>>383
BeginPath(hdc);
Polyline(hdc, ..., 3);
EndPath(hdc);
hRgn1 = PathToRegion(hdc);

BeginPath(hdc);
Polyline(hdc, ..., 4);
EndPath(hdc);
hRgn2 = PathToRegion(hdc);

hRgn = CreateRectRgn(0, 0, 0, 0);
if (CombineRgn(hRgn, hRgn1, hRgn2, RGN_AND) == NULLREGION) {
...
} else {
...
}