GrScratchKey Class Reference

A key used for scratch resources. More...

#include <GrResourceKey.h>

Inheritance diagram for GrScratchKey:

Classes
class	Builder

Public Types
typedef uint32_t	ResourceType
	Uniquely identifies the type of resource that is cached as scratch. More...

Public Member Functions
	GrScratchKey ()
	Creates an invalid scratch key. More...
	GrScratchKey (const GrScratchKey &that)
ResourceType	resourceType () const
GrScratchKey &	operator= (const GrScratchKey &that)
bool	operator== (const GrScratchKey &that) const
bool	operator!= (const GrScratchKey &that) const
Public Member Functions inherited from GrResourceKey
uint32_t	hash () const
size_t	size () const

Static Public Member Functions
static ResourceType	GenerateResourceType ()
	Generate a unique ResourceType. More...

Private Types
typedef GrResourceKey	INHERITED

Additional Inherited Members
Protected Member Functions inherited from GrResourceKey
void	reset ()
	Reset to an invalid key. More...
bool	operator== (const GrResourceKey &that) const
GrResourceKey &	operator= (const GrResourceKey &that)
bool	isValid () const
uint32_t	domain () const
size_t	dataSize () const
	size of the key data, excluding meta-data (hash, domain, etc). More...
const uint32_t *	data () const
	ptr to the key data, excluding meta-data (hash, domain, etc). More...
Static Protected Attributes inherited from GrResourceKey
static const uint32_t	kInvalidDomain = 0

Detailed Description

A key used for scratch resources.

There are three important rules about scratch keys:

• Multiple resources can share the same scratch key. Therefore resources assigned the same scratch key should be interchangeable with respect to the code that uses them.
• A resource can have at most one scratch key and it is set at resource creation by the resource itself.
• When a scratch resource is ref'ed it will not be returned from the cache for a subsequent cache request until all refs are released. This facilitates using a scratch key for multiple render-to-texture scenarios. An example is a separable blur:

GrTexture* texture[2]; texture[0] = get_scratch_texture(scratchKey); texture[1] = get_scratch_texture(scratchKey); // texture[0] is already owned so we will get a // different one for texture[1] draw_mask(texture[0], path); // draws path mask to texture[0] blur_x(texture[0], texture[1]); // blurs texture[0] in y and stores result in texture[1] blur_y(texture[1], texture[0]); // blurs texture[1] in y and stores result in texture[0] texture[1]->unref(); // texture 1 can now be recycled for the next request with scratchKey consume_blur(texture[0]); texture[0]->unref(); // texture 0 can now be recycled for the next request with scratchKey

Member Typedef Documentation

typedef uint32_t GrScratchKey::ResourceType

Uniquely identifies the type of resource that is cached as scratch.

Constructor & Destructor Documentation

GrScratchKey::GrScratchKey ( )

inline

Creates an invalid scratch key.

It must be initialized using a Builder object before use.

Member Function Documentation

static ResourceType GrScratchKey::GenerateResourceType ( )

static

Generate a unique ResourceType.

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The documentation for this class was generated from the following file:

• include/gpu/GrResourceKey.h