[求助]：如何填充由一大一小两个同心圆组成的圆环?

rackyye

如题,我想把圆环部分填充起来,但Arx里的AcDbHatch好像只能填充有相交的两实体组成的闭合区域,求该填充的实现方法.最好能贴个代码上来!

binbin

源自帮助



The following example shows how to acquire an associative hatch entity on the WCS XY plane. The hatch boundary consists of an external rectangular loop with an internal circular hole. The hatch pattern is the ANSI31 predefined type with current AutoCAD default color. The newly created hatch is associative, in which you can change the source boundary geometry to update the hatch pattern.

Acad::ErrorStatus acqHatch2()
{
    AcDbHatch* pHatch = new AcDbHatch();

    // Set hatch plane
    //
    AcGeVector3d normal(0.0, 0.0, 1.0);
    pHatch->setNormal(normal);
    pHatch->setElevation(0.0);

    // Set hatch pattern to ANSI31 predefined type
    //
    pHatch->setHatchPattern(AcDbHatch::kPreDefined, "ANSI31");

    // Set Associativity
    //
    pHatch->setAssociative(Adesk::kTrue);

    // Construct database AcDbLines
    //
    AcGePoint2d vertexPts[4];
    AcDbObjectId lineId, cirId, hatchId;
    AcDbObjectIdArray dbObjIds;
    AcDbLine *line;

    vertexPts[0].set(2.0, 2.0, 0.0);
    vertexPts[1].set(8.0, 2.0, 0.0);
    vertexPts[2].set(8.0, 8.0, 0.0);
    vertexPts[3].set(2.0, 8.0, 0.0);

    for (int i = 0; i < 4; i++) {
        line =  new AcDbLine();
        line->setStartPoint(vertexPts)
        line->setEndPoint(vertexPts[(i == 3) ? 0 : i+1])
        line->postToDb(line, lineId);
        dbObjIds.append(lineId);
    }

    // Append an external rectangular loop to hatch boundary
    //
    pHatch->appendLoop(AcDbHatch::kExternal, dbObjIds);

    // Create a AcDbCircle and post it to database
    //
    AcGePoint2d cenPt(5.0, 5.0, 0.0);
    AcGeVector3d normal(0.0, 0.0, 1.0);
    AcDbCircle *circle = new AcDbCircle();
    circle->setNormal(normal);
    circle->setCenter(cenPt);
    circle->setRadius(1.0);
    circle->postToDb(circle, cirId);
    dbObjIds.setLogicalLength(0);
    dbObjIds.append(cirId);  

    // Append an internal loop (circle) to hatch boundary
    //
    pHatch->appendLoop(AcDbHatch::kDefault, dbObjIds);

    // Elaborate hatch lines
    //
    pHatch->evaluateHatch();

    // Get all associative source boundary object Ids for later use.
    //
    dbObjIds.setLogicalLength(0);
    pHatch->getAssocObjIds(dbObjIds);

    // Post hatch entity to database
    //
    pHatch->postToDb(pHatch, hatchId);

    // Attach hatchId to all source boundary objects for notification.
    //
    AcDbEntity *pEnt;
    int numObjs = dbObjIds.length();
    Acad::ErrorStatus es;
    for (i = 0; i < numObjs; i++) {
        es = acdbOpenAcDbEntity(pEnt, dbObjIds, AcDb::kForWrite);
        if (es == Acad::eOk) {
            pEnt->addPersistentReactor(hatchId);
            pEnt->close();
        }
    }
    return eOk;
}

rackyye

谢谢 binbin ，问题已解决