Open CASCADE学习|分割曲线

1、通过参数进行分割

分别获得曲线的 FirstParameter 和 LastParameter ，然后对参数进行分割，获得n个ui，并对每个ui调用D0（获得这个点的坐标值）或D1（获得这个点的坐标值和切向量）。这个方法的优点是，简单易行，好操作，缺点均分参数轴获得的曲线的分割可能不是均匀的。

#include <Geom_CylindricalSurface.hxx>
#include <gp_Ax3.hxx>
#include <GeomAPI_Interpolate.hxx>
#include <BRepAdaptor_Curve.hxx>
#include <BRepBuilderAPI_MakeEdge.hxx>
#include <Geom2d_TrimmedCurve.hxx>
#include <GCE2d_MakeSegment.hxx>
​
#include <GeomAPI_PointsToBSpline.hxx>
#include <BRepBuilderAPI_MakeFace.hxx>
#include <GC_MakeCircle.hxx>
#include <BRepBuilderAPI_MakeWire.hxx>
#include <BRepOffsetAPI_MakePipe.hxx>
#include <GC_MakeArcOfCircle.hxx>
#include <BRepAlgoAPI_Fuse.hxx>
​
#include <gp_GTrsf.hxx>
#include <BRepBuilderAPI_Transform.hxx>
​
#include"Viewer.h"
​
​
#include <BRepBuilderAPI_MakeVertex.hxx>
#include <BRepBuilderAPI_GTransform.hxx>
​
​
int main(int argc, char* argv[])
{gp_Dir  Z(0.0, 0.0, 1.0);gp_Pnt center(0, 0, 0.0);gp_Pnt xr(0.5, 0, 0.0);gp_Pnt yr(0.0, 1.0, 0.0);gp_Pnt zr(0.0, 0.0, 7.0);gp_Ax2  wb(center, Z);gp_Circ  wbcircle(wb, 0.125 / 2);TopoDS_Edge wbe = BRepBuilderAPI_MakeEdge(wbcircle);TopoDS_Edge xline = BRepBuilderAPI_MakeEdge(center, xr);TopoDS_Edge yline = BRepBuilderAPI_MakeEdge(center, yr);TopoDS_Edge zline = BRepBuilderAPI_MakeEdge(center, zr);gp_Pnt p1(-5, 0, 0.0);gp_Pnt p2(5, 0, 0.0);gp_Ax2  sr(center, Z);gp_Circ  bcircle(sr, 5);Handle(Geom_TrimmedCurve) bc = GC_MakeArcOfCircle(bcircle, p1, p2, 0);TopoDS_Edge anEdge = BRepBuilderAPI_MakeEdge(bc);Standard_Integer splitN = 10;Standard_Real firstParam = bc->FirstParameter();Standard_Real lastParam = bc->LastParameter();Viewer vout(50, 50, 500, 500);for (Standard_Integer i = 0; i < splitN + 1; ++i){Standard_Real ui = i * (lastParam - firstParam) / splitN;gp_Pnt pi;gp_Vec veci;bc->D1(ui, pi, veci);TopoDS_Vertex verti = BRepBuilderAPI_MakeVertex(pi);vout << verti;}vout << anEdge;vout << xline;vout << yline;vout << zline;vout.StartMessageLoop();return 0;
}
​

2、直接对曲线分割

通过类 GCPnts_UniformAbscissa 实现对一个Geom_Curve对象的平均分割，获得分割点的坐标及对应的参数，将坐标和参数存入一个列表中，供其他操作使用。

#include <Geom_CylindricalSurface.hxx>
#include <gp_Ax3.hxx>
#include <GeomAPI_Interpolate.hxx>
#include <BRepAdaptor_Curve.hxx>
#include <BRepBuilderAPI_MakeEdge.hxx>
#include <Geom2d_TrimmedCurve.hxx>
#include <GCE2d_MakeSegment.hxx>
​
#include <GeomAPI_PointsToBSpline.hxx>
#include <BRepBuilderAPI_MakeFace.hxx>
#include <GC_MakeCircle.hxx>
#include <BRepBuilderAPI_MakeWire.hxx>
#include <BRepOffsetAPI_MakePipe.hxx>
#include <GC_MakeArcOfCircle.hxx>
#include <BRepAlgoAPI_Fuse.hxx>
​
#include <gp_GTrsf.hxx>
#include <BRepBuilderAPI_Transform.hxx>
​
#include"Viewer.h"
​
​
#include <BRepBuilderAPI_MakeVertex.hxx>
#include <GCPnts_UniformAbscissa.hxx>
​
​
int main(int argc, char* argv[])
{gp_Dir  Z(0.0, 0.0, 1.0);gp_Pnt center(0, 0, 0.0);gp_Pnt xr(0.5, 0, 0.0);gp_Pnt yr(0.0, 1.0, 0.0);gp_Pnt zr(0.0, 0.0, 7.0);gp_Ax2  wb(center, Z);gp_Circ  wbcircle(wb, 0.125 / 2);TopoDS_Edge wbe = BRepBuilderAPI_MakeEdge(wbcircle);TopoDS_Edge xline = BRepBuilderAPI_MakeEdge(center, xr);TopoDS_Edge yline = BRepBuilderAPI_MakeEdge(center, yr);TopoDS_Edge zline = BRepBuilderAPI_MakeEdge(center, zr);gp_Pnt p1(-5, 0, 0.0);gp_Pnt p2(5, 0, 0.0);gp_Ax2  sr(center, Z);gp_Circ  bcircle(sr, 5);Handle(Geom_TrimmedCurve) bc = GC_MakeArcOfCircle(bcircle, p1, p2, 0);TopoDS_Edge anEdge = BRepBuilderAPI_MakeEdge(bc);Standard_Integer splitN = 10;GeomAdaptor_Curve GAC(bc);GCPnts_UniformAbscissa UA(GAC, splitN + 1);gp_Pnt* pnts = new gp_Pnt[splitN + 1];Standard_Real* params = new Standard_Real[splitN + 1];Viewer vout(50, 50, 500, 500);if (UA.IsDone()){Standard_Real n = UA.NbPoints();Standard_Integer index = 0;for (; index < n + 1; index++){Standard_Real parami = UA.Parameter(index + 1);params[index] = parami;gp_Pnt tpnt;bc->D0(parami, tpnt);pnts[index] = tpnt;TopoDS_Vertex verti = BRepBuilderAPI_MakeVertex(tpnt);vout << verti;}}vout << anEdge;vout << xline;vout << yline;vout << zline;vout.StartMessageLoop();return 0;
}
​