 	RNA_def_property_ui_text(prop, "Collapse Short Edges",
 							 "In dynamic-topology mode, collapse short edges "
 							 "in addition to subdividing long ones");
+
+	prop = RNA_def_property(srna, "symmetrize_direction", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_items(prop, symmetrize_direction_items);
+	RNA_def_property_ui_text(prop, "Direction", "Source and destination for symmetrize operator");
 }