STATIC SUB Ortho ( Left AS Float, Right AS Float, Bottom AS Float, Top AS Float, Near AS Float, Far AS Float )
Gl.Ortho describes a matrix that produces a parallel projection. (Left, Bottom, -Near) and (Right, Top, -Near) specify the points on the near clipping plane that are mapped to the lower left and upper right corners of the window, respectively, assuming that the eye is located at (0, 0, 0). -Far specifies the location of the far clipping plane. Both near and far can be either positive or negative. The corresponding matrix is
where
The current matrix is multiplied by this matrix with the result replacing the current matrix. That is, if M is the current matrix and O is the ortho matrix, then M is replaced with M * O.
Use Gl.PushMatrix and Gl.PopMatrix to save and restore the current matrix stack.
Gl.GL_INVALID_OPERATION is generated if Gl.Ortho is called between a call to Gl.Begin and the corresponding call to Gl.End.
Gl.GetMatrixMode
Gl.GetModelviewMatrix
Gl.GetProjectionMatrix
Gl.GetTextureMatrix