Color.h

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/**
 *  \file IMP/display/Color.h
 *  \brief Represent a color
 *
 *  Copyright 2007-2015 IMP Inventors. All rights reserved.
 */

#ifndef IMPDISPLAY_COLOR_H
#define IMPDISPLAY_COLOR_H

#include <IMP/display/display_config.h>
#include <IMP/base/Value.h>
#include <IMP/base/showable_macros.h>
#include <IMP/base/comparison_macros.h>
#include <IMP/base/check_macros.h>
#include <IMP/base/value_macros.h>
#include <boost/array.hpp>

IMPDISPLAY_BEGIN_NAMESPACE

//! Represent an RGB color
/**
 */
class IMPDISPLAYEXPORT Color : public base::Value {
  boost::array<double, 3> c_;
  int compare(double a, double b) const {
    if (a < b)
      return -1;
    else if (a > b)
      return 1;
    else
      return 0;
  }
  int compare(const Color &o) const {
    for (unsigned int i = 0; i < 3; ++i) {
      int c = compare(c_[i], o.c_[i]);
      if (c != 0) return c;
    }
    return 0;
  }

 public:
  IMP_CXX11_DEFAULT_COPY_CONSTRUCTOR(Color);

  Color();

  /** Components must be between 0 and 1
   */
  Color(double r, double g, double b);

  /** Components must be between 0 and 1
    */
  template <class It>
  Color(It b, It e) {
    std::copy(b, e, c_.begin());
  }

  ~Color();
  /** @name Component access
   @{
   */
  double get_red() const { return c_[0]; }

  double get_green() const { return c_[1]; }
  double get_blue() const { return c_[2]; }
#ifndef SWIG
  typedef const double *ComponentIterator;
  ComponentIterator components_begin() const { return c_.begin(); }
  ComponentIterator components_end() const { return c_.end(); }
  const boost::array<double, 3> &get_rgb() const { return c_; }
#endif
  //!@}

  void show(std::ostream &out, std::string delim) const {
    out << get_red() << delim << get_green() << delim << get_blue();
  }

  IMP_SHOWABLE_INLINE(Color, show(out, " "););

  IMP_COMPARISONS(Color);
};

/** Produce a color that is attempted to be contrasting with the
    i-1 previous colors. Currently, they recycle after 11, but they
    can be darkened instead. Just ask.
 */
IMPDISPLAYEXPORT Color get_display_color(unsigned int i);

#ifndef SWIG
#ifndef IMP_DOXYGEN
struct SpacesIO {
  const Color &v_;
  explicit SpacesIO(const Color &v) : v_(v) {}
};

struct CommasIO {
  const Color &v_;
  explicit CommasIO(const Color &v) : v_(v) {}
};
inline std::ostream &operator<<(std::ostream &out, const SpacesIO &s) {
  s.v_.show(out, " ");
  return out;
}
inline std::ostream &operator<<(std::ostream &out, const CommasIO &s) {
  s.v_.show(out, ", ");
  return out;
}

//! Use this before outputting to delimited vector entries with a space
/** std::cout << spaces_io(v);
    produces "1.0 2.0 3.0"
    \see Color
 */
inline SpacesIO spaces_io(const Color &v) { return SpacesIO(v); }

//! Use this before outputting to delimited vector entries with a comma
/** std::cout << commas_io(v);
    produces "1.0, 2.0, 3.0"
    \see Color
 */
inline CommasIO commas_io(const Color &v) { return CommasIO(v); }

//! Multiply a color by a value less than 1
/** \unstable{Color multiplication}
 */
inline Color operator*(double d, Color c) {
  IMP_USAGE_CHECK(d <= 1 && d >= 0, "Colors can only fade with multiplication");
  return Color(c.get_red() * d, c.get_green() * d, c.get_blue() * d);
}

//! Multiply a color by a value less than 1
/** \unstable{Color multiplication}
 */
inline Color operator*(Color c, double d) { return d * c; }
#endif

#endif  // SWIG

//! Return a color interpolated between a and b in RGB space
/** If f is 0, then a is returned, if f is 1, b is returned.
    \see Color
 */
inline Color get_interpolated_rgb(const Color &a, const Color &b, double f) {
  return Color((1 - f) * a.get_red() + f * b.get_red(),
               (1 - f) * a.get_green() + f * b.get_green(),
               (1 - f) * a.get_blue() + f * b.get_blue());
}

/** Return a number suitable for being passed to a color
    map that is gotten by linearly scaling between the
    passed min and max (and truncating values that are out
    of range).
*/
IMPDISPLAYEXPORT double get_linear_color_map_value(double min, double max,
                                                   double value);

/** \name Colormaps
    These functions map a number in the interval [0,1]
    to a color using some color map.
@{
 */
//! Return the color for f from the jet color map
/** \see Color
 */
IMPDISPLAYEXPORT Color get_jet_color(double f);

//! Return the color for f from the hot color map
/** \see Color
 */
IMPDISPLAYEXPORT Color get_hot_color(double f);

//! Return the color for f from the RGB color map
/** \see Color
 */
IMPDISPLAYEXPORT Color get_rgb_color(double f);

//! Return the a grayscale value for f
/** \see Color
 */
IMPDISPLAYEXPORT Color get_gray_color(double f);

//! Return colors using the gnuplot default color map
/** \see Color
 */
IMPDISPLAYEXPORT Color get_gnuplot_color(double f);
/** @} */

IMP_VALUES(Color, Colors);

IMPDISPLAY_END_NAMESPACE

#endif /* IMPDISPLAY_COLOR_H */