private static Triangle_dt find(Triangle_dt curr, Point_dt p)
{
if (p == null)
{
return(null);
}
Triangle_dt next_t;
if (curr.halfplane)
{
next_t = findnext2(p, curr);
if (next_t == null || next_t.halfplane)
{
return(curr);
}
curr = next_t;
}
while (true)
{
next_t = findnext1(p, curr);
if (next_t == null)
{
return(curr);
}
if (next_t.halfplane)
{
return(next_t);
}
curr = next_t;
}
}
/*
* assumes v is NOT an halfplane!
* returns the next triangle for find.
*/
private static Triangle_dt findnext1(Point_dt p, Triangle_dt v)
{
if (p.pointLineTest(v.a, v.b) == Point_dt.RIGHT && !v.abnext.halfplane)
{
return(v.abnext);
}
if (p.pointLineTest(v.b, v.c) == Point_dt.RIGHT && !v.bcnext.halfplane)
{
return(v.bcnext);
}
if (p.pointLineTest(v.c, v.a) == Point_dt.RIGHT && !v.canext.halfplane)
{
return(v.canext);
}
if (p.pointLineTest(v.a, v.b) == Point_dt.RIGHT)
{
return(v.abnext);
}
if (p.pointLineTest(v.b, v.c) == Point_dt.RIGHT)
{
return(v.bcnext);
}
if (p.pointLineTest(v.c, v.a) == Point_dt.RIGHT)
{
return(v.canext);
}
return(null);
}
private Triangle_dt extendInside(Triangle_dt t, Point_dt p)
{
Triangle_dt h1, h2;
h1 = treatDegeneracyInside(t, p);
if (h1 != null)
{
return(h1);
}
h1 = new Triangle_dt(t.c, t.a, p);
h2 = new Triangle_dt(t.b, t.c, p);
t.c = p;
t.circumcircle();
h1.abnext = t.canext;
h1.bcnext = t;
h1.canext = h2;
h2.abnext = t.bcnext;
h2.bcnext = h1;
h2.canext = t;
h1.abnext.switchneighbors(t, h1);
h2.abnext.switchneighbors(t, h2);
t.bcnext = h2;
t.canext = h1;
return(t);
}
private Triangle_dt extendOutside(Triangle_dt t, Point_dt p)
{
if (p.pointLineTest(t.a, t.b) == Point_dt.ONSEGMENT)
{
Triangle_dt dg = new Triangle_dt(t.a, t.b, p);
Triangle_dt hp = new Triangle_dt(p, t.b);
t.b = p;
dg.abnext = t.abnext;
dg.abnext.switchneighbors(t, dg);
dg.bcnext = hp;
hp.abnext = dg;
dg.canext = t;
t.abnext = dg;
hp.bcnext = t.bcnext;
hp.bcnext.canext = hp;
hp.canext = t;
t.bcnext = hp;
return(dg);
}
Triangle_dt ccT = extendcounterclock(t, p);
Triangle_dt cT = extendclock(t, p);
ccT.bcnext = cT;
cT.canext = ccT;
startTriangleHull = cT;
return(cT.abnext);
}
/**
* returns an iterator to the set of all the points on the XY-convex hull
* @return iterator to the set of all the points on the XY-convex hull.
*/
public List <Point_dt> CH_vertices_Iterator()
{
List <Point_dt> ans = new List <Point_dt>();
Triangle_dt curr = this.startTriangleHull;
bool cont = true;
double x0 = _bb_min.x, x1 = _bb_max.x;
double y0 = _bb_min.y, y1 = _bb_max.y;
bool sx, sy;
while (cont)
{
sx = curr.p1().x == x0 || curr.p1().x == x1;
sy = curr.p1().y == y0 || curr.p1().y == y1;
if ((sx & sy) | (!sx & !sy))
{
ans.Add(curr.p1());
}
if (curr.bcnext != null && curr.bcnext.halfplane)
{
curr = curr.bcnext;
}
if (curr == this.startTriangleHull)
{
cont = false;
}
}
return(ans);
}
/**
*
* @param x
* - X cordination of the query point
* @param y
* - Y cordination of the query point
* @return the q point with updated Z value (z value is as given the
* triangulation).
*/
public double z(double x, double y)
{
Point_dt q = new Point_dt(x, y);
Triangle_dt t = find(q);
return(t.z_value(q));
}
static void DoMemoryTest()
{
int i = 0;
try
{
Point_dt p1 = new Point_dt(1, 1);
Point_dt p3 = new Point_dt(1, 0);
Point_dt p2 = new Point_dt(0, 0);
List<Triangle_dt> vec = new List<Triangle_dt>();
while (true)
{
Triangle_dt t = new Triangle_dt(p1, p2, p3);
vec.Add(t);
i++;
if (i % 10000 == 0)
Console.WriteLine(i);
}
}
catch (OutOfMemoryException oome)
{
Console.WriteLine("out of MEMORY: points: " + i);
}
catch (Exception e)
{
Console.WriteLine("out of MEMORY: points: " + i);
}
}
private void startTriangulation(Point_dt p1, Point_dt p2)
{
Point_dt ps, pb;
if (p1.isLess(p2))
{
ps = p1;
pb = p2;
}
else
{
ps = p2;
pb = p1;
}
firstT = new Triangle_dt(pb, ps);
lastT = firstT;
Triangle_dt t = new Triangle_dt(ps, pb);
firstT.abnext = t;
t.abnext = firstT;
firstT.bcnext = t;
t.canext = firstT;
firstT.canext = t;
t.bcnext = firstT;
firstP = firstT.b;
lastP = lastT.a;
startTriangleHull = firstT;
}
private void allTriangles(Triangle_dt curr, List <Triangle_dt> front, int mc)
{
if (curr != null && curr._mc == mc && !front.Contains <Triangle_dt>(curr))
{
front.Add(curr);
allTriangles(curr.abnext, front, mc);
allTriangles(curr.bcnext, front, mc);
allTriangles(curr.canext, front, mc);
}
}
/**
* finds the triangle the query point falls in, note if out-side of this
* triangulation a half plane triangle will be returned (see contains). the
* search starts from the the start triangle
*
* @param p
* query point
* @param start
* the triangle the search starts at.
* @return the triangle that point p is in..
*/
public Triangle_dt find(Point_dt p, Triangle_dt start)
{
if (start == null)
{
start = this.startTriangle;
}
Triangle_dt T = find(start, p);
return(T);
}
private Triangle_dt insertPointSimple(Point_dt p)
{
nPoints++;
if (!allCollinear)
{
Triangle_dt t = find(startTriangle, p);
if (t.halfplane)
{
startTriangle = extendOutside(t, p);
}
else
{
startTriangle = extendInside(t, p);
}
return(startTriangle);
}
if (nPoints == 1)
{
firstP = p;
return(null);
}
if (nPoints == 2)
{
startTriangulation(firstP, p);
return(null);
}
switch (p.pointLineTest(firstP, lastP))
{
case Point_dt.LEFT:
startTriangle = extendOutside(firstT.abnext, p);
allCollinear = false;
break;
case Point_dt.RIGHT:
startTriangle = extendOutside(firstT, p);
allCollinear = false;
break;
case Point_dt.ONSEGMENT:
insertCollinear(p, Point_dt.ONSEGMENT);
break;
case Point_dt.INFRONTOFA:
insertCollinear(p, Point_dt.INFRONTOFA);
break;
case Point_dt.BEHINDB:
insertCollinear(p, Point_dt.BEHINDB);
break;
}
return(null);
}
/**
* returns an iterator object involved in the last update.
* @return iterator to all triangles involved in the last update of the
* triangulation NOTE: works ONLY if the are triangles (it there is
* only a half plane - returns an empty iterator
*/
public List <Triangle_dt> getLastUpdatedTriangles()
{
List <Triangle_dt> tmp = new List <Triangle_dt>();
if (this.trianglesSize() > 1)
{
Triangle_dt t = currT;
allTriangles(t, tmp, this._modCount);
}
return(tmp);
}
public object Clone()
{
Triangle_dt cloned = new Triangle_dt(a,b,c);
cloned._mark = _mark;
cloned._mc = _mc;
cloned.abnext = abnext;
cloned.bcnext = bcnext;
cloned.canext = canext;
cloned.halfplane = halfplane;
cloned.canext = canext;
cloned.circum = circum;
return cloned;
}
public object Clone()
{
Triangle_dt cloned = new Triangle_dt(a, b, c);
cloned._mark = _mark;
cloned._mc = _mc;
cloned.abnext = abnext;
cloned.bcnext = bcnext;
cloned.canext = canext;
cloned.halfplane = halfplane;
cloned.canext = canext;
cloned.circum = circum;
return(cloned);
}
private void flip(Triangle_dt t, int mc)
{
var bkpT = (Triangle_dt)t.Clone();
Triangle_dt u = t.abnext, v;
t._mc = mc;
if (u.halfplane || !u.circumcircle_contains(t.c))
{
return;
}
if (t.a == u.a)
{
v = new Triangle_dt(u.b, t.b, t.c);
v.abnext = u.bcnext;
t.abnext = u.abnext;
}
else if (t.a == u.b)
{
v = new Triangle_dt(u.c, t.b, t.c);
v.abnext = u.canext;
t.abnext = u.bcnext;
}
else if (t.a == u.c)
{
v = new Triangle_dt(u.a, t.b, t.c);
v.abnext = u.abnext;
t.abnext = u.canext;
}
else
{
throw new Exception("Error in flip.");
}
v._mc = mc;
v.bcnext = t.bcnext;
v.abnext.switchneighbors(u, v);
v.bcnext.switchneighbors(t, v);
t.bcnext = v;
v.canext = t;
t.b = v.a;
t.abnext.switchneighbors(u, t);
t.circumcircle();
currT = v;
flip(t, mc);
flip(v, mc);
}
/** assumes v is an halfplane! - returns another (none halfplane) triangle */
private static Triangle_dt findnext2(Point_dt p, Triangle_dt v)
{
if (v.abnext != null && !v.abnext.halfplane)
{
return(v.abnext);
}
if (v.bcnext != null && !v.bcnext.halfplane)
{
return(v.bcnext);
}
if (v.canext != null && !v.canext.halfplane)
{
return(v.canext);
}
return(null);
}
private Triangle_dt treatDegeneracyInside(Triangle_dt t, Point_dt p)
{
if (t.abnext.halfplane &&
p.pointLineTest(t.b, t.a) == Point_dt.ONSEGMENT)
{
return(extendOutside(t.abnext, p));
}
if (t.bcnext.halfplane &&
p.pointLineTest(t.c, t.b) == Point_dt.ONSEGMENT)
{
return(extendOutside(t.bcnext, p));
}
if (t.canext.halfplane &&
p.pointLineTest(t.a, t.c) == Point_dt.ONSEGMENT)
{
return(extendOutside(t.canext, p));
}
return(null);
}
private Triangle_dt extendclock(Triangle_dt t, Point_dt p)
{
t.halfplane = false;
t.c = p;
t.circumcircle();
Triangle_dt tbc = t.bcnext;
if (p.pointLineTest(tbc.a, tbc.b) >= Point_dt.RIGHT)
{
Triangle_dt nT = new Triangle_dt(p, t.b);
nT.abnext = t;
t.bcnext = nT;
nT.bcnext = tbc;
tbc.canext = nT;
return(nT);
}
return(extendclock(tbc, p));
}
private Triangle_dt extendcounterclock(Triangle_dt t, Point_dt p)
{
t.halfplane = false;
t.c = p;
t.circumcircle();
Triangle_dt tca = t.canext;
if (p.pointLineTest(tca.a, tca.b) >= Point_dt.RIGHT)
{
Triangle_dt nT = new Triangle_dt(t.a, p);
nT.abnext = t;
t.canext = nT;
nT.canext = tca;
tca.bcnext = nT;
return(nT);
}
return(extendcounterclock(tca, p));
}
internal void switchneighbors(Triangle_dt Old, Triangle_dt New)
{
if (abnext == Old)
{
abnext = New;
}
else if (bcnext == Old)
{
bcnext = New;
}
else if (canext == Old)
{
canext = New;
}
else
{
Console.WriteLine("Error, switchneighbors can't find Old.");
}
}
private void initTriangles()
{
if (_modCount == _modCount2)
{
return;
}
if (this.size() > 2)
{
_modCount2 = _modCount;
List <Triangle_dt> front = new List <Triangle_dt>();
_triangles = new List <Triangle_dt>();
front.Add(this.startTriangle);
while (front.Count > 0)
{
Triangle_dt t = front.ElementAt(0);
front.RemoveAt(0);
if (t._mark == false)
{
t._mark = true;
_triangles.Add(t);
if (t.abnext != null && !t.abnext._mark)
{
front.Add(t.abnext);
}
if (t.bcnext != null && !t.bcnext._mark)
{
front.Add(t.bcnext);
}
if (t.canext != null && !t.canext._mark)
{
front.Add(t.canext);
}
}
}
// _triNum = _triangles.size();
for (int i = 0; i < _triangles.Count; i++)
{
_triangles.ElementAt <Triangle_dt>(i)._mark = false;
}
}
}
/**
* insert the point to this Delaunay Triangulation. Note: if p is null or
* already exist in this triangulation p is ignored.
*
* @param p
* new vertex to be inserted the triangulation.
*/
public void insertPoint(Point_dt p)
{
if (this._vertices.Contains <Point_dt>(p))
{
return;
}
_modCount++;
updateBoundingBox(p);
this._vertices.Add(p);
Triangle_dt t = insertPointSimple(p);
if (t == null) //
{
return;
}
Triangle_dt tt = t;
currT = t; // recall the last point for - fast (last) update iterator.
do
{
flip(tt, _modCount);
tt = tt.canext;
} while (tt != t && !tt.halfplane);
}
void drawTriangleTopoLines(Graphics g, Triangle_dt t, double dz, Color cl)
{
if (t.p1().z < 0 | t.p2().z < 0 | t.p3().z < 0)
return;
Point_dt[] p12 = computePoints(t.p1(), t.p2(), dz);
Point_dt[] p23 = computePoints(t.p2(), t.p3(), dz);
Point_dt[] p31 = computePoints(t.p3(), t.p1(), dz);
int i12 = 0, i23 = 0, i31 = 0;
bool cont = true;
while (cont)
{
cont = false;
if (i12 < p12.Length && i23 < p23.Length && p12[i12].z == p23[i23].z)
{
if (p12[i12].z % 200 > 100)
drawLine(g, p12[i12], p23[i23], Color.Red);
else
drawLine(g, p12[i12], p23[i23], Color.Yellow);
i12++;
i23++;
cont = true;
}
if (i23 < p23.Length && i31 < p31.Length && p23[i23].z == p31[i31].z)
{
if (p23[i23].z % 200 > 100)
drawLine(g, p23[i23], p31[i31], Color.Red);
else
drawLine(g, p23[i23], p31[i31], Color.Yellow);
i23++;
i31++;
cont = true;
}
if (i12 < p12.Length && i31 < p31.Length && p12[i12].z == p31[i31].z)
{
if (p12[i12].z % 200 > 100)
drawLine(g, p12[i12], p31[i31], Color.Red);
else
drawLine(g, p12[i12], p31[i31], Color.Yellow);
i12++;
i31++;
cont = true;
}
}
}
void MainForm_Click(object sender, MouseEventArgs e)
{
int xx = e.X;
int yy = e.Y;
switch (_stage)
{
case 0:
{
Console.WriteLine("[" + xx + "," + yy + "]");
break;
}
case POINT:
{
Point_dt q = new Point_dt(xx, yy);
Point_dt p = screen2world(q);
_ajd.insertPoint(p);
Refresh();
break;
}
case FIND:
{
Point_dt q = new Point_dt(xx, yy);
Point_dt p = screen2world(q);
//_t1 = _ajd.find(p);
_t1 = _ajd.FastFind(p);
Refresh();
break;
}
case SECTION1:
{
Point_dt q = new Point_dt(xx, yy);
_p1 = screen2world(q);
// _p1 = new Point_dt(99792.03,1073355.0,30.0);
// _t1 = _ajd.find(_p1);
_stage = SECTION2;
break;
}
case SECTION2:
{
Point_dt q = new Point_dt(xx, yy);
_p2 = screen2world(q);
// _p2 = new Point_dt(149587.055,1040477.0,5.0);
// _t2 = _ajd.find(_p2);
_los = new Visibility(_ajd);
_los.computeSection(_p1, _p2);
Refresh();
_stage = SECTION1;
break;
}
case GUARD:
{
Point_dt q = new Point_dt(xx, yy);
_p1 = screen2world(q);
if (_guards == null)
_guards = new List<Point_dt>();
_guards.Add(new Point_dt(_p1.x, _p1.y, GH));
/*
* if(_p2!=null) { _los = new Visibility(_ajd);
* _los.computeSection(_p1,_p2); _visible =
* _los.isVisible(30,5); }
*/
Refresh();
break;
}
case CLIENT:
{
Point_dt q = new Point_dt(xx, yy);
_p2 = screen2world(q);
if (_clients == null)
_clients = new List<Point_dt>();
_clients.Add(new Point_dt(_p2.x, _p2.y, CH));
/*
* if(_p1!=null) { _los = new Visibility(_ajd);
* _los.computeSection(_p1,_p2); _visible =
* _los.isVisible(30,5); }
*/
Refresh();
break;
}
}
}
private void allTriangles(Triangle_dt curr, List<Triangle_dt> front, int mc)
{
if (curr != null && curr._mc == mc && !front.Contains<Triangle_dt>(curr))
{
front.Add(curr);
allTriangles(curr.abnext, front, mc);
allTriangles(curr.bcnext, front, mc);
allTriangles(curr.canext, front, mc);
}
}
/*
* assumes v is NOT an halfplane!
* returns the next triangle for find.
*/
private static Triangle_dt findnext1(Point_dt p, Triangle_dt v)
{
if (p.pointLineTest(v.a, v.b) == Point_dt.RIGHT && !v.abnext.halfplane)
return v.abnext;
if (p.pointLineTest(v.b, v.c) == Point_dt.RIGHT && !v.bcnext.halfplane)
return v.bcnext;
if (p.pointLineTest(v.c, v.a) == Point_dt.RIGHT && !v.canext.halfplane)
return v.canext;
if (p.pointLineTest(v.a, v.b) == Point_dt.RIGHT)
return v.abnext;
if (p.pointLineTest(v.b, v.c) == Point_dt.RIGHT)
return v.bcnext;
if (p.pointLineTest(v.c, v.a) == Point_dt.RIGHT)
return v.canext;
return null;
}
/**
* finds the triangle the query point falls in, note if out-side of this
* triangulation a half plane triangle will be returned (see contains). the
* search starts from the the start triangle
*
* @param p
* query point
* @param start
* the triangle the search starts at.
* @return the triangle that point p is in..
*/
public Triangle_dt find(Point_dt p, Triangle_dt start)
{
if (start == null)
start = this.startTriangle;
Triangle_dt T = find(start, p);
return T;
}
private void insertCollinear(Point_dt p, int res)
{
Triangle_dt t, tp, u;
switch (res)
{
case Point_dt.INFRONTOFA:
t = new Triangle_dt(firstP, p);
tp = new Triangle_dt(p, firstP);
t.abnext = tp;
tp.abnext = t;
t.bcnext = tp;
tp.canext = t;
t.canext = firstT;
firstT.bcnext = t;
tp.bcnext = firstT.abnext;
firstT.abnext.canext = tp;
firstT = t;
firstP = p;
break;
case Point_dt.BEHINDB:
t = new Triangle_dt(p, lastP);
tp = new Triangle_dt(lastP, p);
t.abnext = tp;
tp.abnext = t;
t.bcnext = lastT;
lastT.canext = t;
t.canext = tp;
tp.bcnext = t;
tp.canext = lastT.abnext;
lastT.abnext.bcnext = tp;
lastT = t;
lastP = p;
break;
case Point_dt.ONSEGMENT:
u = firstT;
while (p.isGreater(u.a))
u = u.canext;
t = new Triangle_dt(p, u.b);
tp = new Triangle_dt(u.b, p);
u.b = p;
u.abnext.a = p;
t.abnext = tp;
tp.abnext = t;
t.bcnext = u.bcnext;
u.bcnext.canext = t;
t.canext = u;
u.bcnext = t;
tp.canext = u.abnext.canext;
u.abnext.canext.bcnext = tp;
tp.bcnext = u.abnext;
u.abnext.canext = tp;
if (firstT == u)
{
firstT = t;
}
break;
}
}
private Triangle_dt extendOutside(Triangle_dt t, Point_dt p)
{
if (p.pointLineTest(t.a, t.b) == Point_dt.ONSEGMENT)
{
Triangle_dt dg = new Triangle_dt(t.a, t.b, p);
Triangle_dt hp = new Triangle_dt(p, t.b);
t.b = p;
dg.abnext = t.abnext;
dg.abnext.switchneighbors(t, dg);
dg.bcnext = hp;
hp.abnext = dg;
dg.canext = t;
t.abnext = dg;
hp.bcnext = t.bcnext;
hp.bcnext.canext = hp;
hp.canext = t;
t.bcnext = hp;
return dg;
}
Triangle_dt ccT = extendcounterclock(t, p);
Triangle_dt cT = extendclock(t, p);
ccT.bcnext = cT;
cT.canext = ccT;
startTriangleHull = cT;
return cT.abnext;
}
private Triangle_dt extendcounterclock(Triangle_dt t, Point_dt p)
{
t.halfplane = false;
t.c = p;
t.circumcircle();
Triangle_dt tca = t.canext;
if (p.pointLineTest(tca.a, tca.b) >= Point_dt.RIGHT)
{
Triangle_dt nT = new Triangle_dt(t.a, p);
nT.abnext = t;
t.canext = nT;
nT.canext = tca;
tca.bcnext = nT;
return nT;
}
return extendcounterclock(tca, p);
}
public void drawTriangle(Graphics g, Triangle_dt t, Color cl)
{
if (_view_flag == VIEW1 || t.isHalfplane())
{
if (t.isHalfplane())
{
if (cl == Color.Empty)
drawLine(g, t.p1(), t.p2(), Color.Blue);
else
drawLine(g, t.p1(), t.p2(), cl);
}
else
{
if (cl == Color.Empty)
{
drawLine(g, t.p1(), t.p2(), Color.Black);
drawLine(g, t.p2(), t.p3(), Color.Black);
drawLine(g, t.p3(), t.p1(), Color.Black);
}
{
drawLine(g, t.p1(), t.p2(), cl);
drawLine(g, t.p2(), t.p3(), cl);
drawLine(g, t.p3(), t.p1(), cl);
}
}
}
else
{
// //////////////////////////////////////////////////////////////////
double maxZ = _ajd.maxBoundingBox().z;
double minZ = _ajd.minBoundingBox().z;
double z = (t.p1().z + t.p2().z + t.p3().z) / 3.0;
double dz = maxZ - minZ;
if (dz == 0)
dz = 1;
int co = 30 + (int)(220 * ((z - minZ) / dz));
if (cl == Color.Empty)
cl = Color.FromArgb(co, co, co);
int[] xx = new int[3], yy = new int[3];
// double f = 0;
// double dx_map = _dx_map.y- _dx_map.x;
// double dy_map = _dy_map.y- _dy_map.x;
// f = (t.p1().x -_dx_map.x)/dx_map;
Point_dt p1 = world2screen(t.p1());
xx[0] = (int)p1.x;
yy[0] = (int)p1.y;
Point_dt p2 = world2screen(t.p2());
xx[1] = (int)p2.x;
yy[1] = (int)p2.y;
Point_dt p3 = world2screen(t.p3());
xx[2] = (int)p3.x;
yy[2] = (int)p3.y;
Brush b = new SolidBrush(cl);
g.FillPolygon(b, ToPoints(xx, yy));
// ////////////////////////////////////
}
}
internal void switchneighbors(Triangle_dt Old, Triangle_dt New)
{
if ( abnext == Old )
abnext = New;
else if ( bcnext == Old )
bcnext = New;
else if ( canext == Old )
canext=New;
else
Console.WriteLine( "Error, switchneighbors can't find Old." );
}
private static Triangle_dt find(Triangle_dt curr, Point_dt p)
{
if (p == null)
return null;
Triangle_dt next_t;
if (curr.halfplane)
{
next_t = findnext2(p, curr);
if (next_t == null || next_t.halfplane)
return curr;
curr = next_t;
}
while (true)
{
next_t = findnext1(p, curr);
if (next_t == null)
return curr;
if (next_t.halfplane)
return next_t;
curr = next_t;
}
}
/**
*
* @param p
* query point
* @return true iff p is within this triangulation (in its 2D convex hull).
*/
public bool contains(Point_dt p)
{
Triangle_dt tt = find(p);
return(!tt.halfplane);
}
/** assumes v is an halfplane! - returns another (none halfplane) triangle */
private static Triangle_dt findnext2(Point_dt p, Triangle_dt v)
{
if (v.abnext != null && !v.abnext.halfplane)
return v.abnext;
if (v.bcnext != null && !v.bcnext.halfplane)
return v.bcnext;
if (v.canext != null && !v.canext.halfplane)
return v.canext;
return null;
}
/**
*
* @param q
* Query point
* @return the q point with updated Z value (z value is as given the
* triangulation).
*/
public Point_dt z(Point_dt q)
{
Triangle_dt t = find(q);
return(t.z(q));
}
private Triangle_dt extendclock(Triangle_dt t, Point_dt p)
{
t.halfplane = false;
t.c = p;
t.circumcircle();
Triangle_dt tbc = t.bcnext;
if (p.pointLineTest(tbc.a, tbc.b) >= Point_dt.RIGHT)
{
Triangle_dt nT = new Triangle_dt(p, t.b);
nT.abnext = t;
t.bcnext = nT;
nT.bcnext = tbc;
tbc.canext = nT;
return nT;
}
return extendclock(tbc, p);
}
private void insertCollinear(Point_dt p, int res)
{
Triangle_dt t, tp, u;
switch (res)
{
case Point_dt.INFRONTOFA:
t = new Triangle_dt(firstP, p);
tp = new Triangle_dt(p, firstP);
t.abnext = tp;
tp.abnext = t;
t.bcnext = tp;
tp.canext = t;
t.canext = firstT;
firstT.bcnext = t;
tp.bcnext = firstT.abnext;
firstT.abnext.canext = tp;
firstT = t;
firstP = p;
break;
case Point_dt.BEHINDB:
t = new Triangle_dt(p, lastP);
tp = new Triangle_dt(lastP, p);
t.abnext = tp;
tp.abnext = t;
t.bcnext = lastT;
lastT.canext = t;
t.canext = tp;
tp.bcnext = t;
tp.canext = lastT.abnext;
lastT.abnext.bcnext = tp;
lastT = t;
lastP = p;
break;
case Point_dt.ONSEGMENT:
u = firstT;
while (p.isGreater(u.a))
{
u = u.canext;
}
t = new Triangle_dt(p, u.b);
tp = new Triangle_dt(u.b, p);
u.b = p;
u.abnext.a = p;
t.abnext = tp;
tp.abnext = t;
t.bcnext = u.bcnext;
u.bcnext.canext = t;
t.canext = u;
u.bcnext = t;
tp.canext = u.abnext.canext;
u.abnext.canext.bcnext = tp;
tp.bcnext = u.abnext;
u.abnext.canext = tp;
if (firstT == u)
{
firstT = t;
}
break;
}
}
private Triangle_dt extendInside(Triangle_dt t, Point_dt p)
{
Triangle_dt h1, h2;
h1 = treatDegeneracyInside(t, p);
if (h1 != null)
return h1;
h1 = new Triangle_dt(t.c, t.a, p);
h2 = new Triangle_dt(t.b, t.c, p);
t.c = p;
t.circumcircle();
h1.abnext = t.canext;
h1.bcnext = t;
h1.canext = h2;
h2.abnext = t.bcnext;
h2.bcnext = h1;
h2.canext = t;
h1.abnext.switchneighbors(t, h1);
h2.abnext.switchneighbors(t, h2);
t.bcnext = h2;
t.canext = h1;
return t;
}
private void startTriangulation(Point_dt p1, Point_dt p2)
{
Point_dt ps, pb;
if (p1.isLess(p2))
{
ps = p1;
pb = p2;
}
else
{
ps = p2;
pb = p1;
}
firstT = new Triangle_dt(pb, ps);
lastT = firstT;
Triangle_dt t = new Triangle_dt(ps, pb);
firstT.abnext = t;
t.abnext = firstT;
firstT.bcnext = t;
t.canext = firstT;
firstT.canext = t;
t.bcnext = firstT;
firstP = firstT.b;
lastP = lastT.a;
startTriangleHull = firstT;
}
private void flip(Triangle_dt t, int mc)
{
var bkpT = (Triangle_dt) t.Clone();
Triangle_dt u = t.abnext, v;
t._mc = mc;
if (u.halfplane || !u.circumcircle_contains(t.c))
return;
if (t.a == u.a)
{
v = new Triangle_dt(u.b, t.b, t.c);
v.abnext = u.bcnext;
t.abnext = u.abnext;
}
else if (t.a == u.b)
{
v = new Triangle_dt(u.c, t.b, t.c);
v.abnext = u.canext;
t.abnext = u.bcnext;
}
else if (t.a == u.c)
{
v = new Triangle_dt(u.a, t.b, t.c);
v.abnext = u.abnext;
t.abnext = u.canext;
}
else
{
throw new Exception("Error in flip.");
}
v._mc = mc;
v.bcnext = t.bcnext;
v.abnext.switchneighbors(u, v);
v.bcnext.switchneighbors(t, v);
t.bcnext = v;
v.canext = t;
t.b = v.a;
t.abnext.switchneighbors(u, t);
t.circumcircle();
currT = v;
flip(t, mc);
flip(v, mc);
}
/**
* Add the intersections of triangle t with the section to the list of
* intersection (set)
*/
void cut(Triangle_dt t)
{
if (t.isHalfplane())
return;
Point_dt p1 = t.p1(), p2 = t.p2(), p3 = t.p3();
int f1 = p1.pointLineTest(_p1, _p2);
int f2 = p2.pointLineTest(_p1, _p2);
int f3 = p3.pointLineTest(_p1, _p2);
if ((f1 == Point_dt.LEFT | f1 == Point_dt.RIGHT)
&& (f1 == f2 && f1 == f3))
return;
if (f1 != f2 && _p1.pointLineTest(p1, p2) != _p2.pointLineTest(p1, p2))
Add(intersection(p1, p2));
if (f2 != f3 && _p1.pointLineTest(p2, p3) != _p2.pointLineTest(p2, p3))
Add(intersection(p2, p3));
if (f3 != f1 && _p1.pointLineTest(p3, p1) != _p2.pointLineTest(p3, p1))
Add(intersection(p3, p1));
}
private Triangle_dt insertPointSimple(Point_dt p)
{
nPoints++;
if (!allCollinear)
{
Triangle_dt t = find(startTriangle, p);
if (t.halfplane)
startTriangle = extendOutside(t, p);
else
startTriangle = extendInside(t, p);
return startTriangle;
}
if (nPoints == 1)
{
firstP = p;
return null;
}
if (nPoints == 2)
{
startTriangulation(firstP, p);
return null;
}
switch (p.pointLineTest(firstP, lastP))
{
case Point_dt.LEFT:
startTriangle = extendOutside(firstT.abnext, p);
allCollinear = false;
break;
case Point_dt.RIGHT:
startTriangle = extendOutside(firstT, p);
allCollinear = false;
break;
case Point_dt.ONSEGMENT:
insertCollinear(p, Point_dt.ONSEGMENT);
break;
case Point_dt.INFRONTOFA:
insertCollinear(p, Point_dt.INFRONTOFA);
break;
case Point_dt.BEHINDB:
insertCollinear(p, Point_dt.BEHINDB);
break;
}
return null;
}
Triangle_dt next_t(Point_dt pp1, Point_dt pp2, Triangle_dt curr,
List<Triangle_dt> tr)
{
Triangle_dt ans = null, t12, t23, t31;
t12 = curr.next_12();
t23 = curr.next_23();
t31 = curr.next_31();
if (t12 != null && cut(pp1, pp2, t12) && !tr.Contains(t12))
ans = t12;
else if (t23 != null && cut(pp1, pp2, t23) && !tr.Contains(t23))
ans = t23;
else if (t31 != null && cut(pp1, pp2, t31) && !tr.Contains(t31))
ans = t31;
return ans;
}
private Triangle_dt treatDegeneracyInside(Triangle_dt t, Point_dt p)
{
if (t.abnext.halfplane
&& p.pointLineTest(t.b, t.a) == Point_dt.ONSEGMENT)
return extendOutside(t.abnext, p);
if (t.bcnext.halfplane
&& p.pointLineTest(t.c, t.b) == Point_dt.ONSEGMENT)
return extendOutside(t.bcnext, p);
if (t.canext.halfplane
&& p.pointLineTest(t.a, t.c) == Point_dt.ONSEGMENT)
return extendOutside(t.canext, p);
return null;
}
/** return true iff the segment _p1,_p2 is cutting t */
bool cut(Point_dt pp1, Point_dt pp2, Triangle_dt t)
{
bool ans = false;
if (t.isHalfplane())
return false;
Point_dt p1 = t.p1(), p2 = t.p2(), p3 = t.p3();
int f1 = p1.pointLineTest(pp1, pp2);
int f2 = p2.pointLineTest(pp1, pp2);
int f3 = p3.pointLineTest(pp1, pp2);
if ((f1 == Point_dt.LEFT | f1 == Point_dt.RIGHT)
&& (f1 == f2 && f1 == f3))
return false;
if (f1 != f2 && pp1.pointLineTest(p1, p2) != pp2.pointLineTest(p1, p2))
return true;
if (f2 != f3 && pp1.pointLineTest(p2, p3) != pp2.pointLineTest(p2, p3))
return true;
if (f3 != f1 && pp1.pointLineTest(p3, p1) != pp2.pointLineTest(p3, p1))
return true;
return ans;
}