SkImageFilter Class Reference

Base class for image filters. More...

#include <SkImageFilter.h>

Inheritance diagram for SkImageFilter:

Public Types
enum	MapDirection { kForward_MapDirection , kReverse_MapDirection }
enum	Type {   kSkColorFilter_Type , kSkBlender_Type , kSkDrawable_Type , kSkDrawLooper_Type ,   kSkImageFilter_Type , kSkMaskFilter_Type , kSkPathEffect_Type , kSkShader_Type }
typedef sk_sp< SkFlattenable >(*	Factory) (SkReadBuffer &)

Public Member Functions
SkIRect	filterBounds (const SkIRect &src, const SkMatrix &ctm, MapDirection, const SkIRect *inputRect=nullptr) const
	Map a device-space rect recursively forward or backward through the filter DAG. More...
bool	isColorFilterNode (SkColorFilter **filterPtr) const
	Returns whether this image filter is a color filter and puts the color filter into the "filterPtr" parameter if it can. More...
bool	asColorFilter (SkColorFilter **filterPtr) const
bool	asAColorFilter (SkColorFilter **filterPtr) const
	Returns true (and optionally returns a ref'd filter) if this imagefilter can be completely replaced by the returned colorfilter. More...
int	countInputs () const
	Returns the number of inputs this filter will accept (some inputs can be NULL). More...
const SkImageFilter *	getInput (int i) const
	Returns the input filter at a given index, or NULL if no input is connected. More...
virtual SkRect	computeFastBounds (const SkRect &bounds) const
bool	canComputeFastBounds () const
sk_sp< SkImageFilter >	makeWithLocalMatrix (const SkMatrix &matrix) const
	If this filter can be represented by another filter + a localMatrix, return that filter, else return null. More...
virtual Factory	getFactory () const =0
	Implement this to return a factory function pointer that can be called to recreate your class given a buffer (previously written to by your override of flatten(). More...
virtual const char *	getTypeName () const =0
	Returns the name of the object's class. More...
virtual void	flatten (SkWriteBuffer &) const
	Override this if your subclass needs to record data that it will need to recreate itself from its CreateProc (returned by getFactory()). More...
virtual Type	getFlattenableType () const =0
sk_sp< SkData >	serialize (const SkSerialProcs *=nullptr) const
size_t	serialize (void *memory, size_t memory_size, const SkSerialProcs *=nullptr) const
bool	unique () const
	May return true if the caller is the only owner. More...
void	ref () const
	Increment the reference count. More...
void	unref () const
	Decrement the reference count. More...

Static Public Member Functions
static sk_sp< SkImageFilter >	Deserialize (const void *data, size_t size, const SkDeserialProcs *procs=nullptr)
static Factory	NameToFactory (const char name[])
static const char *	FactoryToName (Factory)
static void	Register (const char name[], Factory)
static sk_sp< SkFlattenable >	Deserialize (Type, const void *data, size_t length, const SkDeserialProcs *procs=nullptr)

Protected Member Functions
sk_sp< SkImageFilter >	refMe () const

Friends
class	SkImageFilter_Base

Detailed Description

Base class for image filters.

If one is installed in the paint, then all drawing occurs as usual, but it is as if the drawing happened into an offscreen (before the xfermode is applied). This offscreen bitmap will then be handed to the imagefilter, who in turn creates a new bitmap which is what will finally be drawn to the device (using the original xfermode).

The local space of image filters matches the local space of the drawn geometry. For instance if there is rotation on the canvas, the blur will be computed along those rotated axes and not in the device space. In order to achieve this result, the actual drawing of the geometry may happen in an unrotated coordinate system so that the filtered image can be computed more easily, and then it will be post transformed to match what would have been produced if the geometry were drawn with the total canvas matrix to begin with.

Member Typedef Documentation

Factory

typedef sk_sp<SkFlattenable>(* SkFlattenable::Factory) (SkReadBuffer &)

inherited

Member Enumeration Documentation

MapDirection

enum SkImageFilter::MapDirection

Enumerator
kForward_MapDirection
kReverse_MapDirection

Type

enum SkFlattenable::Type

inherited

Enumerator
kSkColorFilter_Type
kSkBlender_Type
kSkDrawable_Type
kSkDrawLooper_Type
kSkImageFilter_Type
kSkMaskFilter_Type
kSkPathEffect_Type
kSkShader_Type

Member Function Documentation

asAColorFilter()

bool SkImageFilter::asAColorFilter

(

SkColorFilter **

filterPtr

)

const

Returns true (and optionally returns a ref'd filter) if this imagefilter can be completely replaced by the returned colorfilter.

i.e. the two effects will affect drawing in the same way.

asColorFilter()

bool SkImageFilter::asColorFilter ( SkColorFilter **  filterPtr ) const

inline

canComputeFastBounds()

bool SkImageFilter::canComputeFastBounds

(

)

const

computeFastBounds()

virtual SkRect SkImageFilter::computeFastBounds ( const SkRect &  bounds ) const

virtual

countInputs()

int SkImageFilter::countInputs

(

)

const

Returns the number of inputs this filter will accept (some inputs can be NULL).

Deserialize() [1/2]

static sk_sp<SkImageFilter> SkImageFilter::Deserialize ( const void *  data, size_t  size, const SkDeserialProcs *  procs = nullptr  )

inlinestatic

Deserialize() [2/2]

static sk_sp<SkFlattenable> SkFlattenable::Deserialize ( Type  , const void *  data, size_t  length, const SkDeserialProcs *  procs = nullptr  )

staticinherited

FactoryToName()

static const char* SkFlattenable::FactoryToName ( Factory  )

staticinherited

filterBounds()

SkIRect SkImageFilter::filterBounds	(	const SkIRect &	src,
		const SkMatrix &	ctm,
		MapDirection	,
		const SkIRect *	inputRect = nullptr
	)		const

Map a device-space rect recursively forward or backward through the filter DAG.

kForward_MapDirection is used to determine which pixels of the destination canvas a source image rect would touch after filtering. kReverse_MapDirection is used to determine which rect of the source image would be required to fill the given rect (typically, clip bounds). Used for clipping and temp-buffer allocations, so the result need not be exact, but should never be smaller than the real answer. The default implementation recursively unions all input bounds, or returns the source rect if no inputs.

In kReverse mode, 'inputRect' is the device-space bounds of the input pixels. In kForward mode it should always be null. If 'inputRect' is null in kReverse mode the resulting answer may be incorrect.

flatten()

virtual void SkFlattenable::flatten ( SkWriteBuffer &  ) const

inlinevirtualinherited

Override this if your subclass needs to record data that it will need to recreate itself from its CreateProc (returned by getFactory()).

DEPRECATED public : will move to protected ... use serialize() instead

Reimplemented in SkLayerDrawLooper.

getFactory()

virtual Factory SkFlattenable::getFactory ( ) const

pure virtualinherited

Implement this to return a factory function pointer that can be called to recreate your class given a buffer (previously written to by your override of flatten().

Implemented in SkDrawable.

getFlattenableType()

virtual Type SkFlattenable::getFlattenableType ( ) const

pure virtualinherited

Implemented in SkDrawLooper, and SkDrawable.

getInput()

const SkImageFilter* SkImageFilter::getInput

(

int

i

)

const

Returns the input filter at a given index, or NULL if no input is connected.

The indices used are filter-specific.

getTypeName()

virtual const char* SkFlattenable::getTypeName ( ) const

pure virtualinherited

Returns the name of the object's class.

Implemented in SkDrawable.

isColorFilterNode()

bool SkImageFilter::isColorFilterNode

(

SkColorFilter **

filterPtr

)

const

Returns whether this image filter is a color filter and puts the color filter into the "filterPtr" parameter if it can.

Does nothing otherwise. If this returns false, then the filterPtr is unchanged. If this returns true, then if filterPtr is not null, it must be set to a ref'd colorfitler (i.e. it may not be set to NULL).

makeWithLocalMatrix()

sk_sp<SkImageFilter> SkImageFilter::makeWithLocalMatrix

(

const SkMatrix &

matrix

)

const

If this filter can be represented by another filter + a localMatrix, return that filter, else return null.

NameToFactory()

static Factory SkFlattenable::NameToFactory ( const char  name[] )

staticinherited

ref()

void SkRefCntBase::ref ( ) const

inlineinherited

Increment the reference count.

Must be balanced by a call to unref().

refMe()

sk_sp<SkImageFilter> SkImageFilter::refMe ( ) const

inlineprotected

Register()

static void SkFlattenable::Register ( const char  name[], Factory    )

staticinherited

serialize() [1/2]

sk_sp<SkData> SkFlattenable::serialize ( const SkSerialProcs *  = nullptr ) const

inherited

serialize() [2/2]

size_t SkFlattenable::serialize ( void *  memory, size_t  memory_size, const SkSerialProcs *  = nullptr  ) const

inherited

unique()

bool SkRefCntBase::unique ( ) const

inlineinherited

May return true if the caller is the only owner.

Ensures that all previous owner's actions are complete.

unref()

void SkRefCntBase::unref ( ) const

inlineinherited

Decrement the reference count.

If the reference count is 1 before the decrement, then delete the object. Note that if this is the case, then the object needs to have been allocated via new, and not on the stack.

Friends And Related Function Documentation

SkImageFilter_Base

friend class SkImageFilter_Base

friend

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

• /CHECKOUT/include/core/SkImageFilter.h