Scene

A class to composite children paints. More...

Inheritance diagram for Scene:

Collaboration diagram for Scene:

Public Member Functions
Result	push (std::unique_ptr< Paint > paint) noexcept
	Passes drawing elements to the Scene using Paint objects. More...
std::list< Paint * > &	paints () noexcept
	Returns the list of the paints that currently held by the Scene. More...
Result	clear (bool free=true) noexcept
	Sets the total number of the paints pushed into the scene to be zero. Depending on the value of the free argument, the paints are freed or not. More...
Result	push (SceneEffect effect,...) noexcept
	Apply a post-processing effect to the scene. More...
Type	type () const noexcept override
	Returns the ID value of this class. More...
Public Member Functions inherited from Paint
Result	rotate (float degree) noexcept
	Sets the angle by which the object is rotated. More...
Result	scale (float factor) noexcept
	Sets the scale value of the object. More...
Result	translate (float x, float y) noexcept
	Sets the values by which the object is moved in a two-dimensional space. More...
Result	transform (const Matrix &m) noexcept
	Sets the matrix of the affine transformation for the object. More...
Matrix	transform () noexcept
	Gets the matrix of the affine transformation of the object. More...
Result	opacity (uint8_t o) noexcept
	Sets the opacity of the object. More...
Result	composite (std::unique_ptr< Paint > target, CompositeMethod method) noexcept
	Sets the composition target object and the composition method. More...
Result	clip (std::unique_ptr< Paint > clipper) noexcept
	Clip the drawing region of the paint object. More...
Result	blend (BlendMethod method) noexcept
	Sets the blending method for the paint object. More...
TVG_DEPRECATED Result	bounds (float *x, float *y, float *w, float *h) const noexcept
Result	bounds (float *x, float *y, float *w, float *h, bool transformed) const noexcept
	Gets the axis-aligned bounding box of the paint object. More...
Paint *	duplicate () const noexcept
	Duplicates the object. More...
uint8_t	opacity () const noexcept
	Gets the opacity value of the object. More...
CompositeMethod	composite (const Paint **target) const noexcept
	Gets the composition target object and the composition method. More...
TVG_DEPRECATED uint32_t	identifier () const noexcept

Static Public Member Functions
static std::unique_ptr< Scene >	gen () noexcept
	Creates a new Scene object. More...
static TVG_DEPRECATED uint32_t	identifier () noexcept

Additional Inherited Members
Public Attributes inherited from Paint
uint32_t	id = 0
	Unique ID of this instance. More...

Detailed Description

A class to composite children paints.

As the traditional graphics rendering method, TVG also enables scene-graph mechanism. This feature supports an array function for managing the multiple paints as one group paint.

As a group, the scene can be transformed, made translucent and composited with other target paints, its children will be affected by the scene world.

Member Function Documentation

clear()

Result clear ( bool  free = true )

noexcept

Sets the total number of the paints pushed into the scene to be zero. Depending on the value of the free argument, the paints are freed or not.

Parameters

[in]

free

If true, the memory occupied by paints is deallocated, otherwise it is not.

Warning

If you don't free the paints they become dangled. They are supposed to be reused, otherwise you are responsible for their lives. Thus please use the free argument only when you know how it works, otherwise it's not recommended.

Since

0.2

gen()

static std::unique_ptr<Scene> gen ( )

staticnoexcept

Creates a new Scene object.

Returns

A new Scene object.

identifier()

static TVG_DEPRECATED uint32_t identifier ( )

staticnoexcept

See also

Scene::type()

paints()

std::list<Paint*>& paints ( )

noexcept

Returns the list of the paints that currently held by the Scene.

This function provides the list of paint nodes, allowing users a direct opportunity to modify the scene tree.

Warning

Please avoid accessing the paints during Scene update/draw. You can access them after calling Canvas::sync().

See also

Canvas::sync()

Scene::push(std::unique_ptr<Paint> paint)

Scene::clear()

Note

Experimental API

push() [1/2]

Result push ( SceneEffect  effect,   ...  )

noexcept

Apply a post-processing effect to the scene.

This function adds a specified scene effect, such as clearing all effects or applying a Gaussian blur, to the scene after it has been rendered. Multiple effects can be applied in sequence.

Parameters

[in]	effect	The scene effect to apply. Options are defined in the SceneEffect enum. For example, use SceneEffect::GaussianBlur to apply a blur with specific parameters.
[in]	...	Additional variadic parameters required for certain effects (e.g., sigma and direction for GaussianBlur).

Note

Experimental API

push() [2/2]

Result push ( std::unique_ptr< Paint >  paint )

noexcept

Passes drawing elements to the Scene using Paint objects.

Only the paints pushed into the scene will be the drawn targets. The paints are retained by the scene until Scene::clear() is called.

Parameters

[in]

paint

A Paint object to be drawn.

Note

The rendering order of the paints is the same as the order as they were pushed. Consider sorting the paints before pushing them if you intend to use layering.

See also

Scene::paints()

Scene::clear()

type()

Type type ( ) const

overridevirtualnoexcept

Returns the ID value of this class.

This method can be used to check the current concrete instance type.

Returns

The class type ID of the Scene instance.

Since

Experimental API

Implements Paint.