Remove unused navigation polygon properties

Removes unused navigation polygon properties, a leftover from the old Godot 3 days that used polygon center to polygon center distance for (rather inaccurate) pathfinding cost calculation.

modules/navigation/nav_map.cpp

@@ -1127,13 +1127,6 @@ void NavMap::sync() {
 				new_polygon.points.push_back({ closest_end_point, get_point_key(closest_end_point) });
 				new_polygon.points.push_back({ closest_end_point, get_point_key(closest_end_point) });
 
-				Vector3 center;
-				for (int p = 0; p < 4; ++p) {
-					center += new_polygon.points[p].pos;
-				}
-				new_polygon.center = center / real_t(new_polygon.points.size());
-				new_polygon.clockwise = true;
-
 				// Setup connections to go forward in the link.
 				{
 					gd::Edge::Connection entry_connection;

modules/navigation/nav_region.cpp

@@ -277,9 +277,6 @@ void NavRegion::update_polygons() {
 		polygon.surface_area = _new_polygon_surface_area;
 		_new_region_surface_area += _new_polygon_surface_area;
 
-		Vector3 polygon_center;
-		real_t sum(0);
-
 		for (int j(0); j < navigation_mesh_polygon_size; j++) {
 			int idx = indices[j];
 			if (idx < 0 || idx >= len) {
@@ -290,25 +287,11 @@ void NavRegion::update_polygons() {
 			Vector3 point_position = transform.xform(vertices_r[idx]);
 			polygon.points[j].pos = point_position;
 			polygon.points[j].key = map->get_point_key(point_position);
-
-			polygon_center += point_position; // Composing the center of the polygon
-
-			if (j >= 2) {
-				Vector3 epa = transform.xform(vertices_r[indices[j - 2]]);
-				Vector3 epb = transform.xform(vertices_r[indices[j - 1]]);
-
-				sum += map->get_up().dot((epb - epa).cross(point_position - epa));
-			}
 		}
 
 		if (!valid) {
 			ERR_BREAK_MSG(!valid, "The navigation mesh set in this region is not valid!");
 		}
-
-		polygon.clockwise = sum > 0;
-		if (!navigation_mesh_polygon.is_empty()) {
-			polygon.center = polygon_center / real_t(navigation_mesh_polygon.size());
-		}
 	}
 
 	surface_area = _new_region_surface_area;

modules/navigation/nav_utils.h

@@ -104,15 +104,9 @@ struct Polygon {
 	/// The points of this `Polygon`
 	LocalVector<Point> points;
 
-	/// Are the points clockwise?
-	bool clockwise;
-
 	/// The edges of this `Polygon`
 	LocalVector<Edge> edges;
 
-	/// The center of this `Polygon`
-	Vector3 center;
-
 	real_t surface_area = 0.0;
 };