void LoadOffsetMatrix(GLdouble l, GLdouble r,
	GLdouble b, GLdouble t,
	GLdouble n, GLdouble f,
	GLfloat delta, GLfloat pz)
{
	GLfloat    matrix[16];

	// Set up standard perspective projection
	glMatrixMode(GL_PROJECTION);
	glFrustum(l, r, b, t, n, f);

	// Retrieve the projection matrix
	glGetFloatv(GL_PROJECTION_MATRIX, matrix);

	// Calculate epsilon with Equation (9.7)
	GLfloat epsilon = -2.0F * f * n * delta /
		((f + n) * pz * (pz + delta));

	// Modify entry (3,3) of the projection matrix
	matrix[10] *= 1.0F + epsilon;

	// Send the projection matrix back to OpenGL
	glLoadMatrix(matrix);
}