Render shadow per tile in sorted order

assets/index.html

@@ -186,11 +186,6 @@
 
                 drawTile(wx, wy, level, true, hRight, hBack, false);
             }
-        }
-
-        for (var i = 0; i < tiles.length; i++) {
-            var t = tiles[i];
-            var wx = t.x, wy = t.y, h = t.h;
 
             for (var level = 1; level <= h; level++) {
                 var sunX = wx + TILE;
@@ -203,7 +198,7 @@
                     var top3 = project(wx + TILE - GAP/2, wy + GAP/2, level * HEIGHT_UNIT);
                     var top4 = project(wx + GAP/2, wy + GAP/2, level * HEIGHT_UNIT);
 
-                    ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
+                    ctx.fillStyle = 'rgba(0, 0, 0, 0.4)';
                     ctx.beginPath();
                     ctx.moveTo(top1[0], top1[1]);
                     ctx.lineTo(top2[0], top2[1]);