components.h

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Authors:
 *   Jon A. Cruz <jon@joncruz.org>
 *   Martin Owens <doctormo@geek-2.com>
 *
 * Copyright (C) 2013-2023 Authors
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#ifndef SEEN_COLORS_COMPONENTS_H
#define SEEN_COLORS_COMPONENTS_H
 
#include <lcms2.h>
#include <map>
#include <string>
#include <vector>
 
#include "enum.h"
 
namespace Inkscape::Colors::Space {
 
enum class Type;
 
enum class Traits {
    None = 0,
    Picker = 1,   // show color picker of this type in UI
    Internal = 2, // internal use only, has converters and tests, or is supported by CSS toString
    CMS = 4,      // CMS use only, no conversion math available
};
inline Traits operator & (const Traits lhs, const Traits rhs) {
    using underlying = std::underlying_type_t<Traits>;
    return static_cast<Traits>(static_cast<underlying>(lhs) & static_cast<underlying>(rhs));
}
inline Traits operator | (const Traits lhs, const Traits rhs) {
    using underlying = std::underlying_type_t<Traits>;
    return static_cast<Traits>(static_cast<underlying>(lhs) | static_cast<underlying>(rhs));
}
 
// Unit impacts component presentation in the UI and dictates what its scale is
enum class Unit {
    EightBit,   // one byte, values from 0..255, unitless
    Percent,    // 0..100%
    Degree,     // 0..360 degree
    Linear1024, // 0..1024 for linear RGB
    Chroma40    // an oddball 0..40 for OkLch hue encoding
};
 
struct Component
{
    Component(Type type, unsigned int index, std::string id, std::string name, std::string tip, Unit unit = Unit::EightBit);
    Component(std::string id, std::string name, std::string tip, Unit unit = Unit::EightBit);
 
    Type type;
    unsigned int index;
    std::string id;
    std::string name;
    std::string tip;
    unsigned scale;
    Unit unit = Unit::EightBit;
 
    double normalize(double value) const;
};
 
class Components
{
public:
    Components() = default;
    Components(Type type, Type wheel, Traits traits, std::vector<Component> components):
        _type(type), _wheel_type(wheel), _components(std::move(components)), _traits(traits) {}
 
    static Components const &get(Type type, bool alpha = false);
 
    const std::vector<Component>& getAll() const { return _components; }
 
    std::vector<Component>::const_iterator begin() const { return std::begin(_components); }
    std::vector<Component>::const_iterator end() const { return std::end(_components); }
    Component const &operator[](const unsigned int index) const { return _components[index]; }
 
    Type getType() const { return _type; }
    unsigned size() const { return _components.size(); }
 
    void add(std::string id, std::string name, std::string tip, Unit unit = Unit::EightBit);
    void setType(Type type, Type color_wheel = Type::NONE) { _type = type; _wheel_type = color_wheel; }
    // Says which space the color wheel should be in when picking this color space
    Type get_wheel_type() const;
    // Trait(s) of those components
    Traits traits() const { return _traits; }
 
private:
    Type _type = Type::NONE;
    std::vector<Component> _components;
    Type _wheel_type = Type::NONE;
    Traits _traits = Traits::None;
};
 
} // namespace Inkscape::Colors::Space
 
#endif // SEEN_COLORS_COMPONENTS_H