/* returns true if p is to right of halfedge e */
private bool right_of(Halfedge el, PointFortune p)
{
EdgeF e;
PointFortune topsite;
bool right_of_site;
bool above, fast;
double dxp, dyp, dxs, t1, t2, t3, yl;
e = el.ELedge;
topsite = e.reg[1];
if (p.X > topsite.X)
{
right_of_site = true;
}
else
{
right_of_site = false;
}
if (right_of_site && el.ELpm == LE)
{
return(true);
}
if (!right_of_site && el.ELpm == RE)
{
return(false);
}
if (e.a == 1.0)
{
dxp = p.X - topsite.X;
dyp = p.Y - topsite.Y;
fast = false;
if ((!right_of_site & (e.b < 0.0)) | (right_of_site & (e.b >= 0.0)))
{
above = dyp >= e.b * dxp;
fast = above;
}
else
{
above = p.X + p.Y * e.b > e.c;
if (e.b < 0.0)
{
above = !above;
}
if (!above)
{
fast = true;
}
}
if (!fast)
{
dxs = topsite.X - (e.reg[0]).X;
above = e.b * (dxp * dxp - dyp * dyp)
< dxs * dyp * (1.0 + 2.0 * dxp / dxs + e.b * e.b);
if (e.b < 0)
{
above = !above;
}
}
}
else // e.b == 1.0
{
yl = e.c - e.a * p.X;
t1 = p.Y - yl;
t2 = p.X - topsite.X;
t3 = yl - topsite.Y;
above = t1 * t1 > t2 * t2 + t3 * t3;
}
return(el.ELpm == LE ? above : !above);
}
/*
* This delete routine can't reclaim node, since pointers from hash table
* may be present.
*/
private void ELdelete(Halfedge he)
{
(he.ELleft).ELright = he.ELright;
(he.ELright).ELleft = he.ELleft;
he.deleted = true;
}
private Halfedge ELright(Halfedge he)
{
return(he.ELright);
}
private Halfedge ELleft(Halfedge he)
{
return(he.ELleft);
}
public Halfedge()
{
PQnext = null;
}