ObjectARX自定义实体

说明：此次绘制的CAD自定义实体是一个矩形，具有拉伸功能。因为初次接触自定义实体，在一次次制作的过程中遇到了很多困难，幸好有老大和同事的帮助，当然还有广大网友们的文章协助，才完成了这个自定义实体的绘制。我不敢说到目前还会有什么问题，但希望能帮助到别人。

一、需要重载的函数

//绘制夹点
    virtual Acad::ErrorStatus getGripPoints(AcDbGripDataPtrArray& grips, const double curViewUnitSize, const int gripSize, const AcGeVector3d& curViewDir, const int bitflags) const;
	//移动夹点
	virtual Acad::ErrorStatus moveGripPointsAt(const AcDbVoidPtrArray& gripAppData,const AcGeVector3d& offset,const int bitflags);
	//加载数据
	virtual Acad::ErrorStatus dwgInFields(AcDbDwgFiler* pFiler);
	//保存数据
	virtual Acad::ErrorStatus dwgOutFields(AcDbDwgFiler* pFiler) const;
	//矩阵转换
	virtual Acad::ErrorStatus transformBy(const AcGeMatrix3d& xform);
	//分解（炸开）
	virtual Acad::ErrorStatus explode(ZcDbVoidPtrArray& entitySet) const;
	//夹点状态
	virtual void gripStatus(const AcDb::GripStat status);
	//实体绘制
	virtual Adesk::Boolean worldDraw(AcGiWorldDraw* pWd);
	//捕捉点
	virtual Acad::ErrorStatus getOsnapPoints(AcDb::OsnapMode osnapMode, Adesk::GsMarker gsSelectionMark, const AcGePoint3d& pickPoint, const AcGePoint3d& lastPoint,
		const AcGeMatrix3d& viewXform, AcGePoint3dArray& snapPoints, AcDbIntArray & geomIds) const;
	//外包矩形
	virtual Acad::ErrorStatus getGeomExtents(AcDbExtents& extents) const;
	//删除
	virtual	Acad::ErrorStatus erase(Adesk::Boolean erasing = true);

二、成员变量

因为这个自定义实体是矩形，所以是由四个直线组成，且由三个夹点。

AcDbLine m_lineHori1;
	AcDbLine m_lineHori2;
	AcDbLine m_lineVert1;
	AcDbLine m_lineVert2;

	AcGePoint3d m_ptBase;		
	AcGePoint3d m_ptRight;	
	AcGePoint3d m_ptTop;

所以在写重载函数时，每个直线实体都要写一下。例如在worldDraw函数：

Adesk::Boolean CDiBanCsm::worldDraw(AcGiWorldDraw* pWd)
{
	assertReadEnabled();
	m_lineHori1.worldDraw(pWd);
	m_lineHori2.worldDraw(pWd);
	m_lineVert1.worldDraw(pWd);
	m_lineVert2.worldDraw(pWd);
	return Adesk::kTrue;
}

因为有夹点这个成员变量，所以，在dwgInFields函数、dwgOutFields函数、transformBy函数中也要将夹点添加进去：

Acad::ErrorStatus CDiBanCsm::dwgInFields(AcDbDwgFiler* pFiler)
{
	assertWriteEnabled();
	AcDbEntity::dwgInFields(pFiler);

	m_lineHori1.dwgInFields(pFiler);
	m_lineHori2.dwgInFields(pFiler);
	m_lineVert1.dwgInFields(pFiler);
	m_lineVert2.dwgInFields(pFiler);
	
	pFiler->readPoint3d(&m_ptBase);
	pFiler->readPoint3d(&m_ptRight);
	pFiler->readPoint3d(&m_ptTop);

	return pFiler->filerStatus();
}

三、夹点绘制

绘制夹点比较麻烦，如果你不是要绘制夹点的形状，可以重载

Acad::ErrorStatus getGripPoints(
    AcGePoint3dArray& gripPoints, 
    AcDbIntArray & osnapModes, 
    AcDbIntArray & geomIds
) const;

只需要在gripPoints参数中添加夹点坐标就可以，夹点为默认夹点。

这里，我们需要改变夹点的形状，所以这里我们需要绘制夹点。夹点用AcDbGripData类绘制，它是new出来的，所以我们需要将它delete。

我们需要重载gripStatus函数，在AcDb::kGripsDone状态下，将new的AcDbGripData指针delte。

我们要声明一个全局的map变量来存放AcDbGripData指针：

//键：自定义实体指针		值：AcDbGripData指针数组
static std::map<const AcDbEntity*, AcDbGripDataPtrArray> s_mapGripPtr;

直接上代码了：

Acad::ErrorStatus CDiBanCsm::getGripPoints(AcDbGripDataPtrArray& grips, const double curViewUnitSize, 
	const int gripSize, const AcGeVector3d& curViewDir, const int bitflags) const
{
	assertReadEnabled();
	std::vector<CString>::const_iterator appIter = GetGripName();//这里appIter是一个字符串容器，存放的是夹点名称
	AcDbGripDataPtrArray tempGripArr;

	//BasePt
	AcDbGripData* pGripBase = new AcDbGripData();
	pGripBase->setAppData((void*)&(*appIter));//将夹点名称设置到数据中
	pGripBase->setGripPoint(m_ptBase);//设置夹点坐标
	grips.append(pGripBase);
	tempGripArr.append(pGripBase);
	appIter++;

	//RightPt
	AcDbGripData* pGripRight = new AcDbGripData();
	pGripRight->setAppData((void*)&(*appIter));
	pGripRight->setGripPoint(m_ptRight);
	pGripRight->setWorldDraw(DrawStretchGrip);
	grips.append(pGripRight);
	tempGripArr.append(pGripRight);
	appIter++;

	//TopPt
	AcDbGripData* pGripTop = new AcDbGripData();
	pGripTop->setAppData((void*)&(*appIter));
	pGripTop->setGripPoint(m_ptTop);
	pGripTop->setWorldDraw(DrawStretchGrip);
	grips.append(pGripTop);
	tempGripArr.append(pGripTop);
	appIter++;

	auto a = this;
	CCustomBase::s_mapGripPtr[this] = tempGripArr;//将new出来的AcDbGripData指针添加到s_mapGripPtr变量中
	return Acad::eOk;
}

bool CDiBanCsm::DrawStretchGrip(AcDbGripData *pThis, AcGiWorldDraw *pWd, const AcDbObjectId& entId, AcDbGripOperations::DrawType type, AcGePoint3d *cursor, double dGripSize)
{
	dGripSize *= CCustomBase::s_gripSize / 2;//夹点的大小 CCustomBase::s_gripSize == 2.8
	AcGePoint3d	pt = pThis->gripPoint();
	CString* pStr = (CString*)(pThis->appData());
	AcGeVector3d vec = AcGeVector3d::kXAxis;
	AcDbObjectPointer<CDiBanCsm> m_pDiBan(entId, AcDb::kForRead);
	if (m_pDiBan.openStatus() != Acad::eOk)
		return false;

	if (*pStr == _T("RightPt"))
		vec = m_pDiBan->GetHoriDirection().normal();//得到实体的水平向量，这个接口自己写，通过直线的两点坐标
	else if (*pStr == _T("TopPt"))
		vec = m_pDiBan->GetVertDirection().normal();//得到实体的垂直向量

	auto vecUp = AcGeVector3d::kZAxis.crossProduct(vec).normal();
	AcGePoint3d pts[3];
	pts[0] = pt + vec * dGripSize;
	pts[1] = pt - vec * dGripSize / 2 + vecUp * dGripSize * .7;
	pts[2] = pt - vec * dGripSize / 2 - vecUp * dGripSize * .7;

	pWd->subEntityTraits().setFillType(kAcGiFillAlways);
	pWd->geometry().polygon(3, pts);

	return true;
}

在重载的gripStatus函数中delete夹点指针

void CDiBanCsm::gripStatus(const AcDb::GripStat status)
{
	AcDbEntity::gripStatus(status);

	switch (status)
	{
	case AcDb::kGripsDone:
		CCustomBase::DeleteGrip(this);
		break;
	case AcDb::kGripsToBeDeleted:
		
		break;
	case AcDb::kDimDataToBeDeleted:

		break;
	}
}

bool CCustomBase::DeleteGrip(const AcDbEntity* pEnt)
{
	std::map<const AcDbEntity*, AcDbGripDataPtrArray>::iterator iter;
	for (iter = s_mapGripPtr.begin(); iter != s_mapGripPtr.end(); iter++)
	{
		if (pEnt == iter->first)
		{
			AcDbGripDataPtrArray tempGripArr = iter->second;
			for (int i = 0; i < tempGripArr.length(); ++i)
			{
				DEL(tempGripArr[i]);//这里delete 指针
				tempGripArr[i] = NULL;
			}
		}
	}
	int n = CCustomBase::s_mapGripPtr.erase(pEnt);//如果删除了会返回1，否则返回0  
	return n;
}

移动夹点就比较简单了，重写moveGripPointsAt函数就可以了

Acad::ErrorStatus CDiBanCsm::moveGripPointsAt(const AcDbVoidPtrArray& gripAppData,const AcGeVector3d& offset,
const int bitflags)
{
	assertWriteEnabled();
	CString* pStrTemp = NULL;
	for (int i = 0; i < gripAppData.length(); i++)
	{
		pStrTemp = static_cast<CString*>(gripAppData[i]);
		if (*pStrTemp == _T("BasePt"))//通过点的名称，判断移动的是哪个夹点
		{
			//这里我是通过偏移向量，来移动直线的两点位置
			SetLinePoint(m_lineHori1, 3, offset);
			SetLinePoint(m_lineHori2, 3, offset);
			SetLinePoint(m_lineVert1, 3, offset);
			SetLinePoint(m_lineVert2, 3, offset);
			m_ptBase = GetBaseGripPt();//重新定义夹点的位置
			m_ptRight = GetRightGripPt();
			m_ptTop = GetTopGripPt();
		}
		else if (*pStrTemp == _T("RightPt"))
		{
			AcGePoint3d ptStart = m_lineHori2.startPoint();
			AcGePoint3d ptEnd = m_lineHori2.endPoint();
			AcGeVector3d vctHori = ptEnd - ptStart;
			AcGeVector3d vctOffset = GetProjectVector(m_ptBase, offset, vctHori);
			SetLinePoint(m_lineHori1,2,vctOffset);
			SetLinePoint(m_lineHori2, 2, vctOffset);
			SetLinePoint(m_lineVert2, 3, vctOffset);
			m_ptBase = GetBaseGripPt();
			m_ptRight = GetRightGripPt();
			m_ptTop = GetTopGripPt();
		}
		else if (*pStrTemp == _T("TopPt"))
		{
			AcGePoint3d ptStart = m_lineVert1.startPoint();
			AcGePoint3d ptEnd = m_lineVert1.endPoint();
			AcGeVector3d vctHori = ptEnd - ptStart;
			AcGeVector3d vctOffset = GetProjectVector(m_ptBase, offset, vctHori);
			SetLinePoint(m_lineVert1, 2, vctOffset);
			SetLinePoint(m_lineVert2, 2, vctOffset);
			SetLinePoint(m_lineHori1, 3, vctOffset);
			m_ptBase = GetBaseGripPt();
			m_ptRight = GetRightGripPt();
			m_ptTop = GetTopGripPt();
		}
	}
	return Acad::eOk;
}

AcGeVector3d CCustomBase::GetProjectVector(const AcGePoint3d& ptBase, const AcGeVector3d& vctOffset, const AcGeVector3d& vctDirection)
{//得到某一向量在指定向量上的投影向量
	AcGePoint3d ptOffset = ptBase + vctOffset;
	AcGeLine3d geLine(ptBase, vctDirection);
	AcGePoint3d ptTarget = geLine.closestPointTo(ptOffset);
	return ptTarget - ptBase;
}

四、实体分解

需要重写explode函数，这里有两个知识要说，一个是如果自定义实体可以分解，需要添加克隆的直线指针

Acad::ErrorStatus CDiBanCsm::explode(ZcDbVoidPtrArray& entitySet) const
{
	assertReadEnabled();
 	entitySet.append(m_lineHori1.clone());
 	entitySet.append(m_lineHori2.clone());
 	entitySet.append(m_lineVert1.clone());
 	entitySet.append(m_lineVert2.clone());
	return Acad::eOk;
}

如果你想让自定义实体不能分解，返回值返回：Acad::eCannotExplodeEntity即可。

五、总结

其实原本的代码比这个多很多，这里我只是截取了重要部分展示。这是目前绘制的自定义实体，某些地方还需要改进。

ObjectARX自定义实体

一、需要重载的函数

二、成员变量

三、夹点绘制

四、实体分解

五、总结

继续阅读

ObjextArx初试：选择一条直线

acad.exe启动参数

2.4、在ObjectARX中创建对象

ObjectARX文档设置和ObjectARX标准程序

ObjectARX编程环境概述

3.1、创建一个ObjectARX应用程序

ObjectARX编程环境

ObjectArx获取角度angle、angleTo

ObjectARX中扩展记录和扩展字典

ObjectArx:插入光栅图像

在ObjectARX中使用MFC-标签式对话框

[ObjectARX]创建一个浏览器(iterator),遍历符号表记录

四、二维线实体类（AcGeLinearEnt2d）

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