/// <summary>
/// Divide the source polygon to compute link distance.
/// </summary>
public void Divide()
{
LineSegment2D entrance = this.LastDiviser;
LineSegment2D path = new LineSegment2D(entrance.FirstPoint, this.LastPoint);
if (this.CurrentPolygon.Contains(path))
{
return;
}
path = new LineSegment2D(entrance.LastPoint, this.LastPoint);
if (this.CurrentPolygon.Contains(path))
{
return;
}
for (int i = 0; i < this.CurrentPolygon.VertexCount; i++)
{
if (this.CurrentPolygon.GetPoint(i) == entrance.FirstPoint)
{
continue;
}
LineSegment2D lineSegment = new LineSegment2D(entrance.FirstPoint, this.CurrentPolygon.GetPoint(i));
if (!this.CurrentPolygon.Contains(lineSegment) && !this.CurrentPolygon.isEdge(lineSegment))
{
continue;
}
LineSegment2D lineDiviser = this.ChooseDiviser(lineSegment);
if (lineDiviser == null)
{
continue;
}
Polygon2D testPoly = new Polygon2D(this.CurrentPolygon);
if (!testPoly.isVertex(lineDiviser.LastPoint))
{
testPoly.Add(lineDiviser.LastPoint, testPoly.OnEdge(lineDiviser.LastPoint));
}
Polygon2D polygon = this.DividedBy(lineDiviser, testPoly);
if (polygon.isVertex(this.LastPoint))
{
testPoly = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
else
{
testPoly = polygon;
polygon = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
if (entrance.FirstPoint == entrance.LastPoint)
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(testPoly);
this.SubDivision.Add(polygon);
}
else
{
LineSegment2D testLine = new LineSegment2D(entrance.LastPoint, lineDiviser.FirstPoint);
if (!testLine.isRegular)
{
entrance = new LineSegment2D(entrance.LastPoint, entrance.LastPoint);
continue;
}
if (this.CurrentPolygon.Contains(testLine))
{
testLine = this.ChooseDiviser(testLine);
if (testLine != null && !testPoly.Contains(testLine))
{
lineDiviser = testLine;
testPoly = new Polygon2D(this.CurrentPolygon);
if (!testPoly.isVertex(lineDiviser.LastPoint))
{
testPoly.Add(lineDiviser.LastPoint, testPoly.OnEdge(lineDiviser.LastPoint));
}
polygon = this.DividedBy(lineDiviser, testPoly);
testPoly = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
else if (testLine == null)
{
continue;
}
}
if (!polygon.isVertex(this.LastPoint))
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(polygon);
this.SubDivision.Add(testPoly);
}
else
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(testPoly);
this.SubDivision.Add(polygon);
}
}
this.Divisers.Add(lineDiviser);
this.Divide();
return;
}
}
/// <summary>
/// Construct a minimum link path of a polygon.
/// </summary>
public void BuildPath()
{
this.LinkDivisers.Clear();
Point2D CurrentPoint = this.LastPoint;
Point2D IntersectPoint = null;
LineSegment2D CurrentLine = null;
LineSegment2D IntersectLine = null;
for (int i = this.Divisers.Count - 1; i >= 0; i--)
{
double position = -1.0;
Polygon2D currentPolygon = this.SubDivision[i + 1];
CurrentLine = this.Divisers[i];
if (CurrentLine.Contains(CurrentPoint))
{
this.LinkDivisers.Add(CurrentPoint);
Vector2D vector = CurrentLine.ToVector().Normal().Normalize();
IntersectPoint = CurrentLine.MidPoint + vector;
if (!this.SubDivision[i].Contains(IntersectPoint))
{
vector = -vector;
}
double length = CurrentLine.Length;
LineSegment2D testLine = null;
do
{
IntersectPoint = CurrentLine.MidPoint + vector * length;
length /= 2;
testLine = new LineSegment2D(CurrentPoint, IntersectPoint);
} while (!this.SubDivision[i].Contains(testLine));
continue;
}
for (int j = 0; j < currentPolygon.VertexCount; j++)
{
Point2D point = currentPolygon.GetPoint(j);
if (CurrentPoint == point)
{
continue;
}
LineSegment2D lineSegment = new LineSegment2D(CurrentPoint, point);
if (currentPolygon.Contains(lineSegment) || currentPolygon.isEdge(lineSegment))
{
if (CurrentLine.LineIntersects(lineSegment))
{
IntersectPoint = CurrentLine.ToLine().Intersects(lineSegment.ToLine());
if (position < 0)
{
position = CurrentLine.GetPosition(IntersectPoint);
}
else
{
position += CurrentLine.GetPosition(IntersectPoint);
position /= 2;
}
}
}
}
if (position < -0.5)
{
CurrentPoint = IntersectPoint + IntersectLine.ToVector().Normalize();
i++;
continue;
}
this.LinkDivisers.Add(CurrentPoint);
IntersectPoint = CurrentLine.GetPoint(position);
IntersectLine = new LineSegment2D(CurrentPoint, IntersectPoint);
double extend = IntersectLine.Length;
do
{
extend /= 2;
CurrentPoint = IntersectLine.Extend(extend);
} while (!this.SubDivision[i].Contains(CurrentPoint));
//CurrentPoint = CurrentLine.GetPoint(position);
}
CurrentLine = new LineSegment2D(CurrentPoint, this.FirstPoint);
if (this.Parent.Contains(CurrentLine))
{
this.LinkDivisers.Add(CurrentPoint);
this.LinkDivisers.Add(this.FirstPoint);
}
else if (IntersectLine != null)
{
CurrentPoint = IntersectPoint + IntersectLine.ToVector().Normalize();
this.LinkDivisers.Add(CurrentPoint);
this.LinkDivisers.Add(this.FirstPoint);
}
else
{
Vector2D vector = CurrentLine.ToVector().Normal().Normalize();
IntersectPoint = CurrentLine.MidPoint + vector;
if (!this.Parent.Contains(IntersectPoint))
{
vector = -vector;
}
IntersectPoint = CurrentLine.MidPoint;
double length = CurrentLine.Length;
do
{
length /= 2;
CurrentPoint = IntersectPoint + vector * length;
}while (!this.Parent.Contains(CurrentPoint));
this.LinkDivisers.Add(this.LastPoint);
this.LinkDivisers.Add(CurrentPoint);
this.LinkDivisers.Add(this.FirstPoint);
}
}
/// <summary>
/// Divide the source polygon to compute link distance.
/// </summary>
public void Divide()
{
LineSegment2D entrance = this.LastDiviser;
LineSegment2D path = new LineSegment2D(entrance.FirstPoint, this.LastPoint);
if (this.CurrentPolygon.Contains(path))
{
return;
}
path = new LineSegment2D(entrance.LastPoint, this.LastPoint);
if (this.CurrentPolygon.Contains(path))
{
return;
}
for (int i = 0; i < this.CurrentPolygon.VertexCount; i++)
{
if (this.CurrentPolygon.GetPoint(i) == entrance.FirstPoint)
{
continue;
}
LineSegment2D lineSegment = new LineSegment2D(entrance.FirstPoint, this.CurrentPolygon.GetPoint(i));
if(!this.CurrentPolygon.Contains(lineSegment) && !this.CurrentPolygon.isEdge(lineSegment))
{
continue;
}
LineSegment2D lineDiviser = this.ChooseDiviser(lineSegment);
if (lineDiviser == null)
{
continue;
}
Polygon2D testPoly = new Polygon2D(this.CurrentPolygon);
if (!testPoly.isVertex(lineDiviser.LastPoint))
{
testPoly.Add(lineDiviser.LastPoint, testPoly.OnEdge(lineDiviser.LastPoint));
}
Polygon2D polygon = this.DividedBy(lineDiviser, testPoly);
if (polygon.isVertex(this.LastPoint))
{
testPoly = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
else
{
testPoly = polygon;
polygon = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
if (entrance.FirstPoint == entrance.LastPoint)
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(testPoly);
this.SubDivision.Add(polygon);
}
else
{
LineSegment2D testLine = new LineSegment2D(entrance.LastPoint, lineDiviser.FirstPoint);
if (!testLine.isRegular)
{
entrance = new LineSegment2D(entrance.LastPoint, entrance.LastPoint);
continue;
}
if (this.CurrentPolygon.Contains(testLine))
{
testLine = this.ChooseDiviser(testLine);
if (testLine != null && !testPoly.Contains(testLine))
{
lineDiviser = testLine;
testPoly = new Polygon2D(this.CurrentPolygon);
if (!testPoly.isVertex(lineDiviser.LastPoint))
{
testPoly.Add(lineDiviser.LastPoint, testPoly.OnEdge(lineDiviser.LastPoint));
}
polygon = this.DividedBy(lineDiviser, testPoly);
testPoly = this.CurrentPolygon;
this.SubDivision.Remove(this.SubDivision.Count - 1);
}
else if (testLine == null)
{
continue;
}
}
if (!polygon.isVertex(this.LastPoint))
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(polygon);
this.SubDivision.Add(testPoly);
}
else
{
this.SubDivision.Remove(this.SubDivision.Count - 1);
this.SubDivision.Add(testPoly);
this.SubDivision.Add(polygon);
}
}
this.Divisers.Add(lineDiviser);
this.Divide();
return;
}
}
