// Copyright (c) 2015 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 License 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 _Graphic3d_CView_HeaderFile
#define _Graphic3d_CView_HeaderFile

#include "Aspect_GridParams.hxx"
#include "Aspect_RenderingContext.hxx"
#include "Aspect_SkydomeBackground.hxx"
#include "Aspect_Window.hxx"
#include "gp_Ax3.hxx"
#include "Graphic3d_BufferType.hxx"
#include "Graphic3d_CubeMap.hxx"
#include "Graphic3d_DataStructureManager.hxx"
#include "Graphic3d_DiagnosticInfo.hxx"
#include "Graphic3d_GraduatedTrihedron.hxx"
#include "Graphic3d_Vertex.hxx"
#include "Standard_Transient.hxx"
#include "NCollection_Map.hxx"
#include "NCollection_Shared.hxx"
#include "Graphic3d_RenderingParams.hxx"
#include "Graphic3d_Structure.hxx"
#include "NCollection_Sequence.hxx"
#include "Graphic3d_TextureEnv.hxx"
#include "Graphic3d_TypeOfAnswer.hxx"
#include "Graphic3d_TypeOfBackfacingModel.hxx"
#include "Graphic3d_TypeOfBackground.hxx"
#include "Graphic3d_TypeOfShadingModel.hxx"
#include "Graphic3d_TypeOfVisualization.hxx"
#include "NCollection_Vec3.hxx"
#include "Standard_TypeDef.hxx"
#include "Graphic3d_ZLayerId.hxx"
#include "Graphic3d_ZLayerSettings.hxx"
#include "Image_PixMap.hxx"
#include "TCollection_AsciiString.hxx"
#include "NCollection_IndexedDataMap.hxx"

class Aspect_NeutralWindow;
class Aspect_XRSession;
class Graphic3d_CView;
class Graphic3d_Layer;
class Graphic3d_StructureManager;

//! Base class of a graphical view that carries out rendering process for a concrete
//! implementation of graphical driver. Provides virtual interfaces for redrawing its
//! contents, management of displayed structures and render settings. The source code
//! of the class itself implements functionality related to management of
//! computed (HLR or "view-dependent") structures.
class Graphic3d_CView : public Graphic3d_DataStructureManager
{
  friend class Graphic3d_StructureManager;
  DEFINE_STANDARD_RTTIEXT(Graphic3d_CView, Graphic3d_DataStructureManager)
public:
  //! Constructor.
  Standard_EXPORT Graphic3d_CView(const occ::handle<Graphic3d_StructureManager>& theMgr);

  //! Destructor.
  Standard_EXPORT ~Graphic3d_CView() override;

  //! Returns the identification number of the view.
  int Identification() const { return myId; }

  //! Activates the view. Maps presentations defined within structure manager onto this view.
  Standard_EXPORT virtual void Activate();

  //! Deactivates the view. Unmaps presentations defined within structure manager.
  //! The view in deactivated state will ignore actions on structures such as Display().
  Standard_EXPORT virtual void Deactivate();

  //! Returns the activity flag of the view.
  bool IsActive() const { return myIsActive; }

  //! Erases the view and removes from graphic driver.
  //! No more graphic operations are allowed in this view after the call.
  Standard_EXPORT virtual void Remove();

  //! Returns true if the view was removed.
  bool IsRemoved() const { return myIsRemoved; }

  //! Returns camera object of the view.
  const occ::handle<Graphic3d_Camera>& Camera() const override { return myCamera; }

  //! Sets camera used by the view.
  virtual void SetCamera(const occ::handle<Graphic3d_Camera>& theCamera) { myCamera = theCamera; }

  //! Returns necessity to flip OY in projection matrix
  virtual bool ToFlipOutput() const { return false; }

  //! Sets state of flip OY necessity in projection matrix
  virtual void SetToFlipOutput(const bool) {}

public:
  //! Returns default Shading Model of the view; Graphic3d_TypeOfShadingModel_Phong by default.
  Graphic3d_TypeOfShadingModel ShadingModel() const { return myRenderParams.ShadingModel; }

  //! Sets default Shading Model of the view.
  //! Will throw an exception on attempt to set Graphic3d_TypeOfShadingModel_DEFAULT.
  Standard_EXPORT void SetShadingModel(Graphic3d_TypeOfShadingModel theModel);

  //! Return backfacing model used for the view; Graphic3d_TypeOfBackfacingModel_Auto by default,
  //! which means that backface culling is defined by each presentation.
  Graphic3d_TypeOfBackfacingModel BackfacingModel() const { return myBackfacing; }

  //! Sets backfacing model for the view.
  void SetBackfacingModel(const Graphic3d_TypeOfBackfacingModel theModel)
  {
    myBackfacing = theModel;
  }

  //! Returns visualization type of the view.
  Graphic3d_TypeOfVisualization VisualizationType() const { return myVisualization; }

  //! Sets visualization type of the view.
  void SetVisualizationType(const Graphic3d_TypeOfVisualization theType)
  {
    myVisualization = theType;
  }

  //! Returns ZLayerId target
  Graphic3d_ZLayerId ZLayerTarget() const { return myZLayerTarget; }

  //! Sets ZLayerId target.
  void SetZLayerTarget(const Graphic3d_ZLayerId theTarget) { myZLayerTarget = theTarget; }

  //! Returns ZLayerId redraw mode
  bool ZLayerRedrawMode() const { return myZLayerRedrawMode; }

  //! Sets ZLayerId redraw mode.
  void SetZLayerRedrawMode(const bool theMode) { myZLayerRedrawMode = theMode; }

  //! Switches computed HLR mode in the view
  Standard_EXPORT void SetComputedMode(const bool theMode);

  //! Returns the computed HLR mode state
  bool ComputedMode() const { return myIsInComputedMode; }

  //! Computes the new presentation of the structure  displayed in this view with the type
  //! Graphic3d_TOS_COMPUTED.
  Standard_EXPORT void ReCompute(const occ::handle<Graphic3d_Structure>& theStructure);

  //! Invalidates bounding box of specified ZLayerId.
  Standard_EXPORT void Update(const Graphic3d_ZLayerId theLayerId = Graphic3d_ZLayerId_UNKNOWN);

  //! Computes the new presentation of the structures displayed in this view with the type
  //! Graphic3d_TOS_COMPUTED.
  Standard_EXPORT void Compute();

  //! Returns the set of structures displayed in this view.
  Standard_EXPORT void DisplayedStructures(
    NCollection_Map<occ::handle<Graphic3d_Structure>>& theStructures) const;

  //! Returns number of displayed structures in the view.
  virtual int NumberOfDisplayedStructures() const { return myStructsDisplayed.Extent(); }

  //! Returns true in case if the structure with the given <theStructId> is
  //! in list of structures to be computed and stores computed struct to <theComputedStruct>.
  Standard_EXPORT bool IsComputed(const int                         theStructId,
                                  occ::handle<Graphic3d_Structure>& theComputedStruct) const;

  //! Returns the bounding box of all structures displayed in the view.
  //! If theToIncludeAuxiliary is TRUE, then the boundary box also includes minimum and maximum
  //! limits of graphical elements forming parts of infinite and other auxiliary structures.
  //! @param theToIncludeAuxiliary consider also auxiliary presentations (with infinite flag or with
  //! trihedron transformation persistence)
  //! @return computed bounding box
  Standard_EXPORT virtual Bnd_Box MinMaxValues(const bool theToIncludeAuxiliary = false) const;

  //! Return primary and graphical bounding boxes used by camera Z fitting.
  virtual void ZFitAllBounds(Bnd_Box& thePrimaryBox, Bnd_Box& theGraphicBox) const
  {
    thePrimaryBox = MinMaxValues(false);
    theGraphicBox = MinMaxValues(true);
  }

  //! Returns the coordinates of the boundary box of all structures in the set <theSet>.
  //! If <theToIgnoreInfiniteFlag> is TRUE, then the boundary box
  //! also includes minimum and maximum limits of graphical elements
  //! forming parts of infinite structures.
  Standard_EXPORT Bnd_Box
    MinMaxValues(const NCollection_Map<occ::handle<Graphic3d_Structure>>& theSet,
                 const bool theToIncludeAuxiliary = false) const;

  //! Returns the structure manager handle which manage structures associated with this view.
  const occ::handle<Graphic3d_StructureManager>& StructureManager() const
  {
    return myStructureManager;
  }

private:
  //! Is it possible to display the structure in the view?
  Standard_EXPORT Graphic3d_TypeOfAnswer
    acceptDisplay(const Graphic3d_TypeOfStructure theStructType) const;

  //! Clears the structure in this view.
  Standard_EXPORT void Clear(Graphic3d_Structure* theStructure, const bool theWithDestruction);

  //! Connects the structures.
  Standard_EXPORT void Connect(const Graphic3d_Structure* theMother,
                               const Graphic3d_Structure* theDaughter);

  //! Disconnects the structures.
  Standard_EXPORT void Disconnect(const Graphic3d_Structure* theMother,
                                  const Graphic3d_Structure* theDaughter);

  //! Displays the structure in the view.
  Standard_EXPORT void Display(const occ::handle<Graphic3d_Structure>& theStructure);

  //! Erases the structure from the view.
  Standard_EXPORT void Erase(const occ::handle<Graphic3d_Structure>& theStructure);

  //! Highlights the structure in the view.
  Standard_EXPORT void Highlight(const occ::handle<Graphic3d_Structure>& theStructure);

  //! Transforms the structure in the view.
  Standard_EXPORT void SetTransform(const occ::handle<Graphic3d_Structure>& theStructure,
                                    const occ::handle<TopLoc_Datum3D>&      theTrsf);

  //! Suppress the highlighting on the structure <AStructure>
  //! in the view <me>.
  Standard_EXPORT void UnHighlight(const occ::handle<Graphic3d_Structure>& theStructure);

  //! Returns an index != 0 if the structure have another structure computed for the view <me>.
  Standard_EXPORT int IsComputed(const Graphic3d_Structure* theStructure) const;

  int IsComputed(const occ::handle<Graphic3d_Structure>& theStructure) const
  {
    return IsComputed(theStructure.get());
  }

  //! Returns true if the structure is displayed in the view.
  Standard_EXPORT bool IsDisplayed(const occ::handle<Graphic3d_Structure>& theStructure) const;

  //! Changes the display priority of the structure.
  Standard_EXPORT void ChangePriority(const occ::handle<Graphic3d_Structure>& theStructure,
                                      const Graphic3d_DisplayPriority         theOldPriority,
                                      const Graphic3d_DisplayPriority         theNewPriority);

  //! Change Z layer of already displayed structure in the view.
  Standard_EXPORT void ChangeZLayer(const occ::handle<Graphic3d_Structure>& theStructure,
                                    const Graphic3d_ZLayerId                theLayerId);

  //! Returns an index != 0 if the structure have the same owner than another structure
  //! in the sequence of the computed structures.
  Standard_EXPORT int HaveTheSameOwner(const occ::handle<Graphic3d_Structure>& theStructure) const;

public:
  //! Redraw content of the view.
  virtual void Redraw() = 0;

  //! Redraw immediate content of the view.
  virtual void RedrawImmediate() = 0;

  //! Invalidates content of the view but does not redraw it.
  virtual void Invalidate() = 0;

  //! Return true if view content cache has been invalidated.
  virtual bool IsInvalidated() = 0;

  //! Handle changing size of the rendering window.
  Standard_EXPORT virtual void Resized() = 0;

  //! @param theDrawToFrontBuffer Advanced option to modify rendering mode:
  //! 1. TRUE.  Drawing immediate mode structures directly to the front buffer over the scene image.
  //! Fast, so preferred for interactive work (used by default).
  //! However these extra drawings will be missed in image dump since it is performed from back
  //! buffer. Notice that since no pre-buffering used the V-Sync will be ignored and rendering could
  //! be seen in run-time (in case of slow hardware) and/or tearing may appear. So this is strongly
  //! recommended to draw only simple (fast) structures.
  //! 2. FALSE. Drawing immediate mode structures to the back buffer.
  //! The complete scene is redrawn first, so this mode is slower if scene contains complex data
  //! and/or V-Sync is turned on. But it works in any case and is especially useful for view dump
  //! because the dump image is read from the back buffer.
  //! @return previous mode.
  virtual bool SetImmediateModeDrawToFront(const bool theDrawToFrontBuffer) = 0;

  //! Creates and maps rendering window to the view.
  //! @param[in] theParentVIew parent view or NULL
  //! @param[in] theWindow the window
  //! @param[in] theContext the rendering context; if NULL the context will be created internally
  virtual void SetWindow(const occ::handle<Graphic3d_CView>& theParentVIew,
                         const occ::handle<Aspect_Window>&   theWindow,
                         const Aspect_RenderingContext       theContext) = 0;

  //! Returns the window associated to the view.
  virtual occ::handle<Aspect_Window> Window() const = 0;

  //! Returns True if the window associated to the view is defined.
  virtual bool IsDefined() const = 0;

  //! Dump active rendering buffer into specified memory buffer.
  virtual bool BufferDump(Image_PixMap& theImage, const Graphic3d_BufferType& theBufferType) = 0;

  //! Dumps the graphical contents of a shadowmap framebuffer into an image.
  //! @param theImage the image to store the shadow map.
  //! @param[in] theLightName  name of the light used to generate the shadow map.
  virtual bool ShadowMapDump(Image_PixMap&                  theImage,
                             const TCollection_AsciiString& theLightName) = 0;

  //! Marks BVH tree and the set of BVH primitives of correspondent priority list with id theLayerId
  //! as outdated.
  virtual void InvalidateBVHData(const Graphic3d_ZLayerId theLayerId) = 0;

  //! Add a layer to the view.
  //! @param[in] theNewLayerId  id of new layer, should be > 0 (negative values are reserved for
  //! default layers).
  //! @param[in] theSettings    new layer settings
  //! @param[in] theLayerAfter  id of layer to append new layer before
  virtual void InsertLayerBefore(const Graphic3d_ZLayerId        theNewLayerId,
                                 const Graphic3d_ZLayerSettings& theSettings,
                                 const Graphic3d_ZLayerId        theLayerAfter) = 0;

  //! Add a layer to the view.
  //! @param[in] theNewLayerId   id of new layer, should be > 0 (negative values are reserved for
  //! default layers).
  //! @param[in] theSettings     new layer settings
  //! @param[in] theLayerBefore  id of layer to append new layer after
  virtual void InsertLayerAfter(const Graphic3d_ZLayerId        theNewLayerId,
                                const Graphic3d_ZLayerSettings& theSettings,
                                const Graphic3d_ZLayerId        theLayerBefore) = 0;

  //! Returns the maximum Z layer ID.
  //! First layer ID is Graphic3d_ZLayerId_Default, last ID is ZLayerMax().
  virtual int ZLayerMax() const = 0;

  //! Returns the list of layers.
  virtual const NCollection_List<occ::handle<Graphic3d_Layer>>& Layers() const = 0;

  //! Returns layer with given ID or NULL if undefined.
  virtual occ::handle<Graphic3d_Layer> Layer(const Graphic3d_ZLayerId theLayerId) const = 0;

  //! Returns the bounding box of all structures displayed in the Z layer.
  Standard_EXPORT virtual void InvalidateZLayerBoundingBox(const Graphic3d_ZLayerId theLayerId);

  //! Remove Z layer from the specified view. All structures
  //! displayed at the moment in layer will be displayed in default layer
  //! ( the bottom-level z layer ). To unset layer ID from associated
  //! structures use method UnsetZLayer (...).
  virtual void RemoveZLayer(const Graphic3d_ZLayerId theLayerId) = 0;

  //! Sets the settings for a single Z layer of specified view.
  virtual void SetZLayerSettings(const Graphic3d_ZLayerId        theLayerId,
                                 const Graphic3d_ZLayerSettings& theSettings) = 0;

  //! Returns zoom-scale factor.
  Standard_EXPORT double ConsiderZoomPersistenceObjects();

  //! Returns pointer to an assigned framebuffer object.
  virtual occ::handle<Standard_Transient> FBO() const = 0;

  //! Sets framebuffer object for offscreen rendering.
  virtual void SetFBO(const occ::handle<Standard_Transient>& theFbo) = 0;

  //! Generate offscreen FBO in the graphic library.
  //! If not supported on hardware returns NULL.
  virtual occ::handle<Standard_Transient> FBOCreate(const int theWidth, const int theHeight) = 0;

  //! Remove offscreen FBO from the graphic library
  virtual void FBORelease(occ::handle<Standard_Transient>& theFbo) = 0;

  //! Read offscreen FBO configuration.
  virtual void FBOGetDimensions(const occ::handle<Standard_Transient>& theFbo,
                                int&                                   theWidth,
                                int&                                   theHeight,
                                int&                                   theWidthMax,
                                int&                                   theHeightMax) = 0;

  //! Change offscreen FBO viewport.
  virtual void FBOChangeViewport(const occ::handle<Standard_Transient>& theFbo,
                                 const int                              theWidth,
                                 const int                              theHeight) = 0;

public:
  //! Copy visualization settings from another view.
  //! Method is used for cloning views in viewer when its required to create view
  //! with same view properties.
  Standard_EXPORT virtual void CopySettings(const occ::handle<Graphic3d_CView>& theOther);

  //! Returns current rendering parameters and effect settings.
  const Graphic3d_RenderingParams& RenderingParams() const { return myRenderParams; }

  //! Returns reference to current rendering parameters and effect settings.
  Graphic3d_RenderingParams& ChangeRenderingParams() { return myRenderParams; }

public:
  //! Returns background  fill color.
  virtual Aspect_Background Background() const { return Aspect_Background(myBgColor.GetRGB()); }

  //! Sets background fill color.
  virtual void SetBackground(const Aspect_Background& theBackground)
  {
    myBgColor.SetRGB(theBackground.Color());
  }

  //! Returns gradient background fill colors.
  virtual Aspect_GradientBackground GradientBackground() const = 0;

  //! Sets gradient background fill colors.
  virtual void SetGradientBackground(const Aspect_GradientBackground& theBackground) = 0;

  //! Returns background image texture map.
  const occ::handle<Graphic3d_TextureMap>& BackgroundImage() { return myBackgroundImage; }

  //! Returns cubemap being set last time on background.
  const occ::handle<Graphic3d_CubeMap>& BackgroundCubeMap() const { return myCubeMapBackground; }

  //! Returns cubemap being set last time on background.
  const occ::handle<Graphic3d_CubeMap>& IBLCubeMap() const { return myCubeMapIBL; }

  //! Sets image texture or environment cubemap as background.
  //! @param[in] theTextureMap  source to set a background;
  //!                           should be either Graphic3d_Texture2D or Graphic3d_CubeMap
  //! @param[in] theToUpdatePBREnv  defines whether IBL maps will be generated or not
  //!                               (see GeneratePBREnvironment())
  virtual void SetBackgroundImage(const occ::handle<Graphic3d_TextureMap>& theTextureMap,
                                  bool theToUpdatePBREnv = true) = 0;

  //! Returns background image fill style.
  virtual Aspect_FillMethod BackgroundImageStyle() const = 0;

  //! Sets background image fill style.
  virtual void SetBackgroundImageStyle(const Aspect_FillMethod theFillStyle) = 0;

  //! Returns background type.
  Graphic3d_TypeOfBackground BackgroundType() const { return myBackgroundType; }

  //! Sets background type.
  void SetBackgroundType(Graphic3d_TypeOfBackground theType) { myBackgroundType = theType; }

  //! Returns skydome aspect;
  const Aspect_SkydomeBackground& BackgroundSkydome() const { return mySkydomeAspect; }

  //! Sets skydome aspect
  Standard_EXPORT void SetBackgroundSkydome(const Aspect_SkydomeBackground& theAspect,
                                            bool theToUpdatePBREnv = true);

  //! Enables or disables IBL (Image Based Lighting) from background cubemap.
  //! Has no effect if PBR is not used.
  //! @param[in] theToEnableIBL enable or disable IBL from background cubemap
  virtual void SetImageBasedLighting(bool theToEnableIBL) = 0;

  //! Display a shader-rendered grid on the given plane.
  //! The default implementation is a no-op; drivers with shader support override it.
  //! @param[in] theParams appearance parameters
  //! @param[in] thePlane  grid plane in world coordinates (origin + X/Y directions)
  virtual void GridDisplay(const Aspect_GridParams& theParams, const gp_Ax3& thePlane)
  {
    (void)theParams;
    (void)thePlane;
  }

  //! Erase the shader-rendered grid.
  //! The default implementation is a no-op; drivers with shader support override it.
  virtual void GridErase() {}

  //! Return snapped point for the shader-rendered grid under the window pixel.
  //! The default implementation is a no-op; drivers with shader grid support override it.
  virtual bool ShaderGridEcho(const int theX, const int theY, Graphic3d_Vertex& thePoint) const
  {
    (void)theX;
    (void)theY;
    (void)thePoint;
    return false;
  }

  //! Return snapped point and display point for the shader-rendered grid under the window pixel.
  //! The snapped point is the geometric grid point in world coordinates.
  //! The display point is a clip-safe proxy projected to the same window position for echo marker
  //! presentation; it should not be used as the geometric snap result.
  virtual bool ShaderGridEcho(const int         theX,
                              const int         theY,
                              Graphic3d_Vertex& thePoint,
                              Graphic3d_Vertex& theDisplayPoint) const
  {
    if (!ShaderGridEcho(theX, theY, thePoint))
    {
      return false;
    }
    theDisplayPoint = thePoint;
    return true;
  }

  //! Return snapped point for the shader-rendered grid from an arbitrary world point.
  //! The default implementation is a no-op; drivers with shader grid support override it.
  virtual bool ShaderGridSnapPoint(const Graphic3d_Vertex& thePoint,
                                   Graphic3d_Vertex&       theGridPoint) const
  {
    (void)thePoint;
    (void)theGridPoint;
    return false;
  }

  //! Returns environment texture set for the view.
  const occ::handle<Graphic3d_TextureEnv>& TextureEnv() const { return myTextureEnvData; }

  //! Sets environment texture for the view.
  virtual void SetTextureEnv(const occ::handle<Graphic3d_TextureEnv>& theTextureEnv) = 0;

public:
  //! Returns list of lights of the view.
  virtual const occ::handle<Graphic3d_LightSet>& Lights() const = 0;

  //! Sets list of lights for the view.
  virtual void SetLights(const occ::handle<Graphic3d_LightSet>& theLights) = 0;

  //! Returns list of clip planes set for the view.
  virtual const occ::handle<Graphic3d_SequenceOfHClipPlane>& ClipPlanes() const = 0;

  //! Sets list of clip planes for the view.
  virtual void SetClipPlanes(const occ::handle<Graphic3d_SequenceOfHClipPlane>& thePlanes) = 0;

  //! Fill in the dictionary with diagnostic info.
  //! Should be called within rendering thread.
  //!
  //! This API should be used only for user output or for creating automated reports.
  //! The format of returned information (e.g. key-value layout)
  //! is NOT part of this API and can be changed at any time.
  //! Thus application should not parse returned information to weed out specific parameters.
  Standard_EXPORT virtual void DiagnosticInformation(
    NCollection_IndexedDataMap<TCollection_AsciiString, TCollection_AsciiString>& theDict,
    Graphic3d_DiagnosticInfo theFlags) const = 0;

  //! Returns string with statistic performance info.
  virtual TCollection_AsciiString StatisticInformation() const = 0;

  //! Fills in the dictionary with statistic performance info.
  virtual void StatisticInformation(
    NCollection_IndexedDataMap<TCollection_AsciiString, TCollection_AsciiString>& theDict)
    const = 0;

public:
  //! Return unit scale factor defined as scale factor for m (meters); 1.0 by default.
  //! Normally, view definition is unitless, however some operations like VR input requires proper
  //! units mapping.
  double UnitFactor() const { return myUnitFactor; }

  //! Set unit scale factor.
  Standard_EXPORT void SetUnitFactor(double theFactor);

  //! Return XR session.
  const occ::handle<Aspect_XRSession>& XRSession() const { return myXRSession; }

  //! Set XR session.
  void SetXRSession(const occ::handle<Aspect_XRSession>& theSession) { myXRSession = theSession; }

  //! Return TRUE if there is active XR session.
  Standard_EXPORT bool IsActiveXR() const;

  //! Initialize XR session.
  Standard_EXPORT virtual bool InitXR();

  //! Release XR session.
  Standard_EXPORT virtual void ReleaseXR();

  //! Process input.
  Standard_EXPORT virtual void ProcessXRInput();

  //! Compute PosedXRCamera() based on current XR head pose and make it active.
  Standard_EXPORT void SetupXRPosedCamera();

  //! Set current camera back to BaseXRCamera() and copy temporary modifications of PosedXRCamera().
  //! Calls SynchronizeXRPosedToBaseCamera() beforehand.
  Standard_EXPORT void UnsetXRPosedCamera();

  //! Returns transient XR camera position with tracked head orientation applied.
  const occ::handle<Graphic3d_Camera>& PosedXRCamera() const { return myPosedXRCamera; }

  //! Sets transient XR camera position with tracked head orientation applied.
  void SetPosedXRCamera(const occ::handle<Graphic3d_Camera>& theCamera)
  {
    myPosedXRCamera = theCamera;
  }

  //! Returns anchor camera definition (without tracked head orientation).
  const occ::handle<Graphic3d_Camera>& BaseXRCamera() const { return myBaseXRCamera; }

  //! Sets anchor camera definition.
  void SetBaseXRCamera(const occ::handle<Graphic3d_Camera>& theCamera)
  {
    myBaseXRCamera = theCamera;
  }

  //! Convert XR pose to world space.
  //! @param[in] thePoseXR  transformation defined in VR local coordinate system,
  //!                       oriented as Y-up, X-right and -Z-forward
  //! @return transformation defining orientation of XR pose in world space
  gp_Trsf PoseXRToWorld(const gp_Trsf& thePoseXR) const
  {
    const occ::handle<Graphic3d_Camera>& anOrigin = myBaseXRCamera;
    const gp_Ax3                         anAxVr(gp::Origin(), gp::DZ(), gp::DX());
    const gp_Ax3 aCameraCS(anOrigin->Eye().XYZ(), -anOrigin->Direction(), -anOrigin->SideRight());
    gp_Trsf      aTrsfCS;
    aTrsfCS.SetTransformation(aCameraCS, anAxVr);
    return aTrsfCS * thePoseXR;
  }

  //! Returns view direction in the world space based on XR pose.
  //! @param[in] thePoseXR  transformation defined in VR local coordinate system,
  //!                       oriented as Y-up, X-right and -Z-forward
  gp_Ax1 ViewAxisInWorld(const gp_Trsf& thePoseXR) const
  {
    return gp_Ax1(gp::Origin(), -gp::DZ()).Transformed(PoseXRToWorld(thePoseXR));
  }

  //! Recomputes PosedXRCamera() based on BaseXRCamera() and head orientation.
  Standard_EXPORT void SynchronizeXRBaseToPosedCamera();

  //! Checks if PosedXRCamera() has been modified since SetupXRPosedCamera()
  //! and copies these modifications to BaseXRCamera().
  Standard_EXPORT void SynchronizeXRPosedToBaseCamera();

  //! Compute camera position based on XR pose.
  Standard_EXPORT void ComputeXRPosedCameraFromBase(Graphic3d_Camera& theCam,
                                                    const gp_Trsf&    theXRTrsf) const;

  //! Update based camera from posed camera by applying reversed transformation.
  Standard_EXPORT void ComputeXRBaseCameraFromPosed(const Graphic3d_Camera& theCamPosed,
                                                    const gp_Trsf&          thePoseTrsf);

  //! Turn XR camera direction using current (head) eye position as anchor.
  Standard_EXPORT void TurnViewXRCamera(const gp_Trsf& theTrsfTurn);

public: //! @name obsolete Graduated Trihedron functionality
  //! Returns data of a graduated trihedron
  virtual const Graphic3d_GraduatedTrihedron& GetGraduatedTrihedron() { return myGTrihedronData; }

  //! Displays Graduated Trihedron.
  virtual void GraduatedTrihedronDisplay(const Graphic3d_GraduatedTrihedron& theTrihedronData)
  {
    (void)theTrihedronData;
  }

  //! Erases Graduated Trihedron.
  virtual void GraduatedTrihedronErase() {}

  //! Sets minimum and maximum points of scene bounding box for Graduated Trihedron stored in
  //! graphic view object.
  //! @param[in] theMin  the minimum point of scene.
  //! @param[in] theMax  the maximum point of scene.
  virtual void GraduatedTrihedronMinMaxValues(const NCollection_Vec3<float> theMin,
                                              const NCollection_Vec3<float> theMax)
  {
    (void)theMin;
    (void)theMax;
  }

  //! Dumps the content of me into the stream
  Standard_EXPORT void DumpJson(Standard_OStream& theOStream, int theDepth = -1) const override;

public: //! @name subview properties
  //! Return TRUE if this is a subview of another view.
  bool IsSubview() const { return myParentView != nullptr; }

  //! Return parent View or NULL if this is not a subview.
  Graphic3d_CView* ParentView() { return myParentView; }

  //! Return TRUE if this is view performs rendering of subviews and nothing else; FALSE by default.
  //! By default, view with subviews will render main scene and blit subviews on top of it.
  //! Rendering of main scene might become redundant in case if subviews cover entire window of
  //! parent view. This flag allows to disable rendering of the main scene in such scenarios without
  //! creation of a dedicated V3d_Viewer instance just for composing subviews.
  bool IsSubviewComposer() const { return myIsSubviewComposer; }

  //! Set if this view should perform composing of subviews and nothing else.
  void SetSubviewComposer(bool theIsComposer) { myIsSubviewComposer = theIsComposer; }

  //! Return subview list.
  const NCollection_Sequence<occ::handle<Graphic3d_CView>>& Subviews() const { return mySubviews; }

  //! Add subview to the list.
  Standard_EXPORT void AddSubview(const occ::handle<Graphic3d_CView>& theView);

  //! Remove subview from the list.
  Standard_EXPORT bool RemoveSubview(const Graphic3d_CView* theView);

  //! Return subview position within parent view; Aspect_TOTP_LEFT_UPPER by default.
  Aspect_TypeOfTriedronPosition SubviewCorner() const { return mySubviewCorner; }

  //! Set subview position within parent view.
  void SetSubviewCorner(Aspect_TypeOfTriedronPosition thePos) { mySubviewCorner = thePos; }

  //! Return subview top-left position relative to parent view in pixels.
  const NCollection_Vec2<int>& SubviewTopLeft() const { return mySubviewTopLeft; }

  //! Return TRUE if subview size is set as proportions relative to parent view.
  bool IsSubViewRelativeSize() const
  {
    return mySubviewSize.x() <= 1.0 && mySubviewSize.y() <= 1.0;
  }

  //! Return subview dimensions; (1.0, 1.0) by default.
  //! Values >= 2   define size in pixels;
  //! Values <= 1.0 define size as fraction of parent view.
  const NCollection_Vec2<double>& SubviewSize() const { return mySubviewSize; }

  //! Set subview size relative to parent view.
  void SetSubviewSize(const NCollection_Vec2<double>& theSize) { mySubviewSize = theSize; }

  //! Return corner offset within parent view; (0.0,0.0) by default.
  //! Values >= 2   define offset in pixels;
  //! Values <= 1.0 define offset as fraction of parent view dimensions.
  const NCollection_Vec2<double>& SubviewOffset() const { return mySubviewOffset; }

  //! Set corner offset within parent view.
  void SetSubviewOffset(const NCollection_Vec2<double>& theOffset) { mySubviewOffset = theOffset; }

  //! Return subview margins in pixels; (0,0) by default
  const NCollection_Vec2<int>& SubviewMargins() const { return mySubviewMargins; }

  //! Set subview margins in pixels.
  void SetSubviewMargins(const NCollection_Vec2<int>& theMargins) { mySubviewMargins = theMargins; }

  //! Update subview position and dimensions.
  Standard_EXPORT void SubviewResized(const occ::handle<Aspect_NeutralWindow>& theWindow);

private:
  //! Adds the structure to display lists of the view.
  virtual void displayStructure(const occ::handle<Graphic3d_CStructure>& theStructure,
                                const Graphic3d_DisplayPriority          thePriority) = 0;

  //! Erases the structure from display lists of the view.
  virtual void eraseStructure(const occ::handle<Graphic3d_CStructure>& theStructure) = 0;

  //! Change Z layer of a structure already presented in view.
  virtual void changeZLayer(const occ::handle<Graphic3d_CStructure>& theCStructure,
                            const Graphic3d_ZLayerId                 theNewLayerId) = 0;

  //! Changes the priority of a structure within its Z layer in the specified view.
  virtual void changePriority(const occ::handle<Graphic3d_CStructure>& theCStructure,
                              const Graphic3d_DisplayPriority          theNewPriority) = 0;

protected:
  int                       myId;
  Graphic3d_RenderingParams myRenderParams;

  NCollection_Sequence<occ::handle<Graphic3d_CView>> mySubviews; //!< list of child views
  Graphic3d_CView* myParentView;           //!< back-pointer to the parent view
                                           // clang-format off
  bool              myIsSubviewComposer;        //!< flag to skip rendering of viewer contents
  Aspect_TypeOfTriedronPosition mySubviewCorner;            //!< position within parent view
  NCollection_Vec2<int>               mySubviewTopLeft;           //!< subview top-left position relative to parent view
  NCollection_Vec2<int>               mySubviewMargins;           //!< subview margins in pixels
  NCollection_Vec2<double>               mySubviewSize;              //!< subview size
  NCollection_Vec2<double>               mySubviewOffset;            //!< subview corner offset within parent view
                                           // clang-format on

  occ::handle<Graphic3d_StructureManager>                myStructureManager;
  occ::handle<Graphic3d_Camera>                          myCamera;
  NCollection_Sequence<occ::handle<Graphic3d_Structure>> myStructsToCompute;
  NCollection_Sequence<occ::handle<Graphic3d_Structure>> myStructsComputed;
  NCollection_Map<occ::handle<Graphic3d_Structure>>      myStructsDisplayed;
  bool                                                   myIsInComputedMode;
  bool                                                   myIsActive;
  bool                                                   myIsRemoved;
  Graphic3d_TypeOfBackfacingModel                        myBackfacing;
  Graphic3d_TypeOfVisualization                          myVisualization;

  // clang-format off
  Graphic3d_ZLayerId      myZLayerTarget;      //!< ZLayerId for redrawing the content of specific zlayers.
  bool        myZLayerRedrawMode;  //!< If true redraws single layer, otherwise redraws group of layers.
  // clang-format on

  Quantity_ColorRGBA                myBgColor;
  occ::handle<Graphic3d_TextureMap> myBackgroundImage;
  occ::handle<Graphic3d_CubeMap>    myCubeMapBackground; //!< Cubemap displayed at background
  occ::handle<Graphic3d_CubeMap>    myCubeMapIBL;        //!< Cubemap used for environment lighting
  occ::handle<Graphic3d_TextureEnv> myTextureEnvData;
  Graphic3d_GraduatedTrihedron      myGTrihedronData;
  Graphic3d_TypeOfBackground        myBackgroundType; //!< Current type of background
  Aspect_SkydomeBackground          mySkydomeAspect;
  bool                              myToUpdateSkydome;

  occ::handle<Aspect_XRSession> myXRSession;
  // clang-format off
  occ::handle<Graphic3d_Camera> myBackXRCamera;       //!< camera projection parameters to restore after closing XR session (FOV, aspect and similar)
  occ::handle<Graphic3d_Camera> myBaseXRCamera;       //!< neutral camera orientation defining coordinate system in which head tracking is defined
  occ::handle<Graphic3d_Camera> myPosedXRCamera;      //!< transient XR camera orientation with tracked head orientation applied (based on myBaseXRCamera)
  occ::handle<Graphic3d_Camera> myPosedXRCameraCopy;  //!< neutral camera orientation copy at the beginning of processing input
  double            myUnitFactor;         //!< unit scale factor defined as scale factor for m (meters)
  // clang-format on
};

#endif // _Graphic3d_CView_HeaderFile