#include <stdlib.h>

#include "patron.h"

note_val
next_note(position pos, score *sc, int track)
{
  unsigned char ii, n = track;
  for (ii = 0; ii != 4; ii++) {
    unsigned char idx = pos & 3;
    pos >>= 2;
    n = (*sc)[ii][n & width_mask][idx];
  }
  return n;
}

void
generate_score(score *sc)
{
  unsigned char ii, jj, kk;
  for (ii = 0; ii != 4; ii++) {
    for (jj = 0; jj != width; jj++) {
      for (kk = 0; kk != 4; kk++) {
	(*sc)[ii][jj][kk] = rand() >> 8;
      }
    }
  }
}

void
mutate_score(score *sc)
{
  unsigned char ii = rand(), jj = rand(), kk = rand();
  (*sc)[ii & 3][jj & width_mask][kk & 3] = rand() >> 8;
}

// Interpret a note_val as a frequency,
// within a couple of octaves
/* Use the first 8 of these:
>>> [int(round(256 * 2**((x * 7 % 24)/12.0))) 
     for x in range(25)]
[256, 384, 575, 861, 323, 483, 724, 271,
 406, 609, 912, 342, 512, 767, 287, 431,
 645, 967, 362, 542, 813, 304, 456, 683, 
 256]
*/
int
freq(note_val n)
{
  static int table[] = {
    256, 384, 575, 861, 323, 483, 724, 271,
    406, 609, 912, 342, 512, 767, 287, 431,
    645, 967, 362, 542, 813, 304, 456, 683, 
    256
  };
  if (!(n & 8)) return 0;	// silence ½ of the time
  return table[n & 7];
}