/* ichika6.c - Don Yang (uguu.org)

   11/20/04
                                                                           */

#include<stdio.h>
#include<stdlib.h>


#define z return

typedef float s;
typedef unsigned char W;
typedef int _;

_ I, C, H, i, K, A, ta, n;
W *M, *X, *m, *x, y;
s R, G, B, r, g, b, V, v, w, MA, N, a, T, S, U;
char *t[] =
   {"read error", "write error", "invalid image", "out of memory"},
   e[64];

FILE *f;

_ c()
{
   N = U = r;
   if( N > g ) N = g; if( U < g ) U = g;
   if( N > b ) N = b; if( U < b ) U = b;
   V = v = w = 0;
   if( N != U )
   {
      N = U - N;
      V = (r == U) ? ((g - b) / N)
                   : (g == U) ? ((b - r) / N + 2)
                              : ((r - g) / N + 4);
      w = N / (v = U);
   }
   z 0;
}

_ j(_ k)
{
   if( k < C || k > I - C ||
       !(k % C) || !((k + 1) % C) )
      z 1;
   r = (s)*(X + k * 3) / 255;
   g = (s)*(X + k * 3 + 1) / 255;
   b = (s)*(X + k * 3 + 2) / 255;
   c();
   z
      ((.3 < V && V < .45) ||
       4.3 < V ||
       V < .1)
      ? 0 : j(k + K);
}

_ Q()
{
   z f ? fclose(f) : 0;
}

_ q()
{
   z puts(t[K]);
}

_ E(_ k)
{
   if( M[k] - 255 )
   {
      M[k] = 255;
      if( (k % C) < C - 1 )  E(k + 1);
      if( (k / C) < H - 1 ) E(k + C);
      if( k % C )                E(k - 1);
      if( k / C )                E(k - C);
   }
   z 0;
}

_ P()
{
   x = X - 1;
   for(i = 0; i < I; i++)
   {
      y = *++x;
      *x = *(x + 2);
      *(x += 2) = y;
   }
   z 0;
}

_ O()
{
   z fwrite(x, n, 1, f);
}


_ main(_ D, char **d)
{
   if( D < 3 )
      z printf("%s <infile.bmp|infile.ppm> <outfile>\n", *d);

   K = C = 0;
   if( !(f = fopen(*++d, "rb")) )
      z q();

   X = 0;
   if( fread(e, 64, 1, f) - 1 )
      z q();
   K += 2;
   if( *e == 66 && e[1] == 77 )
   {
      if( *(_*)(e + 28) - 24 )
         z q();
      C = *(_*)(e + 18);
      H = *(_*)(e + 22);
      ta = (4 - ((C * 3) & 3)) & 3;
      n = 54;
   }
   else if( *e == 80 && e[1] == 54 )
   {
      for(i = A = n = 0; i < 63; i++)
         if( e[i] == 10 )
            if( ++A == 3 )
            {
               e[n = ++i] = 0;
               i = 64;
            }
      if( !n ||
          (sscanf(e, "P6\n%d %d\n", &C, &H) - 2) )
         z q();
      ta = 0;
   }
   if( C < 16 || H < 16 )
      z q();

   K++;
   if( !(X = (W*)malloc((I = C * H) * 3)) )
      z q();
   x = X;
   for(fseek(f, n, i = 0); i < H; i++)
   {
      fread(x, C * 3, 1, f);
      x += C * 3;
      for(A = 0; A++ < ta; fgetc(f));
   }
   Q();
   f = 0;

   if( *e - 80 )
      P();

   if( !(m = M = (W*)malloc(I)) )
      z q();
   x = X;
   for(A = 0; A < I; A++)
   {
      r = (s)*(x++) / 255;
      g = (s)*(x++) / 255;
      b = (s)*(x++) / 255;
      c();
      *m = 255;
      if( 3.6 < V && V < 4.24 )
      {
         S = (w-.65)*(w-.65)
            + (v-.42)*(v-.42) * 1.29;
         T = (w-.36)*(w-.36)
            + (v-.6)*(v-.6) * 1.29;
         if( S < .6 || T < .6 )
            *m = (W)(255 *
                    ((S < .6) ? (S / .6)
                                          : (T / .6)));
      }
      m++;
   }

   for(i = A = K = 0; A < C;)
   {
      E(A);
      E(A + C);
      E(A + I - C * 2);
      E(A++ + I - C);
   }
   for(; K < H;)
   {
      E(K * C);
      E(K * C + 1);
      E((K + 1) * C - 2);
      E(++K * C - 1);
   }

   for(m = M; i < I; i++)
   {
      if( *m - 255 )
         if( (j(i + (K = 1)) ? 1 :
              j(i + (K = -1)) ? 1 :
              j(i + (K = C)) ? 1 :
              j(i + (K = -C)) ? 1 : 0) )
            E(i);
      m++;
   }

   x = X;
   m = M;
   for(i = 0; i < I; i++)
   {
      if( *m - 255 )
      {
         S = (s)*m / 255;
         T = 1 - S;

         r = R = (s)*x / 255;
         g = G = (s)*(x+1) / 255;
         b = B = (s)*(x+2) / 255;
         c();
         if( (V += 2) >= 6 )   V -= 6;
         if( (w += .7) > 1 )    w = 1;
         if( (v += .1) > 1 )    v = 1;

         K = (_)V;
         MA = V - (s)K;
         N = v * (1 - w);
         U = v * (1 - w * MA);
         a = v * (1 - w * (1 - MA));
         r = (K < 4) ? (K < 2) ? K ? U : v
                               : N
                     : (K > 4) ? v : a;
         g = (K < 3) ? K ? v : a
                     : K > 3 ? N : U;
         b = (K < 3) ? (K > 1) ? a : N
                     : (K > 4) ? U : v;

         r = R * S + r * T;
         g = R * S + g * T;
         b = R * S + b * T;
         *x = (W)(r * 255);
         x[1] = (W)(g * 255);
         x[2] = (W)(b * 255);
      }
      x += 3;
      m++;
   }

   free(M);

   if( *e - 80 )
      P();

   K = 1;
   if( !(f = fopen(*++d, "wb+")) )
      z q();
   x = (W*)e;
   O();
   n = C * 3;
   x = X;
   for(A = 0; A < H; A++)
   {
      O();
      for(K = 0; K < ta; K++)
         fputc(0, f);
      x += C * 3;
   }

   free(X);
   z Q();
}