/**
* 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));
}
}
/** 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);
}
//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 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;
}
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);
}
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);
}
/*
* 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;
}
/**
* 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;
}
/** 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;
}