Curve Handle Recalculate (Ctrl+N)

T37799 Patch from Simon Repp
with added option to recalculate handle lengths.

release/scripts/startup/bl_ui/space_view3d.py

@@ -2356,6 +2356,7 @@ class VIEW3D_MT_edit_curve_ctrlpoints(Menu):
             layout.separator()
 
             layout.operator_menu_enum("curve.handle_type_set", "type")
+            layout.operator("curve.normals_make_consistent")
 
             layout.separator()
 

release/scripts/startup/bl_ui/space_view3d_toolbar.py

@@ -291,6 +291,9 @@ class VIEW3D_PT_tools_curveedit(View3DPanel, Panel):
         row.operator("curve.handle_type_set", text="Align").type = 'ALIGNED'
         row.operator("curve.handle_type_set", text="Free").type = 'FREE_ALIGN'
 
+        col = layout.column(align=True)
+        col.operator("curve.normals_make_consistent")
+
         col = layout.column(align=True)
         col.label(text="Modeling:")
         col.operator("curve.extrude_move", text="Extrude")

source/blender/blenkernel/BKE_curve.h

@@ -113,6 +113,7 @@ int BKE_nurbList_verts_count_without_handles(struct ListBase *nurb);
 void BKE_nurbList_free(struct ListBase *lb);
 void BKE_nurbList_duplicate(struct ListBase *lb1,  struct ListBase *lb2);
 void BKE_nurbList_handles_set(struct ListBase *editnurb, short code);
+void BKE_nurbList_handles_recalculate(struct ListBase *editnurb, const bool calc_length, const char flag);
 
 void BKE_nurbList_handles_autocalc(ListBase *editnurb, int flag);
 void BKE_nurbList_flag_set(ListBase *editnurb, short flag);

source/blender/blenkernel/intern/curve.c

@@ -3393,6 +3393,72 @@ void BKE_nurbList_handles_set(ListBase *editnurb, short code)
 	}
 }
 
+void BKE_nurbList_handles_recalculate(ListBase *editnurb, const bool calc_length, const char flag)
+{
+	Nurb *nu;
+	BezTriple *bezt;
+	int a;
+
+	for (nu = editnurb->first; nu; nu = nu->next) {
+		if (nu->type == CU_BEZIER) {
+			bool changed = false;
+
+			for (a = nu->pntsu, bezt = nu->bezt; a--; bezt++) {
+
+				const bool h1_select = (bezt->f1 & flag) == flag;
+				const bool h2_select = (bezt->f3 & flag) == flag;
+
+				if (h1_select || h2_select) {
+
+					/* Override handle types to HD_AUTO and recalculate */
+
+					char h1_back, h2_back;
+					float co1_back[3], co2_back[3];
+
+					h1_back = bezt->h1;
+					h2_back = bezt->h2;
+
+					bezt->h1 = HD_AUTO;
+					bezt->h2 = HD_AUTO;
+
+					copy_v3_v3(co1_back, bezt->vec[0]);
+					copy_v3_v3(co2_back, bezt->vec[2]);
+
+					BKE_nurb_handle_calc_simple(nu, bezt);
+
+					bezt->h1 = h1_back;
+					bezt->h2 = h2_back;
+
+					if (h1_select) {
+						if (!calc_length) {
+							dist_ensure_v3_v3fl(bezt->vec[0], bezt->vec[1], len_v3v3(co1_back, bezt->vec[1]));
+						}
+					}
+					else {
+						copy_v3_v3(bezt->vec[0], co1_back);
+					}
+
+					if (h2_select) {
+						if (!calc_length) {
+							dist_ensure_v3_v3fl(bezt->vec[2], bezt->vec[1], len_v3v3(co2_back, bezt->vec[1]));
+						}
+					}
+					else {
+						copy_v3_v3(bezt->vec[2], co2_back);
+					}
+
+					changed = true;
+				}
+			}
+
+			if (changed) {
+				/* Recalculate the whole curve */
+				BKE_nurb_handles_calc(nu);
+			}
+		}
+	}
+}
+
 void BKE_nurbList_flag_set(ListBase *editnurb, short flag)
 {
 	Nurb *nu;

source/blender/editors/curve/curve_intern.h

@@ -88,6 +88,7 @@ void CURVE_OT_spline_type_set(struct wmOperatorType *ot);
 void CURVE_OT_radius_set(struct wmOperatorType *ot);
 void CURVE_OT_spline_weight_set(struct wmOperatorType *ot);
 void CURVE_OT_handle_type_set(struct wmOperatorType *ot);
+void CURVE_OT_normals_make_consistent(struct wmOperatorType *ot);
 void CURVE_OT_shade_smooth(struct wmOperatorType *ot);
 void CURVE_OT_shade_flat(struct wmOperatorType *ot);
 void CURVE_OT_tilt_clear(struct wmOperatorType *ot);

source/blender/editors/curve/curve_ops.c

@@ -95,6 +95,7 @@ void ED_operatortypes_curve(void)
 	WM_operatortype_append(CURVE_OT_radius_set);
 	WM_operatortype_append(CURVE_OT_spline_weight_set);
 	WM_operatortype_append(CURVE_OT_handle_type_set);
+	WM_operatortype_append(CURVE_OT_normals_make_consistent);
 	WM_operatortype_append(CURVE_OT_shade_smooth);
 	WM_operatortype_append(CURVE_OT_shade_flat);
 	WM_operatortype_append(CURVE_OT_tilt_clear);
@@ -266,6 +267,8 @@ void ED_keymap_curve(wmKeyConfig *keyconf)
 	kmi = WM_keymap_add_item(keymap, "CURVE_OT_hide", HKEY, KM_PRESS, KM_SHIFT, 0);
 	RNA_boolean_set(kmi->ptr, "unselected", TRUE);
 
+	WM_keymap_add_item(keymap, "CURVE_OT_normals_make_consistent", NKEY, KM_PRESS, KM_CTRL, 0);
+
 	WM_keymap_add_item(keymap, "OBJECT_OT_vertex_parent_set", PKEY, KM_PRESS, KM_CTRL, 0);
 	
 	WM_keymap_add_menu(keymap, "VIEW3D_MT_edit_curve_specials", WKEY, KM_PRESS, 0, 0);

source/blender/editors/curve/editcurve.c

@@ -3676,6 +3676,40 @@ void CURVE_OT_handle_type_set(wmOperatorType *ot)
 	ot->prop = RNA_def_enum(ot->srna, "type", editcurve_handle_type_items, 1, "Type", "Spline type");
 }
 
+/***************** recalculate handles operator **********************/
+
+static int curve_normals_make_consistent_exec(bContext *C, wmOperator *op)
+{
+	Object *obedit = CTX_data_edit_object(C);
+	ListBase *editnurb = object_editcurve_get(obedit);
+	const bool calc_length = RNA_boolean_get(op->ptr, "calc_length");
+
+	BKE_nurbList_handles_recalculate(editnurb, calc_length, SELECT);
+
+	WM_event_add_notifier(C, NC_GEOM | ND_DATA, obedit->data);
+	DAG_id_tag_update(obedit->data, 0);
+
+	return OPERATOR_FINISHED;
+}
+
+void CURVE_OT_normals_make_consistent(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Recalc Normals";
+	ot->description = "Recalculate the direction of selected handles";
+	ot->idname = "CURVE_OT_normals_make_consistent";
+
+	/* api callbacks */
+	ot->exec = curve_normals_make_consistent_exec;
+	ot->poll = ED_operator_editcurve;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* props */
+	RNA_def_boolean(ot->srna, "calc_length", false, "Length", "Recalculate handle length");
+}
+
 /***************** make segment operator **********************/
 
 /* ******************** SKINNING LOFTING!!! ******************** */