[每日一码] ARX射线法判断点是否在多边形内
//*************************************************************//利用射线法判断一点是否在窗口内，如果在内部返回1，否则返回0
//其中输入参数pt是被判断点，boundarypt是辅助边界点，用于作射线用
//*********************1-14-2001 by Meishuli
int inwindow(ads采用point pt,ads采用point boundarypt,ads采用name windowent)
{
ads采用name ent0;
int rt;
AcDbEntity *pent,*pwindowent;
AcDbObjectId pentId,pwindowentId;
AcGePoint3dArray points;
int CrossPtsNum;
AcGePoint3d Pts,BoundaryPts;
AcDbObjectId auxlineId;
Acad::ErrorStatus es;
Pts.set(pt,pt,0);
BoundaryPts.set(boundarypt,boundarypt,0);
auxlineId=createLine(Pts,BoundaryPts);
acdbEntLast(ent0);
pwindowent=selectEntity(pwindowentId,windowent,AcDb::kForRead);
pent=selectEntity(pentId,ent0,AcDb::kForRead);
es=pwindowent->intersectWith(pent,AcDb::kOnBothOperands,points,0,0);
if (es == Acad::eOk) {
CrossPtsNum=points.length(); //计算交点的数量CrossPtsNum
points.setLogicalLength(0);
}
else {
acutPrintf("\nerror!--inwindow()\n");
pent->close();
acdbEntDel(ent0);
pwindowent->close();
return -1;
}
pent->close();
acdbEntDel(ent0);
pwindowent->close();
if(CrossPtsNum % 2 == 0)
rt = 0;
else rt = 1;
return rt;
}
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