title: Midi Gate
tags: reaper jsfx midi

The idea here is that you play a held chord on channel 1,
and then channel 2 you play a rhythm, and that controls when
the notes are played. Generally this is for generating chord
stab patterns.

Still buggy. Debugging in Reaper JSFX is a nightmare.

```
desc: jda midi gate 1
//tags: MIDI processing

in_pin:none
out_pin:none

@init 
gate = 0;
gatecount = 0;
notes = 100;

r = 0;
loop(128,(notes[r] = 0; r+=1;));

function heldon(ts) local(r) (
  r = 0;
  loop(128,(
    (notes[r] > 0) ? (
      midisend(ts,0x90,r,notes[r]);    
    );
    r += 1;
  ));
);

function heldoff(ts) local(r) (
  r = 0;
  loop(128,(
    (notes[r] > 0) ? (
      midisend(ts,0x80,r,0);    
    );
    r += 1;
  ));
);

nheld = 0;
ax = 0;
bx = 0;
cx = 0;
dx = 0;

@block

while (
midirecv(ts,msg1,msg2,msg3) ? 
(
  c = msg1 & 0xF;
  s = msg1 >> 4;
  p = msg2;
  v = msg3;

  ( c == 1 ) ? (
    ( s == 8 || ( s == 9 && v == 0 ) ) ? (
     gate = 0;
      heldoff();
    ) : ( s == 9 ) ? (
      gate = 1;
      heldon();
    );
    // no pass thru
  ) : ( c == 0 && ( s == 8 || s == 9 ) ) ? (
    ( s == 8 || ( s == 9 && v == 0 ) ) ? (
      notes[p] = 0;
      ( gate == 0 ) ? (
        ax += 1;
      ) : (
        bx += 1;
        midisend(ts,0x80,p,0);
      );
    ) : ( s == 9 ) ? (
      notes[p] = v;
      ( gate == 0 ) ? (
        cx += 1;
      ) : (
        dx += 1;
        midisend(ts,0x90,p,v);
      );
    );
  ) : (
    // pass thru
    midisend(ts,msg1,msg2,msg3);
  );
));

@sample

```