{
        XTriangle Tris[] = {
            {{0,0},{100,0},{100,100}},
            {{0,0},{0,100},{100,100}},
            {{0,0},{0,100},{100,100}},
            {{0,0},{100,0},{100,100}},
        };
        int nTris = sizeof(Tris)/sizeof(XTriangle);
        printf("nTris:%d\n",nTris);
        XCompositeSetTriangularCoordinateMesh(w->screen->display->display,
                w->id,Tris,nTris);
    }