判断一个点是否在面域上（包括在面域的边上），都投影到XY平面上

admin1

bool isPointOnRegion(AcGePoint3d pt,AcDbObjectId regionId)
{
Acad::ErrorStatus es;

AcDbRegion* pRegion ;
es = acdbOpenObject( pRegion, regionId, AcDb::kForRead );
if( es ) return false;

//创建射线，根据射线与面域边线相交的点数为奇数就说明点在面域上的理论
AcDbRay* pRay = new AcDbRay ;
pRay->setBasePoint( pt );
pRay->setUnitDir( AcGeVector3d(1, 0, 0));

   AcGePlane  projPlane = AcGePlane(AcGePoint3d(0,0,0), AcGeVector3d(0,0,1));
AcGePoint3dArray ptArray;
es = pRegion->intersectWith( pRay, AcDb::kOnBothOperands,projPlane, ptArray,0,0 );//AcDb::kExtendArg
  pRegion->close();
  delete pRay;
  if(es )
{
  return false;
}

int iNum = ptArray.length();

if( (iNum%2 ) == 0 ) return false;
  

return true;
}