// @(#)root/base:$Id: TColor.h 20877 2007-11-19 11:17:07Z rdm $
// Author: Rene Brun   12/12/94

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TColor
#define ROOT_TColor

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TColor                                                               //
//                                                                      //
// Color defined by RGB or HLS.                                         //
// At initialization time, a table of colors is generated. This linked  //
// list can be accessed from the ROOT object                            //
// (see TROOT::GetListOfColors()). When a color is defined in the range //
// of [1,50], two "companion" colors are also defined:                  //
//    - the dark version (color_index + 100)                            //
//    - the bright version (color_index + 150)                          //
// The dark and bright color are used to give 3-D effects when drawing  //
// various boxes (see TWbox, TPave, TPaveText, TPaveLabel,etc).         //
//                                                                      //
// This is the list of currently supported basic colors (here dark and  //
// bright colors are not shown).                                        //
//Begin_Html
/*
<img src="gif/colors.gif">
*/
//End_Html
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#ifndef ROOT_TNamed
#include "TNamed.h"
#endif
#ifndef ROOT_TArrayI
#include "TArrayI.h"
#endif


class TColor : public TNamed {

private:
   Int_t          fNumber;        //Color number identifier
   Float_t        fRed;           //Fraction of Red
   Float_t        fGreen;         //Fraction of Green
   Float_t        fBlue;          //Fraction of Blue
   Float_t        fHue;           //Hue
   Float_t        fLight;         //Light
   Float_t        fSaturation;    //Saturation
   Float_t        fAlpha;         //Alpha (transparency)
   static Bool_t  fgGrayscaleMode;//if set, GetColor will return grayscale
   static Bool_t  fgInitDone;     //kTRUE once ROOT colors have been initialized
   static TArrayI fgPalette;      //Color palette

   void           Allocate();
   static Float_t HLStoRGB1(Float_t rn1, Float_t rn2, Float_t huei);

public:
   TColor();
   TColor(Int_t color, Float_t r, Float_t g, Float_t b, const char *name="", Float_t a = 1);
   TColor(const TColor &color);
   virtual ~TColor();
   const char   *AsHexString() const;
   void          Copy(TObject &color) const;
   static void   CreateColorWheel();
   static void   CreateColorsGray();
   static void   CreateColorsCircle(Int_t offset, const char *name, UChar_t *rgb);
   static void   CreateColorsRectangle(Int_t offset, const char *name, UChar_t *rgb); 
   static Int_t  CreateGradientColorTable(UInt_t Number, Double_t* Length,
                    Double_t* Red, Double_t* Green, Double_t* Blue, UInt_t NColors);
   static Int_t  GetColorPalette(Int_t i);
   static Int_t  GetNumberOfColors();
   virtual void  GetRGB(Float_t &r, Float_t &g, Float_t &b) const 
                    { r=GetRed(); g=GetGreen(); b=GetBlue(); }
   virtual void  GetHLS(Float_t &h, Float_t &l, Float_t &s) const
                    { h=GetHue(); l=GetLight(); s=GetSaturation(); }
   Int_t         GetNumber() const { return fNumber; }
   ULong_t       GetPixel() const;
   Float_t       GetRed() const { return IsGrayscale() ? GetGrayscale() : fRed; }
   Float_t       GetGreen() const { return IsGrayscale() ? GetGrayscale() : fGreen; }
   Float_t       GetBlue() const { return IsGrayscale() ? GetGrayscale() : fBlue; }
   Float_t       GetHue() const { return fHue; }
   Float_t       GetLight() const { return fLight; }
   Float_t       GetSaturation() const { return IsGrayscale() ? 0 : fSaturation; }
   Float_t       GetAlpha() const { return fAlpha; }
   virtual Float_t GetGrayscale() const { /*ITU*/ return 0.299f*fRed + 0.587f*fGreen + 0.114f*fBlue; }
   virtual void  ls(Option_t *option="") const;
   virtual void  Print(Option_t *option="") const;
   virtual void  SetRGB(Float_t r, Float_t g, Float_t b);

   static void    InitializeColors();
   static void    HLS2RGB(Float_t h, Float_t l, Float_t s, Float_t &r, Float_t &g, Float_t &b);
   static void    HLS2RGB(Int_t h, Int_t l, Int_t s, Int_t &r, Int_t &g, Int_t &b);
   static void    HLStoRGB(Float_t h, Float_t l, Float_t s, Float_t &r, Float_t &g, Float_t &b)
                     { TColor::HLS2RGB(h, l, s, r, g, b); } // backward compatible
   static void    HSV2RGB(Float_t h, Float_t s, Float_t v, Float_t &r, Float_t &g, Float_t &b);
   static void    RGB2HLS(Float_t r, Float_t g, Float_t b, Float_t &h, Float_t &l, Float_t &s);
   static void    RGB2HLS(Int_t r, Int_t g, Int_t b, Int_t &h, Int_t &l, Int_t &s);
   static void    RGBtoHLS(Float_t r, Float_t g, Float_t b, Float_t &h, Float_t &l, Float_t &s)
                     { TColor::RGB2HLS(r, g, b, h, l, s); } // backward compatible
   static void    RGB2HSV(Float_t r, Float_t g, Float_t b, Float_t &h, Float_t &s, Float_t &v);
   static Int_t   GetColor(const char *hexcolor);
   static Int_t   GetColor(Float_t r, Float_t g, Float_t b);
   static Int_t   GetColor(Int_t r, Int_t g, Int_t b);
   static Int_t   GetColor(ULong_t pixel);
   static Int_t   GetColorBright(Int_t color);
   static Int_t   GetColorDark(Int_t color);
   static ULong_t Number2Pixel(Int_t ci);
   static ULong_t RGB2Pixel(Int_t r, Int_t g, Int_t b);
   static ULong_t RGB2Pixel(Float_t r, Float_t g, Float_t b);
   static void    Pixel2RGB(ULong_t pixel, Int_t &r, Int_t &g, Int_t &b);
   static void    Pixel2RGB(ULong_t pixel, Float_t &r, Float_t &g, Float_t &b);
   static const char *PixelAsHexString(ULong_t pixel);
   static void    SaveColor(ostream &out, Int_t ci);
   static Bool_t  IsGrayscale();
   static void    SetGrayscale(Bool_t set = kTRUE);
   static void    SetPalette(Int_t ncolors, Int_t *colors);

   ClassDef(TColor,2)  //Color defined by RGB or HLS
};

#endif