OpenCaseCade标注显示类（独立）
比如我在OCC绘图区画一个点P，然后在点P附近显示部分标注说明，如下图：
上图在指定位置 显示了指示性文字描述，OCC实现过程，一个类实现此功能 ISession_Text 类，在OCC例子程序中可以找到，这里是把它单独分离出来，只依赖OCC标准库文件。
ISession_Text.h:
// ISession_Text.h: interface for the ISession_Text class.
//
//////////////////////////////////////////////////////////////////////
#if !defined(AFX_ISESSION_TEXT_H__A9B277C4_A69E_11D1_8DA4_0800369C8A03__INCLUDED_)
#define AFX_ISESSION_TEXT_H__A9B277C4_A69E_11D1_8DA4_0800369C8A03__INCLUDED_
#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
#include <Standard_Macro.hxx>
#include <Standard_DefineHandle.hxx>
#include <TCollection_AsciiString.hxx>
#include <Aspect_TypeOfText.hxx>
#include <Standard_Real.hxx>
#include <Standard_Integer.hxx>
#include <Quantity_Factor.hxx>
#include <Quantity_PlaneAngle.hxx>
#include <PrsMgr_PresentationManager3d.hxx>
#include <SelectMgr_Selection.hxx>
#include <Standard_OStream.hxx>
#include <Standard_IStream.hxx>
#include <Standard_CString.hxx>
#include <SelectMgr_SelectableObject.hxx>
//新增
#include "Prs3d_Text.hxx"
#include <AIS_Shape.hxx>
#include <V3d_Viewer.hxx>
class TCollection_AsciiString;
class SelectMgr_Selection;
DEFINE_STANDARD_HANDLE(ISession_Text,AIS_InteractiveObject)
class ISession_Text : public AIS_InteractiveObject
{
public:
ISession_Text();
ISession_Text (const TCollection_AsciiString& aText,
const Standard_Real anX = 0 ,
const Standard_Real anY = 0 ,
const Standard_Real aZ = 0 ,
const Aspect_TypeOfText aType = Aspect_TOT_SOLID,
const Quantity_PlaneAngle anAngle = 0.0 ,
const Standard_Real aSlant = 0.0 ,
const Standard_Integer aColorIndex = 1 ,
const Standard_Integer aFontIndex = 1 ,
const Quantity_Factor aScale = 0.1 );
ISession_Text
(const TCollection_AsciiString& aText,
gp_Pnt& aPoint,
const Aspect_TypeOfText aType = Aspect_TOT_SOLID,
const Quantity_PlaneAngle anAngle = 0.0 ,
const Standard_Real aSlant = 0.0 ,
const Standard_Integer aColorIndex = 1 ,
const Standard_Integer aFontIndex = 1 ,
const Quantity_Factor aScale = 0.1 );
virtual ~ISession_Text();
inline Standard_Integer NbPossibleSelection() const;
inline TCollection_AsciiString GetText() const;
inline void SetText(const TCollection_AsciiString& atext) ;
inline void GetCoord(Standard_Real& X, Standard_Real& Y, Standard_Real& Z) const ;
inline void SetCoord(const Standard_Real X, const Standard_Real Y, const Standard_Real Z=0);
inline Aspect_TypeOfText GetTypeOfText() const;
inline void SetTypeOfText(const Aspect_TypeOfText aNewTypeOfText) ;
inline Standard_Real GetAngle() const;
inline void SetAngle(const Standard_Real aNewAngle) ;
inline Standard_Real GetSlant() const;
inline void SetSlant(const Standard_Real aNewSlant) ;
inline Standard_Integer GetColorIndex() const;
inline void SetColorIndex(const Standard_Integer aNewColorIndex) ;
inline Standard_Integer GetFontIndex() const;
inline void SetFontIndex(const Standard_Integer aNewFontIndex) ;
inline Quantity_Factor GetScale() const;
inline void SetScale (const Quantity_Factor aNewScale) ;
DEFINE_STANDARD_RTTI(ISession_Text)
private:
void Compute (const Handle(PrsMgr_PresentationManager3d)& aPresentationManager,
const Handle(Prs3d_Presentation)& aPresentation,
const Standard_Integer aMode);
void Compute (const Handle(Prs3d_Projector)& aProjector,
const Handle(Prs3d_Presentation)& aPresentation);
void ComputeSelection (const Handle(SelectMgr_Selection)& aSelection,
const Standard_Integer unMode) ;
// Fields PRIVATE
//
TCollection_AsciiString MyText ;
Standard_Real MyX ;
Standard_Real MyY ;
Standard_Real MyZ ;
Aspect_TypeOfText MyTypeOfText ;
Standard_Real MyAngle ;
Standard_Real MySlant ;
Standard_Integer MyColorIndex ;
Standard_Integer MyFontIndex ;
Quantity_Factor MyScale ;
Standard_Real MyWidth ;
Standard_Real MyHeight ;
};
inline Standard_Integer ISession_Text::NbPossibleSelection() const
{ return 1; }
inline TCollection_AsciiString ISession_Text::GetText() const
{ return MyText ; }
inline void ISession_Text::SetText(const TCollection_AsciiString& atext)
{ MyText = atext; }
inline void ISession_Text::GetCoord(Standard_Real& X, Standard_Real& Y, Standard_Real& Z) const
{ X = MyX; Y = MyY; Z = MyZ;}
inline void ISession_Text::SetCoord(const Standard_Real X, const Standard_Real Y, const Standard_Real Z)
{ MyX = X ; MyY = Y ; MyZ = Z ;}
inline Aspect_TypeOfText ISession_Text::GetTypeOfText() const
{ return MyTypeOfText; }
inline void ISession_Text::SetTypeOfText(const Aspect_TypeOfText aNewTypeOfText)
{ MyTypeOfText = aNewTypeOfText; }
inline Standard_Real ISession_Text::GetAngle() const
{ return MyAngle; }
inline void ISession_Text::SetAngle(const Standard_Real aNewAngle)
{ MyAngle = aNewAngle; }
inline Standard_Real ISession_Text::GetSlant() const
{ return MySlant; }
inline void ISession_Text::SetSlant(const Standard_Real aNewSlant)
{ MySlant = aNewSlant; }
inline Standard_Integer ISession_Text::GetColorIndex() const
{ return MyColorIndex; }
inline void ISession_Text::SetColorIndex(const Standard_Integer aNewColorIndex)
{ MyColorIndex = aNewColorIndex; }
inline Standard_Integer ISession_Text::GetFontIndex() const
{ return MyFontIndex; }
inline void ISession_Text::SetFontIndex(const Standard_Integer aNewFontIndex)
{ MyFontIndex = aNewFontIndex; }
inline Quantity_Factor ISession_Text::GetScale() const
{ return MyScale; }
inline void ISession_Text::SetScale(const Quantity_Factor aNewScale)
{ MyScale = aNewScale; }
#endif // !defined(AFX_ISESSION_TEXT_H__A9B277C4_A69E_11D1_8DA4_0800369C8A03__INCLUDED_)
ISession_Text.cpp:
// ISession_Text.cpp: implementation of the ISession_Text class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "ISession_Text.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
//#define new DEBUG_NEW
#endif
IMPLEMENT_STANDARD_HANDLE(ISession_Text,AIS_InteractiveObject)
IMPLEMENT_STANDARD_RTTIEXT(ISession_Text,AIS_InteractiveObject)
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
ISession_Text::ISession_Text()
{
}
ISession_Text::ISession_Text
(const TCollection_AsciiString& aText,
const Standard_Real anX , // = 0
const Standard_Real anY , // = 0
const Standard_Real aZ , // = 0
const Aspect_TypeOfText aType, // = SOLID,
const Quantity_PlaneAngle anAngle, // = 0.0
const Standard_Real aslant, // = 0.0
const Standard_Integer aColorIndex, // = 0
const Standard_Integer aFontIndex, // = 1
const Quantity_Factor aScale) // = 1
:AIS_InteractiveObject(),MyText(aText),MyX(anX),MyY(anY),MyZ(aZ),
MyTypeOfText(aType),MyAngle(anAngle),MySlant(aslant),MyFontIndex(aFontIndex),
MyColorIndex(aColorIndex),MyScale(aScale),MyWidth(0),MyHeight(0)
{
}
ISession_Text::ISession_Text
(const TCollection_AsciiString& aText,
gp_Pnt& aPoint,
const Aspect_TypeOfText aType, // = SOLID,
const Quantity_PlaneAngle anAngle, // = 0.0
const Standard_Real aslant, // = 0.0
const Standard_Integer aColorIndex, // = 0
const Standard_Integer aFontIndex, // = 1
const Quantity_Factor aScale) // = 1
:AIS_InteractiveObject(),MyText(aText),MyX(aPoint.X()),MyY(aPoint.Y()),MyZ(aPoint.Z()),
MyTypeOfText(aType),MyAngle(anAngle),MySlant(aslant),MyFontIndex(aFontIndex),
MyColorIndex(aColorIndex),MyScale(aScale),MyWidth(0),MyHeight(0)
{
}
ISession_Text::~ISession_Text()
{
}
void ISession_Text::Compute(const Handle(PrsMgr_PresentationManager3d)& /*aPresentationManager*/,
const Handle(Prs3d_Presentation)& aPresentation,
const Standard_Integer /*aMode*/)
{
Prs3d_Text::Draw(aPresentation,myDrawer,MyText,gp_Pnt( MyX ,MyY,MyZ ));
}
void ISession_Text::Compute(const Handle(Prs3d_Projector)& /*aProjector*/,
const Handle(Prs3d_Presentation)& /*aPresentation*/)
{
}
void ISession_Text::ComputeSelection(const Handle(SelectMgr_Selection)& /*aSelection*/,
const Standard_Integer /*unMode*/)
{
}
简单使用例子：
void OccEditView::DrawPoint(const Standard_Real Xp, const Standard_Real Yp, const Standard_Real Zp)
{
gp_Pnt P(Xp,Yp,Zp);
Handle(AIS_Point) aPoint = new AIS_Point(new Geom_CartesianPoint(P));
myAISContext->SetColor(aPoint,Quantity_NOC_BLUE3);
myAISContext->Display(aPoint);
//在实例化类的时候输入需要显示的字符，目前不支持中文
Handle(ISession_Text) aGraphicText = new ISession_Text("This a Point!",P.X()+50.,P.Y()+10.,P.Z()+10.,);
myAISContext->Display(aGraphicText);
}
