static public void AddRectangle <T>(this SurfaceSelection <T> item, VectorF2 point1, VectorF2 point2)
{
VectorF2 lower;
VectorF2 upper;
point1.Order(point2, out lower, out upper);
lower = lower.BindBetween(VectorF2.ZERO, item.GetDimensions());
upper = upper.BindBetween(VectorF2.ZERO, item.GetDimensions());
for (float y = lower.y; y <= upper.y; y++)
{
for (float x = lower.x; x <= upper.x; x++)
{
item.Add(new VectorF2(x, y));
}
}
}
public SurfaceSelection <T> PolygonSelect(Surface <T> surface, IEnumerable <VectorF2> points)
{
SurfaceSelection <T> selection = new SurfaceSelection <T>(surface);
Spectrum <LineSegmentF2> y_spectrum = new Spectrum <LineSegmentF2>(
points.CloseLoop().ConvertConnections((p1, p2) => new SpectrumBand <LineSegmentF2>(new LineSegmentF2(p1, p2), p1.y, p2.y))
);
for (float y = y_spectrum.GetLowerBound(); y < y_spectrum.GetUpperBound(); y++)
{
LineF2 scanline = new LineF2(new VectorF2(0.0f, y), new VectorF2(1.0f, 0.0f));
y_spectrum.LookupData(y)
.Convert(l => {
VectorF2 point;
if (scanline.TryGetIntersection(l.GetLine(), out point))
{
return(point.x);
}
return(l.p1.x.Min(l.p2.x));
})
.Sort(z => z)
.ConvertConnections((p, c) => Tuple.New(p, c))
.SkipEvery(1)
.Process(t =>
selection.AddRectangle(
new VectorF2(t.item1, y),
new VectorF2(t.item2, y)
)
);
}
return(selection);
}
static public VectorF2 GetDimensions <T>(this SurfaceSelection <T> item)
{
return(new VectorF2(item.GetWidth(), item.GetHeight()));
}
static public bool Add <T>(this SurfaceSelection <T> item, VectorF2 point)
{
return(item.Add(point.GetVectorI2()));
}