objectarx 按比例分割面积

测试结果：这个是按0.1,0.1,0.1,0.3,0.4的比例划分的。

插件描述：这个插件主要是选择一个多段线poly，设置poly的close属性为true，在poly任意一侧画一条长线line（line画的时候不能与poly相交），找到line的垂直向量p'yXl，这个pyXl是要往与poly能相交的方向。在找到这个line与poly相切的时候。然后取每次平移的步进值bujin，因为这个poly的总面积有大有小，所以我是取总面积totaArea/2000在开方，如果这个bujin<=1,则直接取1，这样对于面积很大的poly也不需要平移很多次。然后就是利用acedTraceBoundary函数来获取平移后的
切线与poly形成的封闭多段线pl，求这个pl的面积是否大与按比例分割后的面积。

需要注意的地方：在使用acedTraceBoundary的时候，必须确认poly和平移的切线都是close掉的，不然无法求出pl。如果没有acedTraceBoundary函数，可以这样：

//ads_point pt = { seedPoint.x,seedPoint.y,seedPoint.z };
    //acedCommandS(RTSTR, L"-boundary", RTPOINT, pt, RTSTR, L"", RTNONE);
    //acdbEntLast(pent);
    ////acedRedraw(pent, 3);
    //AcDbObjectId eId;

    //acdbGetObjectId(eId, pent);

    //AcDbPolyline * pEnt = NULL;

    //ErrorStatus es = acdbOpenObject(pEnt, eId, AcDb::OpenMode::kForWrite);

来获得封闭的多段线，然后在求面积。

下面给出详细代码:
求pyXl：

AcGeVector3d CAreaFenGe::GetDirection()
{
    //l2pt和l1pt是在poly侧边画的线的端点
    AcGeVector3d lineDirc = l2Pt - l1Pt;
    AcGeVector3d lineDirc2 = l2Pt - l1Pt;

    AcGePoint3d centerPt((l2Pt.x + l1Pt.x) / 2, (l2Pt.y + l1Pt.y) / 2, 0);
    AcGePoint3d ptCloset;

    poly->getClosestPointTo(centerPt, ptCloset, false);

    AcDbLine *line1 = AcDbLine::cast(line->clone());
    AcDbLine *line2 = AcDbLine::cast(line->clone());
    double len = ptCloset.distanceTo(centerPt);

    AcGeVector3d pyXl1 = lineDirc.rotateBy(-1 * CMathUtil::PI() / 2, AcGeVector3d::kZAxis);
    AcGeVector3d pyXl2 = lineDirc2.rotateBy(CMathUtil::PI() / 2, AcGeVector3d::kZAxis);

    line1->transformBy(AcGeMatrix3d::translation(pyXl1.normal()*len*1.5));
    line2->transformBy(AcGeMatrix3d::translation(pyXl2.normal()*len*1.5));
    AcGePoint3dArray p3dArr1, p3dArr2;

    poly->intersectWith(line1, AcDb::Intersect::kExtendArg, p3dArr1, 0, 0);
    poly->intersectWith(line2, AcDb::Intersect::kExtendArg, p3dArr2, 0, 0);

    if (p3dArr1.length() > 0) {        
        pyXl = pyXl1;    
    }
    else if(p3dArr2.length()>0){        
        pyXl = pyXl2;
    }
    else {
        pyXl = AcGeVector3d(3, -1, 0);//这个可以注释掉
    }
    delete line1;
    line1 = NULL;
    delete line2;
    line2 = NULL;

    return pyXl;
}

获得切线:

//得到切线
AcGePoint3d CAreaFenGe::GetQieDian(AcDbLine * &line1)
{

    line1 = new AcDbLine(l1Pt, l2Pt);

    AcGePoint3dArray ptArr;

    while (ptArr.length() < 1) {

        poly->intersectWith(line1, AcDb::Intersect::kOnBothOperands, ptArr, 0, 0);

        line1->transformBy(AcGeMatrix3d::translation(pyXl.normal() * 1));

    }
    poly->close();

    if (ptArr.length() > 0)
        return ptArr[0];
    else
        return AcGePoint3d::kOrigin;

}

得到面积:

bool  CAreaFenGe::GetPyPolyline(AcGePoint3d seedPoint, double & a)
{

    AcDbVoidPtrArray ptrArr;
    ErrorStatus es = acedTraceBoundary(seedPoint, false, ptrArr);

    if (es != Acad::eOk) {
        acutPrintf(L"
boundary=%d", es);
        return false;
    }

    AcDbPolyline * pl = NULL;
    pl = (AcDbPolyline*)ptrArr[0];

    pl->setColorIndex(1);

    pl->getArea(a);

    pl->erase();
    pl->close();
    pl = NULL;
    return true;

}

主要步骤：

void CAreaFenGe::Command()
{

    ErrorStatus es;
    AcDbLine * lQieXian = NULL;
    AcGePoint3d ptQieDian = GetQieDian(lQieXian);

    acutPrintf(L"
ptQieDian=[%.2f,%.2f,%.2f]", ptQieDian.x, ptQieDian.y, ptQieDian.z);

    ptQieDian=ptQieDian.transformBy(AcGeMatrix3d::translation(pyXl.normal() * 5));
    acutPrintf(L"
ptQieDian2=[%.2f,%.2f,%.2f]", ptQieDian.x, ptQieDian.y, ptQieDian.z);

    if (ptQieDian.x == 0 && ptQieDian.y == 0) {
        return;
    }
    double bujin = sqrt(totalArea * 1 / 2000);

    if (bujin <= 1) {
        bujin = 1;
    }

    AcDbObjectId qxId;
    lQieXian->transformBy(AcGeMatrix3d::translation(pyXl.normal() * bujin*3));


    es = acdbOpenObject(poly, plId, AcDb::kForRead);

    AcGePoint3dArray ptJdArr;

    poly->intersectWith(lQieXian, AcDb::Intersect::kOnBothOperands, ptJdArr, 0, 0);


    if (ptJdArr.length() >= 2) {

        ptQieDian=AcGePoint3d((ptJdArr[0].x+ ptJdArr[1].x)/2, (ptJdArr[0].y + ptJdArr[1].y) / 2,0);

        ptQieDian= ptQieDian.transformBy(AcGeMatrix3d::translation(pyXl.normal() * -bujin*1.5));

    }
    poly->close();


    qxId = CDwgDataBaseUtil::PostToModelSpace(lQieXian);

    lQieXian->close();

    lQieXian = NULL;

    //AcDbPolyline * ptPy = new AcDbPolyline();

    //ptPy->setColorIndex(5);

    //AcDbObjectId ptId;

    AcGePoint3dArray ptJdArr2;


    for (int i = 0; i < (int)vecArea.size(); i++)
    {


        AcGePoint3d ptCopyQd = ptQieDian;

        double a = 0.0;
        
        while (a < vecArea[i]) {

            bool flag = GetPyPolyline(ptQieDian, a);

            if (!flag) {
                return;
            }
            es = acdbOpenObject(lQieXian, qxId, AcDb::kForWrite);
            lQieXian->transformBy(AcGeMatrix3d::translation(pyXl.normal() * bujin));

            ptJdArr2.removeAll();

            es = acdbOpenObject(poly, plId, AcDb::kForRead);
            poly->intersectWith(lQieXian, AcDb::Intersect::kExtendArg, ptJdArr2, 0, 0);

            poly->close();

            if (ptJdArr2.length() < 1) {

                lQieXian->close();
                break;
                
            }


            lQieXian->close();

        }

        acdbOpenObject(lQieXian, qxId, AcDb::kForWrite);

        es = acdbOpenObject(poly, plId, AcDb::kForRead);

         ptJdArr.removeAll();

        poly->intersectWith(lQieXian, AcDb::Intersect::kExtendArg, ptJdArr, 0, 0);

        AcGePoint3d preCenter;
        if (ptJdArr.length() >= 2) {

            AcDbLine* lFg = new AcDbLine(ptJdArr[0], ptJdArr[1]);

            preCenter = AcGePoint3d((ptJdArr[0].x + ptJdArr[1].x) / 2, (ptJdArr[0].y + ptJdArr[1].y) / 2, 0);
            lFg->setColorIndex(2);

            CDwgDataBaseUtil::PostToModelSpace(lFg);

            lFg->close();

        }
        else {

            poly->close();
            lQieXian->erase();
            lQieXian->close();
            lQieXian = NULL;
            //ptId = CDwgDataBaseUtil::PostToModelSpace(ptPy);
            return;

        }
    
        poly->close();

        AcDbPolyline *pCopyQx = (AcDbPolyline*)lQieXian->clone();

        pCopyQx->transformBy(AcGeMatrix3d::translation(pyXl.normal() *bujin));

        if (i != (int)vecArea.size() - 1) {


            es = acdbOpenObject(poly, plId, AcDb::kForRead);

            ptJdArr.removeAll();

            poly->intersectWith(pCopyQx, AcDb::Intersect::kExtendArg, ptJdArr, 0, 0);

            if (ptJdArr.length() >= 2) {
                ptQieDian = AcGePoint3d((ptJdArr[0].x + ptJdArr[1].x) / 2, (ptJdArr[0].y + ptJdArr[1].y) / 2, 0);

                ptQieDian = AcGePoint3d((preCenter.x + ptQieDian.x) / 2, (preCenter.y + ptQieDian.y) / 2, 0);

            }
            qxId = CDwgDataBaseUtil::PostToModelSpace(pCopyQx);

            pCopyQx->close();
            poly->close();
            pCopyQx = NULL;
        }
        lQieXian->erase();
        lQieXian->close();
        lQieXian = NULL;

        //当运行到最后一个面积时，就不复制了
        if (i == (int)vecArea.size() - 1) {

            delete pCopyQx;
            pCopyQx = NULL;

            break;
        }
    }

    /*if (ptId.isNull()) {
        ptId = CDwgDataBaseUtil::PostToModelSpace(ptPy);
        ptPy->close();
    }*/
}

构造函数：

CAreaFenGe::CAreaFenGe(ACHAR *fenGeStr, AcDbPolyline *&p, AcDbLine *&l)
{
    
    vector<CString> vec;

    CStringUtil::Split(W2T(fenGeStr), L",", vec, false);

    for (int i = 0; i < (int)vec.size(); i++)
    {
        vecFenGe.push_back(_wtof(vec.at(i)));
    }
    this->poly = p;
    this->line = l;

    l1Pt = l->startPoint();
    l2Pt = l->endPoint();

    if (poly->isClosed() == false) {
        poly->setClosed(true);
    }

    poly->getArea(totalArea);

    for (int i = 0; i < (int)vecFenGe.size(); i++)
    {
        vecArea.push_back(totalArea*vecFenGe.at(i));
        acutPrintf(L"%.2f", vecArea[i]);
    }
    GetDirection();
    plId = poly->objectId();
}