Done with the rendering never toucnhing it again.

twentyfortyeight/src/twentyfortyeight/Main.java

@@ -10,21 +10,35 @@ import tester.Tester;
 
 class ImgUtil {
     static Color color(int n) {
-        int hash = Integer.hashCode(n);
+        Double hh = Math.log(n) / Math.log(2);
+        int hash = Integer.hashCode(hh.intValue() << 5);
         int r, g, b;
 
         // Shift the hash so the least significant byte is the part you want,
-        // and mask to isolate that byte.
-        r = (hash >> 16) & 0xff;
-        g = (hash >> 8) & 0xff;
-        b = (hash) & 0xff;
+        // and mask to isolate that byte. Also bias towards yellow a bit (heh).
+        r = ((hash >> 16) & 0xff) | 0xa0; // Boost red by setting the high bit.
+        g = ((hash >> 8) & 0xff) | 0x90; // Boost green by setting the high bit.
+        b = (hash & 0xff) & 0x7f; // Reduce blue by clearing the high bit.
 
-        return new Color(r, g, b);
+        return new Color(r, g + 20, b);
     }
 
+    // Create a tile image for a number.
     static WorldImage mktile(int n) {
+        return new OverlayImage(
+            new TextImage(
+                String.valueOf(n), Game.SCALE / 2, FontStyle.BOLD, Color.BLACK
+            ),
+            new RectangleImage(
+                Game.SCALE, Game.SCALE, OutlineMode.SOLID, ImgUtil.color(n)
+            )
+        );
+    }
+
+    // Create a fee space image.
+    static WorldImage mkfree() {
         return new RectangleImage(
-            Game.SCALE, Game.SCALE, OutlineMode.SOLID, ImgUtil.color(n)
+            Game.SCALE, Game.SCALE, OutlineMode.OUTLINE, Color.GRAY
         );
     }
 }
@@ -72,9 +86,7 @@ class Game extends World {
     }
 
     // Draw current game state.
-    void draw() {
-        this.scene.placeImageXY(this.grid.render(), this.w / 2, this.h / 2);
-    }
+    void draw() { this.scene = this.grid.render(); }
 }
 
 // The grid in which the game is played.
@@ -125,10 +137,20 @@ class Grid {
     }
 
     // Render the grid.
-    WorldImage render() {
-        WorldImage bg = ImgUtil.mktile(this.buf.get(0));
-        for (int i = 0; i < this.h) {
-            for (int j = 0; j < this.w) {}
+    WorldScene render() {
+        WorldScene bg =
+            new WorldScene(Game.SCALE * this.w, Game.SCALE * this.h);
+        for (int i = 0; i < this.h; i++) {
+            for (int j = 0; j < this.w; j++) {
+                int n = this.get(i, j);
+                int coordx = i * Game.SCALE + Game.SCALE / 2;
+                int coordy = j * Game.SCALE + Game.SCALE / 2;
+                if (n == 0) {
+                    bg.placeImageXY(ImgUtil.mkfree(), coordx, coordy);
+                } else {
+                    bg.placeImageXY(ImgUtil.mktile(n), coordx, coordy);
+                }
+            }
         }
         return bg;
     }
@@ -203,6 +225,23 @@ class Examples {
 
     void testGame(Tester t) {
         game = new Game();
+        game.grid.set(0, 0, 2);
+        game.grid.set(0, 1, 4);
+        // Random free space.
+        game.grid.set(0, 3, 8);
+        game.grid.set(1, 0, 16);
+        game.grid.set(1, 1, 32);
+        game.grid.set(1, 2, 64);
+        game.grid.set(1, 3, 128);
+        game.grid.set(2, 0, 256);
+        game.grid.set(2, 1, 512);
+        game.grid.set(2, 2, 1024);
+        game.grid.set(2, 3, 2048);
+        game.grid.set(3, 0, 4096);
+        // Random free space.
+        game.grid.set(3, 2, 8192);
+        game.grid.set(3, 3, 16384);
+
         game.launchGame();
     }
 }