// -----------------------------------------------------------------------------
// Colors convertions
//
// rgb2hsv : conveesion d'une couleour definie par les trois composants rouge,
//           vert et bleu en teinte, saturation et intensite.
// hsv2rgb : convesion d'une couleur definie par les trois composants teinte,
//           saturation et intensite en rouge, vert et bleu.
//          
// les deux macros attendent un "vecteur rgb" et retourne un "vecteur rgb" :
// - rgb2hsv : on passe <rouge, vert, bleu>, on obtient <teinte, saturation, intensite>    
// - hsv2rgb : on passe   <teinte, saturation, intensite>, on obtient <rouge, vert, bleu>
//   rouge, vert, bleu, saturation, intensite : 0.00 .. 1.00
//   teinte : 0.00 .. 360.00
//
//
// louis bellotto - louisbel@free.fr
// -----------------------------------------------------------------------------


// -----------------------------------------------------------------------------
#version unofficial MegaPov 0.7;


// -----------------------------------------------------------------------------
#macro maxValue(thisColor)
  max(max(thisColor.red,thisColor.green),thisColor.blue)
#end


// -----------------------------------------------------------------------------
#macro minValue(thisColor)
  min(min(thisColor.red,thisColor.green),thisColor.blue)
#end


// -----------------------------------------------------------------------------
#macro rgb2hsv(thisRGB)
  #local maxComp = maxValue(thisRGB);
  #local minComp = minValue(thisRGB);
  #local diff = maxComp-minComp;
  #local value = maxComp;

  #local hue = 0.00;
  #local saturation = 0.00;

  #if(maxComp!=0)
    #set saturation = diff/maxComp;
  #end

  #if(saturation=0)
    #set hue=-1;
    #debug"\n\nTeinte indefinie !\n\n"
  #else
    #local rValue=(maxComp-thisRGB.red)/diff;
    #local gValue=(maxComp-thisRGB.green)/diff;
    #local bValue=(maxComp-thisRGB.blue)/diff;
    #if(thisRGB.red=maxComp)
      #set hue = bValue-gValue;
    #else
      #if (thisRGB.green=maxComp)
        #set hue = 2+rValue-bValue;
      #else
        #if(thisRGB.blue=maaxComp)
          #set hue = 4+gValue-rValue;
        #else
          #warning "\nConversion impossible !!!"
        #end
      #end
    #end
  #set hue=hue*60;
  #if (hue<0) #set hue=hue+360; #end
  #end
  <hue, saturation, value>
#end
// -----------------------------------------------------------------------------


// -----------------------------------------------------------------------------
#macro hsv2rgb(thisHSV)
  #local redValue = 0.00;
  #local greenValue = 0.00;
  #local blueValue = 0.00;

  #local hh = 1.0*thisHSV.red;
  #local vv = 1.0*thisHSV.blue;
  #if (thisHSV.green != 0)
    #if (hh=360)
      #set hh = 0.00;
    #end
    #set hh=hh/60;
    #local ii=int (hh);
    #local ff=hh-ii;
    #local pp=1.0*thisHSV.blue*(1-thisHSV.green);
    #local qq=1.0*thisHSV.blue*(1-(thisHSV.green*ff));
    #local tt=1.0*thisHSV.blue*(1-thisHSV.green*(1-ff));
    #switch (ii)
      #case (0)
        #set redValue = vv ;
        #set greenValue = tt;
        #set blueValue = pp;
      #break
      #case (1)
        #set redValue = qq;
        #set greenValue = vv;
        #set blueValue = pp;
      #break
      #case (2)
        #set redValue = pp;
        #set greenValue = vv;
        #set blueValue = tt;
      #break
      #case (3)
        #set redValue = pp;
        #set greenValue = qq;
        #set blueValue = vv;
      #break
      #case (4)
        #set redValue = tt;
        #set greenValue = pp;
        #set blueValue = vv;
      #break
      #case (5)
        #set redValue = vv;
        #set greenValue = pp;
        #set blueValue = qq;
      #break
      #else
        #warning "\nConversion impossible !!!"
      #end
  #end
  <redValue, greenValue, blueValue>
#end



// --- eof ---------------------------------------------------------------------