ObjectARX自定义实体的最近点和垂点捕捉算法

 最近点用pickPoint来计算,垂点用lastPoint计算.

一般AcDbCurve类可以用AcGe类的 getClosestPointTo 来实现计算需要的点值.

下面是代码示例: 

case AcDb::kOsModeNear:        {            AcGeLine3d line3d(m_ptA,m_ptC);                     AcGePointOnCurve3d tmpPt;            line3d.getClosestPointTo(pickPoint,tmpPt);            AcGePoint3d pt=tmpPt.point();                       snapPoints.append(AcGePoint3d(pt));            line3d.set(m_ptB,m_ptD);            line3d.getClosestPointTo(pickPoint,tmpPt);            pt=tmpPt.point();            snapPoints.append(AcGePoint3d(pt));        }        break;     case AcDb::kOsModePerp:        {            AcGeLine3d line3d(m_ptA,m_ptC);                     AcGePointOnCurve3d tmpPt;            line3d.getClosestPointTo(lastPoint,tmpPt);            AcGePoint3d pt=tmpPt.point();              snapPoints.append(AcGePoint3d(pt));            line3d.set(m_ptB,m_ptD);            line3d.getClosestPointTo(lastPoint,tmpPt);            pt=tmpPt.point();            snapPoints.append(AcGePoint3d(pt));        }        break;