xm-rand-pattern.c

来自「Genetic Programing of music」· C语言 代码 · 共 123 行

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "xm_lib.h"

#define MALLOC malloc

/*
 *   createRandomNoteSequence - generates a string of 'length' random notes
 *      between lowOctave and highOctave, with a probability of a note at
 *      any point being noteProb (the rest are rests).  Notes will fall between
 *      the C of the low octave and the C of the high octave. Octave values
 *      should range between 0 and 5.
 *
 *      Note: drand48() is used; the caller should seed the f'n if needed
 *            with srand48()
 */      
char *
createRandomNoteSequence(int length, double noteProb,
			 int lowOctave, int highOctave)
{

  char *noteString;
  int i;

  /* allocate noteString */
  noteString=(char *)MALLOC((length+1)*sizeof(char));

  /* generate notes */
  for(i=0;i<length;i++)
    if ( drand48() < noteProb )
      noteString[i]=(char)floor(12*(drand48()*(highOctave-lowOctave+1)
				    +lowOctave)+1);
    else
      noteString[i]=88;

  return noteString;

} /* end of createRandomNoteSequence */

int
main(int argc, char *argv[]) {

  int i;
  int playFile=0;
  long seed;
  char command[255];
  char *filename=NULL;
  FILE *xmFile=NULL;
  FILE *outPutFile=NULL;
  char *noteString;
  time_t tempTime;
  
  /* seed the random number generator */
  seed=(long)time(&tempTime);
  srand48(seed);

  /* parse command line arguments */
  for (i=1; i<argc; i++) {
    
    if (strcmp (argv[i], "-v") == 0) {
      outPutFile=stdout;     
    } else if (strcmp (argv[i], "-p") == 0) {
      playFile=1;     
    } else if (strcmp (argv[i], "-h") == 0) {
      fprintf(stderr, "\nSyntax: %s [-h] [-v] <filename>\n\n"
	      "\tCreates a random XM pattern, with four channels. "
	      "Only the first\nhas notes, and only instrument 0 is used. "
	      "The output\nis placed into <filename>\n\n"
	      "\t-h  = display this help message\n"
	      "\t-v  = verbose description of created pattern\n"
	      "\t-p  = play created file\n\n",
	      argv[0]);
      exit(1);
    } else {
      filename = argv[i];
    }
  }

  /* set appropriate output file */
  if(outPutFile==NULL)
    outPutFile=fopen("/dev/null","w+");
  
  /*
   * Open XM File
   */
  if(filename != NULL)
    xmFile = fopen(filename,"w+");
  
  if (xmFile==NULL) {
    
    fprintf(stderr,"Couln't open %s\n",filename);

    exit(1);

  }

  /* Create the pattern information */
  noteString=createRandomNoteSequence(200, 0.25, 0, 5);
  fwriteXMPatternInfo(xmFile, noteString);

  /* Now print pattern info */
  fseek(xmFile, 0, SEEK_SET);
  fprintf(outPutFile, "Pattern Information:\n");
  fprintXMPatternInfo(xmFile, outPutFile, 4, 1);

  /* Now play the file if requested */
  if(playFile) {
    sprintf(command, "play_pattern %s", filename); 
    system(command);
  }
  
  fclose(outPutFile);
  fclose(xmFile);
  
  return 0;
  
} /* end of main */