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 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);
}
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));
}
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);
}
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 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);
}
