fall back to lines when radius is zero

src/satx.js

@@ -49,7 +49,11 @@ export default class SATX {
     return 1 / Math.cos(Math.PI / numberOfVertices)
   }
 
-  static entityTunnel(from, to, radius) {
+  static entityTunnel(from, to, radius = 0) {
+    if (radius <= 0) {
+      return this.line(from, to)
+    }
+
     const length = to.clone().sub(from)
     const halfWidth = length.clone().normalize().multiplyScalar(radius).rotateAround(new Vector2(), Math.PI / 2)
     const width = halfWidth.clone().multiplyScalar(2)
@@ -79,6 +83,10 @@ export default class SATX {
     return position
   }
 
+  static line(from, to) {
+    return new SAT.Polygon(new SAT.Vector(...from.toArray()), [new SAT.Vector(), new SAT.Vector(...to.toArray())])
+  }
+
   static polygonToThreeVector2(polygon) {
     const position = new Vector2(polygon.pos.x, polygon.pos.y)
     return polygon.points.map((p) => new Vector2(p.x, p.y).add(position))