liboce-visualization-dev 0.15-5 / usr / include / oce / OpenGl_GraphicDriver.hxx

// Created on: 2011-10-20
// Created by: Sergey ZERCHANINOV
// Copyright (c) 2011-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and / or modify it
// under the terms of the GNU Lesser General Public version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _OpenGl_GraphicDriver_HeaderFile
#define _OpenGl_GraphicDriver_HeaderFile

#include <Graphic3d_GraphicDriver.hxx>
#include <Handle_OpenGl_GraphicDriver.hxx>
#include <Handle_OpenGl_View.hxx>
#include <Handle_OpenGl_Workspace.hxx>
#include <Handle_OpenGl_Display.hxx>
#include <OpenGl_Context.hxx>
#include <OpenGl_PrinterContext.hxx>

#include <Standard_CString.hxx>

#include <Handle_TColStd_HArray1OfByte.hxx>
#include <Handle_TColStd_HArray1OfReal.hxx>
#include <Quantity_PlaneAngle.hxx>
#include <Quantity_NameOfColor.hxx>
#include <Handle_OpenGl_View.hxx>
#include <Handle_OpenGl_Workspace.hxx>

#include <Aspect_Display.hxx>
#include <Aspect_DisplayConnection.hxx>
#include <Aspect_GradientFillMethod.hxx>
#include <Aspect_FillMethod.hxx>
#include <Aspect_CLayer2d.hxx>
#include <Aspect_TypeOfTriedronPosition.hxx>
#include <Aspect_TypeOfTriedronEcho.hxx>
#include <Aspect_Handle.hxx>
#include <Aspect_PrintAlgo.hxx>
#include <gp_Ax2.hxx>
#include <Graphic3d_CView.hxx>
#include <Graphic3d_CStructure.hxx>
#include <Graphic3d_CGroup.hxx>
#include <Graphic3d_TypeOfPrimitive.hxx>
#include <Graphic3d_CPick.hxx>
#include <Graphic3d_TextPath.hxx>
#include <Graphic3d_HorizontalTextAlignment.hxx>
#include <Graphic3d_VerticalTextAlignment.hxx>
#include <Graphic3d_PrimitiveArray.hxx>
#include <Graphic3d_CUserDraw.hxx>
#include <Graphic3d_CGraduatedTrihedron.hxx>
#include <Graphic3d_TypeOfComposition.hxx>
#include <Graphic3d_ExportFormat.hxx>
#include <Graphic3d_SortType.hxx>
#include <Graphic3d_PtrFrameBuffer.hxx>
#include <Graphic3d_Array1OfVertex.hxx>
#include <Graphic3d_Array2OfVertex.hxx>
#include <Graphic3d_BufferType.hxx>
#include <NCollection_DataMap.hxx>

class TColStd_Array1OfInteger;
class TColStd_Array1OfReal;
class TColStd_Array2OfReal;
class TColStd_HArray1OfByte;
class Graphic3d_Vector;
class Quantity_Color;
class Graphic3d_Vertex;
class Aspect_Array1OfEdge;
class TCollection_ExtendedString;
class Image_PixMap;
class TColStd_HArray1OfReal;
class Handle(OpenGl_Workspace);
class OpenGl_Element;
class OpenGl_Structure;
class OpenGl_Text;

//! Tool class to implement consistent state counter
//! for objects inside the same driver instance.
class OpenGl_StateCounter
{
public:

  OpenGl_StateCounter() : myCounter (0) { }

  Standard_Size Increment() { return ++myCounter; }

private:
  
  Standard_Size myCounter;
};

//! This class defines an OpenGl graphic driver <br>
class OpenGl_GraphicDriver : public Graphic3d_GraphicDriver
{
public:

  //! Constructor
  Standard_EXPORT OpenGl_GraphicDriver (const Handle(Aspect_DisplayConnection)& theDisplayConnection);

  //! Constructor
  Standard_EXPORT OpenGl_GraphicDriver (const Standard_CString theShrName = "TKOpenGl");
  Standard_EXPORT Standard_Boolean Begin (const Handle(Aspect_DisplayConnection)& theDisplayConnection);
  Standard_EXPORT void End ();

  Standard_EXPORT Standard_Integer InquireLightLimit ();
  Standard_EXPORT void InquireMat (const Graphic3d_CView& ACView, TColStd_Array2OfReal& AMatO, TColStd_Array2OfReal& AMatM);
  Standard_EXPORT Standard_Integer InquireViewLimit ();
  Standard_EXPORT void Blink (const Graphic3d_CStructure& ACStructure,const Standard_Boolean Create);
  Standard_EXPORT void BoundaryBox (const Graphic3d_CStructure& ACStructure, const Standard_Boolean Create);
  Standard_EXPORT void HighlightColor (const Graphic3d_CStructure& ACStructure, const Standard_ShortReal R, const Standard_ShortReal G, const Standard_ShortReal B, const Standard_Boolean Create);
  Standard_EXPORT void NameSetStructure (const Graphic3d_CStructure& ACStructure);

public: // Methods for graphical groups

  Standard_EXPORT void ClearGroup (const Graphic3d_CGroup& ACGroup);
  Standard_EXPORT void FaceContextGroup (const Graphic3d_CGroup& theCGroup,
                                         const Standard_Integer  theNoInsert);
  Standard_EXPORT void Group (Graphic3d_CGroup& theCGroup);
  Standard_EXPORT void LineContextGroup (const Graphic3d_CGroup& theCGroup,
                                         const Standard_Integer  theNoInsert);
  Standard_EXPORT void MarkerContextGroup (const Graphic3d_CGroup& theCGroup,
                                           const Standard_Integer  theNoInsert);
  Standard_EXPORT void RemoveGroup (const Graphic3d_CGroup& theCGroup);
  Standard_EXPORT void TextContextGroup (const Graphic3d_CGroup& theCGroup,
                                         const Standard_Integer  theNoInsert);

public: // Methods for graphical structures

  Standard_EXPORT void ClearStructure (const Graphic3d_CStructure& theCStructure);
  Standard_EXPORT void ContextStructure (const Graphic3d_CStructure& theCStructure);
  Standard_EXPORT void Connect (const Graphic3d_CStructure& theFather,
                                const Graphic3d_CStructure& theSon);
  Standard_EXPORT void Disconnect (const Graphic3d_CStructure& theFather,
                                   const Graphic3d_CStructure& theSon);
  Standard_EXPORT void DisplayStructure (const Graphic3d_CView&      theCView,
                                         const Graphic3d_CStructure& theCStructure,
                                         const Standard_Integer      thePriority);
  Standard_EXPORT void EraseStructure (const Graphic3d_CView&      theCView,
                                       const Graphic3d_CStructure& theCStructure);
  Standard_EXPORT void RemoveStructure (const Graphic3d_CStructure& theCStructure);
  Standard_EXPORT void Structure (Graphic3d_CStructure& theCStructure);

public:

  Standard_EXPORT void ActivateView (const Graphic3d_CView& ACView);
  Standard_EXPORT void AntiAliasing (const Graphic3d_CView& ACView, const Standard_Boolean AFlag);
  Standard_EXPORT void Background (const Graphic3d_CView& ACView);
  Standard_EXPORT void GradientBackground (const Graphic3d_CView& ACView, const Quantity_Color& AColor1, const Quantity_Color& AColor2, const Aspect_GradientFillMethod FillStyle);
  Standard_EXPORT void BackgroundImage (const Standard_CString FileName, const Graphic3d_CView& ACView, const Aspect_FillMethod FillStyle);
  Standard_EXPORT void SetBgImageStyle (const Graphic3d_CView& ACView, const Aspect_FillMethod FillStyle);
  Standard_EXPORT void SetBgGradientStyle (const Graphic3d_CView& ACView, const Aspect_GradientFillMethod FillStyle);
  Standard_EXPORT void ClipLimit (const Graphic3d_CView& ACView, const Standard_Boolean AWait);
  Standard_EXPORT void DeactivateView (const Graphic3d_CView& ACView);
  Standard_EXPORT void DepthCueing (const Graphic3d_CView& ACView, const Standard_Boolean AFlag);
  Standard_EXPORT Standard_Boolean ProjectRaster (const Graphic3d_CView& ACView, const Standard_ShortReal AX, const Standard_ShortReal AY, const Standard_ShortReal AZ, Standard_Integer& AU, Standard_Integer& AV);
  Standard_EXPORT Standard_Boolean UnProjectRaster (const Graphic3d_CView& ACView, const Standard_Integer Axm, const Standard_Integer Aym, const Standard_Integer AXM, const Standard_Integer AYM, const Standard_Integer AU, const Standard_Integer AV, Standard_ShortReal& AX, Standard_ShortReal& AY, Standard_ShortReal& AZ);
  Standard_EXPORT Standard_Boolean UnProjectRasterWithRay (const Graphic3d_CView& ACView, const Standard_Integer Axm, const Standard_Integer Aym, const Standard_Integer AXM, const Standard_Integer AYM, const Standard_Integer AU, const Standard_Integer AV, Standard_ShortReal& AX, Standard_ShortReal& AY, Standard_ShortReal& AZ, Standard_ShortReal& DX, Standard_ShortReal& DY, Standard_ShortReal& DZ);
  Standard_EXPORT void RatioWindow (const Graphic3d_CView& ACView);
  Standard_EXPORT void Redraw (const Graphic3d_CView& ACView, const Aspect_CLayer2d& ACUnderLayer, const Aspect_CLayer2d& ACOverLayer, const Standard_Integer x = 0, const Standard_Integer y = 0, const Standard_Integer width = 0, const Standard_Integer height = 0);
  Standard_EXPORT void RemoveView (const Graphic3d_CView& ACView);
  Standard_EXPORT void SetLight (const Graphic3d_CView& ACView);
  Standard_EXPORT void SetClipPlanes (const Graphic3d_CView& theCView);
  Standard_EXPORT void SetClipPlanes (const Graphic3d_CStructure& theCStructure);
  Standard_EXPORT void SetVisualisation (const Graphic3d_CView& ACView);
  Standard_EXPORT void TransformStructure (const Graphic3d_CStructure& ACStructure);
  Standard_EXPORT void Transparency (const Graphic3d_CView& ACView, const Standard_Boolean AFlag);
  Standard_EXPORT void Update (const Graphic3d_CView& ACView, const Aspect_CLayer2d& ACUnderLayer, const Aspect_CLayer2d& ACOverLayer);
  Standard_EXPORT Standard_Boolean View (Graphic3d_CView& ACView);
  Standard_EXPORT void ViewMapping (const Graphic3d_CView& ACView, const Standard_Boolean AWait);
  Standard_EXPORT void ViewOrientation (const Graphic3d_CView& ACView,const Standard_Boolean AWait);
  Standard_EXPORT void Environment (const Graphic3d_CView& ACView);
  Standard_EXPORT void SetStencilTestOptions (const Graphic3d_CGroup& theCGroup, const Standard_Boolean theIsEnabled);
  Standard_EXPORT void Text (const Graphic3d_CGroup& ACGroup, const Standard_CString AText, const Graphic3d_Vertex& APoint, const Standard_Real AHeight, const Quantity_PlaneAngle AAngle, const Graphic3d_TextPath ATp, const Graphic3d_HorizontalTextAlignment AHta, const Graphic3d_VerticalTextAlignment AVta, const Standard_Boolean EvalMinMax = Standard_True);
  Standard_EXPORT void Text (const Graphic3d_CGroup& ACGroup, const Standard_CString AText, const Graphic3d_Vertex& APoint, const Standard_Real AHeight, const Standard_Boolean EvalMinMax = Standard_True);
  Standard_EXPORT void Text (const Graphic3d_CGroup& ACGroup, const TCollection_ExtendedString& AText, const Graphic3d_Vertex& APoint, const Standard_Real AHeight, const Quantity_PlaneAngle AAngle, const Graphic3d_TextPath ATp, const Graphic3d_HorizontalTextAlignment AHta, const Graphic3d_VerticalTextAlignment AVta, const Standard_Boolean EvalMinMax = Standard_True);
  Standard_EXPORT void Text (const Graphic3d_CGroup& ACGroup, const TCollection_ExtendedString& AText, const Graphic3d_Vertex& APoint, const Standard_Real AHeight, const Standard_Boolean EvalMinMax = Standard_True);
  Standard_EXPORT void PrimitiveArray (const Graphic3d_CGroup& ACGroup,const Graphic3d_PrimitiveArray& parray,const Standard_Boolean EvalMinMax = Standard_True);
  Standard_EXPORT void UserDraw (const Graphic3d_CGroup& ACGroup,const Graphic3d_CUserDraw& AUserDraw);
  Standard_EXPORT void ZBufferTriedronSetup (const Quantity_NameOfColor XColor = Quantity_NOC_RED, const Quantity_NameOfColor YColor = Quantity_NOC_GREEN, const Quantity_NameOfColor ZColor = Quantity_NOC_BLUE1, const Standard_Real SizeRatio = 0.8, const Standard_Real AxisDiametr = 0.05, const Standard_Integer NbFacettes = 12);
  Standard_EXPORT void TriedronDisplay (const Graphic3d_CView& ACView, const Aspect_TypeOfTriedronPosition APosition = Aspect_TOTP_CENTER, const Quantity_NameOfColor AColor = Quantity_NOC_WHITE, const Standard_Real AScale = 0.02, const Standard_Boolean AsWireframe = Standard_True);
  Standard_EXPORT void TriedronErase (const Graphic3d_CView& ACView);
  Standard_EXPORT void TriedronEcho (const Graphic3d_CView& ACView, const Aspect_TypeOfTriedronEcho AType = Aspect_TOTE_NONE);
  Standard_EXPORT void GraduatedTrihedronDisplay (const Graphic3d_CView& view, const Graphic3d_CGraduatedTrihedron& cubic);
  Standard_EXPORT void GraduatedTrihedronErase (const Graphic3d_CView& view);
  Standard_EXPORT void GraduatedTrihedronMinMaxValues (const Standard_ShortReal xmin, const Standard_ShortReal ymin, const Standard_ShortReal zmin, const Standard_ShortReal xmax, const Standard_ShortReal ymax, const Standard_ShortReal zmax);
  Standard_EXPORT Standard_Boolean SetImmediateModeDrawToFront (const Graphic3d_CView& theCView,
                                                                const Standard_Boolean theDrawToFrontBuffer);
  Standard_EXPORT Standard_Boolean BeginAddMode (const Graphic3d_CView& ACView);
  Standard_EXPORT void EndAddMode ();
  Standard_EXPORT Standard_Boolean BeginImmediatMode(const Graphic3d_CView& ACView, const Aspect_CLayer2d& ACUnderLayer, const Aspect_CLayer2d& ACOverLayer, const Standard_Boolean DoubleBuffer, const Standard_Boolean RetainMode);
  Standard_EXPORT void ClearImmediatMode (const Graphic3d_CView& ACView,const Standard_Boolean aFlush = Standard_True);
  Standard_EXPORT void DrawStructure (const Graphic3d_CStructure& ACStructure);
  Standard_EXPORT void EndImmediatMode (const Standard_Integer Synchronize);
  Standard_EXPORT void Layer (Aspect_CLayer2d& ACLayer);
  Standard_EXPORT void RemoveLayer (const Aspect_CLayer2d& ACLayer);
  Standard_EXPORT void BeginLayer (const Aspect_CLayer2d& ACLayer);
  Standard_EXPORT void BeginPolygon2d ();
  Standard_EXPORT void BeginPolyline2d ();
  Standard_EXPORT void ClearLayer (const Aspect_CLayer2d& ACLayer);
  Standard_EXPORT void Draw (const Standard_ShortReal X,const Standard_ShortReal Y);
  Standard_EXPORT void Edge (const Standard_ShortReal X,const Standard_ShortReal Y);
  Standard_EXPORT void EndLayer ();
  Standard_EXPORT void EndPolygon2d ();
  Standard_EXPORT void EndPolyline2d ();
  Standard_EXPORT void Move (const Standard_ShortReal X,const Standard_ShortReal Y);
  Standard_EXPORT void Rectangle (const Standard_ShortReal X,const Standard_ShortReal Y,const Standard_ShortReal Width,const Standard_ShortReal Height);
  Standard_EXPORT void SetColor (const Standard_ShortReal R,const Standard_ShortReal G,const Standard_ShortReal B);
  Standard_EXPORT void SetTransparency (const Standard_ShortReal ATransparency);
  Standard_EXPORT void UnsetTransparency ();
  Standard_EXPORT void SetLineAttributes (const Standard_Integer Type,const Standard_ShortReal Width);
  Standard_EXPORT void SetFlippingOptions (const Graphic3d_CGroup& theCGroup, const Standard_Boolean theIsEnabled, const gp_Ax2& theRefPlane);

  //! Set text attributes for under-/overlayer. <br>
  //! <Font> argument defines the name of the font to be used, <br>
  //! <Type> argument defines the display type of the text, <br>
  //! <R> <G> <B> values define the color of decal or subtitle background. <br>
  //! To set the color of the text you can use the SetColor method. <br>
  Standard_EXPORT void SetTextAttributes (const Standard_CString FontName,const Standard_Integer Type,const Standard_ShortReal R,const Standard_ShortReal G,const Standard_ShortReal B);
  Standard_EXPORT void Text (const Standard_CString AText,const Standard_ShortReal X,const Standard_ShortReal Y,const Standard_ShortReal AHeight);
  Standard_EXPORT void TextSize (const Standard_CString AText,const Standard_ShortReal AHeight,Standard_ShortReal& AWidth,Standard_ShortReal& AnAscent,Standard_ShortReal& ADescent) const;
  Standard_EXPORT void SetBackFacingModel (const Graphic3d_CView& aView);
  //! print the contents of all layers of the view to the printer. <br>
  //! <hPrnDC> : Pass the PrinterDeviceContext (HDC), <br>
  //! <showBackground> : When set to FALSE then print the view without background color <br>
  //! (background is white) <br>
  //! else set to TRUE for printing with current background color. <br>
  //! <filename>: If != NULL, then the view will be printed to a file. <br>
  //! <printAlgorithm>: Select print algorithm: stretch, tile. <br>
  //! <theScaleFactor>: Scaling coefficient, used internally to scale the <br>
  //! printings accordingly to the scale factor selected in the printer <br>
  //! properties dialog. <br>
  //! Returns Standard_True if the data is passed to the printer, otherwise <br>
  //! Standard_False if the print operation failed due to the printer errors, <br>
  //! or lack of system memory. This might be related to insufficient memory <br>
  //! or some internal errors. All this errors are indicated by the message <br>
  //! boxes (on level of OpenGl_GraphicDriver). <br>
  //! Warning: This function can reuse FBO assigned to the view <br>
  //! Please take it into account if you use it for your purposes; <br>
  Standard_EXPORT Standard_Boolean Print (const Graphic3d_CView& ACView, const Aspect_CLayer2d& ACUnderLayer, const Aspect_CLayer2d& ACOverLayer, const Aspect_Handle hPrnDC, const Standard_Boolean showBackground, const Standard_CString filename, const Aspect_PrintAlgo printAlgorithm = Aspect_PA_STRETCH, const Standard_Real theScaleFactor = 1.0) const;
  Standard_EXPORT void SetDepthTestEnabled (const Graphic3d_CView& view,const Standard_Boolean isEnabled) const;
  Standard_EXPORT Standard_Boolean IsDepthTestEnabled (const Graphic3d_CView& view) const;
  //! Reads depths of shown pixels of the given rectangle (glReadPixels with GL_DEPTH_COMPONENT) <br>
  Standard_EXPORT void ReadDepths (const Graphic3d_CView& view,const Standard_Integer x,const Standard_Integer y,const Standard_Integer width,const Standard_Integer height,const Standard_Address buffer) const;
  //! Generate offscreen FBO (needs OpenGL2+ hardware) <br>
  //! If not supported on hardware returns NULL. <br>
  Standard_EXPORT Graphic3d_PtrFrameBuffer FBOCreate (const Graphic3d_CView& view, const Standard_Integer width, const Standard_Integer height);
  //! Remove offscreen FBO <br>
  Standard_EXPORT void FBORelease (const Graphic3d_CView& view, Graphic3d_PtrFrameBuffer& fboPtr);
  //! Dump active rendering buffer into specified memory buffer. <br>
  Standard_EXPORT Standard_Boolean BufferDump (const Graphic3d_CView&      theCView,
                                               Image_PixMap&               theImage,
                                               const Graphic3d_BufferType& theBufferType);
  Standard_EXPORT void SetGLLightEnabled (const Graphic3d_CView& view,const Standard_Boolean isEnabled) const;
  Standard_EXPORT Standard_Boolean IsGLLightEnabled (const Graphic3d_CView& view) const;
  //! Clear visualization data in graphical driver and stop <br>
  //! displaying the primitives array of the graphical group <theCGroup>. <br>
  //! This method is internal and should be used by Graphic3d_Group only. <br>
  Standard_EXPORT Standard_Integer InquirePlaneLimit();
  Standard_EXPORT Standard_ShortReal DefaultTextHeight() const;
  Standard_EXPORT void FBOGetDimensions(const Graphic3d_CView& view,const Graphic3d_PtrFrameBuffer fboPtr,Standard_Integer& width,Standard_Integer& height,Standard_Integer& widthMax,Standard_Integer& heightMax);
  Standard_EXPORT void FBOChangeViewport(const Graphic3d_CView& view,Graphic3d_PtrFrameBuffer& fboPtr,const Standard_Integer width,const Standard_Integer height);
  Standard_EXPORT Standard_Boolean Export(const Standard_CString theFileName,const Graphic3d_ExportFormat theFormat,const Graphic3d_SortType theSortType,const Standard_Integer theWidth,const Standard_Integer theHeight,const Graphic3d_CView& theView,const Aspect_CLayer2d& theLayerUnder,const Aspect_CLayer2d& theLayerOver,const Standard_Real thePrecision = 0.005,const Standard_Address theProgressBarFunc = NULL,const Standard_Address theProgressObject = NULL);

  //! Add a new top-level z layer with ID <theLayerId> for <br>
  //! the view. Z layers allow drawing structures in higher layers <br>
  //! in foreground of structures in lower layers. To add a structure <br>
  //! to desired layer on display it is necessary to set the layer <br>
  //! index for the structure. <br>
  Standard_EXPORT void AddZLayer(const Graphic3d_CView& theCView,
                                 const Standard_Integer theLayerId);

  //! Remove Z layer from the specified view. All structures <br>
  //! displayed at the moment in layer will be displayed in default layer <br>
  //! ( the bottom-level z layer ). To unset layer index from associated <br>
  //! structures use method UnsetZLayer (...). <br>
  Standard_EXPORT void RemoveZLayer(const Graphic3d_CView& theCView,
                                    const Standard_Integer theLayerId);

  //! Unset Z layer ID for all structures. The structure <br>
  //! indexes will be set to default layer ( the bottom-level z layer with <br>
  //! ID = 0 ). <br>
  Standard_EXPORT void UnsetZLayer(const Standard_Integer theLayerId);

  //! Change Z layer of a structure. The new z layer ID will <br>
  //! be used to define the associated layer for structure on display. <br>
  //! It is recommended to take care of redisplaying the structures already <br>
  //! presented in view with previously set layer index. This is usually <br>
  //! done by viewer manager. Z layers allow drawing structures in <br>
  //! higher layers in foreground of structures in lower layers. <br>
  Standard_EXPORT void ChangeZLayer(const Graphic3d_CStructure& theCStructure,
                                    const Standard_Integer theLayerId);

  //! Change Z layer of a structure already presented in view. <br>
  //! It is recommended to update z layer of already <br>
  //! displayed structures with this method before setting new z layer <br>
  //! index to the structure. This is usually done by viewer manager. <br>
  Standard_EXPORT void ChangeZLayer(const Graphic3d_CStructure& theCStructure,
                                    const Graphic3d_CView& theCView,
                                    const Standard_Integer theNewLayerId);

  //! Get Z layer ID of the structure. If the structure doesn't exists in <br>
  //! graphic driver, the method returns -1. <br>
  Standard_EXPORT Standard_Integer GetZLayer(const Graphic3d_CStructure& theCStructure) const;

public:

  //! @return the visualization options
  inline const OpenGl_Caps& Options() const
  {
    return *myCaps.operator->();
  }

  //! @return the visualization options
  inline OpenGl_Caps& ChangeOptions()
  {
    return *myCaps.operator->();
  }

  //! VBO usage can be forbidden by this method even if it is supported by GL driver.
  //! Notice that disabling of VBO will cause rendering performance degradation.
  //! Warning! This method should be called only before any primitives are displayed in GL scene!
  Standard_EXPORT void EnableVBO (const Standard_Boolean theToTurnOn);

  //! Returns information about GPU memory usage.
  //! Please read OpenGl_Context::MemoryInfo() for more description.
  Standard_EXPORT Standard_Boolean MemoryInfo (Standard_Size&           theFreeBytes,
                                               TCollection_AsciiString& theInfo) const;

  //! UserDraw function prototype
  typedef OpenGl_Element* (*OpenGl_UserDrawCallback_t )(const CALL_DEF_USERDRAW* );

  //! Method to setup UserDraw callback
  Standard_EXPORT OpenGl_UserDrawCallback_t& UserDrawCallback();

public:
  
  //! Returns information about OpenCL device used for computations.
  Standard_EXPORT Standard_Boolean GetOpenClDeviceInfo (const Graphic3d_CView& theCView,
                      NCollection_DataMap<TCollection_AsciiString, TCollection_AsciiString>& theInfo);

private:

  //! Method to retrieve valid GL context.
  //! Could return NULL-handle if no window created by this driver.
  Standard_EXPORT const Handle(OpenGl_Context)& GetSharedContext() const;

public:

  DEFINE_STANDARD_RTTI(OpenGl_GraphicDriver)

private:

  Handle(OpenGl_Display)                                          myGlDisplay;
  Handle(OpenGl_Caps)                                             myCaps;
  NCollection_DataMap<Standard_Integer, Handle(OpenGl_View)>      myMapOfView;
  NCollection_DataMap<Standard_Integer, Handle(OpenGl_Workspace)> myMapOfWS;
  NCollection_DataMap<Standard_Integer, OpenGl_Structure*>        myMapOfStructure;
  Handle(OpenGl_Workspace)                                        myImmediateWS;
  mutable Handle(OpenGl_PrinterContext)                           myPrintContext;
  OpenGl_UserDrawCallback_t                                       myUserDrawCallback;
  OpenGl_Text*                                                    myTempText;         //!< variable for compatibility (drawing text in layers)

public:

  OpenGl_StateCounter* GetStateCounter() const { return &myStateCounter; }

private:

  mutable OpenGl_StateCounter myStateCounter;

};

#endif //_OpenGl_GraphicDriver_HeaderFile