Scene

A class to composite children paints. More...

Inheritance diagram for Scene:

Public Member Functions
Result	push (std::unique_ptr< Paint > paint) noexcept
	Passes drawing elements to the Scene using Paint objects. More...
Result	reserve (uint32_t size) noexcept
	Sets the size of the container, where all the paints pushed into the Scene are stored. 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...
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...
TVG_DEPRECATED Result	bounds (float *x, float *y, float *w, float *h) const noexcept
	Gets the bounding box of the paint object before any transformation. More...
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...

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

Returns

Result::Success when succeed

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.

Please do not use it, this API is not official one. It could be modified in the next version.

Since

0.2

gen()

static std::unique_ptr<Scene> gen ( )

staticnoexcept

Creates a new Scene object.

Returns

A new Scene object.

push()

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

noexcept

Passes drawing elements to the Scene using Paint objects.

Only pushed paints in the scene will be drawing targets. They are retained by the scene until you call Scene::clear(). If you know the number of the pushed objects in the advance, please call Scene::reserve().

Parameters

[in]

paint

A Paint object to be drawn.

Returns

Result::Success when succeed, Result::MemoryCorruption otherwise.

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::reserve()

reserve()

Result reserve ( uint32_t  size )

noexcept

Sets the size of the container, where all the paints pushed into the Scene are stored.

If the number of objects pushed into the scene is known in advance, calling the function prevents multiple memory reallocation, thus improving the performance.

Parameters

[in]

size

The number of objects for which the memory is to be reserved.

Returns

Result::Success when succeed.