STATIC SUB ClearDepth ( Depth AS Float )
Gl.ClearDepth specifies the depth value used by Gl.Clear to clear the depth buffer. Values specified by Gl.ClearDepth are clamped to the range [0, 1].
Gl.GL_INVALID_OPERATION is generated if Gl.ClearDepth is called between a call to Gl.Begin and the corresponding call to Gl.End.