Implement snapping in the CSG gizmos and 3D polygon editor

The spatial editor snap settings will now affect the CSG gizmos
and 3D polygon editor (which is used in CSGPolygon).

editor/plugins/collision_polygon_editor_plugin.cpp

@@ -346,8 +346,10 @@ bool Polygon3DEditor::forward_spatial_gui_input(Camera *p_camera, const Ref<Inpu
 				snap_ignore = false;
 			}
 
-			if (!snap_ignore) {
-				cpoint = CanvasItemEditor::get_singleton()->snap_point(cpoint);
+			if (!snap_ignore && SpatialEditor::get_singleton()->is_snap_enabled()) {
+				cpoint = cpoint.snapped(Vector2(
+						SpatialEditor::get_singleton()->get_translate_snap(),
+						SpatialEditor::get_singleton()->get_translate_snap()));
 			}
 			edited_point_pos = cpoint;
 

modules/csg/csg_gizmos.cpp

@@ -120,6 +120,10 @@ void CSGShapeSpatialGizmoPlugin::set_handle(EditorSpatialGizmo *p_gizmo, int p_i
 		Vector3 ra, rb;
 		Geometry::get_closest_points_between_segments(Vector3(), Vector3(4096, 0, 0), sg[0], sg[1], ra, rb);
 		float d = ra.x;
+		if (SpatialEditor::get_singleton()->is_snap_enabled()) {
+			d = Math::stepify(d, SpatialEditor::get_singleton()->get_translate_snap());
+		}
+
 		if (d < 0.001)
 			d = 0.001;
 
@@ -135,6 +139,10 @@ void CSGShapeSpatialGizmoPlugin::set_handle(EditorSpatialGizmo *p_gizmo, int p_i
 		Vector3 ra, rb;
 		Geometry::get_closest_points_between_segments(Vector3(), axis * 4096, sg[0], sg[1], ra, rb);
 		float d = ra[p_idx];
+		if (SpatialEditor::get_singleton()->is_snap_enabled()) {
+			d = Math::stepify(d, SpatialEditor::get_singleton()->get_translate_snap());
+		}
+
 		if (d < 0.001)
 			d = 0.001;
 
@@ -154,6 +162,9 @@ void CSGShapeSpatialGizmoPlugin::set_handle(EditorSpatialGizmo *p_gizmo, int p_i
 		Vector3 ra, rb;
 		Geometry::get_closest_points_between_segments(Vector3(), axis * 4096, sg[0], sg[1], ra, rb);
 		float d = axis.dot(ra);
+		if (SpatialEditor::get_singleton()->is_snap_enabled()) {
+			d = Math::stepify(d, SpatialEditor::get_singleton()->get_translate_snap());
+		}
 
 		if (d < 0.001)
 			d = 0.001;
@@ -173,6 +184,9 @@ void CSGShapeSpatialGizmoPlugin::set_handle(EditorSpatialGizmo *p_gizmo, int p_i
 		Vector3 ra, rb;
 		Geometry::get_closest_points_between_segments(Vector3(), axis * 4096, sg[0], sg[1], ra, rb);
 		float d = axis.dot(ra);
+		if (SpatialEditor::get_singleton()->is_snap_enabled()) {
+			d = Math::stepify(d, SpatialEditor::get_singleton()->get_translate_snap());
+		}
 
 		if (d < 0.001)
 			d = 0.001;