//
// Programmer:    Craig Stuart Sapp <craig@ccrma.stanford.edu>
// Creation Date: Fri Dec 18 23:05:42 PST 1998
// Last Modified: Thu Dec 24 15:56:37 PST 1998
// Filename:      ...linuxmidi/output/ranwalk.cpp
// Syntax:        C++
// $Smake:        g++ -O3 -Wall -o %b %f && strip %b
//

#include <linux/soundcard.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <iostream.h>

#include "SigTimer.cpp"

// global variables:
const char* dev = "/dev/sequencer";     // name of sequencer file
int status;                             // for error checking


// function declarations:
void randomwalk(int seqfd, int device);


int main(int argc, char** argv) {
   int seqfd = open(dev, O_WRONLY, 0);
   if (seqfd < 0) {
      cout << "Error: cannot open " << dev << endl;
      exit(1);
   }

   int numMidi;                        // number of midi outputs
   status = ioctl(seqfd, SNDCTL_SEQ_NRMIDIS, &numMidi);
   if (status != 0) {
      cout << "Error: cannot access MIDI devices on soundcard" << endl;
      exit(1);
   }
   cout << "\nThere are: " << numMidi << " Midi output devices" << endl;

   int device = 0;                    // MIDI output device to use
   if (argc >= 2) {
      device = argv[1][0] - '0';
   }
   if (device >= numMidi) {
      cout << "Error: specified device is not valid: " << device << endl;
      exit(1);
   } else {
      cout << "Device set to: " << device << endl;
   }
   

   randomwalk(seqfd, device);

   close(seqfd);
   return 0;
}



void randomwalk(int seqfd, int device) {
   unsigned char outpacket[4];
   outpacket[0] = SEQ_MIDIPUTC;
   outpacket[2] = device;
   outpacket[3] = 0;
   
   cout << "What timbre do you want: ";
   int userinput;
   cin  >> userinput;

   outpacket[1] = 0xc0;
   write(seqfd, outpacket, 4);

   outpacket[1] = userinput & 0xff;
   write(seqfd, outpacket, 4);


   SigTimer timer;
   cout << "Enter a tempo for quarter notes per minute: ";
   double tempo = 120.0;
   cin >> tempo;
   timer.setTempo(tempo);  
   timer.reset();
   timer.update(-1);

   int key = 60;
   while (1) {
      if (timer.expired()) {
         timer.update();

         switch (rand() % 2) {
            case 0:   key--;    if (key < 0) key = 0;       break;
            case 1:   key++;    if (key > 127) key = 127;   break;
         }

         outpacket[1] = 0x90;            // note-on MIDI command
         write(seqfd, outpacket, 4);

         outpacket[1] = key;             // note-on key MIDI data
         write(seqfd, outpacket, 4);

         outpacket[1] = 127;             // note-on velocity MIDI data
         write(seqfd, outpacket, 4);
     }
   
   }

   close(seqfd);
}