File indexing completed on 2024-05-12 04:44:34

 // SPDX-FileCopyrightText: Lukas Sommer <sommerluk@gmail.com>
 // SPDX-License-Identifier: BSD-2-Clause OR MIT
 
 #ifndef LCHDOUBLE_H
 #define LCHDOUBLE_H
 
 #include "importexport.h"
 #include <qdebug.h>
 #include <qmetatype.h>
 
 namespace PerceptualColor
 {
 /** @brief A LCH color (Oklch, CielchD50, CielchD65…)
  *
  * Storage of floating point LCH values with <tt>double</tt> precision.
  *
  * The data is not default-initialized; it is undefined when the object
  * is created.
  *
  * Example:
  * @snippet testlchdouble.cpp Use LchDouble
  *
  * More details about the valid range: @ref lchrange
  *
  * This class intentionally does not provide the operators <em>equal
  * to</em> (<tt>operator==</tt>) and <em>not equal to</em>
  * (<tt>operator!=</tt>). As LCH colors are polar coordinates,
  * there are various valid representations of the same angle.
  * And h is even meaningless when C is zero; on the other hand,
  * there might nevertheless be an interest in preserving h. And
  * invalid values with L=200 or L=300: Should they be equal because
  * both are invalid? Or are they different? The answer to all
  * these questions depends on your use case. To avoid confusion,
  * no comparison operators are provided by this class. See also
  * @ref hasSameCoordinates.
  *
  * This type is declared as type to Qt’s type system via
  * <tt>Q_DECLARE_METATYPE</tt>. Depending on your use case (for
  * example if you want to use for <em>queued</em> signal-slot connections),
  * you might consider calling <tt>qRegisterMetaType()</tt> for
  * this type, once you have a QApplication object.
  *
  * This data type can be passed to QDebug thanks to
  * @ref operator<<(QDebug dbg, const PerceptualColor::LchDouble &value)
  *
  * @internal
  *
  * @todo Would it make sense to normalize the hue (1° instead
  * of 361°, and only non-negative radii)? */
 struct PERCEPTUALCOLOR_IMPORTEXPORT LchDouble {
 public:
     /** @brief Lightness, mesured in percent.
      *
      * The valid range is <tt>[0, 100]</tt>. */
     double l;
     /** @brief Chroma.
      *
      * <tt>0</tt> means no chroma (grayscale). The maximum value depends on
      * the gamut. For sRGB for example it’s a given value, but other gamuts
      * can be bigger, but the practical limit is the gamut of the
      * @ref lchrange "human perception", beyond which a
      * Chroma value does not make sense. */
     double c;
     /** @brief Hue, measured in degree.
      *
      * The valid range is <tt>[0, 360[</tt>. */
     double h;
     [[nodiscard]] bool hasSameCoordinates(const LchDouble &other) const;
 };
 
 PERCEPTUALCOLOR_IMPORTEXPORT QDebug operator<<(QDebug dbg, const PerceptualColor::LchDouble &value);
 
 } // namespace PerceptualColor
 
 Q_DECLARE_METATYPE(PerceptualColor::LchDouble)
 
 #endif // LCHDOUBLE_H