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This commit is contained in:
Bozo the Builder
2024-03-13 09:41:56 -07:00
parent 19df200382
commit cf8984bb9a
47 changed files with 397 additions and 11738 deletions
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113
opennurbs_convex_poly.cpp
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@@ -1112,29 +1112,52 @@ bool ON_ConvexPoly::GetClosestPointSeeded(const ON_ConvexPoly& B,
}
// Is PQR a right hnd turn
// Is PQR a strictly left hand turn.
// Will return false if the point Q*, closest to PR from Q,
// IsCoincident to Q.
static bool IsLeftTurn(const ON_2dPoint& P, const ON_2dPoint& Q, const ON_2dPoint& R)
{
ON_2dVector A = R - Q;
ON_2dVector B = P - Q;
double det = A.x* B.y - B.x*A.y;
return det > 0.0;
bool Left = det > 0.0;
if (Left)
{
ON_2dVector Dir = R - P;
ON_2dVector N(-Dir.y, Dir.x);
N.Unitize();
// todo choose A or B
ON_2dVector Delta = B * N * N; // Delta from Q to PR
// Is Q.IsCoincident(Q+Delta)
Left = false;
for (int di = 0; !Left && di < 2; di++)
{
if( fabs(Delta[di])>ON_ZERO_TOLERANCE && fabs(Delta[di])>ON_RELATIVE_TOLERANCE* fabs( Q[di]) )
Left = true;
}
}
return Left;
}
int ON_ConvexHull2d(const ON_SimpleArray<ON_2dPoint>& Pnt, ON_SimpleArray<ON_2dPoint>& Hull, ON_SimpleArray< int>* PntInd)
{
int rval = -1;
int dim = -1;
if (Pnt.Count() == 0)
return dim;
Hull.Empty();
if (PntInd)
PntInd->Empty();
ON_SimpleArray<int> Ind(Pnt.Count());
Ind.SetCount(Pnt.Count());
if (PntInd)
PntInd->Empty();
if (!Pnt.Sort(ON::sort_algorithm::quick_sort, Ind,
[](const ON_2dPoint* A, const ON_2dPoint* B) { return ON_2dPoint::Compare(*A, *B); }))
return rval;
if (Pnt.Count() == 0)
return rval;
return dim;
Hull.Append(Pnt[Ind[0]]);
if (PntInd)
@@ -1146,22 +1169,36 @@ int ON_ConvexHull2d(const ON_SimpleArray<ON_2dPoint>& Pnt, ON_SimpleArray<ON_2dP
{
for ( /*empty*/; ri < Pnt.Count() && ri >= 0; ri += inc)
{
ON_2dPoint R = Pnt[Ind[ri]];
ON_2dPoint Q = *Hull.Last();
ON_2dPoint R = Pnt[Ind[ri]];
// Ensure R is sufficiently distinct from Q
if (R.IsCoincident(Q))
{
if (ri == Pnt.Count() - 1 && Hull.Count()>1)
{
// Use x-most point as second fixed end
*Hull.Last() = R;
if (PntInd)
*PntInd->Last() = Ind[ri];
}
}
if (Hull.Count() == fixed)
else if (Hull.Count() == fixed)
{
if (R != *Hull.Last())
{
Hull.Append(R);
if (PntInd)
PntInd->Append(Ind[ri]);
}
Hull.Append(R);
if (PntInd)
PntInd->Append(Ind[ri]);
}
else
{
int pi = Hull.Count() - 2;
ON_2dPoint P = Hull[pi];
ON_2dPoint Q = *Hull.Last();
if (R.IsCoincident(P))
{
//TODO what about this case?!
}
if (IsLeftTurn(P, Q, R))
{
Hull.Append(R);
@@ -1171,20 +1208,19 @@ int ON_ConvexHull2d(const ON_SimpleArray<ON_2dPoint>& Pnt, ON_SimpleArray<ON_2dP
else
{
bool done = false;
while (!done)
{
Hull.Remove();
if (PntInd)
PntInd->Remove();
Q = P;
done = (pi == ((inc==1)?0:fixed-1));
if (!done)
{
P = Hull[--pi];
done = IsLeftTurn(P, Q, R);
}
}
while (!done)
{
Hull.Remove();
if (PntInd)
PntInd->Remove();
Q = P;
done = (pi == ((inc == 1) ? 0 : fixed - 1));
if (!done)
{
P = Hull[--pi];
done = IsLeftTurn(P, Q, R);
}
}
Hull.Append(R);
if (PntInd)
PntInd->Append(Ind[ri]);
@@ -1192,18 +1228,23 @@ int ON_ConvexHull2d(const ON_SimpleArray<ON_2dPoint>& Pnt, ON_SimpleArray<ON_2dP
}
}
if (Hull.Count() == 1) {
rval = 0;
dim = 0;
break;
}
fixed = Hull.Count();
ri = Pnt.Count() - 2;
}
// Deal with dim=1 case
if (Hull.Count() == 3)
Hull.Remove();
if (Hull.Count() == 2)
rval = 1;
else
rval = 2;
return rval;
dim = 1;
else if(Hull.Count() > 2)
dim = 2;
return dim;
}