public void Case1(Sink sink, Edge edge, Trapezoid[] tList)
{
YNode yNode = new YNode(edge, Sink.Isink(tList[1]), Sink.Isink(tList[2]));
XNode qNode = new XNode(edge.Q, yNode, Sink.Isink(tList[3]));
XNode pNode = new XNode(edge.P, Sink.Isink(tList[0]), qNode);
Replace(sink, pNode);
}
// Case 2: Trapezoid contains point p, q lies outside
// break trapezoid into 3 smaller trapezoids
public Trapezoid[] Case2(Trapezoid t, Edge e)
{
Point rp;
if (e.Q.X == t.RightPoint.X)
rp = e.Q;
else
rp = t.RightPoint;
Trapezoid[] trapezoids = new Trapezoid[3];
trapezoids[0] = new Trapezoid(t.LeftPoint, e.P, t.Top, t.Bottom);
trapezoids[1] = new Trapezoid(e.P, rp, t.Top, e);
trapezoids[2] = new Trapezoid(e.P, rp, e, t.Bottom);
trapezoids[0].UpdateLeft(t.UpperLeft, t.LowerLeft);
trapezoids[1].UpdateLeftRight(trapezoids[0], null, t.UpperRight, null);
trapezoids[2].UpdateLeftRight(null, trapezoids[0], null, t.LowerRight);
_bCross = t.Bottom;
_cross = t.Top;
e.Above = trapezoids[1];
e.Below = trapezoids[2];
return trapezoids;
}
// Update neighbors to the left
public void UpdateLeft(Trapezoid ul, Trapezoid ll)
{
UpperLeft = ul;
if (ul != null) ul.UpperRight = this;
LowerLeft = ll;
if (ll != null) ll.LowerRight = this;
}
// Update neighbors to the right
public void UpdateRight(Trapezoid ur, Trapezoid lr)
{
UpperRight = ur;
if (ur != null) ur.UpperLeft = this;
LowerRight = lr;
if (lr != null) lr.LowerLeft = this;
}
// Update neighbors on both sides
public void UpdateLeftRight(Trapezoid ul, Trapezoid ll, Trapezoid ur, Trapezoid lr)
{
UpperLeft = ul;
if (ul != null) ul.UpperRight = this;
LowerLeft = ll;
if (ll != null) ll.LowerRight = this;
UpperRight = ur;
if (ur != null) ur.UpperLeft = this;
LowerRight = lr;
if (lr != null) lr.LowerLeft = this;
}
public Trapezoid(Point leftPoint, Point rightPoint, Edge top, Edge bottom)
{
LeftPoint = leftPoint;
RightPoint = rightPoint;
Top = top;
Bottom = bottom;
UpperLeft = null;
UpperRight = null;
LowerLeft = null;
LowerRight = null;
Inside = true;
Sink = null;
}
public Trapezoid(Point leftPoint, Point rightPoint, Edge top, Edge bottom)
{
this.LeftPoint = leftPoint;
this.RightPoint = rightPoint;
this.Top = top;
this.Bottom = bottom;
this.UpperLeft = null;
this.UpperRight = null;
this.LowerLeft = null;
this.LowerRight = null;
this.Inside = true;
this.Sink = null;
}
// Update neighbors to the left
public void UpdateLeft(Trapezoid ul, Trapezoid ll)
{
UpperLeft = ul;
if (ul != null)
{
ul.UpperRight = this;
}
LowerLeft = ll;
if (ll != null)
{
ll.LowerRight = this;
}
}
// Update neighbors to the right
public void UpdateRight(Trapezoid ur, Trapezoid lr)
{
UpperRight = ur;
if (ur != null)
{
ur.UpperLeft = this;
}
LowerRight = lr;
if (lr != null)
{
lr.LowerLeft = this;
}
}
public Triangulator(List <Point> polyLine, float sheer)
{
_sheer = sheer;
Triangles = new List <List <Point> >();
Trapezoids = new List <Trapezoid>();
_xMonoPoly = new List <MonotoneMountain>();
_edgeList = InitEdges(polyLine);
_trapezoidalMap = new TrapezoidalMap();
_boundingBox = _trapezoidalMap.BoundingBox(_edgeList);
_queryGraph = new QueryGraph(Sink.Isink(_boundingBox));
Process();
}
public Trapezoid(Point leftPoint, Point rightPoint, Edge top, Edge bottom)
{
LeftPoint = leftPoint;
RightPoint = rightPoint;
Top = top;
Bottom = bottom;
UpperLeft = null;
UpperRight = null;
LowerLeft = null;
LowerRight = null;
Inside = true;
Sink = null;
}
// Case 1: segment completely enclosed by trapezoid
// break trapezoid into 4 smaller trapezoids
public Trapezoid[] Case1(Trapezoid t, Edge e)
{
Trapezoid[] trapezoids = new Trapezoid[4];
trapezoids[0] = new Trapezoid(t.LeftPoint, e.P, t.Top, t.Bottom);
trapezoids[1] = new Trapezoid(e.P, e.Q, t.Top, e);
trapezoids[2] = new Trapezoid(e.P, e.Q, e, t.Bottom);
trapezoids[3] = new Trapezoid(e.Q, t.RightPoint, t.Top, t.Bottom);
trapezoids[0].UpdateLeft(t.UpperLeft, t.LowerLeft);
trapezoids[1].UpdateLeftRight(trapezoids[0], null, trapezoids[3], null);
trapezoids[2].UpdateLeftRight(null, trapezoids[0], null, trapezoids[3]);
trapezoids[3].UpdateRight(t.UpperRight, t.LowerRight);
return(trapezoids);
}
// Case 1: segment completely enclosed by trapezoid
// break trapezoid into 4 smaller trapezoids
public Trapezoid[] Case1(Trapezoid t, Edge e)
{
Trapezoid[] trapezoids = new Trapezoid[4];
trapezoids[0] = new Trapezoid(t.LeftPoint, e.P, t.Top, t.Bottom);
trapezoids[1] = new Trapezoid(e.P, e.Q, t.Top, e);
trapezoids[2] = new Trapezoid(e.P, e.Q, e, t.Bottom);
trapezoids[3] = new Trapezoid(e.Q, t.RightPoint, t.Top, t.Bottom);
trapezoids[0].UpdateLeft(t.UpperLeft, t.LowerLeft);
trapezoids[1].UpdateLeftRight(trapezoids[0], null, trapezoids[3], null);
trapezoids[2].UpdateLeftRight(null, trapezoids[0], null, trapezoids[3]);
trapezoids[3].UpdateRight(t.UpperRight, t.LowerRight);
return trapezoids;
}
// Case 3: Trapezoid is bisected
public Trapezoid[] Case3(Trapezoid t, Edge e)
{
Point lp;
if (e.P.X == t.LeftPoint.X)
lp = e.P;
else
lp = t.LeftPoint;
Point rp;
if (e.Q.X == t.RightPoint.X)
rp = e.Q;
else
rp = t.RightPoint;
Trapezoid[] trapezoids = new Trapezoid[2];
if (_cross == t.Top)
{
trapezoids[0] = t.UpperLeft;
trapezoids[0].UpdateRight(t.UpperRight, null);
trapezoids[0].RightPoint = rp;
}
else
{
trapezoids[0] = new Trapezoid(lp, rp, t.Top, e);
trapezoids[0].UpdateLeftRight(t.UpperLeft, e.Above, t.UpperRight, null);
}
if (_bCross == t.Bottom)
{
trapezoids[1] = t.LowerLeft;
trapezoids[1].UpdateRight(null, t.LowerRight);
trapezoids[1].RightPoint = rp;
}
else
{
trapezoids[1] = new Trapezoid(lp, rp, e, t.Bottom);
trapezoids[1].UpdateLeftRight(e.Below, t.LowerLeft, null, t.LowerRight);
}
_bCross = t.Bottom;
_cross = t.Top;
e.Above = trapezoids[0];
e.Below = trapezoids[1];
return trapezoids;
}
public Edge(Point p, Point q)
{
P = p;
Q = q;
if (q.X - p.X != 0)
Slope = (q.Y - p.Y) / (q.X - p.X);
else
Slope = 0;
B = p.Y - (p.X * Slope);
Above = null;
Below = null;
MPoints = new HashSet<Point>();
MPoints.Add(p);
MPoints.Add(q);
}
// Case 4: Trapezoid contains point q, p lies outside
// break trapezoid into 3 smaller trapezoids
public Trapezoid[] Case4(Trapezoid t, Edge e)
{
Point lp;
if (e.P.X == t.LeftPoint.X)
{
lp = e.P;
}
else
{
lp = t.LeftPoint;
}
Trapezoid[] trapezoids = new Trapezoid[3];
if (_cross == t.Top)
{
trapezoids[0] = t.UpperLeft;
trapezoids[0].RightPoint = e.Q;
}
else
{
trapezoids[0] = new Trapezoid(lp, e.Q, t.Top, e);
trapezoids[0].UpdateLeft(t.UpperLeft, e.Above);
}
if (_bCross == t.Bottom)
{
trapezoids[1] = t.LowerLeft;
trapezoids[1].RightPoint = e.Q;
}
else
{
trapezoids[1] = new Trapezoid(lp, e.Q, e, t.Bottom);
trapezoids[1].UpdateLeft(e.Below, t.LowerLeft);
}
trapezoids[2] = new Trapezoid(e.Q, t.RightPoint, t.Top, t.Bottom);
trapezoids[2].UpdateLeftRight(trapezoids[0], trapezoids[1], t.UpperRight, t.LowerRight);
return(trapezoids);
}
public Edge(Point p, Point q)
{
P = p;
Q = q;
if (q.X - p.X != 0)
{
Slope = (q.Y - p.Y) / (q.X - p.X);
}
else
{
Slope = 0;
}
B = p.Y - (p.X * Slope);
Above = null;
Below = null;
MPoints = new HashSet <Point>();
MPoints.Add(p);
MPoints.Add(q);
}
public Edge(Point p, Point q)
{
this.P = p;
this.Q = q;
if (q.X - p.X != 0)
{
this.Slope = (q.Y - p.Y) / (q.X - p.X);
}
else
{
this.Slope = 0;
}
this.B = p.Y - (p.X * this.Slope);
this.Above = null;
this.Below = null;
this.MPoints = new HashSet <Point>();
this.MPoints.Add(p);
this.MPoints.Add(q);
}
// Update neighbors on both sides
public void UpdateLeftRight(Trapezoid ul, Trapezoid ll, Trapezoid ur, Trapezoid lr)
{
UpperLeft = ul;
if (ul != null)
{
ul.UpperRight = this;
}
LowerLeft = ll;
if (ll != null)
{
ll.LowerRight = this;
}
UpperRight = ur;
if (ur != null)
{
ur.UpperLeft = this;
}
LowerRight = lr;
if (lr != null)
{
lr.LowerLeft = this;
}
}
public void Case3(Sink sink, Edge edge, Trapezoid[] tList)
{
YNode yNode = new YNode(edge, Sink.Isink(tList[0]), Sink.Isink(tList[1]));
Replace(sink, yNode);
}
// Case 4: Trapezoid contains point q, p lies outside
// break trapezoid into 3 smaller trapezoids
public Trapezoid[] Case4(Trapezoid t, Edge e)
{
Point lp;
if (e.P.X == t.LeftPoint.X)
lp = e.P;
else
lp = t.LeftPoint;
Trapezoid[] trapezoids = new Trapezoid[3];
if (_cross == t.Top)
{
trapezoids[0] = t.UpperLeft;
trapezoids[0].RightPoint = e.Q;
}
else
{
trapezoids[0] = new Trapezoid(lp, e.Q, t.Top, e);
trapezoids[0].UpdateLeft(t.UpperLeft, e.Above);
}
if (_bCross == t.Bottom)
{
trapezoids[1] = t.LowerLeft;
trapezoids[1].RightPoint = e.Q;
}
else
{
trapezoids[1] = new Trapezoid(lp, e.Q, e, t.Bottom);
trapezoids[1].UpdateLeft(e.Below, t.LowerLeft);
}
trapezoids[2] = new Trapezoid(e.Q, t.RightPoint, t.Top, t.Bottom);
trapezoids[2].UpdateLeftRight(trapezoids[0], trapezoids[1], t.UpperRight, t.LowerRight);
return trapezoids;
}