/**
* determinates if this triangle contains the point p.
* @param p the query point
* @return true iff p is not null and is inside this triangle (Note: on boundary is considered inside!!).
*/
public bool contains(Point_dt p)
{
bool ans = false;
if (this.halfplane || p == null)
{
return(false);
}
if ((p.x == a.x && p.y == a.y) || (p.x == b.x && p.y == b.y) || (p.x == c.x && p.y == c.y))
{
return(true);
}
int a12 = p.pointLineTest(a, b);
int a23 = p.pointLineTest(b, c);
int a31 = p.pointLineTest(c, a);
if ((a12 == Point_dt.LEFT && a23 == Point_dt.LEFT && a31 == Point_dt.LEFT) ||
(a12 == Point_dt.RIGHT && a23 == Point_dt.RIGHT && a31 == Point_dt.RIGHT) ||
(a12 == Point_dt.ONSEGMENT || a23 == Point_dt.ONSEGMENT || a31 == Point_dt.ONSEGMENT))
{
ans = true;
}
return(ans);
}
//public int _id;
/** constructs a triangle form 3 point - store it in counterclockwised order.*/
public Triangle_dt(Point_dt A, Point_dt B, Point_dt C)
{
//visitflag=visitValue;
a = A;
int res = C.pointLineTest(A, B);
if ((res <= Point_dt.LEFT) ||
(res == Point_dt.INFRONTOFA) ||
(res == Point_dt.BEHINDB))
{
b = B;
c = C;
}
else
{ // RIGHT
Console.WriteLine("Warning, ajTriangle(A,B,C) " + "expects points in counterclockwise order.");
Console.WriteLine("" + A + B + C);
b = C;
c = B;
}
circumcircle();
//_id = _counter++;
//_counter++;_c2++;
//if(_counter%10000 ==0) System.out.println("Triangle: "+_counter);
}
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 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 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);
}
/*
* 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 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));
}
