code: public void makeRotationMatrix(double angle) {
  		final double sinAngle = Math.sin(angle);
  		final double cosAngle = Math.cos(angle);
  
  		this.m00 = cosAngle;
  		this.m01 = -sinAngle;
  		this.m02 = 0.;
  
  		this.m11 = cosAngle;
  		this.m10 = sinAngle;
  		this.m12 = 0.;
  
  		this.m20 = 0.;
  		this.m21 = 0.;
  		this.m22 = 1.;
  	}
docs: Sets the value of this matrix to a counter clockwise rotation about the x
  axis, and no translation
  
  <p>This function changes all the elements of
  the matrix, icluding the translation.
  
  <p>After a call to this function, the matrix will
  contains (? means any value):
  <pre>
  [   cos(theta)  -sin(theta)  0   ]
  [   sin(theta)  cos(theta)   0   ]
  [   0           0            1   ]
  </pre>
  
  @param angle
  the angle to rotate about the X axis in radians
  @see #setRotation(double)