public static Matrix4x4L Perspective(FloatL fov, FloatL aspect /*纵横比*/, FloatL zNear, FloatL zFar)
{
// 为什么这里用的是opengl的透视矩阵？
Matrix4x4L ret = Matrix4x4L.zero;
FloatL fovRad = FixPointMath.Deg2Rad * fov;
ret.m00 = 1 / FixPointMath.Tan(fovRad * 0.5f) / aspect;
ret.m11 = 1 / FixPointMath.Tan(fovRad * 0.5f);
ret.m22 = -(zFar + zNear) / (zFar - zNear);
ret.m23 = -2 * zNear * zFar / (zFar - zNear);
ret.m32 = -1;
return(ret);
}