chromium/skia/ext/skcolorspace_primaries.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SKIA_EXT_SKCOLORSPACE_PRIMARIES_H_
#define SKIA_EXT_SKCOLORSPACE_PRIMARIES_H_

#include "third_party/skia/include/core/SkColorSpace.h"

#include <string>

// TODO(https://crbug.com/skia/13721): Add these operators to Skia source.
SK_API bool operator==(const SkColorSpacePrimaries& a,
                       const SkColorSpacePrimaries& b);

SK_API bool operator!=(const SkColorSpacePrimaries& a,
                       const SkColorSpacePrimaries& b);

namespace skia {

// Display SkColorSpacePrimaries as a string.
SK_API std::string SkColorSpacePrimariesToString(
    const SkColorSpacePrimaries& primaries);

// Given a matrix that transforms to XYZD50, compute the primaries with a D65
// white point that would produce this matrix.
SK_API SkColorSpacePrimaries
GetD65PrimariesFromToXYZD50Matrix(const skcms_Matrix3x3& m);

}  // namespace skia

namespace SkNamedPrimariesExt {

////////////////////////////////////////////////////////////////////////////////
// Color primaries defined by ITU-T H.273, table 2. Names are given by the first
// specification referenced in the value's row.

// Rec. ITU-R BT.709-6, value 1.
static constexpr SkColorSpacePrimaries kRec709 = …;

// Rec. ITU-R BT.470-6 System M (historical), value 4.
static constexpr SkColorSpacePrimaries kRec470SystemM = …;

// Rec. ITU-R BT.470-6 System B, G (historical), value 5.
static constexpr SkColorSpacePrimaries kRec470SystemBG = …;

// Rec. ITU-R BT.601-7 525, value 6.
static constexpr SkColorSpacePrimaries kRec601 = …;

// SMPTE ST 240, value 7 (functionally the same as value 6).
static constexpr SkColorSpacePrimaries kSMPTE_ST_240 = …;

// Generic film (colour filters using Illuminant C), value 8.
static constexpr SkColorSpacePrimaries kGenericFilm = …;

// Rec. ITU-R BT.2020-2, value 9.
static constexpr SkColorSpacePrimaries kRec2020{ … };

// SMPTE ST 428-1, value 10.
static constexpr SkColorSpacePrimaries kSMPTE_ST_428_1 = …;

// SMPTE RP 431-2, value 11.
static constexpr SkColorSpacePrimaries kSMPTE_RP_431_2 = …;

// SMPTE EG 432-1, value 12.
static constexpr SkColorSpacePrimaries kSMPTE_EG_432_1 = …;

// No corresponding industry specification identified, value 22.
// This is sometimes referred to as EBU 3213-E, but that document doesn't
// specify these values.
static constexpr SkColorSpacePrimaries kITU_T_H273_Value22 = …;

////////////////////////////////////////////////////////////////////////////////
// CSS Color Level 4 predefined and xyz color spaces.

// 'srgb'
static constexpr SkColorSpacePrimaries kSRGB = …;

// 'display-p3' (and also 'p3' as a color gamut).
static constexpr SkColorSpacePrimaries kP3 = …;

// 'a98-rgb'
static constexpr SkColorSpacePrimaries kA98RGB = …;

// 'prophoto-rgb'
static constexpr SkColorSpacePrimaries kProPhotoRGB = …;

// 'rec2020' (as both a predefined color space and color gamut).
// The value kRec2020 is already defined above.

// 'xyzd50'
static constexpr SkColorSpacePrimaries kXYZD50 = …;

// 'xyz' and 'xyzd65'
static constexpr SkColorSpacePrimaries kXYZD65 = …;

////////////////////////////////////////////////////////////////////////////////
// Additional helper color primaries.

// Invalid primaries, initialized to zero.
static constexpr SkColorSpacePrimaries kInvalid = …;

// The GenericRGB space on macOS.
static constexpr SkColorSpacePrimaries kAppleGenericRGB = …;

// Primaries where the colors are rotated and the gamut is huge. Good for
// testing.
static constexpr SkColorSpacePrimaries kWideGamutColorSpin = …;

}  // namespace SkNamedPrimariesExt

#endif  // SKIA_EXT_SKCOLORSPACE_PRIMARIES_H_