colorspace.h

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/*
    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
#pragma once
#include <optional>
 
#include <QMatrix4x4>
#include <QVector2D>
 
#include "kwin_export.h"
 
namespace KWin
{
 
enum class NamedColorimetry {
    BT709,
    BT2020,
};
 
class KWIN_EXPORT Colorimetry
{
public:
    static const Colorimetry &fromName(NamedColorimetry name);
    static QVector3D xyToXYZ(QVector2D xy);
    static QVector2D xyzToXY(QVector3D xyz);
    static QMatrix4x4 chromaticAdaptationMatrix(QVector2D sourceWhitepoint, QVector2D destinationWhitepoint);
 
    static QMatrix4x4 calculateToXYZMatrix(QVector3D red, QVector3D green, QVector3D blue, QVector3D white);
 
    explicit Colorimetry(QVector2D red, QVector2D green, QVector2D blue, QVector2D white);
    explicit Colorimetry(QVector3D red, QVector3D green, QVector3D blue, QVector3D white);
 
    const QMatrix4x4 &toXYZ() const;
    const QMatrix4x4 &fromXYZ() const;
    QMatrix4x4 toOther(const Colorimetry &colorimetry) const;
    bool operator==(const Colorimetry &other) const;
    bool operator==(NamedColorimetry name) const;
    Colorimetry adaptedTo(QVector2D newWhitepoint) const;
    Colorimetry interpolateGamutTo(const Colorimetry &one, double factor) const;
 
    const QVector2D &red() const;
    const QVector2D &green() const;
    const QVector2D &blue() const;
    const QVector2D &white() const;
 
private:
    QVector2D m_red;
    QVector2D m_green;
    QVector2D m_blue;
    QVector2D m_white;
    QMatrix4x4 m_toXYZ;
    QMatrix4x4 m_fromXYZ;
};
 
enum class NamedTransferFunction {
    sRGB = 0,
    linear = 1,
    PerceptualQuantizer = 2,
    scRGB = 3,
    gamma22 = 4,
};
 
class KWIN_EXPORT ColorDescription
{
public:
    explicit ColorDescription(const Colorimetry &colorimety, NamedTransferFunction tf, double sdrBrightness, double minHdrBrightness, double maxFrameAverageBrightness, double maxHdrHighlightBrightness, const Colorimetry &sdrColorimetry = Colorimetry::fromName(NamedColorimetry::BT709));
    explicit ColorDescription(NamedColorimetry colorimetry, NamedTransferFunction tf, double sdrBrightness, double minHdrBrightness, double maxFrameAverageBrightness, double maxHdrHighlightBrightness, const Colorimetry &sdrColorimetry = Colorimetry::fromName(NamedColorimetry::BT709));
 
    const Colorimetry &colorimetry() const;
    const Colorimetry &sdrColorimetry() const;
    NamedTransferFunction transferFunction() const;
    double sdrBrightness() const;
    double minHdrBrightness() const;
    double maxFrameAverageBrightness() const;
    double maxHdrHighlightBrightness() const;
 
    bool operator==(const ColorDescription &other) const;
 
    QVector3D mapTo(QVector3D rgb, const ColorDescription &other) const;
 
    static const ColorDescription sRGB;
    static QVector3D encodedToNits(const QVector3D &nits, NamedTransferFunction tf, double sdrBrightness);
    static QVector3D nitsToEncoded(const QVector3D &rgb, NamedTransferFunction tf, double sdrBrightness);
 
private:
    Colorimetry m_colorimetry;
    NamedTransferFunction m_transferFunction;
    Colorimetry m_sdrColorimetry;
    double m_sdrGamutWideness;
    double m_sdrBrightness;
    double m_minHdrBrightness;
    double m_maxFrameAverageBrightness;
    double m_maxHdrHighlightBrightness;
};
}