RandomColor.h

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#pragma once
 
#ifndef _RANDOM_COLOR_H_
#define _RANDOM_COLOR_H_
 
// Andrew Copland (2016/03/10 )This is a port of a port! Done under the MIT license (see ^^^Above^^^).
// Originally pointed out to me by RobN in a forum thread (https://forum.pioneerspacesim.net/viewtopic.php?f=3&t=221)
// I was deterred by A) not knowing any javascript, B) the more I saw of it the more I hated it.
// Then I noticed the C# port by Nathan Jones (https://github.com/nathanpjones/randomColorSharped) which was a much more logical starting point.
// I have included a snippet of his readme below about how he himself came to port it.
 
//randomColorSharped
//==================
//
// This is a port to c# (.NET 4.0) of [randomColor](http://llllll.li/randomColor/), David Merfield's javascript random color generator.
// This was ported by [Nathan Jones](http://www.nathanpjones.com/) so that users of the .NET family of languages could enjoy these attractive colors.
//
// I saw this project linked on [Scott Hanselman's](http://www.hanselman.com/) excellent [Newsletter of Wonderful Things](http://www.hanselman.com/newsletter/)
// around the same time a coworker was creating an ad hoc visualization app. As we watched the data appear on screen, we had to squint as some of the colors
// were very difficult to make out against the background. This should make things easier to see and will hopefully help others as well.
 
#include "Color.h"
#include "Random.h"
 
#include <cstdlib>
#include <map>
#include <vector>
 
namespace RandomColorGenerator {
    // Represents a range using an upper and lower value.
    class Range {
    public:
        int Lower;
        int Upper;
 
        Range() {}
        Range(int lower, int upper)
        {
            Lower = lower;
            Upper = upper;
        }
 
        // Gets the lower range for an index of 0 and the upper for an index of 1.
        const int &operator[](const size_t index) const
        {
            if (index == 0)
                return Lower;
            else
                return Upper;
        }
    };
 
    enum ColorScheme {
        // Select randomly from among the other color schemes.
        SCHEME_RANDOM = 0,
        // Generates only grayscale colors.
        SCHEME_MONOCHROME,
        // Generates only red colors.
        SCHEME_RED,
        // Generates only orange colors.
        SCHEME_ORANGE,
        // Generates only yellow colors.
        SCHEME_YELLOW,
        // Generates only green colors.
        SCHEME_GREEN,
        // Generates only blue colors.
        SCHEME_BLUE,
        // Generates only purple colors.
        SCHEME_PURPLE,
        // Generates only pink colors.
        SCHEME_PINK
    };
 
    enum Luminosity {
        // Select randomly from among the other luminosities.
        LUMINOSITY_RANDOM = 0,
        // Generate dark colors.
        LUMINOSITY_DARK,
        // Generate light, pastel colors.
        LUMINOSITY_LIGHT,
        // Generate vibrant colors.
        LUMINOSITY_BRIGHT
    };
 
    class Point {
    public:
        Point() :
            x(0),
            y(0) {}
        Point(int nx, int ny) :
            x(nx),
            y(ny) {}
        int x, y;
    };
 
    // Generates random numbers.
    class RandomColor {
    private:
        class DefinedColor {
        public:
            DefinedColor() {}
            Range HueRange;
            std::vector<Point> LowerBounds;
            Range SaturationRange;
            Range BrightnessRange;
        };
 
        static std::map<ColorScheme, DefinedColor> ColorDictionary;
 
    public:
        RandomColor();
 
        static Color GetColor(ColorScheme scheme, Luminosity luminosity);
 
        static std::vector<Color> GetColors(Random &rand, ColorScheme scheme, Luminosity luminosity, int count);
 
        static int PickHue(ColorScheme scheme);
 
    private:
        static int PickSaturation(int hue, Luminosity luminosity, ColorScheme scheme);
 
        static int PickBrightness(int H, int S, Luminosity luminosity);
 
        static int GetMinimumBrightness(int H, int S);
 
        static Range GetHueRange(ColorScheme colorInput);
 
        static DefinedColor GetColorInfo(int hue);
 
        static int RandomWithin(Range range);
        static int RandomWithin(int lower, int upper);
 
        static void DefineColor(ColorScheme scheme, Point hueRange, const Point *lowerBounds, const size_t lbCount);
 
        static void LoadColorBounds();
 
    public:
        // Converts hue, saturation, and lightness to a color.
        static Color HsvToColor(int hue, int saturation, double value);
    };
} // namespace RandomColorGenerator
 
#endif // _RANDOM_COLOR_H_