stmg::CachedSurfaces Class Reference

Cairo cached surfaces for an image. More...

Public Member Functions
void	addSize (int32_t nW, int32_t nH) noexcept
	Tells to keep a ref counted cache with a certain size. More...
void	subSize (int32_t nW, int32_t nH) noexcept
	Decrement the ref count for a cached surface. More...
const Cairo::RefPtr< Cairo::Surface > &	getCachedRgba (int32_t nW, int32_t nH, bool &bCreated) noexcept
	Returns a cached rgba surface. More...
Cairo::RefPtr< Cairo::Surface >	getRgba (int32_t nW, int32_t nH, bool &bCreated) noexcept
	Return a rgba (possibly cached) surface of a certain size. More...
const Cairo::RefPtr< Cairo::Surface > &	getCachedA (int32_t nW, int32_t nH, bool &bCreated) noexcept
	Returns a cached alpha channel surface. More...
Cairo::RefPtr< Cairo::Surface >	getA (int32_t nW, int32_t nH, bool &bCreated) noexcept
	Return a possibly cached alpha channel surface of a certain size. More...
void	clear () noexcept
	Clears all ref counted sized surfaces. More...

Detailed Description

Cairo cached surfaces for an image.

Keeps sized surfaces to avoid redrawing the same image. The creation is done lazily.

Member Function Documentation

addSize()

void stmg::CachedSurfaces::addSize ( int32_t  nW, int32_t  nH  )

noexcept

Tells to keep a ref counted cache with a certain size.

The surface isn't created right away but only when first requested by getRgba() or getA().

Parameters

nW	The width of the cached surface(s).
nH	The height of the cached surface(s).

clear()

void stmg::CachedSurfaces::clear ( )

noexcept

Clears all ref counted sized surfaces.

Also resets all the ref counts.

getA()

Cairo::RefPtr<Cairo::Surface> stmg::CachedSurfaces::getA ( int32_t  nW, int32_t  nH, bool &  bCreated  )

noexcept

Return a possibly cached alpha channel surface of a certain size.

Parameters

nW	The width of the surface in pixel.
nH	The height of the surface in pixel.
bCreated	Whether the surface had to be created.

Returns

The alpha channel surface.

getCachedA()

const Cairo::RefPtr<Cairo::Surface>& stmg::CachedSurfaces::getCachedA ( int32_t  nW, int32_t  nH, bool &  bCreated  )

noexcept

Returns a cached alpha channel surface.

Parameters

nW	The width in pixels.
nH	The height in pixels.
bCreated	Whether the surface had to be created.

Returns

The alpha surface or null if the size is not cached.

getCachedRgba()

const Cairo::RefPtr<Cairo::Surface>& stmg::CachedSurfaces::getCachedRgba ( int32_t  nW, int32_t  nH, bool &  bCreated  )

noexcept

Returns a cached rgba surface.

Parameters

nW	The width in pixels.
nH	The height in pixels.
bCreated	Whether the surface had to be created.

Returns

The surface or null if the size is not cached.

getRgba()

Cairo::RefPtr<Cairo::Surface> stmg::CachedSurfaces::getRgba ( int32_t  nW, int32_t  nH, bool &  bCreated  )

noexcept

Return a rgba (possibly cached) surface of a certain size.

Parameters

nW	The width of the cached surface.
nH	The height of the cached surface.
bCreated	Whether the surface had to be created.

Returns

The rgba surface.

subSize()

void stmg::CachedSurfaces::subSize ( int32_t  nW, int32_t  nH  )

noexcept

Decrement the ref count for a cached surface.

If the ref count reaches 0 the cached surface is removed.

Parameters

nW	The width of the cached surface(s).
nH	The height of the cached surface(s).