Issue #84: make connections scale insensitive.

map_machine/road.py

@@ -496,6 +496,10 @@ class Connector:
         self.index_1: int = index_1
         self.index_2: int = index_2
 
+        length: float = abs(road_2.width - road_1.width) * scale
+        road_1.line.shorten(index_1, length)
+        road_2.line.shorten(index_2, length)
+
         node: OSMNode = road_1.nodes[index_1]
         point: np.ndarray = flinger.fling(node.coordinates)
 
@@ -560,11 +564,6 @@ class Roads:
             if road.layer not in layered_roads:
                 layered_roads[road.layer] = []
             layered_roads[road.layer].append(road)
-            for index in 0, -1:
-                id_: int = road.nodes[index].id_
-                if len(self.connections[id_]) != 2:
-                    continue
-                road.line.shorten(index)
 
         for id_ in self.connections:
             if len(self.connections[id_]) != 2:
@@ -572,6 +571,8 @@ class Roads:
             connected: list[tuple[Road, int]] = self.connections[id_]
             road_1, index_1 = connected[0]
             road_2, index_2 = connected[1]
+            if road_1.width == road_2.width:
+                continue
             connector: Connector = Connector(
                 road_1, index_1, road_2, index_2, flinger, scale
             )

map_machine/vector.py

@@ -62,12 +62,12 @@ class Polyline:
         path: str = "M " + " L ".join(f"{x[0]},{x[1]}" for x in points)
         return path + (" Z" if np.allclose(points[0], points[-1]) else "")
 
-    def shorten(self, index: int) -> None:
+    def shorten(self, index: int, length: float) -> None:
         """Make shorten part specified with index."""
         index_2: int = 1 if index == 0 else -2
         diff: np.ndarray = self.points[index_2] - self.points[index]
         self.points[index] = (
-            self.points[index] + diff / np.linalg.norm(diff) * 5
+            self.points[index] + diff / np.linalg.norm(diff) * length
         )