Orthographic projection in mat4 is slightly wrong and needs to be updated.

[liamegan]

Should be:

    const lr = 1 / (right - left),
      bt = 1 / (top - bottom),
      nf = 1 / (far - near);

    return new Mat4(
      2 * lr,
      0,
      0,
      0,

      0,
      2 * bt,
      0,
      0,

      0,
      0,
      -2 * nf,
      0,

      -(right + left) * lr,
      -(top + bottom) * bt,
      -(far + near) * nf,
      1
    );