BMesh: option to flip normals for extrude/spin

3 files changed, 18 insertions, 11 deletions

diff --git a/source/blender/bmesh/intern/bmesh_opdefines.c b/source/blender/bmesh/intern/bmesh_opdefines.c
index 450d49211ec..891a15d4184 100644
--- a/source/blender/bmesh/intern/bmesh_opdefines.c
+++ b/source/blender/bmesh/intern/bmesh_opdefines.c
@@ -881,6 +881,7 @@ static BMOpDefine bmo_extrude_discrete_faces_def = {
 	"extrude_discrete_faces",
 	/* slots_in */
 	{{"faces", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},     /* input faces */
+	 {"use_normal_flip", BMO_OP_SLOT_BOOL},  /* Create faces with reversed direction. */
 	 {"use_select_history", BMO_OP_SLOT_BOOL},  /* pass to duplicate */
 	 {{'\0'}},
 	},
@@ -902,6 +903,7 @@ static BMOpDefine bmo_extrude_edge_only_def = {
 	"extrude_edge_only",
 	/* slots_in */
 	{{"edges", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},    /* input vertices */
+	 {"use_normal_flip", BMO_OP_SLOT_BOOL},  /* Create faces with reversed direction. */
 	 {"use_select_history", BMO_OP_SLOT_BOOL},  /* pass to duplicate */
 	 {{'\0'}},
 	},
@@ -1037,6 +1039,7 @@ static BMOpDefine bmo_extrude_face_region_def = {
 	{{"geom", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},     /* edges and faces */
 	 {"edges_exclude", BMO_OP_SLOT_MAPPING, {(int)BMO_OP_SLOT_SUBTYPE_MAP_EMPTY}},
 	 {"use_keep_orig", BMO_OP_SLOT_BOOL},   /* keep original geometry (requires ``geom`` to include edges). */
+	 {"use_normal_flip", BMO_OP_SLOT_BOOL},  /* Create faces with reversed direction. */
 	 {"use_select_history", BMO_OP_SLOT_BOOL},  /* pass to duplicate */
 	 {{'\0'}},
 	},
@@ -1386,6 +1389,7 @@ static BMOpDefine bmo_spin_def = {
 	 {"angle", BMO_OP_SLOT_FLT},            /* total rotation angle (radians) */
 	 {"space", BMO_OP_SLOT_MAT},            /* matrix to define the space (typically object matrix) */
 	 {"steps", BMO_OP_SLOT_INT},            /* number of steps */
+	 {"use_normal_flip", BMO_OP_SLOT_BOOL}, /* Create faces with reversed direction. */
 	 {"use_duplicate", BMO_OP_SLOT_BOOL},   /* duplicate or extrude? */
 	 {{'\0'}},
 	},
diff --git a/source/blender/bmesh/operators/bmo_dupe.c b/source/blender/bmesh/operators/bmo_dupe.c
index eed87ed20af..af1cd22ac8d 100644
--- a/source/blender/bmesh/operators/bmo_dupe.c
+++ b/source/blender/bmesh/operators/bmo_dupe.c
@@ -486,6 +486,7 @@ void bmo_spin_exec(BMesh *bm, BMOperator *op)
 	steps    = BMO_slot_int_get(op->slots_in,   "steps");
 	phi      = BMO_slot_float_get(op->slots_in, "angle") / steps;
 	do_dupli = BMO_slot_bool_get(op->slots_in,  "use_duplicate");
+	const bool use_normal_flip = BMO_slot_bool_get(op->slots_in,  "use_normal_flip");
 
 	axis_angle_normalized_to_mat3(rmat, axis, phi);
 
@@ -503,8 +504,8 @@ void bmo_spin_exec(BMesh *bm, BMOperator *op)
 			BMO_op_finish(bm, &dupop);
 		}
 		else {
-			BMO_op_initf(bm, &extop, op->flag, "extrude_face_region geom=%S",
-			             op, "geom_last.out");
+			BMO_op_initf(bm, &extop, op->flag, "extrude_face_region geom=%S use_normal_flip=%b",
+			             op, "geom_last.out", use_normal_flip && (a == 0));
 			BMO_op_exec(bm, &extop);
 			BMO_op_callf(bm, op->flag,
 			             "rotate cent=%v matrix=%m3 space=%s verts=%S",
diff --git a/source/blender/bmesh/operators/bmo_extrude.c b/source/blender/bmesh/operators/bmo_extrude.c
index 3a6fbd419c1..8c1624740da 100644
--- a/source/blender/bmesh/operators/bmo_extrude.c
+++ b/source/blender/bmesh/operators/bmo_extrude.c
@@ -186,6 +186,7 @@ void bmo_extrude_edge_only_exec(BMesh *bm, BMOperator *op)
 	BMOperator dupeop;
 	BMFace *f;
 	BMEdge *e, *e_new;
+	const bool use_normal_flip = BMO_slot_bool_get(op->slots_in, "use_normal_flip");
 
 	BMO_ITER (e, &siter, op->slots_in, "edges", BM_EDGE) {
 		BMO_edge_flag_enable(bm, e, EXT_INPUT);
@@ -212,7 +213,9 @@ void bmo_extrude_edge_only_exec(BMesh *bm, BMOperator *op)
 		BMVert *f_verts[4];
 		e_new = BMO_iter_map_value_ptr(&siter);
 
-		if (e->l && e->v1 != e->l->v) {
+
+		const bool edge_normal_flip = !(e->l && e->v1 != e->l->v);
+		if (edge_normal_flip == use_normal_flip) {
 			f_verts[0] = e->v1;
 			f_verts[1] = e->v2;
 			f_verts[2] = e_new->v2;
@@ -332,9 +335,10 @@ void bmo_extrude_face_region_exec(BMesh *bm, BMOperator *op)
 	BMEdge *e, *e_new;
 	BMVert *v;
 	BMFace *f;
-	bool found, fwd, delorig = false;
+	bool found, delorig = false;
 	BMOpSlot *slot_facemap_out;
 	BMOpSlot *slot_edges_exclude;
+	const bool use_normal_flip = BMO_slot_bool_get(op->slots_in, "use_normal_flip");
 
 	/* initialize our sub-operators */
 	BMO_op_initf(
@@ -488,13 +492,11 @@ void bmo_extrude_face_region_exec(BMesh *bm, BMOperator *op)
 		/* orient loop to give same normal as a loop of newedge
 		 * if it exists (will be an extruded face),
 		 * else same normal as a loop of e, if it exists */
-		if (!e_new->l)
-			fwd = !e->l || !(e->l->v == e->v1);
-		else
-			fwd = (e_new->l->v == e_new->v1);
-
-
-		if (fwd) {
+		const bool edge_normal_flip = !(
+		        e_new->l ?
+		        (e_new->l->v == e_new->v1) :
+		        (!e->l || !(e->l->v == e->v1)));
+		if (edge_normal_flip == use_normal_flip) {
 			f_verts[0] = e->v1;
 			f_verts[1] = e->v2;
 			f_verts[2] = e_new->v2;