Class: TRootSceneState

Declaration: SceneState.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

TSceneState

Inherited By:

None.

Purpose:

TRootSceneState is a concrete class, derived from TSceneState, that is ideal for the root 2-D scene state of a graphic hierarchy. The class supplies the default light, camera, and so forth. (The default camera is a perspective camera, the default ambient light is white, and the default atmosphere shader is a TDepthCueingShader whose depth cue color is white and whose near and far Z values are 1e10.) The TRootGrafState class uses a TRootSceneState to represent the default scene state. To create a hierarchy, link TLinkableSceneState objects to a TRootSceneState object by passing it as an argument to their LinkTo member functions.

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

None.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Member Function: TRootSceneState::TRootSceneState

  1. TRootSceneState ()
  2. TRootSceneState (const TRootSceneState &)

Interface Category:

API.

Purpose:

  1. Default constructor. The default camera is a perspective camera, the default ambient light is white, and the default atmosphere shader is a TDepthCueingShader whose depth cue color is white and whose near and far Z values are 1e10.
  2. Copy constructor.

Calling Context:

  1. Called by the stream-in operators. You can also call this function directly.
  2. Called to copy an object.

Parameters:

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::~TRootSceneState

virtual ~ TRootSceneState ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::GetAmbientLight

virtual void GetAmbientLight (TColor &) const

Interface Category:

API.

Purpose:

Returns, in its argument, a TColor indicating the intensity and hue of the ambient light shining on the scene.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::GetAtmosphereShader

virtual const TAtmosphereShader * GetAtmosphereShader () const

Interface Category:

API.

Purpose:

Returns a constant pointer to the TAtmosphereShader, which simulates atmospheric attenuation due to haze, clouds, or fog between the objects in the scene and the viewer.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

Returns a constant pointer to the TAtmosphereShader held by this object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::GetCamera

virtual const TCamera * GetCamera () const

Interface Category:

API.

Purpose:

Returns a constant pointer to the TCamera, which simulates a camera or eye that views the scene.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

Returns a constant pointer to the TCamera held by this object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::GetSceneAttribute

virtual const TGrafAttribute * GetSceneAttribute (const TToken & attributeName) const

Interface Category:

API.

Purpose:

This function always returns NIL because there are no extended attributes in a TRootSceneState. The function is implemented simply to satisfy polymorphism, because this class is a concrete descendant of TSceneState.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

Returns a constant pointer to a TGrafAttribute that is always set to NIL.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::CreateSceneAttributeIterator

virtual TSceneAttributeIterator * CreateSceneAttributeIterator () const

Interface Category:

API.

Purpose:

This function always returns NIL because there are no extended attributes in a TRootSceneState. The function is implemented simply to satisfy polymorphism, because this class is a concrete descendant of TSceneState.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

Returns a constant pointer to a TSceneAttributeIterator that is always set to NIL.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TRootSceneState::CreateLightIterator

virtual TIteratorOver < TKeyValuePair < TLightSurrogate , TLight >>* CreateLightIterator () const

Interface Category:

API.

Purpose:

This function always returns NIL because there is no default set of lights in a TRootSceneState. The function is implemented simply to satisfy polymorphism, because this class is a concrete descendant of TSceneState.

Calling Context:

You can call this function directly.

Parameters:

Return Value:

Always returns NIL.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.
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