Skip to content

Fixed building composite curve 2d segments for raw conics and trimmed/offset conics #560

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Ibrahim5aad merged 1 commit into from
Oct 31, 2025
Merged

Fixed building composite curve 2d segments for raw conics and trimmed/offset conics #560

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion Xbim.Geometry.Engine/Factories/CurveFactory.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -435,7 +435,7 @@ namespace Xbim
if (horizontalProjection.IsNull()) {
throw RaiseGeometryFactoryException("IfcGradientCurve BaseCurve could not be built", ifcGradientCurve);
}

// Building heigth function from the curve Segments
for (int i = 0; i < ifcGradientCurve->NSegments; i++)
{
Expand Down
111 changes: 91 additions & 20 deletions Xbim.Geometry.Engine/Factories/Unmanaged/NCurveFactory.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,8 @@
#include <TopoDS.hxx>
#include <TopoDS_Face.hxx>
#include <GeomAPI_ProjectPointOnCurve.hxx>
#include <GCPnts_AbscissaPoint.hxx>


TColgp_Array1OfPnt NCurveFactory::GetPointsFromProjectionAndHeightCurves(TColgp_Array1OfPnt& points, Standard_Integer nbPoints, Handle(Geom2d_Curve) projection, Handle(Geom2d_Curve) height)
{
Expand Down Expand Up @@ -280,53 +282,55 @@ Handle(Geom2d_BSplineCurve) NCurveFactory::BuildCompositeCurve2d(const TColGeom2
Handle(Geom2d_BoundedCurve) curve = *it;
Handle(Geom2d_Spiral) spiral = Handle(Geom2d_Spiral)::DownCast(curve);
Handle(Geom2d_Polynomial) polynomial = Handle(Geom2d_Polynomial)::DownCast(curve);


const Standard_Real first = curve->FirstParameter();
const Standard_Real last = curve->LastParameter();

Handle(Geom2d_BSplineCurve) toAdd;

if (polynomial) {
// Approximate the curve
Standard_Real firstParam = curve->FirstParameter();
Standard_Real lastParam = curve->LastParameter();
int numPoints = std::max(Geom2d_Spiral::IntegrationSteps, 1000);
TColgp_Array1OfPnt2d points(1, numPoints);

for (Standard_Integer i = 1; i <= numPoints; ++i) {
Standard_Real U = firstParam + (lastParam - firstParam) * (i - 1) / (numPoints - 1);
Standard_Real U = first + (last - first) * (i - 1) / (numPoints - 1);
gp_Pnt2d P;
curve->D0(U, P);
points.SetValue(i, P);
}

Geom2dAPI_PointsToBSpline curveBuilder(points, 8, 8, GeomAbs_CN);
Handle(Geom2d_BSplineCurve) approximate = curveBuilder.Curve();
if (!compositeConverter.Add(approximate, tolerance, false))
{
Standard_Failure::Raise("Compound curve segment is not continuous");
}
toAdd = curveBuilder.Curve();
}
else if (spiral) {
// Approximate the curve
Standard_Real firstParam = curve->FirstParameter();
Standard_Real lastParam = curve->LastParameter();
int numPoints = spiral.get()->GetIntervalsCount();
TColgp_Array1OfPnt2d points(1, numPoints);

for (Standard_Integer i = 1; i <= numPoints; ++i) {
Standard_Real U = firstParam + (lastParam - firstParam) * (i - 1) / (numPoints - 1);
Standard_Real U = first + (last - first) * (i - 1) / (numPoints - 1);
gp_Pnt2d P;
curve->D0(U, P);
points.SetValue(i, P);
}

Geom2dAPI_PointsToBSpline curveBuilder(points, 8, 8, GeomAbs_CN);
Handle(Geom2d_BSplineCurve) approximate = curveBuilder.Curve();
if (!compositeConverter.Add(approximate, tolerance, false))
{
Standard_Failure::Raise("Compound curve segment is not continuous");
}
toAdd = curveBuilder.Curve();
}
else
if (!compositeConverter.Add(curve, tolerance, false))
else if (IsConicLike(curve)) {
// This covers raw conics AND trimmed/offset conics.
toAdd = ApproximateByArcLength(curve, first, last, tolerance, 8, GeomAbs_CN);
}
else if (!compositeConverter.Add(curve, tolerance, false))
{
Standard_Failure::Raise("Compound curve segment is not continuous");
toAdd = ApproximateByArcLength(curve, first, last, tolerance, 8, GeomAbs_CN);
}

if (!toAdd.IsNull()) {
if (!compositeConverter.Add(toAdd, tolerance, false)) {
Standard_Failure::Raise("Compound curve segment is not continuous");
}
}
}
return compositeConverter.BSplineCurve();
Expand All @@ -339,6 +343,72 @@ Handle(Geom2d_BSplineCurve) NCurveFactory::BuildCompositeCurve2d(const TColGeom2

}

Handle(Geom2d_Curve) NCurveFactory::UnwrapBasis(const Handle(Geom2d_Curve)& c)
{
Handle(Geom2d_Curve) cur = c;
// unwrap nested trims/offsets (be defensive)
for (int guard = 0; guard < 8; ++guard) {
if (Handle(Geom2d_TrimmedCurve) t = Handle(Geom2d_TrimmedCurve)::DownCast(cur)) {
cur = t->BasisCurve();
continue;
}
if (Handle(Geom2d_OffsetCurve) o = Handle(Geom2d_OffsetCurve)::DownCast(cur)) {
cur = o->BasisCurve();
continue;
}
break;
}
return cur;
}

bool NCurveFactory::IsConicLike(const Handle(Geom2d_Curve)& c)
{
Handle(Geom2d_Curve) base = UnwrapBasis(c);
return !Handle(Geom2d_Conic)::DownCast(base).IsNull();
}

// Approximate any curve over [First, Last] by equal arc-length samples
Handle(Geom2d_BSplineCurve) NCurveFactory::ApproximateByArcLength(const Handle(Geom2d_Curve)& c,
Standard_Real first, Standard_Real last,
Standard_Real tol,
Standard_Integer deg,
GeomAbs_Shape cont)
{
Geom2dAdaptor_Curve adaptor(c, first, last);

// Choose number of points from length and tolerance
Standard_Real L = 0.0;
try {
L = GCPnts_AbscissaPoint::Length(adaptor, first, last);
}
catch (...) {
L = last - first; // fallback
}
// Rough heuristic: target chord error ~ tol => segment length ~ sqrt(tol)
// Clamp to reasonable range
Standard_Integer nPts = Max(10, Min(2000, (Standard_Integer)std::ceil(Max(5.0, L / Max(1e-6, Sqrt(Max(tol, 1e-12)))))));

// Use equal arc-length stations
TColgp_Array1OfPnt2d pts(1, nPts);

for (Standard_Integer i = 1; i <= nPts; ++i) {
Standard_Real s = L * (i - 1) / (nPts - 1); // target length from 'first'
Standard_Real ui;
if (i == 1) ui = first;
else if (i == nPts) ui = last;
else {
GCPnts_AbscissaPoint abscissa(adaptor, s, first);
ui = abscissa.Parameter();
}
gp_Pnt2d P;
c->D0(ui, P);
pts.SetValue(i, P);
}

Geom2dAPI_PointsToBSpline builder(pts, deg, deg, cont);
return builder.Curve();
}

Handle(Geom2d_BSplineCurve) NCurveFactory::BuildIndexedPolyCurve2d(const TColGeom2d_SequenceOfBoundedCurve& segments, double tolerance)
{

Expand All @@ -358,6 +428,7 @@ Handle(Geom2d_BSplineCurve) NCurveFactory::BuildIndexedPolyCurve2d(const TColGeo
return Handle(Geom2d_BSplineCurve)(); //return null handle for checking
}
}

Handle(Geom_BSplineCurve) NCurveFactory::BuildIndexedPolyCurve3d(const TColGeom_SequenceOfBoundedCurve& segments, double tolerance)
{
try
Expand Down
8 changes: 8 additions & 0 deletions Xbim.Geometry.Engine/Factories/Unmanaged/NCurveFactory.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,14 @@ public class NCurveFactory : public NFactoryBase
private:
bool GetPlaneFromWire(const TopoDS_Wire& wire, gp_Pln& plane);
bool GetPlaneFromFace(const TopoDS_Face& face, gp_Pln& plane);
bool IsConicLike(const Handle(Geom2d_Curve)& c);
Handle(Geom2d_BSplineCurve) ApproximateByArcLength(const Handle(Geom2d_Curve)& c,
Standard_Real first, Standard_Real last,
Standard_Real tol,
Standard_Integer deg = 8,
GeomAbs_Shape cont = GeomAbs_CN);
Handle(Geom2d_Curve) UnwrapBasis(const Handle(Geom2d_Curve)& c);


#pragma endregion

Expand Down
Loading