OCCT

// Created on: 2016-04-07
// Copyright (c) 2016 OPEN CASCADE SAS
// Created by: Oleg AGASHIN
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#include <IMeshTools_ShapeExplorer.hxx>
#include <TopExp.hxx>
#include <TopExp_Explorer.hxx>
#include <TopoDS_Face.hxx>
#include <TopoDS_Shape.hxx>
#include <NCollection_List.hxx>
#include <BRepLib.hxx>
#include <BRep_Tool.hxx>
#include <TopTools_ShapeMapHasher.hxx>
#include <NCollection_Map.hxx>

IMPLEMENT_STANDARD_RTTIEXT(IMeshTools_ShapeExplorer, IMeshData_Shape)

namespace
{
//=======================================================================
// Function: visitEdges
// Purpose : Explodes the given shape on edges according to the specified
//           criteria and visits each one in order to add it to data model.
//=======================================================================
void visitEdges(const occ::handle<IMeshTools_ShapeVisitor>& theVisitor,
                const TopoDS_Shape&                         theShape,
                const bool                                  isResetLocation,
                const TopAbs_ShapeEnum                      theToFind,
                const TopAbs_ShapeEnum                      theToAvoid = TopAbs_SHAPE)
{
  TopExp_Explorer aEdgesIt(theShape, theToFind, theToAvoid);
  for (; aEdgesIt.More(); aEdgesIt.Next())
  {
    const TopoDS_Edge& aEdge = TopoDS::Edge(aEdgesIt.Current());
    if (!BRep_Tool::IsGeometric(aEdge))
    {
      continue;
    }

    theVisitor->Visit(isResetLocation ? TopoDS::Edge(aEdge.Located(TopLoc_Location())) : aEdge);
  }
}
} // namespace

//=================================================================================================

IMeshTools_ShapeExplorer::IMeshTools_ShapeExplorer(const TopoDS_Shape& theShape)
    : IMeshData_Shape(theShape)
{
}

//=================================================================================================

IMeshTools_ShapeExplorer::~IMeshTools_ShapeExplorer() = default;

//=================================================================================================

void IMeshTools_ShapeExplorer::Accept(const occ::handle<IMeshTools_ShapeVisitor>& theVisitor)
{
  // Explore all free edges in shape.
  visitEdges(theVisitor, GetShape(), true, TopAbs_EDGE, TopAbs_FACE);

  // Explore all related to some face edges in shape.
  // make array of faces suitable for processing (excluding faces without surface)
  NCollection_List<TopoDS_Shape> aFaceList;
  BRepLib::ReverseSortFaces(GetShape(), aFaceList);
  NCollection_Map<TopoDS_Shape, TopTools_ShapeMapHasher> aFaceMap;

  const TopLoc_Location                    aEmptyLoc;
  NCollection_List<TopoDS_Shape>::Iterator aFaceIter(aFaceList);
  for (; aFaceIter.More(); aFaceIter.Next())
  {
    TopoDS_Shape aFaceNoLoc = aFaceIter.Value();
    aFaceNoLoc.Location(aEmptyLoc);
    if (!aFaceMap.Add(aFaceNoLoc))
    {
      continue; // already processed
    }

    const TopoDS_Face& aFace = TopoDS::Face(aFaceIter.Value());
    if (!BRep_Tool::IsGeometric(aFace))
    {
      continue;
    }

    // Explore all edges in face.
    visitEdges(theVisitor, aFace, false, TopAbs_EDGE);

    // Store only forward faces in order to prevent inverse issue.
    theVisitor->Visit(TopoDS::Face(aFace.Oriented(TopAbs_FORWARD)));
  }
}