public Matrix4x3f ortho2D(float left, float right, float bottom, float top) {
        return ortho2D(left, right, bottom, top, this);
    }
public Matrix4x3f ortho2D ( float left , float right , float bottom , float top ) { return ortho2D ( left , right , bottom , top , this ) ; }
Apply an orthographic projection transformation for a right-handed coordinate system to this matrix.
<p>
This method is equivalent to calling {@link #ortho(float, float, float, float, float, float) ortho()} with
<code>zNear=-1</code> and <code>zFar=+1</code>.
<p>
If <code>M</code> is <code>this</code> matrix and <code>O</code> the orthographic projection matrix,
then the new matrix will be <code>M * O</code>. So when transforming a
vector <code>v</code> with the new matrix by using <code>M * O * v</code>, the
orthographic projection transformation will be applied first!
<p>
In order to set the matrix to an orthographic projection without post-multiplying it,
use {@link #setOrtho2D(float, float, float, float) setOrtho2D()}.
<p>
Reference: <a href="http://www.songho.ca/opengl/gl_projectionmatrix.html#ortho">http://www.songho.ca</a>

@see #ortho(float, float, float, float, float, float)
@see #setOrtho2D(float, float, float, float)

@param left
the distance from the center to the left frustum edge
@param right
the distance from the center to the right frustum edge
@param bottom
the distance from the center to the bottom frustum edge
@param top
the distance from the center to the top frustum edge
@return this