File indexing completed on 2024-05-19 04:45:51

 // SPDX-FileCopyrightText: Lukas Sommer <sommerluk@gmail.com>
 // SPDX-License-Identifier: BSD-2-Clause OR MIT
 
 #ifndef HELPERCONVERSION_H
 #define HELPERCONVERSION_H
 
 #include "helperqttypes.h"
 #include "lchdouble.h"
 #include <lcms2.h>
 #include <qcolor.h>
 #include <qglobal.h>
 #include <type_traits>
 
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
 #include <qtmetamacros.h>
 #endif
 
 /** @internal
  *
  * @file
  *
  * Provides type conversions. */
 
 namespace PerceptualColor
 {
 
 Q_NAMESPACE
 
 /** @brief Identifiers for color models. */
 enum class ColorModel {
     CielabD50, /**< Cielab color space using a D50 illuminant.
         Lightness: [0, 100].<br/>
         a: unbound.<br/>
         b: unbound. */
     CielchD50, /**< Cielch color space using a D50 illuminant.
         Lightness: [0, 100].<br/>
         Chroma: unbound.<br/>
         Hue: [0, 360[. */
     Hsl360_1_1, /**< A HSL color space.
         Hue: [0, 360[.<br/>
         Saturation: [0, 1].<br/>
         Lightness: [0, 1]. */
     Hwb360_1_1, /**< A HWB color space.
         Hue: [0, 360[.<br/>
         Whiteness: [0, 1].<br/>
         Blackness: [0, 1]. */
     Invalid, /**< Represents invalid data. */
     OklabD65, /**< Oklab color space, which by definition always and
         exclusively uses a D65 illuminant.
 
         Lightness: [0, 1].<br/>
         a: unbound.<br/>
         b: unbound. */
     OklchD65, /**< Oklch color space, which by definition always and
         exclusively uses a D65 illuminant.
 
         Lightness: [0, 1].<br/>
         Chroma: unbound.<br/>
         Hue: [0, 360[. */
     Rgb1, /**< An Rgb color space.
         R: [0, 1].<br/>
         G: [0, 1].<br/>
         B: [0, 1]. */
     XyzD50, /**< Xyz color space using a D50 illuminant.
         X: unbound.<br/>
         Y: [0, 1]. Diffuse white has a luminance (Y) of 1.0<br/>
         Z: unbound. */
     XyzD65 /**< Xzy color space using a D65 illuminant.
         X: unbound.<br/>
         Y: [0, 1]. Diffuse white has a luminance (Y) of 1.0<br/>
         Z: unbound. */
 };
 Q_ENUM_NS(ColorModel)
 
 #if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
 uint qHash(const ColorModel t, uint seed = 0); // clazy:exclude=qt6-qhash-signature
 #endif
 
 /** @internal
  *
  * @brief Converts from <tt>[0, 1]</tt> to <tt>[0, 255]</tt>.
  *
  * @param original A value on a scale <tt>[0, 1]</tt>.
  *
  * @returns Value converted to the scale <tt>[0, 255]</tt>, applying correct
  * rounding. Out-of-range values are bound to the valid range. */
 template<typename T>
 [[nodiscard]] constexpr quint8 fromFloatingToEightBit(const T &original)
 {
     static_assert( //
         std::is_floating_point<T>::value, //
         "Template fromFloatingToEightBit() only works with floating point types");
     const int rounded = qRound(original * 255);
     const auto bounded = qBound<int>(0, rounded, 255);
     return static_cast<quint8>(bounded);
 }
 
 /** @internal
  *
  * @brief Like <tt>QColor::fromRgbF</tt> but for all floating point types.
  *
  * @param red Red component. Range: <tt>[0, 1]</tt>
  * @param green See above.
  * @param blue See above.
  * @returns A corresponding <tt>QColor</tt> object. */
 template<typename T>
 [[nodiscard]] QColor qColorFromRgbDouble(T red, T green, T blue)
 {
     static_assert( //
         std::is_floating_point<T>::value, //
         "Template fromFloatingToEightBit() only works with floating point types");
     return QColor::fromRgbF(static_cast<QColorFloatType>(red), //
                             static_cast<QColorFloatType>(green), //
                             static_cast<QColorFloatType>(blue));
 }
 
 [[nodiscard]] cmsCIELab toCmsLab(const cmsCIELCh &value);
 
 [[nodiscard]] cmsCIELCh toCmsLch(const LchDouble &value);
 
 [[nodiscard]] LchDouble toLchDouble(const cmsCIELCh &value);
 
 [[nodiscard]] LchDouble toLchDouble(const cmsCIELab &value);
 
 /** @internal
  *
  * @brief White point D65 for 2°-observer.
  *
  * According to
  * <a href="https://en.wikipedia.org/w/index.php?title=Illuminant_D65&oldid=1100467073#Definition">
  * Wikipedia</a>:
  *
  * > “Using the standard 2° observer […] of D65 […] Normalizing for
  * > relative luminance (i.e. set Y=100), the XYZ tristimulus
  * > values are:<br/>
  * > X = 95.047<br/>
  * > Y = 100<br/>
  * > Z = 108.883”
  *
  * Normalizing this to Y = 1 as expected by LittleCMS, gives this value. */
 // TODO xxx This seems to be not longer used!?
 constexpr cmsCIEXYZ whitePointD65TwoDegree{0.95047, 1.00000, 1.08883};
 
 } // namespace PerceptualColor
 
 #endif // HELPERCONVERSION_H