const int height = 100;
const int width = 200;
                    
float _dr;
float _db;
float _dg;
float __dr;
float __db;
float __dg;

void Grad(color clr1,color clr2)
{
                          
      _dr = (clr2.R - clr1.R);
      _dg = (clr2.G - clr1.G);
      _db = (clr2.B - clr1.B);

       _dr /= width;
       _dg /= width;
       _db /= width;

       color clr_;

       for (int i = 0; i < width; i++)
       {
            
           __dr += _dr;
           __dg += _dg;
           __db += _db;

           clr_ = RGB(clr1.R + (int)__dr, clr1.G + (int)__dg, clr1.B + (int)__db);

           for (int j = 0; j < height; j++)
           {
               image.putpixel(i, j, clr_);
           }
       }                  
}