colors.h

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/*
 * Copyright (C) 2017 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2017 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef _GTKMM2EXT_COLORS_H_
#define _GTKMM2EXT_COLORS_H_
 
#include<stdint.h>
 
#include <ydkmm/types.h>
#include <cairomm/context.h>
 
#include "gtkmm2ext/visibility.h"
 
namespace Gtkmm2ext
{
 
typedef uint32_t Color;
 
extern LIBGTKMM2EXT_API Color random_color ();
 
/* conventient way to use Gtkmm2ext::Color with libcairo */
extern LIBGTKMM2EXT_API void set_source_rgba (Cairo::RefPtr<Cairo::Context>, Gtkmm2ext::Color);
extern LIBGTKMM2EXT_API void set_source_rgb_a (Cairo::RefPtr<Cairo::Context>, Gtkmm2ext::Color, float alpha);  //override the color's alpha
 
extern LIBGTKMM2EXT_API void set_source_rgba (cairo_t*, Gtkmm2ext::Color);
extern LIBGTKMM2EXT_API void set_source_rgb_a (cairo_t*, Gtkmm2ext::Color, float alpha);  //override the color's alpha
 
extern LIBGTKMM2EXT_API Gdk::Color gdk_color_from_rgb (uint32_t);
extern LIBGTKMM2EXT_API Gdk::Color gdk_color_from_rgba (uint32_t);
extern LIBGTKMM2EXT_API uint32_t gdk_color_to_rgba (Gdk::Color const&);
 
extern LIBGTKMM2EXT_API void set_color_from_rgb (Gdk::Color&, uint32_t);
extern LIBGTKMM2EXT_API void set_color_from_rgba (Gdk::Color&, uint32_t);
 
 
struct LIBGTKMM2EXT_API HSV;
struct LIBGTKMM2EXT_API HSVA;
 
extern LIBGTKMM2EXT_API Color change_alpha (Color, double alpha);
 
extern LIBGTKMM2EXT_API Color hsva_to_color (double h, double s, double v, double a = 1.0);
extern LIBGTKMM2EXT_API void  color_to_hsva (Color color, double& h, double& s, double& v, double& a);
extern LIBGTKMM2EXT_API Color color_at_alpha (Color, double a);
extern LIBGTKMM2EXT_API void  color_to_hsv (Color color, double& h, double& s, double& v);
extern LIBGTKMM2EXT_API void  color_to_rgba (Color, double& r, double& g, double& b, double& a);
extern LIBGTKMM2EXT_API Color rgba_to_color (double r, double g, double b, double a);
extern LIBGTKMM2EXT_API double color_to_luminance (uint32_t c);
 
uint32_t LIBGTKMM2EXT_API contrasting_text_color (uint32_t c);
 
struct LIBGTKMM2EXT_API HSV;
 
class LIBGTKMM2EXT_API SVAModifier
{
public:
        enum Type {
                Add,
                Multiply,
                Assign
        };
 
        SVAModifier (std::string const &);
        SVAModifier (Type t, double ss, double vv, double aa) : type (t), _s (ss) , _v (vv) , _a (aa) {}
        SVAModifier () : type (Add), _s (0), _v (0), _a (0) {} /* no-op modifier */
 
        double s() const { return _s; }
        double v() const { return _v; }
        double a() const { return _a; }
 
        HSV operator () (HSV& hsv) const;
        std::string to_string () const;
        void from_string (std::string const &);
 
private:
        Type type;
        double _s;
        double _v;
        double _a;
};
 
struct LIBGTKMM2EXT_API HSV
{
        HSV ();
        HSV (double h, double s, double v, double a = 1.0);
        HSV (Color);
 
        double h;
        double s;
        double v;
        double a;
 
        std::string to_string() const;
        bool is_gray() const;
 
        Color color() const { return hsva_to_color (h,s, v, a); }
        operator Color() const { return color(); }
 
        HSV mod (SVAModifier const & svam);
 
        HSV operator+ (const HSV&) const;
        HSV operator- (const HSV&) const;
 
        HSV& operator=(Color);
        HSV& operator=(const std::string&);
 
        bool operator== (const HSV& other);
 
        double distance (const HSV& other) const;
        HSV delta (const HSV& other) const;
 
        HSV darker (double factor = 1.3) const;
        HSV lighter (double factor = 0.7) const;
 
        HSV shade (double factor) const;
        HSV mix (const HSV& other, double amt) const;
 
        HSV opposite() const;
        HSV complement() const { return opposite(); }
 
        HSV bw_text () const;
        HSV text() const;
        HSV selected () const;
        HSV outline() const;
 
        void print (std::ostream&) const;
 
protected:
        void clamp ();
};
 
} /* namespace */
 
std::ostream& operator<<(std::ostream& o, const Gtkmm2ext::HSV& hsv);
 
#endif