phrase world pixel-size in terms of fractions of 1080p

GitOrigin-RevId: d2a9cb18d1

Jumpy.Shared/Camera.cs

@@ -4,7 +4,7 @@ using System.Text;
 
 namespace Jumpy {
   class Camera {
-    public const int Width = (int) (320 * 1.0);
-    public const int Height = (int) (180 * 1.0);
+    public const int Width = 1920 / 4;
+    public const int Height = 1080 / 4;
   }
 }