#include <SkBlurMaskFilterImpl.h>

Inheritance diagram for SkBlurMaskFilterImpl:

Public Member Functions
	SkBlurMaskFilterImpl (SkScalar sigma, SkBlurStyle, bool respectCTM)

SkMask::Format	getFormat () const override

bool	filterMask (SkMaskBuilder dst, const SkMask &src, const SkMatrix &, SkIPoint margin) const override

SkMaskFilterBase::Type	type () const override

void	computeFastBounds (const SkRect &, SkRect *) const override

bool	asABlur (BlurRec *) const override

sk_sp< SkImageFilter >	asImageFilter (const SkMatrix &ctm) const override

SkScalar	computeXformedSigma (const SkMatrix &ctm) const

SkBlurStyle	blurStyle () const

SkScalar	sigma () const

bool	ignoreXform () const

Public Member Functions inherited from SkMaskFilterBase
virtual SkMask::Format	getFormat () const =0

virtual bool	filterMask (SkMaskBuilder dst, const SkMask &src, const SkMatrix &, SkIPoint margin) const =0

virtual Type	type () const =0

virtual void	computeFastBounds (const SkRect &src, SkRect *dest) const

virtual bool	asABlur (BlurRec *) const

virtual sk_sp< SkImageFilter >	asImageFilter (const SkMatrix &ctm) const

SkFlattenable::Type	getFlattenableType () const override

Public Member Functions inherited from SkMaskFilter
SkRect	approximateFilteredBounds (const SkRect &src) const

Public Member Functions inherited from SkFlattenable
	SkFlattenable ()

virtual Factory	getFactory () const =0

virtual const char *	getTypeName () const =0

virtual void	flatten (SkWriteBuffer &) const

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

Public Member Functions inherited from SkRefCntBase
	SkRefCntBase ()

virtual	~SkRefCntBase ()

bool	unique () const

void	ref () const

void	unref () const

Friends
class	SkBlurMaskFilter

void	sk_register_blur_maskfilter_createproc ()

Additional Inherited Members
Public Types inherited from SkMaskFilterBase
enum class	Type { kBlur , kEmboss , kSDF , kShader , kTable }

Public Types inherited from SkFlattenable
enum	Type { kSkColorFilter_Type , kSkBlender_Type , kSkDrawable_Type , kSkDrawLooper_Type , kSkImageFilter_Type , kSkMaskFilter_Type , kSkPathEffect_Type , kSkShader_Type }

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

Static Public Member Functions inherited from SkMaskFilterBase
static SkFlattenable::Type	GetFlattenableType ()

Static Public Member Functions inherited from SkMaskFilter
static sk_sp< SkMaskFilter >	MakeBlur (SkBlurStyle style, SkScalar sigma, bool respectCTM=true)

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

Static Public Member Functions inherited from SkFlattenable
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 Types inherited from SkMaskFilterBase
enum	FilterReturn { kFalse_FilterReturn , kTrue_FilterReturn , kUnimplemented_FilterReturn }

Protected Member Functions inherited from SkMaskFilterBase
	SkMaskFilterBase ()

virtual FilterReturn	filterRectsToNine (const SkRect[], int count, const SkMatrix &, const SkIRect &clipBounds, SkTLazy< NinePatch > *) const

virtual FilterReturn	filterRRectToNine (const SkRRect &, const SkMatrix &, const SkIRect &clipBounds, SkTLazy< NinePatch > *) const

Detailed Description

Definition at line 28 of file SkBlurMaskFilterImpl.h.

Constructor & Destructor Documentation

◆ SkBlurMaskFilterImpl()

SkBlurMaskFilterImpl::SkBlurMaskFilterImpl	(	SkScalar	sigma,
		SkBlurStyle	style,
		bool	respectCTM
	)

Definition at line 50 of file SkBlurMaskFilterImpl.cpp.

    : fSigma(sigma)
    , fBlurStyle(style)
    , fRespectCTM(respectCTM) {
    SkASSERT(fSigma > 0);
    SkASSERT((unsigned)style <= kLastEnum_SkBlurStyle);
}

Member Function Documentation

◆ asABlur()

bool SkBlurMaskFilterImpl::asABlur ( BlurRec * ) const

overridevirtual

If this filter can be represented by a BlurRec, return true and (if not null) fill in the provided BlurRec parameter. If this effect cannot be represented as a BlurRec, return false and ignore the BlurRec parameter.

Reimplemented from SkMaskFilterBase.

Definition at line 62 of file SkBlurMaskFilterImpl.cpp.

                                                     {
    if (this->ignoreXform()) {
        return false;
    }
 
    if (rec) {
        rec->fSigma = fSigma;
        rec->fStyle = fBlurStyle;
    }
    return true;
}

◆ asImageFilter()

sk_sp< SkImageFilter > SkBlurMaskFilterImpl::asImageFilter ( const SkMatrix & ctm ) const

overridevirtual

Return an SkImageFilter representation of this mask filter that SkCanvas can apply to an alpha-only image to produce an equivalent effect to running the mask filter directly.

Reimplemented from SkMaskFilterBase.

Definition at line 74 of file SkBlurMaskFilterImpl.cpp.

                                                                                  {
    float sigma = fSigma;
    if (this->ignoreXform()) {
        // This is analogous to computeXformedSigma(), but it might be more correct to wrap the
        // blur image filter in a local matrix with ctm^-1, or to control the skif::Mapping when
        // the mask filter layer is restored. This is inaccurate when 'ctm' has skew or perspective
        const float ctmScaleFactor = fSigma / ctm.mapRadius(fSigma);
        sigma *= ctmScaleFactor;
    }
 
    // The null input image filter will be bound to the original coverage mask.
    sk_sp<SkImageFilter> filter = SkImageFilters::Blur(sigma, sigma, nullptr);
    // Combine the original coverage mask (src) and the blurred coverage mask (dst)
    switch(fBlurStyle) {
        case kInner_SkBlurStyle: //  dst = dst * src
                                 //      = 0 * src + src * dst
            return SkImageFilters::Blend(SkBlendMode::kDstIn, std::move(filter), nullptr);
        case kSolid_SkBlurStyle: //  dst = src + dst - src * dst
                                 //      = 1 * src + (1 - src) * dst
            return SkImageFilters::Blend(SkBlendMode::kSrcOver, std::move(filter), nullptr);
        case kOuter_SkBlurStyle: //  dst = dst * (1 - src)
                                 //      = 0 * src + (1 - src) * dst
            return SkImageFilters::Blend(SkBlendMode::kDstOut, std::move(filter), nullptr);
        case kNormal_SkBlurStyle:
            return filter;
    }
    SkUNREACHABLE;
}

◆ blurStyle()

SkBlurStyle SkBlurMaskFilterImpl::blurStyle ( ) const

inline

Definition at line 44 of file SkBlurMaskFilterImpl.h.

44{return fBlurStyle;}

◆ computeFastBounds()

void SkBlurMaskFilterImpl::computeFastBounds	(	const SkRect &	src,
		SkRect *	dest
	)		const

overridevirtual

The fast bounds function is used to enable the paint to be culled early in the drawing pipeline. This function accepts the current bounds of the paint as its src param and the filter adjust those bounds using its current mask and returns the result using the dest param. Callers are allowed to provide the same struct for both src and dest so each implementation must accommodate that behavior.

The default impl calls filterMask with the src mask having no image, but subclasses may override this if they can compute the rect faster.

Reimplemented from SkMaskFilterBase.

Definition at line 506 of file SkBlurMaskFilterImpl.cpp.

                                                                {
    // TODO: if we're doing kInner blur, should we return a different outset?
    //       i.e. pad == 0 ?
 
    SkScalar pad = 3.0f * fSigma;
 
    dst->setLTRB(src.fLeft  - pad, src.fTop    - pad,
                 src.fRight + pad, src.fBottom + pad);
}

◆ computeXformedSigma()

SkScalar SkBlurMaskFilterImpl::computeXformedSigma ( const SkMatrix & ctm ) const

Definition at line 103 of file SkBlurMaskFilterImpl.cpp.

                                                                            {
    constexpr SkScalar kMaxBlurSigma = SkIntToScalar(128);
    SkScalar xformedSigma = this->ignoreXform() ? fSigma : ctm.mapRadius(fSigma);
    return std::min(xformedSigma, kMaxBlurSigma);
}

◆ filterMask()

bool SkBlurMaskFilterImpl::filterMask	(	SkMaskBuilder *	dst,
		const SkMask &	src,
		const SkMatrix &	,
		SkIPoint *	margin
	)		const

overridevirtual

Create a new mask by filter the src mask. If src.fImage == null, then do not allocate or create the dst image but do fill out the other fields in dstMask. If you do allocate a dst image, use SkMask::AllocImage() If this returns false, dst mask is ignored.

Parameters

dst	the result of the filter. If src.fImage == null, dst should not allocate its image
src	the original image to be filtered.
matrix	the CTM
margin	if not null, return the buffer dx/dy need when calculating the effect. Used when drawing a clipped object to know how much larger to allocate the src before applying the filter. If returning false, ignore this parameter.

Returns: true if the dst mask was correctly created.

Implements SkMaskFilterBase.

Definition at line 109 of file SkBlurMaskFilterImpl.cpp.

                                                              {
    SkScalar sigma = this->computeXformedSigma(matrix);
    return SkBlurMask::BoxBlur(dst, src, sigma, fBlurStyle, margin);
}

◆ getFormat()

SkMask::Format SkBlurMaskFilterImpl::getFormat ( ) const

overridevirtual

Returns the format of the resulting mask that this subclass will return when its filterMask() method is called.

Implements SkMaskFilterBase.

Definition at line 58 of file SkBlurMaskFilterImpl.cpp.

                                                   {
    return SkMask::kA8_Format;
}

◆ ignoreXform()

bool SkBlurMaskFilterImpl::ignoreXform ( ) const

inline

Definition at line 46 of file SkBlurMaskFilterImpl.h.

46{ return !fRespectCTM; }

◆ sigma()

SkScalar SkBlurMaskFilterImpl::sigma ( ) const

inline

Definition at line 45 of file SkBlurMaskFilterImpl.h.

45{return fSigma;}

◆ type()

SkMaskFilterBase::Type SkBlurMaskFilterImpl::type ( ) const

inlineoverridevirtual

Implements SkMaskFilterBase.

Definition at line 36 of file SkBlurMaskFilterImpl.h.

36{ return SkMaskFilterBase::Type::kBlur; }

SkMaskFilterBase::Type::kBlur

@ kBlur

Friends And Related Function Documentation

◆ sk_register_blur_maskfilter_createproc

void sk_register_blur_maskfilter_createproc ( )

friend

Definition at line 533 of file SkBlurMaskFilterImpl.cpp.

533{ SK_REGISTER_FLATTENABLE(SkBlurMaskFilterImpl); }

SK_REGISTER_FLATTENABLE

#define SK_REGISTER_FLATTENABLE(type)

Definition: SkFlattenable.h:105

SkBlurMaskFilterImpl

Definition: SkBlurMaskFilterImpl.h:28

◆ SkBlurMaskFilter

friend class SkBlurMaskFilter

friend

Definition at line 71 of file SkBlurMaskFilterImpl.h.

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

third_party/skia/src/core/SkBlurMaskFilterImpl.h
third_party/skia/src/core/SkBlurMaskFilterImpl.cpp

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SkBlurMaskFilterImpl()

Member Function Documentation

◆ asABlur()

◆ asImageFilter()

◆ blurStyle()

◆ computeFastBounds()

◆ computeXformedSigma()

◆ filterMask()

◆ getFormat()

◆ ignoreXform()

◆ sigma()

◆ type()

Friends And Related Function Documentation

◆ sk_register_blur_maskfilter_createproc

◆ SkBlurMaskFilter