IfcOpenShell/src/ifcgeom/mapping/IfcTrimmedCurve.cpp

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 * This file is part of IfcOpenShell.                                           *
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 * IfcOpenShell is free software: you can redistribute it and/or modify         *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
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 * You should have received a copy of the Lesser GNU General Public License     *
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#include "mapping.h"
#define mapping POSTFIX_SCHEMA(mapping)
using namespace ifcopenshell::geometry;

#include <boost/math/constants/constants.hpp>

taxonomy::ptr mapping::map_impl(const IfcSchema::IfcTrimmedCurve& inst) {
	static const double pi = boost::math::constants::pi<double>();

	auto basis_curve = inst.BasisCurve();
	bool isConic = basis_curve.declaration().is(IfcSchema::IfcConic::Class());
	double parameterFactor = isConic ? angle_unit_ : length_unit_;
	
	auto tc = taxonomy::make<taxonomy::edge>();
	tc->basis = map(inst.BasisCurve());
	
	bool trim_cartesian = inst.MasterRepresentation() != IfcSchema::IfcTrimmingPreference::IfcTrimmingPreference_PARAMETER;
	auto trims1 = inst.Trim1();
	auto trims2 = inst.Trim2();
	
	// reversed orientation handling happens in geometry kernel
	unsigned sense_agreement = 0;
	double flts[2];
	taxonomy::point3::ptr pnts[2];
	bool has_flts[2] = {false,false};
	bool has_pnts[2] = {false,false};
	
	tc->curve_sense = inst.SenseAgreement();

	for (auto it = trims1.begin(); it != trims1.end(); it ++) {
		auto i = *it;
		if (i.as<IfcSchema::IfcCartesianPoint>()) {
			pnts[sense_agreement] = taxonomy::cast<taxonomy::point3>(map(i));
			has_pnts[sense_agreement] = true;
		} else if (i.as<IfcSchema::IfcParameterValue>()) {
			const double value = i.as<IfcSchema::IfcParameterValue>();
			flts[sense_agreement] = value * parameterFactor;
			has_flts[sense_agreement] = true;
		}
	}

	for (auto it = trims2.begin(); it != trims2.end(); it ++) {
		auto i = *it;
		if (i.as<IfcSchema::IfcCartesianPoint>()) {
			pnts[1 - sense_agreement] = taxonomy::cast<taxonomy::point3>(map(i));
			has_pnts[1-sense_agreement] = true;
		} else if (i.as<IfcSchema::IfcParameterValue>()) {
			const double value = i.as<IfcSchema::IfcParameterValue>();
			flts[1-sense_agreement] = value * parameterFactor;
			has_flts[1-sense_agreement] = true;
		}
	}

	const double tol = settings_.get<settings::Precision>().get();

	trim_cartesian &= has_pnts[0] && has_pnts[1];
	bool trim_cartesian_failed = !trim_cartesian;
	if (trim_cartesian) {
		if ((pnts[0]->ccomponents() - pnts[1]->ccomponents()).norm() < (2 * tol)) {
			logger_.Message(Logger::LOG_WARNING, "GEO", 295, "Skipping segment with length below tolerance level:", inst);
			return nullptr;
		}
		tc->start = pnts[0];
		tc->end = pnts[1];
	} else if (has_flts[0] && has_flts[1]) {
		// The Geom_Line is constructed from a gp_Pnt and gp_Dir, whereas the IfcLine
		// is defined by an IfcCartesianPoint and an IfcVector with Magnitude. Because
		// the vector is normalised when passed to Geom_Line constructor the magnitude
		// needs to be factored in with the IfcParameterValue here.
		if (auto lin = basis_curve.as<IfcSchema::IfcLine>()) {
			const double magnitude = lin.Dir().Magnitude();
			flts[0] *= magnitude; flts[1] *= magnitude;
		}
        if (auto ellipse = basis_curve.as<IfcSchema::IfcEllipse>()) {
			double x = ellipse.SemiAxis1() * length_unit_;
			double y = ellipse.SemiAxis2() * length_unit_;
			const bool rotated = y > x;
			// @todo do we apply this rotation here or in the kernel.
			if (rotated) {
				flts[0] -= pi / 2.;
				flts[1] -= pi / 2.;
			}
		}

		double radius = 1.0;
		if (auto typed_circle = taxonomy::dcast<taxonomy::circle>(tc->basis)) {
			radius = typed_circle->radius;
		} else if (auto typed_ellipse = taxonomy::dcast<taxonomy::ellipse>(tc->basis)) {
			radius = (typed_ellipse->radius + typed_ellipse->radius2) / 2.;
		}

		// Fix from @sanderboer to compare using model tolerance, see #744
		// Made dependent on radius, see #928

		// A good criterion for determining whether to take full curve
		// or trimmed segment would be whether there are other curve segments or this
		// is the only one.
		std::optional<size_t> num_segments;
		auto segment = inst.file()->get_inverse(inst.id(),  & IfcSchema::IfcCompositeCurveSegment::Class(), -1);
		if (segment.size() == 1) {
            auto comp = segment.front().file()->get_inverse(segment.front().id(), &IfcSchema::IfcCompositeCurve::Class(), -1);
			if (comp.size() == 1) {
				num_segments = comp.front().as<IfcSchema::IfcCompositeCurve>().Segments().size();
			}
		}

		// @todo is 100. not too much? Check with the original issue.
		const double precision_markup = settings_.get<settings::PrecisionFactor>().get() == 1. ? 1. : 100.;

		if (isConic && std::fabs(fmod(flts[1] - flts[0], pi * 2.)) < precision_markup * tol / (2 * pi * radius)) {
			flts[0] = 0.;
			flts[1] = 2 * pi;
		}

		tc->start = flts[0];
		tc->end = flts[1];

		/*
		// @todo
		if (num_segments && *num_segments > 1) {
			TopoDS_Vertex v0, v1;
			TopExp::Vertices(e, v0, v1);
			if (v0.IsSame(v1)) {
				logger::warning("Skipping degenerate segment", l);
				return false;
			}
		}
		*/
	}

	return tc;

	/*
	// @todo

	if (isConic) {
		// Tiny circle segnments can cause issues later on, for example
		// when the comp curve is used as the sweeping directrix.
		double a, b;
		Handle(Geom_Curve) crv = BRep_Tool::Curve(e, a, b);
		double radius = -1.;
		if (crv->DynamicType() == STANDARD_TYPE(Geom_Circle)) {
			radius = Handle(Geom_Circle)::DownCast(crv)->Radius();
		} else if (crv->DynamicType() == STANDARD_TYPE(Geom_Ellipse)) {
			// The formula in deflection_for_approximating_circle() is for circles, but probably good enough
			radius = Handle(Geom_Ellipse)::DownCast(crv)->MajorRadius();
		}
		if (radius > 0. && util::deflection_for_approximating_circle(radius, b - a) < 100 * getValue(GV_PRECISION) && std::abs(b-a) < M_PI/4.) {
			TopoDS_Vertex v0, v1;
			TopExp::Vertices(e, v0, v1);
			e = TopoDS::Edge(BRepBuilderAPI_MakeEdge(v0, v1).Edge().Oriented(e.Orientation()));
			logger::warning("Substituted edge with linear approximation", l);
		}
	}

	BRepBuilderAPI_MakeWire w;
	w.Add(e);

	if (w.IsDone()) {
		wire = w.Wire();

		// When SenseAgreement == .F. the vertices above have been reversed to
		// comply with the direction of conical curves. The ordering of the
		// vertices then still needs to be reversed in order to have begin and
		// end vertex consistent with IFC.
		if (sense_agreement != 0) { // .F.
			wire.Reverse();
		}

		return true;
	} else {
		return false;
	}
	*/
}