public final void pitch(double angle) {
		if (XAXIS_ANGLE == -angle) {
			XAXIS_ANGLE = angle;
			XAXIS_TURN.entry[1][2] = -XAXIS_TURN.entry[1][2];
			XAXIS_TURN.entry[2][1] = -XAXIS_TURN.entry[2][1];
		} else if (XAXIS_ANGLE != angle) {
			// Cache it!
			XAXIS_ANGLE = angle;
			angle = Math.toRadians(angle);
			double c = Math.cos(angle), s = Math.sin(angle);
			XAXIS_TURN = new Matrix(1.0, 0.0, 0.0, 0.0, 0.0, c, -s, 0.0, 0.0,
					s, c, 0.0);
		}
		premultiply(XAXIS_TURN);
	}