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[TD]fix false positives in isCircle (fix #15979)

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wandererfan
2024-08-21 21:47:38 -04:00
committed by Yorik van Havre
parent 1e0ac05c7b
commit 0d4b04deb3
2 changed files with 45 additions and 17 deletions
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59
src/Mod/TechDraw/App/Geometry.cpp
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@@ -41,6 +41,7 @@
# include <BRepLib.hxx>
# include <BRepLProp_CLProps.hxx>
# include <BRepTools.hxx>
#include <BRepLProp_CurveTool.hxx>
# include <GC_MakeArcOfCircle.hxx>
# include <GC_MakeEllipse.hxx>
#include <GC_MakeCircle.hxx>
@@ -1556,9 +1557,12 @@ bool GeometryUtils::isCircle(TopoDS_Edge occEdge)
return GeometryUtils::getCircleParms(occEdge, radius, center, isArc);
}
//tries to interpret a BSpline edge as a circle. Used by DVDim for approximate dimensions.
//! tries to interpret a BSpline edge as a circle. Used by DVDim for approximate dimensions.
//! calculates the curvature of the spline at a number of places and measures the deviation from the average
//! a true circle has constant curvature and would have no deviation from the average.
bool GeometryUtils::getCircleParms(TopoDS_Edge occEdge, double& radius, Base::Vector3d& center, bool& isArc)
{
int testCount = 5;
double curveLimit = EWTOLERANCE;
BRepAdaptor_Curve c(occEdge);
Handle(Geom_BSplineCurve) spline = c.BSpline();
@@ -1566,7 +1570,6 @@ bool GeometryUtils::getCircleParms(TopoDS_Edge occEdge, double& radius, Base::Ve
f = c.FirstParameter();
l = c.LastParameter();
double parmRange = fabs(l - f);
int testCount = 6;
double parmStep = parmRange/testCount;
std::vector<double> curvatures;
std::vector<gp_Pnt> centers;
@@ -1575,12 +1578,8 @@ bool GeometryUtils::getCircleParms(TopoDS_Edge occEdge, double& radius, Base::Ve
Base::Vector3d sumCenter, valueAt;
try {
GeomLProp_CLProps prop(spline, f, 3, Precision::Confusion());
curvatures.push_back(prop.Curvature());
sumCurvature += prop.Curvature();
prop.CentreOfCurvature(curveCenter);
centers.push_back(curveCenter);
sumCenter += DrawUtil::toVector3d(curveCenter);
// check only the interior points of the edge
for (int i = 1; i < (testCount - 1); i++) {
prop.SetParameter(parmStep * i);
curvatures.push_back(prop.Curvature());
@@ -1589,32 +1588,42 @@ bool GeometryUtils::getCircleParms(TopoDS_Edge occEdge, double& radius, Base::Ve
centers.push_back(curveCenter);
sumCenter += DrawUtil::toVector3d(curveCenter);
}
prop.SetParameter(l);
curvatures.push_back(prop.Curvature());
sumCurvature += prop.Curvature();
prop.CentreOfCurvature(curveCenter);
centers.push_back(curveCenter);
sumCenter += DrawUtil::toVector3d(curveCenter);
}
catch (Standard_Failure&) {
return false;
}
Base::Vector3d avgCenter = sumCenter/testCount;
Base::Vector3d avgCenter = sumCenter/ centers.size();
double avgCurve = sumCurvature/testCount;
double avgCurve = sumCurvature/ centers.size();
double errorCurve = 0;
// sum the errors in curvature
for (auto& cv: curvatures) {
errorCurve += avgCurve - cv;
}
errorCurve = errorCurve/testCount;
double errorCenter{0};
for (auto& observe : centers) {
auto error = (DU::toVector3d(observe)- avgCenter).Length();
errorCenter += error;
}
// calculate average error in curvature. we are only interested in the magnitude of the error
errorCurve = fabs(errorCurve / curvatures.size());
// calculate the average error in center of curvature
errorCenter = errorCenter / curvatures.size();
auto edgeLong = edgeLength(occEdge);
double centerLimit = edgeLong * 0.01;
isArc = !c.IsClosed();
bool isCircle(false);
if ( errorCurve < curveLimit ) {
if ( errorCurve <= curveLimit &&
errorCenter <= centerLimit) {
isCircle = true;
radius = 1.0/avgCurve;
center = avgCenter;
}
return isCircle;
}
@@ -1708,3 +1717,19 @@ TopoDS_Edge GeometryUtils::asLine(TopoDS_Edge occEdge)
return result;
}
double GeometryUtils::edgeLength(TopoDS_Edge occEdge)
{
BRepAdaptor_Curve adapt(occEdge);
const Handle(Geom_Curve) curve = adapt.Curve().Curve();
double first = BRepLProp_CurveTool::FirstParameter(adapt);
double last = BRepLProp_CurveTool::LastParameter(adapt);
try {
GeomAdaptor_Curve adaptor(curve);
return GCPnts_AbscissaPoint::Length(adaptor,first,last,Precision::Confusion());
}
catch (Standard_Failure& exc) {
THROWM(Base::CADKernelError, exc.GetMessageString())
}
}