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/***************************************************************************
* Copyright (c) 2024 WandererFan <wandererfan@gmail.com> *
* *
* This file is part of the FreeCAD CAx development system. *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Library General Public *
* License as published by the Free Software Foundation; either *
* version 2 of the License, or (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Library General Public License for more details. *
* *
* You should have received a copy of the GNU Library General Public *
* License along with this library; see the file COPYING.LIB. If not, *
* write to the Free Software Foundation, Inc., 59 Temple Place, *
* Suite 330, Boston, MA 02111-1307, USA *
* *
***************************************************************************/
//! a class to assist with exporting sketches to dxf
#include <HLRBRep_Algo.hxx>
#include <HLRAlgo_Projector.hxx>
#include <HLRBRep_HLRToShape.hxx>
#include <BRep_Builder.hxx>
#include <BRepBuilderAPI_Transform.hxx>
#include <App/DocumentObject.h>
#include <Base/Placement.h>
#include <Base/Vector3D.h>
#include <Mod/Part/App/PartFeature.h>
#include "SketchExportHelper.h"
using namespace Import;
//! project a shape so that it is represented as a flat shape on the XY plane. Z coordinate
//! information is lost in this process, so it should only be used for flat objects like sketches.
//! Note: this only returns hard and outline edges. Seam, smooth, isoparametric and hidden lines
//! are not returned.
TopoDS_Shape SketchExportHelper::projectShape(const TopoDS_Shape& inShape, const gp_Ax2& projectionCS)
{
Handle(HLRBRep_Algo) brep_hlr = new HLRBRep_Algo();
brep_hlr->Add(inShape);
HLRAlgo_Projector projector(projectionCS);
brep_hlr->Projector(projector);
brep_hlr->Update();
brep_hlr->Hide();
HLRBRep_HLRToShape hlrToShape(brep_hlr);
BRep_Builder builder;
TopoDS_Compound comp;
builder.MakeCompound(comp);
if (!hlrToShape.VCompound().IsNull()) {
builder.Add(comp, hlrToShape.VCompound());
}
if (!hlrToShape.OutLineVCompound().IsNull()) {
builder.Add(comp, hlrToShape.OutLineVCompound());
}
return comp;
}
//! true if obj is a sketch
bool SketchExportHelper::isSketch(App::DocumentObject* obj)
{
// Use name to lookup to avoid dependency on Sketcher module
return obj->isDerivedFrom(Base::Type::fromName("Sketcher::SketchObject"));
}
//! return a version of a sketch's geometry mapped to the OXYZ coordinate system
//! preferred by dxf
TopoDS_Shape SketchExportHelper::getFlatSketchXY(App::DocumentObject* obj)
{
// since we can't reference Sketcher module here, we will cast obj to
// a Part::Feature instead
auto sketch = dynamic_cast<Part::Feature*>(obj);
if (!sketch || !isSketch(obj)) {
return {};
}
auto plm = sketch->Placement.getValue();
Base::Rotation rot = plm.getRotation();
// get the sketch normal
Base::Vector3d stdZ {0.0, 0.0, 1.0};
Base::Vector3d sketchNormal;
rot.multVec(stdZ, sketchNormal);
Base::Vector3d stdX {1.0, 0.0, 0.0};
Base::Vector3d sketchX;
rot.multVec(stdX, sketchX);
// get the sketch origin
Base::Vector3d position = plm.getPosition();
gp_Ax2 projectionCS(
gp_Pnt(position.x, position.y, position.z),
gp_Dir(sketchNormal.x, sketchNormal.y, sketchNormal.z),
gp_Dir(sketchX.x, sketchX.y, sketchX.z)
);
const TopoDS_Shape& shape = sketch->Shape.getValue();
return projectShape(shape, projectionCS);
}
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