Scene

A class to composite children paints. More...

#include <thorvg.h>

Inheritance diagram for Scene:

Collaboration diagram for Scene:

Public Member Functions
Result	push (Paint *target, Paint *at=nullptr) noexcept
	Inserts a paint object to the scene.
const std::list< Paint * > &	paints () const noexcept
	Returns the list of paints currently held by the Scene.
Result	remove (Paint *paint=nullptr) noexcept
	Removes a paint object or all paint objects from the scene.
Result	push (SceneEffect effect,...) noexcept
	Apply a post-processing effect to the scene.
Type	type () const noexcept override
	Returns the ID value of this class.
Public Member Functions inherited from Paint
const Paint *	parent () const noexcept
	Retrieves the parent paint object.
Result	visible (bool on) noexcept
	Sets the visibility of the Paint object.
Result	rotate (float degree) noexcept
	Sets the angle by which the object is rotated.
Result	scale (float factor) noexcept
	Sets the scale value of the object.
Result	translate (float x, float y) noexcept
	Sets the values by which the object is moved in a two-dimensional space.
Result	transform (const Matrix &m) noexcept
	Sets the matrix of the affine transformation for the object.
Matrix &	transform () noexcept
	Gets the matrix of the affine transformation of the object.
Result	opacity (uint8_t o) noexcept
	Sets the opacity of the object.
Result	mask (Paint *target, MaskMethod method) noexcept
	Sets the masking target object and the masking method.
Result	clip (Shape *clipper) noexcept
	Clip the drawing region of the paint object.
Result	blend (BlendMethod method) noexcept
	Sets the blending method for the paint object.
Result	bounds (Point *pt4) noexcept
	Retrieves the object-oriented bounding box (OBB) of the paint object in canvas space.
Result	bounds (float *x, float *y, float *w, float *h) noexcept
	Retrieves the axis-aligned bounding box (AABB) of the paint object in canvas space.
bool	intersects (int32_t x, int32_t y, int32_t w=1, int32_t h=1) noexcept
	Checks whether a given region intersects the filled area of the paint.
Paint *	duplicate () const noexcept
	Duplicates the object.
uint8_t	opacity () const noexcept
	Gets the opacity value of the object.
MaskMethod	mask (const Paint **target) const noexcept
	Gets the masking target object and the masking method.
Shape *	clip () const noexcept
	Get the clipper shape of the paint object.
bool	visible () const noexcept
	Gets the current visibility status of the Paint object.
uint16_t	ref () noexcept
	Increment the reference count for the Paint instance.
uint16_t	unref (bool free=true) noexcept
	Decrement the reference count for the Paint instance.
uint16_t	refCnt () const noexcept
	Retrieve the current reference count of the Paint instance.

Static Public Member Functions
static Scene *	gen () noexcept
	Creates a new Scene object.
Static Public Member Functions inherited from Paint
static void	rel (Paint *paint) noexcept
	Safely releases a Paint object.

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

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.

Warning

This class is not designed for inheritance.

Member Function Documentation

gen()

static Scene * gen ( )

staticnoexcept

Creates a new Scene object.

This function allocates and returns a new Scene instance. To properly destroy the Scene object, use Paint::rel().

Returns

A pointer to the newly created Scene object.

See also

Paint::rel()

paints()

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

noexcept

Returns the list of paints currently held by the Scene.

This function provides a list of paint nodes, allowing users to access scene-graph information.

See also

Scene::push()

Scene:remove()

Warning

This is read-only. Do not modify the list.

Since

1.0

push() [1/2]

Result push ( Paint *  target, Paint *  at = nullptr  )

noexcept

Inserts a paint object to the scene.

This function appends a paint object to the scene. If the optional at is provided, the new paint object will be inserted immediately before the specified paint object in the scene. If at is nullptr, the paint object will be added to the end of the scene.

Parameters

[in]	target	A pointer to the Paint object to be added into the scene. This parameter must not be nullptr.
[in]	at	A pointer to an existing Paint object in the scene before which the new paint object will be added. If nullptr, the new paint object is added to the end of the scene. The default is nullptr.

Note

The ownership of the paint object is transferred to the scene upon addition.

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:remove()

push() [2/2]

Result push ( SceneEffect  effect,   ...  )

noexcept

Apply a post-processing effect to the scene.

This function adds a specified effect—such as clearing all effects, applying a Gaussian blur, or adding a drop shadow—to the scene after rendering. Multiple effects can be applied in sequence by calling this function multiple times.

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).

Since

1.0

remove()

Result remove ( Paint *  paint = nullptr )

noexcept

Removes a paint object or all paint objects from the scene.

This function removes a specified paint object from the scene. If no paint object is specified (i.e., the default nullptr is used), the function performs to clear all paints from the scene.

Parameters

[in]

paint

A pointer to the Paint object to be removed from the scene. If nullptr, remove all the paints from the scene.

See also

Scene::push()

Scene::paints()

Since

1.0

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

1.0

Implements Paint.