swap left shift operators for Math.pow for scoped projection/unprojec…

…tion (#172)

* swap left shift operators for Math.pow for scoped projection/unprojection

* use ** operator instead

src/frontends/static.ts

@@ -36,15 +36,15 @@ const instancedProject = (origin: Point, displayZoom: number) => {
       (projected.x + MAXCOORD) / (MAXCOORD * 2),
       1 - (projected.y + MAXCOORD) / (MAXCOORD * 2),
     );
-    return normalized.mult((1 << displayZoom) * 256).sub(origin);
+    return normalized.mult(2 ** displayZoom * 256).sub(origin);
   };
 };
 
 const instancedUnproject = (origin: Point, displayZoom: number) => {
   return (point: Point) => {
     const normalized = new Point(point.x, point.y)
       .add(origin)
-      .div((1 << displayZoom) * 256);
+      .div(2 ** displayZoom * 256);
     const projected = new Point(
       normalized.x * (MAXCOORD * 2) - MAXCOORD,
       (1 - normalized.y) * (MAXCOORD * 2) - MAXCOORD,