changed w scaling to 1 / yres and updated test file

camera.lua

@@ -30,6 +30,6 @@ function camera:matrix()
     {s, 0,             0,             0,
      0, s,             0,             0,
      0, 0, (n+f) / (n-f), 2*n*f / (n-f),
-     0, 0,      1 / xres,             0})
+     0, 0,      1 / yres,             0})
   return m * self.transform:inv_matrix(true)
 end