Objectarx 相交矩形求并集 面域转多段线

测试结果：

主要思路：拾取一个点作为矩形的插入点，分别以该点进行两次jig操作，就能得到白色的两个相交的polyline，之后需要变成红色的封闭多段线。做法就是：求出两个白色矩形的面域，然后通过bool操作的并集，使得两个面域合并成一个面域。最后就把这个面域在转换成polyline就完成了。其中要注意， 要想在使用向导创建的工程里使用面域的类，需要在头文件：StdAfx.h 中写上这句宏命令#define _BREP_SUPPORT_，就不需要引用库文件了。下面给出详细代码：

拖动矩形的jig操作：

DrawRecJig::DrawRecJig()
{
    pl = NULL;
}

DrawRecJig::~DrawRecJig()
{
}

AcEdJig::DragStatus DrawRecJig::sampler()
{
    setUserInputControls((AcEdJig::UserInputControls)(

        AcEdJig::kAccept3dCoordinates |
        AcEdJig::kNoNegativeResponseAccepted |
        AcEdJig::kNullResponseAccepted
        ));
    AcGePoint3d ptTemp;

    AcEdJig::DragStatus status = acquirePoint(ptTemp);

    if (ptTemp != ptCurrent) {

        ptCurrent= ptTemp;

    }
    else if (status == DragStatus::kNormal) {

        return AcEdJig::kNoChange;
    }
    return status;
}

bool DrawRecJig::update()
{
    double dist = CConvertUtil::ToPoint2d(ptCenter).distanceTo(CConvertUtil::ToPoint2d(ptCurrent));
    // 提取两个角点的坐标值
    double x1 = ptCenter.x, x2 = ptCurrent.x;
    double y1 = ptCenter.y, y2 = ptCurrent.y;

    // 计算矩形的角点
    AcGePoint2d ptLeftBottom(min(x1, x2), min(y1, y2));
    AcGePoint2d ptRightBottom(max(x1, x2), min(y1, y2));
    AcGePoint2d ptRightTop(max(x1, x2), max(y1, y2));
    AcGePoint2d ptLeftTop(min(x1, x2), max(y1, y2));

    pl->setPointAt(0, ptLeftBottom);
    pl->setPointAt(1, ptLeftTop);
    pl->setPointAt(2, ptRightTop);
    pl->setPointAt(3, ptRightBottom);

    return true;
}

AcDbEntity * DrawRecJig::entity() const
{
    return pl;
}

bool DrawRecJig::DoIt(AcGePoint3d & ptCenter, AcDbObjectId &plId)
{
    
    this->ptCenter = ptCenter;

    pl = new AcDbPolyline();

    for (int i = 0; i < 4; i++)
    {
        pl->addVertexAt(i, CConvertUtil::ToPoint2d(ptCenter));
    }
    pl->setClosed(true);

    setDispPrompt(L"请拖动鼠标：");

    if (drag()==kNormal) {

        //加入到模型空间的封装
        plId=CDwgDataBaseUtil::PostToModelSpace(pl);

        return true;
    }
    else {
        delete pl;
        return false;

    }

}

命令类：

static void ECDMyGroupEUnion() {

        DrawRecJig recJig = DrawRecJig();

        ads_point  pt;

        AcDbPolyline *pl1 = NULL, *pl2 = NULL;


        if (acedGetPoint(NULL, L"
请选择插入点：", pt) == RTNORM) {

            AcDbObjectId  oId1, oId2;

            if (recJig.DoIt(asPnt3d(pt), oId1)) {

                pl1 = AcDbPolyline::cast(recJig.entity());
            }

            if (recJig.DoIt(asPnt3d(pt), oId2)) {

                pl2 = AcDbPolyline::cast(recJig.entity());
            }
            
            AcDbVoidPtrArray curveSegments;
            AcDbVoidPtrArray regions;

            curveSegments.append(pl1);
            curveSegments.append(pl2);

            if (AcDbRegion::createFromCurves(curveSegments, regions) == Acad::eOk) {

                AcDbRegion *region =(AcDbRegion *)regions[0];

                region->booleanOper(AcDb::BoolOperType::kBoolUnite, (AcDbRegion *)regions[1]);            

                AcGePoint3dArray ptArr;

                CRegionUtil::GetRegionPoints(region, ptArr);

                for (int i = 0; i < regions.length (); i++)
                {
                    AcDbRegion *regionTemp = (AcDbRegion *)regions[i];

                    regionTemp->erase();

                    regionTemp->close();

                }

                region->close();

                AcDbPolyline *plTemp1 = new AcDbPolyline();

                for (int i = 0; i <ptArr.length(); i++)
                {

                    plTemp1->addVertexAt(plTemp1->numVerts(), CConvertUtil::ToPoint2d(ptArr.at(i)), 0, 0, 0);
                }

                plTemp1->setClosed(Adesk::kTrue);

                plTemp1->setColorIndex(1);

                CDwgDataBaseUtil::PostToModelSpace(plTemp1);

                plTemp1->close();

            }
            pl1->close();
            pl2->close();
        }
    }

面域转AcGePoint3d：

void CRegionUtil::GetRegionPoints(AcDbRegion* pRegion,AcGePoint3dArray &points)

{    
    AcBrBrep*pBrep = new AcBrBrep;

    pBrep->set(*pRegion);

    AcBrBrepFaceTraverser brFaTrav;

    for (brFaTrav.setBrep(*pBrep); !brFaTrav.done(); brFaTrav.next())

    {

        AcBrFaceLoopTraverser faLoTrav;

        AcBrFace face;

        brFaTrav.getFace(face);

        for (faLoTrav.setFace(face); !faLoTrav.done(); faLoTrav.next())

        {

            AcBrLoopEdgeTraverser loEdTrav;

            if (loEdTrav.setLoop(faLoTrav) == AcBr::eOk)

            {

                for (; !loEdTrav.done(); loEdTrav.next())

                {

                    AcBrEdge edge;

                    loEdTrav.getEdge(edge);

                    AcBrVertex start;

                    edge.getVertex1(start);

                    AcGePoint3d pt;

                    start.getPoint(pt);

                    points.append(pt);

                }

            } // else its an isolated loop    

        }

    }

    delete pBrep;

}