Color.h

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/* -*- mode: c++ -*- */
#ifndef BOARD_COLOR_H
#define BOARD_COLOR_H
 
#include <cstddef>
#include <cstdio>
#include <ostream>
#include <string>
#include "Tools.h"
 
namespace LibBoard
{
 
class Color {
 
public:
  inline Color();
  inline Color(const unsigned int rgb, unsigned char alpha = 255);
  inline Color(unsigned char red, unsigned char green, unsigned char blue, unsigned char alpha = 255);
  inline Color(unsigned char gray, unsigned char alpha = 255);
 
  static inline Color fromRGBf(float red, float green, float blue, float alpha = 1.0f);
 
  inline Color(const std::string & htmlColor, unsigned char alpha);
 
  inline Color(const std::string & htmlColor);
 
  inline Color(const char * htmlColor, unsigned char alpha = 255);
 
  inline Color(std::nullptr_t);
 
  inline void red(unsigned char red);
  inline void green(unsigned char green);
  inline void blue(unsigned char blue);
  inline void alpha(unsigned char alpha);
 
  inline unsigned char red() const;
  inline unsigned char green() const;
  inline unsigned char blue() const;
  inline unsigned char alpha() const;
 
  inline Color & setRGBi(const unsigned char red, const unsigned char green, const unsigned char blue, const unsigned char alpha = 255);
 
  Color & setHSV(float hue, float saturation, float value, float alpha = 1.0);
 
  Color & setRGBf(float red, float green, float blue, float alpha = 1.0);
 
  bool operator==(const Color & other) const;
 
  bool operator!=(const Color & other) const;
 
  bool operator<(const Color & other) const;
 
  void flushPostscript(std::ostream &) const;
 
  std::string svg() const;
 
  inline bool isNull() const;
 
  inline bool isValid() const;
 
  std::string svgAlpha(const char * prefix) const;
 
  std::string postscript() const;
 
  std::string tikz() const;
 
  void toHSV(float & hue, float & saturation, float & value, float & alpha) const;
 
  inline bool valid() const { return (*this) != Color::Null; }
 
  static Color fromHSV(float hue, float saturation, float value, float alpha = 1.0f);
 
  static Color midRGB(const Color & a, const Color & b, float t);
 
  static Color midHSV(const Color & a, const Color & b, float t);
 
  static Color fromHueColormap(float t);
 
  std::ostream & flush(std::ostream & out) const;
 
public:
  static const Color Null;
  static const Color Black;
  static const Color Brown;
  static const Color Pink;
  static const Color Gray;
  static const Color White;
  static const Color Red;
  static const Color Green;
  static const Color DarkGreen;
  static const Color Lime;
  static const Color Blue;
  static const Color Cyan;
  static const Color DarkCyan;
  static const Color Magenta;
  static const Color Yellow;
  static const Color Silver;
  static const Color Purple;
  static const Color Navy;
  static const Color Aqua;
 
private:
  int _red;   
  int _green; 
  int _blue;  
  int _alpha; 
};
 
std::ostream & operator<<(std::ostream & out, const Color & color);
 
// Inline methods
 
Color & Color::setRGBi(const unsigned char red, const unsigned char green, const unsigned char blue, const unsigned char alpha)
{
  _red = red;
  _green = green;
  _blue = blue;
  _alpha = alpha;
  return *this;
}
 
bool Color::isNull() const
{
  return _red == -1 && _green == -1 && _blue == -1;
}
 
bool Color::isValid() const
{
  return !isNull();
}
 
Color::Color() : _red(0), _green(0), _blue(0), _alpha(255) {}
 
Color::Color(std::nullptr_t)
{
  _red = _green = _blue = -1;
  _alpha = 255;
}
 
Color::Color(const unsigned int rgb, unsigned char alpha) : _alpha(alpha)
{
  _red = (rgb & 0xFF0000u) >> 16;
  _green = (rgb & 0xFF00u) >> 8;
  _blue = rgb & 0xFF;
}
 
Color::Color(unsigned char red, unsigned char green, unsigned char blue, unsigned char alpha) : _red(red), _green(green), _blue(blue), _alpha(alpha) {}
 
Color::Color(unsigned char gray, unsigned char alpha) : _red(gray), _green(gray), _blue(gray), _alpha(alpha) {}
 
Color Color::fromRGBf(float red, float green, float blue, float alpha)
{
  return Color(static_cast<unsigned char>(red * 255), static_cast<unsigned char>(green * 255), static_cast<unsigned char>(blue * 255), static_cast<unsigned char>(alpha * 255));
}
 
// FIXME : Make alpha parameter take precedence over AA in html string
Color::Color(const std::string & htmlColor, unsigned char alpha) : Color(htmlColor.c_str(), alpha) {}
 
Color::Color(const std::string & htmlColor) : Color(htmlColor.c_str(), 255) {}
 
Color::Color(const char * htmlColor, unsigned char alpha) : _alpha(alpha)
{
  unsigned int r, g, b, a = alpha;
  if (!htmlColor || *htmlColor == '\0') {
    *this = Color::Null;
    return;
  }
  if (strlen(htmlColor) == 7 && sscanf(htmlColor, "#%2x%2x%2x", &r, &g, &b) == 3) {
    _red = (int)r;
    _green = (int)g;
    _blue = (int)b;
    _alpha = (int)a;
  } else if (strlen(htmlColor) == 9 && sscanf(htmlColor, "#%2x%2x%2x%2x", &r, &g, &b, &a) == 4) {
    _red = (int)r;
    _green = (int)g;
    _blue = (int)b;
    _alpha = (int)a;
  } else {
    *this = Color::Null;
    Tools::error << "Color::Color(htmlcolor): cannot parse color string\n";
  }
}
 
void Color::red(const unsigned char red)
{
  _red = red;
}
 
void Color::green(unsigned char green)
{
  _green = green;
}
 
void Color::blue(unsigned char blue)
{
  _blue = blue;
}
 
void Color::alpha(unsigned char alpha)
{
  _alpha = alpha;
}
 
unsigned char Color::red() const
{
  return static_cast<unsigned char>(_red);
}
 
unsigned char Color::green() const
{
  return static_cast<unsigned char>(_green);
}
 
unsigned char Color::blue() const
{
  return static_cast<unsigned char>(_blue);
}
 
unsigned char Color::alpha() const
{
  return static_cast<unsigned char>(_alpha);
}
} // namespace LibBoard
 
#endif // BOARD_COLOR_H