Tizen Native API  3.0
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Dali::RenderTask Class Reference
Rendering & Effect

RenderTasks describe how the Dali scene should be rendered. More...

Inheritance diagram for Dali::RenderTask:
Dali::Handle Dali::BaseHandle

Classes

struct  Property
 Enumeration for instances of properties belonging to the RenderTask class. More...

Public Types

enum  RefreshRate
 Enumeration for the refresh-rate of the RenderTask. More...
typedef Signal< void(RenderTask
&source) > 		RenderTaskSignalType
 Typedef for signals sent by this class.
typedef bool(* ScreenToFrameBufferFunction )(Vector2 &coordinates)
 A pointer to a function for converting screen to frame-buffer coordinates.
typedef bool(*const ConstScreenToFrameBufferFunction )(Vector2 &coordinates)
 A pointer to a function for converting screen to frame-buffer coordinates.

Public Member Functions

 RenderTask ()
 Creates an empty RenderTask handle.
 ~RenderTask ()
 Destructor.
 RenderTask (const RenderTask &handle)
 This copy constructor is required for (smart) pointer semantics.
RenderTask & operator= (const RenderTask &rhs)
 This assignment operator is required for (smart) pointer semantics.
void SetSourceActor (Actor actor)
 Sets the actors to be rendered.
Actor GetSourceActor () const
 Retrieves the actors to be rendered.
void SetExclusive (bool exclusive)
 Sets whether the RenderTask has exclusive access to the source actors; the default is false.
bool IsExclusive () const
 Queries whether the RenderTask has exclusive access to the source actors.
void SetInputEnabled (bool enabled)
 Sets whether the render-task should be considered for input handling; the default is true.
bool GetInputEnabled () const
 Queries whether the render-task should be considered for input handling.
void SetCameraActor (CameraActor cameraActor)
 Sets the actor from which the scene is viewed.
CameraActor GetCameraActor () const
 Retrieves the actor from which the scene is viewed.
void SetTargetFrameBuffer (FrameBufferImage frameBuffer)
 Sets the frame-buffer used as a render target.
FrameBufferImage GetTargetFrameBuffer () const
 Retrieves the frame-buffer used as a render target.
void SetFrameBuffer (FrameBuffer frameBuffer)
 Sets the frame-buffer used as a render target.
FrameBuffer GetFrameBuffer () const
 Retrieves the frame-buffer used as a render target.
void SetScreenToFrameBufferFunction (ScreenToFrameBufferFunction conversionFunction)
 Sets the function used to convert screen coordinates to frame-buffer coordinates.
ScreenToFrameBufferFunction GetScreenToFrameBufferFunction () const
 Retrieves the function used to convert screen coordinates to frame-buffer coordinates.
void SetScreenToFrameBufferMappingActor (Actor mappingActor)
 Sets the actor used to convert screen coordinates to frame-buffer coordinates.
Actor GetScreenToFrameBufferMappingActor () const
 Retrieves the actor used to convert screen coordinates to frame-buffer coordinates.
void SetViewportPosition (Vector2 position)
 Sets the GL viewport position used when rendering.
Vector2 GetCurrentViewportPosition () const
 Retrieves the GL viewport position used when rendering.
void SetViewportSize (Vector2 size)
 Sets the GL viewport size used when rendering.
Vector2 GetCurrentViewportSize () const
 Retrieves the GL viewport size used when rendering.
void SetViewport (Viewport viewport)
 Sets the GL viewport used when rendering.
Viewport GetViewport () const
 Retrieves the GL viewport used when rendering.
void SetClearColor (const Vector4 &color)
 Sets the clear color used when SetClearEnabled(true) is used.
Vector4 GetClearColor () const
 Retrieves the clear color used when SetClearEnabled(true) is used.
void SetClearEnabled (bool enabled)
 Sets whether the render-task will clear the results of previous render-tasks.
bool GetClearEnabled () const
 Queries whether the render-task will clear the results of previous render-tasks.
void SetCullMode (bool cullMode)
 Sets whether the render task will cull the actors to the camera's view frustum.
bool GetCullMode () const
 Gets the cull mode.
void SetRefreshRate (unsigned int refreshRate)
 Sets the refresh-rate of the RenderTask.
unsigned int GetRefreshRate () const
 Queries the refresh-rate of the RenderTask.
RenderTaskSignalType & FinishedSignal ()
 If the refresh rate is REFRESH_ONCE, connect to this signal to be notified when a RenderTask has finished.

Static Public Member Functions

static RenderTask DownCast (BaseHandle handle)
 Downcasts a handle to RenderTask handle.

Static Public Attributes

static
ConstScreenToFrameBufferFunction 		DEFAULT_SCREEN_TO_FRAMEBUFFER_FUNCTION
 The default conversion function returns false for any screen coordinates.
static
ConstScreenToFrameBufferFunction 		FULLSCREEN_FRAMEBUFFER_FUNCTION
 This conversion function outputs the (unmodified) screen coordinates as frame-buffer coordinates.
static const bool DEFAULT_EXCLUSIVE
 false
static const bool DEFAULT_INPUT_ENABLED
 true
static const Vector4 DEFAULT_CLEAR_COLOR
 Color::BLACK.
static const bool DEFAULT_CLEAR_ENABLED
 false
static const bool DEFAULT_CULL_MODE
 true
static const unsigned int DEFAULT_REFRESH_RATE
 REFRESH_ALWAYS.

Detailed Description

RenderTasks describe how the Dali scene should be rendered.

The Stage::GetRenderTaskList() method provides access to an ordered list of render-tasks.

Each RenderTask must specify the source actors to be rendered, and a camera actor from which the scene is viewed.

RenderTasks may optionally target a frame-buffer, otherwise the default GL surface is used; typically this is a window provided by the native system.

By default Dali provides a single RenderTask, which renders the entire actor hierachy using a default camera actor and GL surface. If stereoscopic rendering is enabled, Dali will create two additional render tasks, on for each eye. Each render task will have its own camera parented to the default camera actor.

The first RenderTask used for input handling will be the last one rendered, which also has input enabled, and has a valid source & camera actor; see SetInputEnabled().

If none of the actors are hit in the last RenderTask rendered, then input handling will continue with the second last RenderTask rendered, and so on.

All RenderTasks which target a frame-buffer (i.e. off screen) will be rendered before all RenderTasks which target the default GL surface. This allows the user to render intermediate targets which are used later when targeting the screen.

A RenderTask targeting a frame-buffer can still be hit-tested, provided that the screen->frame-buffer coordinate conversion is successful; see SetScreenToFrameBufferFunction().

If the refresh rate id REFRESH_ONCE and a "Finish" signal is connected, it will be emitted when the RenderTask is completed. Note that all connected signals must be disconnected before the object is destroyed. This is typically done in the object destructor, and requires either the Dali::Connection object or Dali::RenderTask handle to be stored.

Signals | Signal Name | Method | |--------------|-----------------------| | finished | FinishedSignal() |

Since:
2.4, DALi version 1.0.0

Member Typedef Documentation

typedef bool(* const Dali::RenderTask::ConstScreenToFrameBufferFunction)(Vector2 &coordinates)

A pointer to a function for converting screen to frame-buffer coordinates.

Since:
2.4, DALi version 1.0.0
Parameters:
[in,out]coordinatesThe screen coordinates to convert where (0,0) is the top-left of the screen
Returns:
True if the conversion was successful, otherwise coordinates should be unmodified
typedef Signal< void (RenderTask& source) > Dali::RenderTask::RenderTaskSignalType

Typedef for signals sent by this class.

Since:
2.4, DALi version 1.0.0
typedef bool(* Dali::RenderTask::ScreenToFrameBufferFunction)(Vector2 &coordinates)

A pointer to a function for converting screen to frame-buffer coordinates.

Since:
2.4, DALi version 1.0.0
Parameters:
[in,out]coordinatesThe screen coordinates to convert where (0,0) is the top-left of the screen
Returns:
True if the conversion was successful, otherwise coordinates should be unmodified

Member Enumeration Documentation

enum Dali::RenderTask::RefreshRate

Enumeration for the refresh-rate of the RenderTask.

Since:
2.4, DALi version 1.0.0
Enumerator:
REFRESH_ONCE 

Process once only e.g. take a snap-shot of the scene.

Since:
2.4, DALi version 1.0.0
REFRESH_ALWAYS 

Process every frame.

Since:
2.4, DALi version 1.0.0

Constructor & Destructor Documentation

Dali::RenderTask::RenderTask ( )

Creates an empty RenderTask handle.

This can be initialised with RenderTaskList::CreateRenderTask().

Since:
2.4, DALi version 1.0.0
Dali::RenderTask::~RenderTask ( )

Destructor.

This is non-virtual since derived Handle types must not contain data or virtual methods.

Since:
2.4, DALi version 1.0.0
Dali::RenderTask::RenderTask ( const RenderTask &  handle)

This copy constructor is required for (smart) pointer semantics.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]handleA reference to the copied handle

Member Function Documentation

static RenderTask Dali::RenderTask::DownCast ( BaseHandle  handle) [static]

Downcasts a handle to RenderTask handle.

If handle points to a RenderTask, the downcast produces valid handle. If not, the returned handle is left uninitialized.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]handleA handle to an object
Returns:
A handle to a RenderTask or an uninitialized handle

Reimplemented from Dali::Handle.

RenderTaskSignalType& Dali::RenderTask::FinishedSignal ( )

If the refresh rate is REFRESH_ONCE, connect to this signal to be notified when a RenderTask has finished.

Since:
2.4, DALi version 1.0.0
Returns:
The signal to connect to
CameraActor Dali::RenderTask::GetCameraActor ( ) const

Retrieves the actor from which the scene is viewed.

Since:
2.4, DALi version 1.0.0
Returns:
The scene is viewed from the perspective of this actor
Vector4 Dali::RenderTask::GetClearColor ( ) const

Retrieves the clear color used when SetClearEnabled(true) is used.

Since:
2.4, DALi version 1.0.0
Returns:
The clear color
Note:
This property can be animated; the return value may not match the value written with SetClearColor().
bool Dali::RenderTask::GetClearEnabled ( ) const

Queries whether the render-task will clear the results of previous render-tasks.

Since:
2.4, DALi version 1.0.0
Returns:
True if the render-task should clear
bool Dali::RenderTask::GetCullMode ( ) const

Gets the cull mode.

Since:
2.4, DALi version 1.0.0
Returns:
True if the render task should cull the actors to the camera's view frustum
Vector2 Dali::RenderTask::GetCurrentViewportPosition ( ) const

Retrieves the GL viewport position used when rendering.

Since:
2.4, DALi version 1.0.0
Returns:
The viewport
Vector2 Dali::RenderTask::GetCurrentViewportSize ( ) const

Retrieves the GL viewport size used when rendering.

Since:
2.4, DALi version 1.0.0
Returns:
The viewport
FrameBuffer Dali::RenderTask::GetFrameBuffer ( ) const

Retrieves the frame-buffer used as a render target.

Since:
3.0, DALi version 1.1.38
Returns:
The framebuffer
bool Dali::RenderTask::GetInputEnabled ( ) const

Queries whether the render-task should be considered for input handling.

Since:
2.4, DALi version 1.0.0
Returns:
True if the render-task should be considered for input handling
unsigned int Dali::RenderTask::GetRefreshRate ( ) const

Queries the refresh-rate of the RenderTask.

Since:
2.4, DALi version 1.0.0
Returns:
The refresh-rate
ScreenToFrameBufferFunction Dali::RenderTask::GetScreenToFrameBufferFunction ( ) const

Retrieves the function used to convert screen coordinates to frame-buffer coordinates.

Since:
2.4, DALi version 1.0.0
Returns:
The conversion function
Actor Dali::RenderTask::GetScreenToFrameBufferMappingActor ( ) const

Retrieves the actor used to convert screen coordinates to frame-buffer coordinates.

Since:
2.4, DALi version 1.0.0
Returns:
The actor used for conversion
Actor Dali::RenderTask::GetSourceActor ( ) const

Retrieves the actors to be rendered.

Since:
2.4, DALi version 1.0.0
Returns:
This actor and its children will be rendered
FrameBufferImage Dali::RenderTask::GetTargetFrameBuffer ( ) const

Retrieves the frame-buffer used as a render target.

Since:
2.4, DALi version 1.0.0
Returns:
A valid frame-buffer handle, or an uninitialised handle if off-screen rendering is disabled
Viewport Dali::RenderTask::GetViewport ( ) const

Retrieves the GL viewport used when rendering.

Since:
2.4, DALi version 1.0.0
Returns:
The viewport
bool Dali::RenderTask::IsExclusive ( ) const

Queries whether the RenderTask has exclusive access to the source actors.

Since:
2.4, DALi version 1.0.0
Returns:
True if the source actors will only be rendered by this render-task
RenderTask& Dali::RenderTask::operator= ( const RenderTask &  rhs)

This assignment operator is required for (smart) pointer semantics.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]rhsA reference to the copied handle
Returns:
A reference to this
void Dali::RenderTask::SetCameraActor ( CameraActor  cameraActor)

Sets the actor from which the scene is viewed.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]cameraActorThe scene is viewed from the perspective of this actor
void Dali::RenderTask::SetClearColor ( const Vector4 &  color)

Sets the clear color used when SetClearEnabled(true) is used.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]colorThe new clear color
void Dali::RenderTask::SetClearEnabled ( bool  enabled)

Sets whether the render-task will clear the results of previous render-tasks.

The default is false.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]enabledTrue if the render-task should clear
Note:
The default GL surface is cleared automatically at the beginning of each frame; this setting is only useful when 2+ render-tasks are used, and the result of the first task needs to be (partially) cleared before rendering the second.
void Dali::RenderTask::SetCullMode ( bool  cullMode)

Sets whether the render task will cull the actors to the camera's view frustum.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]cullModeTrue if the renderers should be culled
Note:
The default mode is to cull actors.
If the shader uses Shader::Hint::MODIFIES_GEOMETRY then culling optimizations are disabled.
See also:
Shader::Hint
void Dali::RenderTask::SetExclusive ( bool  exclusive)

Sets whether the RenderTask has exclusive access to the source actors; the default is false.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]exclusiveTrue if the source actors will only be rendered by this render-task
void Dali::RenderTask::SetFrameBuffer ( FrameBuffer  frameBuffer)

Sets the frame-buffer used as a render target.

Since:
3.0, DALi version 1.1.38
Parameters:
[in]frameBufferer A valid FrameBuffer handle to enable off-screen rendering, or an uninitialized handle to disable it
void Dali::RenderTask::SetInputEnabled ( bool  enabled)

Sets whether the render-task should be considered for input handling; the default is true.

The task used for input handling will be last task in the RenderTaskList which has input enabled, and has a valid source & camera actor. A RenderTask targetting a frame-buffer can still be hit-tested, provided that the screen->frame-buffer coordinate conversion is successful; see also SetScreenToFrameBufferFunction().

Since:
2.4, DALi version 1.0.0
Parameters:
[in]enabledTrue if the render-task should be considered for input handling
void Dali::RenderTask::SetRefreshRate ( unsigned int  refreshRate)

Sets the refresh-rate of the RenderTask.

The default is REFRESH_ALWAYS (1), meaning that the RenderTask will be processed every frame if the scene graph is changing. It may be desirable to process less frequently. For example, SetRefreshRate(3) will process once every 3 frames if the scene graph is changing. If the scene graph is not changing, then the render task will not be rendered, regardless of this value.

The REFRESH_ONCE value means that the RenderTask will be processed once only, to take a snap-shot of the scene. Repeatedly calling SetRefreshRate(REFRESH_ONCE) will cause more snap-shots to be taken.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]refreshRateThe new refresh rate
void Dali::RenderTask::SetScreenToFrameBufferFunction ( ScreenToFrameBufferFunction  conversionFunction)

Sets the function used to convert screen coordinates to frame-buffer coordinates.

This is useful for hit-testing actors which are rendered off-screen.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]conversionFunctionThe conversion function
void Dali::RenderTask::SetScreenToFrameBufferMappingActor ( Actor  mappingActor)

Sets the actor used to convert screen coordinates to frame-buffer coordinates.

The local coordinates of the actor are mapped as frame-buffer coordinates. This is useful for hit-testing actors which are rendered off-screen.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]mappingActorThe actor used for conversion
Note:
The mapping actor needs to be rendered by the default render task to make the mapping work properly.
void Dali::RenderTask::SetSourceActor ( Actor  actor)

Sets the actors to be rendered.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]actorThis actor and its children will be rendered. If actor is an empty handle, then nothing will be rendered
void Dali::RenderTask::SetTargetFrameBuffer ( FrameBufferImage  frameBuffer)

Sets the frame-buffer used as a render target.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]frameBufferA valid frame-buffer handle to enable off-screen rendering, or an uninitialized handle to disable
void Dali::RenderTask::SetViewport ( Viewport  viewport)

Sets the GL viewport used when rendering.

This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates. By default this will match the target window or frame-buffer size.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]viewportThe new viewport
Note:
Unlike the glViewport method, the x & y coordinates refer to the top-left of the viewport rectangle.
void Dali::RenderTask::SetViewportPosition ( Vector2  position)

Sets the GL viewport position used when rendering.

This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates. By default this will match the target window or frame-buffer size.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]positionThe viewports position (x,y)
Note:
Unlike the glViewport method, the x & y coordinates refer to the top-left of the viewport rectangle.
void Dali::RenderTask::SetViewportSize ( Vector2  size)

Sets the GL viewport size used when rendering.

This specifies the transformation between normalized device coordinates and target window (or frame-buffer) coordinates. By default this will match the target window or frame-buffer size.

Since:
2.4, DALi version 1.0.0
Parameters:
[in]sizeThe viewports size (width,height)

Member Data Documentation

ConstScreenToFrameBufferFunction Dali::RenderTask::DEFAULT_SCREEN_TO_FRAMEBUFFER_FUNCTION [static]

The default conversion function returns false for any screen coordinates.

This effectively disables hit-testing for RenderTasks rendering to a frame buffer. See also FULLSCREEN_FRAMEBUFFER_FUNCTION below.

ConstScreenToFrameBufferFunction Dali::RenderTask::FULLSCREEN_FRAMEBUFFER_FUNCTION [static]

This conversion function outputs the (unmodified) screen coordinates as frame-buffer coordinates.

Therefore the contents of an off-screen image is expected to be rendered "full screen".