private void DrawQuad(IGL gl) { gl.Begin(PrimitiveType.Quads); SetQuadVertex(gl, 0.0f, 0.0f); SetQuadVertex(gl, 1.0f, 0.0f); SetQuadVertex(gl, 1.0f, 1.0f); SetQuadVertex(gl, 0.0f, 1.0f); gl.End(); }