code: public Matrix4x3f setOrtho2D(float left, float right, float bottom, float top) {
          MemUtil.INSTANCE.identity(this);
          m00 = 2.0f / (right - left);
          m11 = 2.0f / (top - bottom);
          m22 = -1.0f;
          m30 = -(right + left) / (right - left);
          m31 = -(top + bottom) / (top - bottom);
          properties = 0;
          return this;
      }
docs: Set this matrix to be an orthographic projection transformation for a right-handed coordinate system.
  <p>
  This method is equivalent to calling {@link #setOrtho(float, float, float, float, float, float) setOrtho()} with
  <code>zNear=-1</code> and <code>zFar=+1</code>.
  <p>
  In order to apply the orthographic projection to an already existing transformation,
  use {@link #ortho2D(float, float, float, float) ortho2D()}.
  <p>
  Reference: <a href="http://www.songho.ca/opengl/gl_projectionmatrix.html#ortho">http://www.songho.ca</a>
  
  @see #setOrtho(float, float, float, float, float, float)
  @see #ortho2D(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