units.h

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Inkscape Units
 * These classes are used for defining different unit systems.
 *
 * Authors:
 *   Matthew Petroff <matthew@mpetroff.net>
 *
 * Copyright (C) 2013 Matthew Petroff
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#ifndef INKSCAPE_UTIL_UNITS_H
#define INKSCAPE_UTIL_UNITS_H
 
#include <unordered_map>
#include <boost/operators.hpp>
#include <glibmm/ustring.h>
#include <glibmm/ustring_hash.h>
#include <2geom/coord.h>
 
#include "svg/svg-length.h"
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
#define DEFAULT_UNIT_NAME "mm"
#endif
 
namespace Inkscape {
namespace Util {
 
enum UnitType {
    UNIT_TYPE_DIMENSIONLESS,     /* Percentage */
    UNIT_TYPE_LINEAR,
    UNIT_TYPE_LINEAR_SCALED,
    UNIT_TYPE_RADIAL,
    UNIT_TYPE_TIME,
    UNIT_TYPE_FONT_HEIGHT,
    UNIT_TYPE_QTY,
    UNIT_TYPE_NONE = -1
};
 
const char DEG[] = "°";
 
class Unit
    : boost::equality_comparable<Unit>
{
public:
    Unit();
    Unit(UnitType type,
         double factor,
         Glib::ustring name,
         Glib::ustring name_plural,
         Glib::ustring abbr,
         Glib::ustring description);
 
    void clear();
 
    bool           isAbsolute() const { return type != UNIT_TYPE_DIMENSIONLESS; }
 
    int            defaultDigits() const;
 
    bool           compatibleWith(Unit const *u) const;
    bool           compatibleWith(Glib::ustring const &) const;
    bool           compatibleWith(char const *) const;
 
    UnitType       type;
    double         factor;
    Glib::ustring  name;
    Glib::ustring  name_plural;
    Glib::ustring  abbr;
    Glib::ustring  description;
    
    bool operator==(Unit const &other) const;
    
    int svgUnit() const;
 
    double convert(double from_dist, Unit const *to) const;
    double convert(double from_dist, Glib::ustring const &to) const;
    double convert(double from_dist, char const *to) const;
};
 
class Quantity
    : boost::totally_ordered<Quantity>
{
public:
    Unit const *unit;
    double quantity;
    
    Quantity(double q, Unit const *u);
    Quantity(double q, Glib::ustring const &u);
    Quantity(double q, char const *u);
    
    bool compatibleWith(Unit const *u) const;
    bool compatibleWith(Glib::ustring const &u) const;
    bool compatibleWith(char const *u) const;
    
    double value(Unit const *u) const;
    double value(Glib::ustring const &u) const;
    double value(char const *u) const;
    
    Glib::ustring string(Unit const *u) const;
    Glib::ustring string(Glib::ustring const &u) const;
    Glib::ustring string() const;
    
    static double convert(double from_dist, Unit const *from, Unit const *to);
    static double convert(double from_dist, Glib::ustring const &from, Unit const *to);
    static double convert(double from_dist, Unit const *from, Glib::ustring const &to);
    static double convert(double from_dist, Glib::ustring const &from, Glib::ustring const &to);
    static double convert(double from_dist, char const *from, char const *to);
 
    bool operator<(Quantity const &rhs) const;
    bool operator==(Quantity const &other) const;
};
 
inline bool are_near(Quantity const &a, Quantity const &b, double eps=Geom::EPSILON)
{
    return Geom::are_near(a.quantity, b.value(a.unit), eps);
}
 
class UnitTable {
public:
    UnitTable();
    virtual ~UnitTable();
 
    typedef std::unordered_map<Glib::ustring, Unit> UnitMap;
    typedef std::unordered_map<unsigned, Unit*> UnitCodeMap;
 
    void    addUnit(Unit const &u, bool primary);
 
    Unit const *getUnit(Glib::ustring const &name) const;
    Unit const *getUnit(char const *name) const;
 
    Unit const *findUnit(double factor, UnitType type) const;
    
    Unit const *getUnit(SVGLength::Unit u) const;
    
    Quantity parseQuantity(Glib::ustring const &q) const;
 
    //bool    deleteUnit(Unit const &u);
 
    bool    hasUnit(Glib::ustring const &name) const;
 
    UnitMap units(UnitType type) const;
 
    Glib::ustring primary(UnitType type) const;
 
    double  getScale() const;
 
    void    setScale();
 
    bool    load(std::string const &filename);
 
    /* * Saves the current UnitTable to the given file. */
    //bool    save(std::string const &filename);
 
    static UnitTable &get();
 
protected:
    UnitCodeMap         _unit_map;
    Glib::ustring       _primary_unit[UNIT_TYPE_QTY];
 
    double              _linear_scale;
    static Unit         _empty_unit;
 
private:
    UnitTable(UnitTable const &t);
    UnitTable operator=(UnitTable const &t);
 
};
 
} // namespace Util
} // namespace Inkscape
 
#endif // define INKSCAPE_UTIL_UNITS_H
/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :