#include <SkMaskGamma.h>

Inheritance diagram for SkColorSpaceLuminance:

Public Member Functions
virtual	~SkColorSpaceLuminance ()

virtual SkScalar	toLuma (SkScalar gamma, SkScalar luminance) const =0

virtual SkScalar	fromLuma (SkScalar gamma, SkScalar luma) const =0

Static Public Member Functions
static U8CPU	computeLuminance (SkScalar gamma, SkColor c)

static const SkColorSpaceLuminance &	Fetch (SkScalar gamma)

Detailed Description

SkColorSpaceLuminance is used to convert luminances to and from linear and perceptual color spaces.

Luma is used to specify a linear luminance value [0.0, 1.0]. Luminance is used to specify a luminance value in an arbitrary color space [0.0, 1.0].

Definition at line 29 of file SkMaskGamma.h.

Constructor & Destructor Documentation

◆ ~SkColorSpaceLuminance()

virtual SkColorSpaceLuminance::~SkColorSpaceLuminance ( )

inlinevirtual

Definition at line 31 of file SkMaskGamma.h.

31{ }

Member Function Documentation

◆ computeLuminance()

static U8CPU SkColorSpaceLuminance::computeLuminance	(	SkScalar	gamma,
		SkColor	c
	)

inlinestatic

Converts a color to a luminance value.

Definition at line 39 of file SkMaskGamma.h.

                                                             {
        const SkColorSpaceLuminance& luminance = Fetch(gamma);
        SkScalar r = luminance.toLuma(gamma, SkIntToScalar(SkColorGetR(c)) / 255);
        SkScalar g = luminance.toLuma(gamma, SkIntToScalar(SkColorGetG(c)) / 255);
        SkScalar b = luminance.toLuma(gamma, SkIntToScalar(SkColorGetB(c)) / 255);
        SkScalar luma = r * SK_LUM_COEFF_R +
                        g * SK_LUM_COEFF_G +
                        b * SK_LUM_COEFF_B;
        SkASSERT(luma <= SK_Scalar1);
        return SkScalarRoundToInt(luminance.fromLuma(gamma, luma) * 255);
    }

◆ Fetch()

const SkColorSpaceLuminance & SkColorSpaceLuminance::Fetch ( SkScalar gamma )

static

Retrieves the SkColorSpaceLuminance for the given gamma.

Definition at line 60 of file SkMaskGamma.cpp.

                                                                          {
    static SkLinearColorSpaceLuminance gSkLinearColorSpaceLuminance;
    static SkGammaColorSpaceLuminance gSkGammaColorSpaceLuminance;
    static SkSRGBColorSpaceLuminance gSkSRGBColorSpaceLuminance;
 
    if (0 == gamma) {
        return gSkSRGBColorSpaceLuminance;
    } else if (SK_Scalar1 == gamma) {
        return gSkLinearColorSpaceLuminance;
    } else {
        return gSkGammaColorSpaceLuminance;
    }
}

◆ fromLuma()

virtual SkScalar SkColorSpaceLuminance::fromLuma	(	SkScalar	gamma,
		SkScalar	luma
	)		const

pure virtual

Converts a linear luma to a color component luminance in the color space.

◆ toLuma()

virtual SkScalar SkColorSpaceLuminance::toLuma	(	SkScalar	gamma,
		SkScalar	luminance
	)		const

pure virtual

Converts a color component luminance in the color space to a linear luma.

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

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

Public Member Functions

Static Public Member Functions