Skia
2D Graphics Library
SkShader Class Referenceabstract

#include <SkShader.h>

Inheritance diagram for SkShader:

Classes

struct  GradientInfo
 

Public Types

enum  GradientType {
  kNone_GradientType, kColor_GradientType, kLinear_GradientType, kRadial_GradientType,
  kSweep_GradientType, kConical_GradientType, kLast_GradientType = kConical_GradientType
}
 If the shader subclass can be represented as a gradient, asAGradient returns the matching GradientType enum (or kNone_GradientType if it cannot). More...
 
enum  Type {
  kSkColorFilter_Type, kSkDrawable_Type, kSkDrawLooper_Type, kSkImageFilter_Type,
  kSkMaskFilter_Type, kSkPathEffect_Type, kSkPixelRef_Type, kSkUnused_Type4,
  kSkShaderBase_Type, kSkUnused_Type, kSkUnused_Type2, kSkUnused_Type3
}
 
typedef sk_sp< SkFlattenable >(* Factory) (SkReadBuffer &)
 

Public Member Functions

virtual bool isOpaque () const
 Returns true if the shader is guaranteed to produce only opaque colors, subject to the SkPaint using the shader to apply an opaque alpha value. More...
 
SkImageisAImage (SkMatrix *localMatrix, SkTileMode xy[2]) const
 Iff this shader is backed by a single SkImage, return its ptr (the caller must ref this if they want to keep it longer than the lifetime of the shader). More...
 
bool isAImage () const
 
virtual GradientType asAGradient (GradientInfo *info) const
 
sk_sp< SkShadermakeWithLocalMatrix (const SkMatrix &) const
 Return a shader that will apply the specified localMatrix to this shader. More...
 
sk_sp< SkShadermakeWithColorFilter (sk_sp< SkColorFilter >) const
 Create a new shader that produces the same colors as invoking this shader and then applying the colorfilter. 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< SkDataserialize (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 Factory NameToFactory (const char name[])
 
static const char * FactoryToName (Factory)
 
static void Register (const char name[], Factory)
 
static sk_sp< SkFlattenableDeserialize (Type, const void *data, size_t length, const SkDeserialProcs *procs=nullptr)
 

Friends

class SkShaderBase
 

Detailed Description

Shaders specify the source color(s) for what is being drawn. If a paint has no shader, then the paint's color is used. If the paint has a shader, then the shader's color(s) are use instead, but they are modulated by the paint's alpha. This makes it easy to create a shader once (e.g. bitmap tiling or gradient) and then change its transparency w/o having to modify the original shader... only the paint's alpha needs to be modified.

Member Typedef Documentation

◆ Factory

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

Member Enumeration Documentation

◆ GradientType

If the shader subclass can be represented as a gradient, asAGradient returns the matching GradientType enum (or kNone_GradientType if it cannot).

Also, if info is not null, asAGradient populates info with the relevant (see below) parameters for the gradient. fColorCount is both an input and output parameter. On input, it indicates how many entries in fColors and fColorOffsets can be used, if they are non-NULL. After asAGradient has run, fColorCount indicates how many color-offset pairs there are in the gradient. If there is insufficient space to store all of the color-offset pairs, fColors and fColorOffsets will not be altered. fColorOffsets specifies where on the range of 0 to 1 to transition to the given color. The meaning of fPoint and fRadius is dependant on the type of gradient.

None: info is ignored. Color: fColorOffsets[0] is meaningless. Linear: fPoint[0] and fPoint[1] are the end-points of the gradient Radial: fPoint[0] and fRadius[0] are the center and radius Conical: fPoint[0] and fRadius[0] are the center and radius of the 1st circle fPoint[1] and fRadius[1] are the center and radius of the 2nd circle Sweep: fPoint[0] is the center of the sweep.

Enumerator
kNone_GradientType 
kColor_GradientType 
kLinear_GradientType 
kRadial_GradientType 
kSweep_GradientType 
kConical_GradientType 
kLast_GradientType 

◆ Type

enum SkFlattenable::Type
inherited
Enumerator
kSkColorFilter_Type 
kSkDrawable_Type 
kSkDrawLooper_Type 
kSkImageFilter_Type 
kSkMaskFilter_Type 
kSkPathEffect_Type 
kSkPixelRef_Type 
kSkUnused_Type4 
kSkShaderBase_Type 
kSkUnused_Type 
kSkUnused_Type2 
kSkUnused_Type3 

Member Function Documentation

◆ asAGradient()

virtual GradientType SkShader::asAGradient ( GradientInfo info) const
virtual

◆ Deserialize()

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

◆ 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 SkPath2DPathEffect, SkLayerDrawLooper, SkLine2DPathEffect, SkPath1DPathEffect, SkDiscretePathEffect, Sk2DPathEffect, and SkCornerPathEffect.

◆ 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

◆ getTypeName()

virtual const char* SkFlattenable::getTypeName ( ) const
pure virtualinherited

Returns the name of the object's class.

Implemented in SkDrawable.

◆ isAImage() [1/2]

bool SkShader::isAImage ( ) const
inline

◆ isAImage() [2/2]

SkImage* SkShader::isAImage ( SkMatrix localMatrix,
SkTileMode  xy[2] 
) const

Iff this shader is backed by a single SkImage, return its ptr (the caller must ref this if they want to keep it longer than the lifetime of the shader).

If not, return nullptr.

◆ isOpaque()

virtual bool SkShader::isOpaque ( ) const
inlinevirtual

Returns true if the shader is guaranteed to produce only opaque colors, subject to the SkPaint using the shader to apply an opaque alpha value.

Subclasses should override this to allow some optimizations.

◆ makeWithColorFilter()

sk_sp<SkShader> SkShader::makeWithColorFilter ( sk_sp< SkColorFilter ) const

Create a new shader that produces the same colors as invoking this shader and then applying the colorfilter.

◆ makeWithLocalMatrix()

sk_sp<SkShader> SkShader::makeWithLocalMatrix ( const SkMatrix ) const

Return a shader that will apply the specified localMatrix to this shader.

The specified matrix will be applied before any matrix associated with this shader.

◆ 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().

◆ 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

◆ SkShaderBase

friend class SkShaderBase
friend

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