#include "slicer.h"
//#define DISTFILENAME "dist"

/* METRICS */

int LIdistance(long a, long b) {
   return MAX3( ABS( TORED(a)-TORED(b) ), ABS( TOGREEN(a)-TOGREEN(b) ), ABS( TOBLUE(a)-TOBLUE(b) ) );
}

int L1distance(long a, long b) {
   return ABS( TORED(a)-TORED(b) ) + ABS( TOGREEN(a)-TOGREEN(b) ) + ABS( TOBLUE(a)-TOBLUE(b) );
}

int Eucldistance(long a, long b) {
   return sqrt( SQR( TORED(a)-TORED(b) ) + SQR( TOGREEN(a)-TOGREEN(b) ) + SQR( TOBLUE(a)-TOBLUE(b) ) );
}


/* THE SLICER FUNCTION */

Graphics::TBitmap *slicer(int (*newDist)(long, long), AnsiString filNam, double TH, double VTH) {
   static Graphics::TBitmap *original;
   static Graphics::TBitmap *processed;
   static Graphics::TBitmap *distance;
   static Graphics::TBitmap *output;
   static int actY, actX;
   static int (*dist)(long, long);
   static int hist[800];
   static int level;
   double THval, VTHval, newTHval;

   /* closing the function usage */
   if (!TH && !VTH) {
      if (original) delete original; if (processed) delete processed;
      if (distance) delete distance; if (output) delete output;
      return NULL;
   }

   /* change distance function used */
   if (newDist) dist = newDist;

   /* initialize if file name is given */
   if (filNam != "") {
      if (original) delete original; if (processed) delete processed;
      if (distance) delete distance; if (output) delete output;
      original = new Graphics::TBitmap();
      original -> LoadFromFile(filNam);
      processed = new Graphics::TBitmap(); distance  = new Graphics::TBitmap();
      output    = new Graphics::TBitmap();
      processed->Height = original->Height; distance->Height = original->Height;
      output->Height = original->Height; processed->Width = original->Width;
      distance->Width = original->Width; output->Width = original->Width;
      actY = actX = 0; level = 0;
      for (int x = 0; x < original->Width; ++x)
         for (int y = 0; y < original->Height; ++y)
            processed->Canvas->Pixels[x][y] = 0;
   }

   /* looking for the seed pixel and returning NULL if no seed is available*/
   while (actY < processed->Height && processed->Canvas->Pixels[actX][actY]) {
     ++actX;
     if (actX == processed->Width) { actX = 0; ++actY; }
   }
   if (actY == processed->Height) return NULL;
   //printf("\nSeed coordinates: %i,%i\n", actX, actY);

   ++level;
   /* calculation THval and VTHval and resetting the histogram */
   THval  = dist(0, 0x00FFFFFF)*TH/100;
   VTHval = original->Height*original->Width*VTH/100;
   for (int i = 0; i < dist(0, 0x00FFFFFF); ++i)
      hist[i] = 0;

   /* creating the distance image and the histogram */
   int actDist; long seedColor = original->Canvas->Pixels[actX][actY];
   for (int x = 0; x < original->Width; ++x)
      for (int y = 0; y < original->Height; ++y) {
         actDist = dist(seedColor, original->Canvas->Pixels[x][y]);
         distance->Canvas->Pixels[x][y] = actDist;
         ++hist[actDist];
      }

   // saving the distance image
   /*{
      Graphics::TBitmap *toSave = new Graphics::TBitmap;
      long c; int maxDist = dist(0, 0x00FFFFFF);
      toSave->Height = distance->Height; toSave->Width = distance->Width;
      for (int x = 0; x < toSave->Width; ++x)
         for (int y = 0; y < toSave->Height; ++y) {
            c = (double) distance->Canvas->Pixels[x][y] / maxDist * 255;
            toSave->Canvas->Pixels[x][y] = TOCOLOR(c, c, c);
         }
      printf("Saving distance image \tno. %i\tby seed at (%i,%i)\n", level-1, actX, actY);
      toSave->SaveToFile((AnsiString) DISTFILENAME + (level-1) + ".BMP");
   }*/

   /* searching for minimal threshold value */
   newTHval = THval;
   {  int numofExtr = 0;
      int extremas[800]; short extrtype[800]; // +1 : max, -1 : min
      // searching for local extremas
      if (hist[0] != hist[1]) {
         ++numofExtr; extremas[0] = 0;
         if (hist[0] > hist[1]) extrtype[0] = 1;
         else extrtype[0] = -1;
      }
      for (int i = 1; i < THval-1; ++i) {
         if (hist[i] > hist[i-1] && hist[i] > hist[i+1]) {
            extremas[numofExtr] = i; extrtype[numofExtr] = 1;
            ++numofExtr;
         } else if (hist[i] < hist[i-1] && hist[i] < hist[i+1]) {
            extremas[numofExtr] = i; extrtype[numofExtr] = -1;
            ++numofExtr;
         }
      }
      // searching for extrema distances larger than Vertical Threshold
      for (int i = 0; i < numofExtr && extremas[i] < newTHval; ++i)
         if (extrtype[i] == 1)
            for (int j = i+1; j < numofExtr && extremas[j] < newTHval; ++j)
               if ((extrtype[j] == -1) && (hist[extremas[i]]-hist[extremas[j]] >= VTHval))
                  newTHval = extremas[j];

   }

   /* thresholding the image */
   for (int y = 0; y < distance->Height; ++y)
      for (int x = 0; x < distance->Width; ++x)
         if (!processed->Canvas->Pixels[x][y] && distance->Canvas->Pixels[x][y] <= newTHval) {
            output->Canvas->Pixels[x][y] = 0x00FFFFFF;
            processed->Canvas->Pixels[x][y] = 1;
         } else output->Canvas->Pixels[x][y] = 0;

   /* saving the histogram
   FILE *fil = fopen(((AnsiString) DISTFILENAME + level + ".TXT").c_str(), "w");
   fprintf(fil, "Seed coordinates: ( %i, %i )\n", actX, actY);
   fprintf(fil, "Seed colour: %x\n\n", original->Canvas->Pixels[actX][actY]);
   fprintf(fil, "Original THval: %i\n", THval);
   fprintf(fil, "New      THval: %i\n", newTHval);
   fprintf(fil, "Vertical TH   : %i\n\n", VTHval);
   for (int i = 0; i < dist(0, 0x00FFFFFF); ++i)
      fprintf(fil, "%i\n", hist[i]);
   fclose(fil);*/

   // marking the seed pixel
   //output->Canvas->Pixels[actX][actY] = 0x00FF0000;
   return output;
}