Apply rotation about the X axis to this matrix by rotating the given amount of radians.
<p>
When used with a right-handed coordinate system, the produced rotation will rotate a vector
counter-clockwise around the rotation axis, when viewing along the negative axis direction towards the origin.
When used with a left-handed coordinate system, the rotation is clockwise.
<p>
If <code>M</code> is <code>this</code> matrix and <code>R</code> the rotation matrix,
then the new matrix will be <code>M * R</code>. So when transforming a
vector <code>v</code> with the new matrix by using <code>M * R * v</code>, the
rotation will be applied first!
<p>
Reference: <a href="http://en.wikipedia.org/wiki/Rotation_matrix#Basic_rotations">http://en.wikipedia.org</a>
Apply rotation about the X axis to this matrix by rotating the given amount of radians. <p> When used with a right-handed coordinate system, the produced rotation will rotate a vector counter-clockwise around the rotation axis, when viewing along the negative axis direction towards the origin. When used with a left-handed coordinate system, the rotation is clockwise. <p> If <code>M</code> is <code>this</code> matrix and <code>R</code> the rotation matrix, then the new matrix will be <code>M * R</code>. So when transforming a vector <code>v</code> with the new matrix by using <code>M * R * v</code>, the rotation will be applied first! <p> Reference: <a href="http://en.wikipedia.org/wiki/Rotation_matrix#Basic_rotations">http://en.wikipedia.org</a>
@param ang the angle in radians @return this