#include <stdlib.h>
#include <string.h>

#include <intuition/screens.h>
#include "ht_colors.h"
#include <proto/intuition.h>
#include <proto/graphics.h>


#define c8tc32(x) (((((((x)<<8)|(x))<<8)|(x))<<8)|(x))


int Colors[216];


UWORD DividedBy51Rounded[256] =
{
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
  5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
};


UWORD DividedBy51[256] =
{
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5
};

UWORD Modulo51[256] =
{
   0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
  16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
  32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
  48, 49, 50,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12,
  13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
  29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,
  45, 46, 47, 48, 49, 50,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
  10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
  26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
  42, 43, 44, 45, 46, 47, 48, 49, 50,  0,  1,  2,  3,  4,  5,  6,
   7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
  23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
  39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,  0,  1,  2,  3,
   4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
  20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
  36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,  0
};

UWORD Times6[6] =
{
  0, 6, 12, 18, 24, 30
};

UWORD Times36[6] =
{
  0, 36, 72, 108, 144, 180
};

UWORD Halftone8x8[64] =
{
   0, 38,  9, 47,  2, 40, 11, 50,
  25, 12, 35, 22, 27, 15, 37, 24,
   6, 44,  3, 41,  8, 47,  5, 43,
  31, 19, 28, 15, 34, 21, 31, 18,
   1, 39, 11, 49,  0, 39, 10, 48,
  27, 14, 36, 23, 26, 13, 35, 23,
   7, 46,  4, 43,  7, 45,  3, 42,
  33, 20, 30, 17, 32, 19, 29, 16
};


BOOL AllocColors(int *colors, struct Screen *Screen)
{
  BOOL fail = FALSE;
  int i = 0, r, g, b;

  for(r = 0 ; r < 6 ; r++)
    for(g = 0 ; g < 6 ; g++)
      for(b = 0 ; b < 6 ; b++)
      {
        if((colors[i] = ObtainBestPen(Screen->ViewPort.ColorMap,
                                      c8tc32(r * 51), c8tc32(g * 51), c8tc32(b * 51),
			              OBP_Precision, PRECISION_EXACT,
                                      TAG_DONE)) == -1)
          fail = TRUE;
        i++;
      };
  return fail;
}


void FreeColors(int *colors, struct Screen *Screen)
{
  int i;
  for(i = 0 ; i < 216 ; i++)
    if(colors[i] != -1)
    {
      ReleasePen(Screen->ViewPort.ColorMap, colors[i]);
      colors[i] = -1;
    }
}


ULONG GetPen(register int *colors, register long r, register long g, register long b)
{
  r = DividedBy51Rounded[r];
  g = DividedBy51Rounded[g];
  b = DividedBy51Rounded[b];
  return (ULONG)colors[Times36[r] + Times6[g] + b];
}


ULONG GetPenDithered(register int *colors, register long r, register long g, register long b, register int x, register int y)
{
  r = DividedBy51[r] + (Modulo51[r] > Halftone8x8[((x & 7) << 3) + (y & 7)]);
  g = DividedBy51[g] + (Modulo51[g] > Halftone8x8[((x & 7) << 3) + (y & 7)]);
  b = DividedBy51[b] + (Modulo51[b] > Halftone8x8[((x & 7) << 3) + (y & 7)]);
  return (ULONG)colors[Times36[r] + Times6[g] + b];
}


void AllocCMap(struct Screen *Scr)
{
  char *dither = getenv("MESADITHER");

  if(dither != NULL)
    AllocColors(Colors, Scr);
}


void FreeCMap(struct Screen *Scr)
{
  FreeColors(Colors, Scr);
}