AcDbHelix Demo

 AcDbObjectPointer<AcDbHelix> aHelix;
 aHelix.create();
 aHelix->setAxisPoint(AcGePoint3d(, , ));
 aHelix->setAxisVector(AcGeVector3d(, , ));
 aHelix->setStartPoint(AcGePoint3d(, , ));
 aHelix->setBaseRadius();
 aHelix->setTopRadius();
 aHelix->setTwist(Adesk::kTrue);

 // case
 aHelix->setConstrain(AcDbHelix::kTurnHeight);
 aHelix->setTurnHeight();
 aHelix->setHeight(); // Turns = Height / TurnHeight

 // case
 aHelix->setConstrain(AcDbHelix::kTurnHeight);
 aHelix->setTurnHeight();
 aHelix->setTurns(); // Height = TurnHeight * Turns

 // case
 aHelix->setConstrain(AcDbHelix::kTurns);
 aHelix->setTurns();
 aHelix->setHeight(); // TurnHeight = Height / Turns

 aHelix->setConstrain(AcDbHelix::kTurns);
 aHelix->setTurns();
 aHelix->setTurnHeight(); // Height = TurnHeight * Turns

 // case
 aHelix->setConstrain(AcDbHelix::kHeight);
 aHelix->setHeight();
 aHelix->setTurns(); // TurnHeight = Height / Turns

 // case
 aHelix->setConstrain(AcDbHelix::kHeight);
 aHelix->setHeight();
 aHelix->setTurnHeight(); // Turns = Height / TurnHeight

 aHelix->createHelix();

 acutPrintf(_T("StartPoint:%lf,%lf,%lf\n"),
     aHelix->startPoint()[], aHelix->startPoint()[], aHelix->startPoint()[]); // 0, 20, 10
 acutPrintf(_T("slope:%lf total length:%lf\n"),
     aHelix->turnSlope(), aHelix->totalLength());

 AcDbObjectPointer<AcDbLine> xAxis;
 AcDbObjectPointer<AcDbLine> yAxis;
 AcDbObjectPointer<AcDbLine> zAxis;
 xAxis.create();
 yAxis.create();
 zAxis.create();
 AcCmColor color;
 color.setRGB(, , );
 xAxis->setColor(color);
 color.setRGB(, , );
 yAxis->setColor(color);
 color.setRGB(, , );
 zAxis->setColor(color);
 xAxis->setStartPoint(AcGePoint3d::kOrigin + AcGeVector3d(, , ));
 yAxis->setStartPoint(AcGePoint3d::kOrigin + AcGeVector3d(, , ));
 zAxis->setStartPoint(AcGePoint3d::kOrigin + AcGeVector3d(, , ));
 xAxis->setEndPoint(xAxis->startPoint() + AcGeVector3d(, , ));
 yAxis->setEndPoint(yAxis->startPoint() + AcGeVector3d(, , ));
 zAxis->setEndPoint(zAxis->startPoint() + AcGeVector3d(, , ));