我自己写了一个判断两条多段线重叠的算法。希望大家给点意见或建议。

我自己写了一个判断两条多段线重叠的算法。希望大家给点意见或建议。

以下为源码：

// 判断两条多段线是否重叠//

// 返回值：-1——(pl1<pl2)

// 0——(pl1=pl2)

// 1——(pl1>pl2)

int PlineOverlap(AcDbPolyline* pl1, AcDbPolyline* pl2)

{

int rtn1(1), rtn2(1);

Acad::ErrorStatus es1, es2;

AcGePoint3d pt1, pt2;

double param1(0), param2(0);

int i,j;

// 先判断其中一条线的所有结点是否在另一条线上

for (i=0,j=1; j<pl1->numVerts(); i++,j++)

{

pl1->getPointAt(i, pt1);

pl1->getPointAt(j, pt2);

if (pl2->getParamAtPoint(pt1, param1)!=Acad::eOk

|| pl2->getParamAtPoint(pt2, param2)!=Acad::eOk)

{

es1 = Acad::ePointNotOnEntity;

break;

}

else

{ //再判断两条线的子段是否有交点

AcDbPolyline* pl2Sub = GetSplitPline(pl2, param1, param2);

if (HasInter(pt1, pt2, pl2Sub))

{

break;

}

rtn1 ++;

}

}

for (i=0,j=1; j<pl2->numVerts(); i++,j++)

{

pl2->getPointAt(i, pt1);

pl2->getPointAt(j, pt2);

if (pl1->getParamAtPoint(pt1, param1)!=Acad::eOk

|| pl1->getParamAtPoint(pt2, param2)!=Acad::eOk)

{

es2 = Acad::ePointNotOnEntity;

break;

}

else

{

AcDbPolyline* pl1Sub = GetSplitPline(pl1, param1, param2);

if (HasInter(pt1, pt2, pl1Sub))

{

break;

}

rtn2 ++;

}

}

if (rtn1==pl1->numVerts()

&& rtn2==pl2->numVerts())

{

return 0;

}

else if (rtn1==pl1->numVerts())

{

return -1;

}

else if (rtn2==pl2->numVerts())

{

return 1;

}

else

{

return (-99);

}

}

//判断线段与多段线是否有交点

BOOL HasInter(AcGePoint3d ptFrom, AcGePoint3d ptTo, AcDbPolyline* pl, BOOL bExtend=FALSE)

{

int i,j;

AcGePoint3d pt1, pt2;

for (i=0,j=1; j<pl->numVerts(); i++,j++)

{

pl->getPointAt(i, pt1);

pl->getPointAt(j, pt2);

ads_point inter;

int teston;

if (bExtend) teston=0;

else teston=1;

if (acdbInters(asDblArray(ptFrom), asDblArray(ptTo), asDblArray(pt1), asDblArray(pt2), teston, inter)==RTNORM)

{

return TRUE;

}

}

return FALSE;

}

//取中间段

AcDbPolyline* GetSplitPline(AcDbPolyline* pl, double param1, double param2)

{

AcGeDoubleArray params;

if (param1<param2)

{

params.append(param1);

params.append(param2);

}

else

{

params.append(param2);

params.append(param1);

}

AcDbVoidPtrArray segs;

if (pl->getSplitCurves(params, segs)==Acad::eOk)

{

if (segs.length()==1)

{

return static_cast<AcDbPolyline*>(segs.at(0));

}

else if (segs.length()==2)

{

if (params.at(0)==0)

{

return static_cast<AcDbPolyline*>(segs.at(0));

}

if (params.at(1)==(pl->numVerts()-1))

{

return static_cast<AcDbPolyline*>(segs.at(1));

}

}

else if (segs.length()==3)

{

return static_cast<AcDbPolyline*>(segs.at(1));

}

}

return pl;

}