public static Crossings FindCrossings(ArrayList curves,
double xlo, double ylo,
double xhi, double yhi)
{
Crossings cross = new EvenOdd(xlo, ylo, xhi, yhi);
IEnumerator enumerator = curves.GetEnumerator();
while (enumerator.MoveNext())
{
Curve c = (Curve)enumerator.Current;
if (c.AccumulateCrossings(cross))
{
return(null);
}
}
return(cross);
}
public bool AccumulateCubic(double x0, double y0, double[] coords)
{
if (y0 < _ylo && coords[1] < _ylo &&
coords[3] < _ylo && coords[5] < _ylo)
{
return(false);
}
if (y0 > _yhi && coords[1] > _yhi &&
coords[3] > _yhi && coords[5] > _yhi)
{
return(false);
}
if (x0 > _xhi && coords[0] > _xhi &&
coords[2] > _xhi && coords[4] > _xhi)
{
return(false);
}
if (x0 < _xlo && coords[0] < _xlo &&
coords[2] < _xlo && coords[4] < _xlo)
{
if (y0 <= coords[5])
{
Record(Math.Max(y0, _ylo), Math.Min(coords[5], _yhi), 1);
}
else
{
Record(Math.Max(coords[5], _ylo), Math.Min(y0, _yhi), -1);
}
return(false);
}
Curve.InsertCubic(_tmp, x0, y0, coords);
IEnumerator enumerator = _tmp.GetEnumerator();
while (enumerator.MoveNext())
{
Curve c = (Curve)enumerator.Current;
if (c.AccumulateCrossings(this))
{
return(true);
}
}
_tmp.Clear();
return(false);
}