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occt/src/BRepPrimAPI/BRepPrimAPI_MakeHalfSpace.cxx

267 lines
9.0 KiB
C++

// Created on: 1995-03-08
// Created by: Bruno DUMORTIER
// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// 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 <BRep_Builder.hxx>
#include <BRep_Tool.hxx>
#include <BRepBuilderAPI_MakeVertex.hxx>
#include <BRepExtrema_DistShapeShape.hxx>
#include <BRepLProp_SLProps.hxx>
#include <BRepPrimAPI_MakeHalfSpace.hxx>
#include <gp.hxx>
#include <gp_Dir.hxx>
#include <gp_Pnt.hxx>
#include <StdFail_NotDone.hxx>
#include <TopExp_Explorer.hxx>
#include <TopoDS.hxx>
#include <TopoDS_Face.hxx>
#include <TopoDS_Shell.hxx>
#include <TopoDS_Solid.hxx>
#include <TopoDS_Vertex.hxx>
//=======================================================================
//function : getNormalOnFace
//purpose :
//=======================================================================
static gp_Dir getNormalOnFace(const TopoDS_Face& theFace,
const Standard_Real theU,
const Standard_Real theV)
{
Standard_Real aPrec = gp::Resolution();
BRepLProp_SLProps aProps(BRepAdaptor_Surface(theFace), theU, theV, 2, aPrec);
gp_Dir aNormal = aProps.Normal();
if (theFace.Orientation() == TopAbs_REVERSED)
aNormal.Reverse();
return aNormal;
}
//=======================================================================
//function : getNormalFromEdge
//purpose : Get average normal at the point with the given parameter on the edge
//=======================================================================
static Standard_Boolean getNormalFromEdge(const TopoDS_Shape& theShape,
const TopoDS_Edge& theEdge,
const Standard_Real thePar,
gp_Dir& theNormal)
{
gp_XYZ aSum;
TopExp_Explorer ex(theShape, TopAbs_FACE);
for (; ex.More(); ex.Next()) {
const TopoDS_Face& aF = TopoDS::Face(ex.Current());
TopExp_Explorer ex1(aF, TopAbs_EDGE);
for (; ex1.More(); ex1.Next()) {
if (ex1.Current().IsSame(theEdge)) {
Standard_Real f, l;
Handle(Geom2d_Curve) aC2d = BRep_Tool::CurveOnSurface(theEdge, aF, f, l);
gp_Pnt2d aP2d = aC2d->Value(thePar);
gp_Dir aNorm = getNormalOnFace(aF, aP2d.X(), aP2d.Y());
aSum += aNorm.XYZ();
}
}
}
if (aSum.SquareModulus() > gp::Resolution()) {
theNormal = aSum;
return Standard_True;
}
return Standard_False;
}
//=======================================================================
//function : getNormalFromVertex
//purpose : Get average normal at the point of the vertex
//=======================================================================
static Standard_Boolean getNormalFromVertex(const TopoDS_Shape& theShape,
const TopoDS_Vertex& theVer,
gp_Dir& theNormal)
{
gp_XYZ aSum;
TopExp_Explorer ex(theShape, TopAbs_FACE);
for (; ex.More(); ex.Next()) {
const TopoDS_Face& aF = TopoDS::Face(ex.Current());
TopExp_Explorer ex1(aF, TopAbs_VERTEX);
for (; ex1.More(); ex1.Next()) {
if (ex1.Current().IsSame(theVer)) {
gp_Pnt2d aP2d = BRep_Tool::Parameters(theVer, aF);
gp_Dir aNorm = getNormalOnFace(aF, aP2d.X(), aP2d.Y());
aSum += aNorm.XYZ();
}
}
}
if (aSum.SquareModulus() > gp::Resolution()) {
theNormal = aSum;
return Standard_True;
}
return Standard_False;
}
//=======================================================================
//function : FindExtrema
//purpose : This finction is called to find the nearest normal projection
// of a point <aPnt> on a shape <aShape>.
// 1) return true if extrema is found.
// 2) Set in:
// - theMinPnt : The solution point
// - theNormal : The normal direction to the shape at projection point
//=======================================================================
static Standard_Boolean FindExtrema(const gp_Pnt& thePnt,
const TopoDS_Shape& theShape,
gp_Pnt& theMinPnt,
gp_Dir& theNormal)
{
TopoDS_Vertex aRefVertex = BRepBuilderAPI_MakeVertex(thePnt);
BRepExtrema_DistShapeShape ext(aRefVertex, theShape);
if (!ext.IsDone() || ext.NbSolution() == 0)
return Standard_False;
// the point projection exist
Standard_Integer nbext = ext.NbSolution();
// try to find a projection on face
for (Standard_Integer iext = 1; iext <= nbext; iext++) {
if (ext.SupportTypeShape2(iext) == BRepExtrema_IsInFace) {
TopoDS_Face aF = TopoDS::Face(ext.SupportOnShape2(iext));
theMinPnt = ext.PointOnShape2(iext);
Standard_Real aU, aV;
ext.ParOnFaceS2(iext, aU, aV);
theNormal = getNormalOnFace(aF, aU, aV);
return Standard_True;
}
}
// if not found then take any edge or vertex solution
for (Standard_Integer iext = 1; iext <= nbext; iext++) {
if (ext.SupportTypeShape2(iext) == BRepExtrema_IsOnEdge) {
theMinPnt = ext.PointOnShape2(iext);
Standard_Real aPar;
ext.ParOnEdgeS2(iext, aPar);
TopoDS_Edge aE = TopoDS::Edge(ext.SupportOnShape2(iext));
if (getNormalFromEdge(theShape, aE, aPar, theNormal))
return Standard_True;
}
else if (ext.SupportTypeShape2(iext) == BRepExtrema_IsVertex) {
theMinPnt = ext.PointOnShape2(iext);
TopoDS_Vertex aV = TopoDS::Vertex(ext.SupportOnShape2(iext));
if (getNormalFromVertex(theShape, aV, theNormal))
return Standard_True;
}
}
return Standard_False;
}
//=======================================================================
//function : isOutside
//purpose :
//=======================================================================
static Standard_Boolean isOutside(const gp_Pnt& thePnt,
const gp_Pnt& thePonF,
const gp_Dir& theNormal)
{
gp_Dir anOppRef(thePnt.XYZ() - thePonF.XYZ());
Standard_Real aSca = theNormal * anOppRef;
// outside if same directions
return aSca > 0.;
}
//=======================================================================
//function : BRepPrimAPI_MakeHalfSpace
//purpose :
//=======================================================================
BRepPrimAPI_MakeHalfSpace::BRepPrimAPI_MakeHalfSpace(const TopoDS_Face& theFace,
const gp_Pnt& theRefPnt)
{
// Set the flag is <IsDone> to False.
NotDone();
TopoDS_Shell aShell;
gp_Pnt aMinPnt;
gp_Dir aNormal;
if (FindExtrema(theRefPnt, theFace, aMinPnt, aNormal)) {
Standard_Boolean toReverse = isOutside(theRefPnt, aMinPnt, aNormal);
// Construction of the open solid.
BRep_Builder().MakeShell(aShell);
BRep_Builder().Add(aShell, theFace);
BRep_Builder().MakeSolid(mySolid);
if (toReverse) {
aShell.Reverse();
}
BRep_Builder().Add(mySolid, aShell);
myShape = mySolid;
Done();
}
}
//=======================================================================
//function : BRepPrimAPI_MakeHalfSpace
//purpose :
//=======================================================================
BRepPrimAPI_MakeHalfSpace::BRepPrimAPI_MakeHalfSpace(const TopoDS_Shell& theShell,
const gp_Pnt& theRefPnt)
{
// Set the flag is <IsDone> to False.
NotDone();
// Find the point of the skin closest to the reference point.
gp_Pnt aMinPnt;
gp_Dir aNormal;
if (FindExtrema(theRefPnt, theShell, aMinPnt, aNormal)) {
Standard_Boolean toReverse = isOutside(theRefPnt, aMinPnt, aNormal);
// Construction of the open solid.
TopoDS_Shell aShell = theShell;
BRep_Builder().MakeSolid(mySolid);
if (toReverse) {
aShell.Reverse();
}
BRep_Builder().Add(mySolid, aShell);
myShape = mySolid;
Done();
}
}
//=======================================================================
//function : Solid
//purpose :
//=======================================================================
const TopoDS_Solid& BRepPrimAPI_MakeHalfSpace::Solid() const
{
StdFail_NotDone_Raise_if( !IsDone(), "BRepPrimAPI_MakeHalfSpace::Solid");
return mySolid;
}
//=======================================================================
//function : TopoDS_Solid
//purpose :
//=======================================================================
BRepPrimAPI_MakeHalfSpace::operator TopoDS_Solid() const
{
return Solid();
}