// discovers the currently connected Launchpad device
// as a MIDI device.
func discover() (input portmidi.DeviceID, output portmidi.DeviceID, err error) {
in := -1
out := -1
for i := 0; i < portmidi.CountDevices(); i++ {
info := portmidi.Info(portmidi.DeviceID(i))
if strings.Contains(info.Name, "Launchpad") {
if info.IsInputAvailable {
in = i
}
if info.IsOutputAvailable {
out = i
}
}
}
if in == -1 || out == -1 {
err = errors.New("launchpad: no launchpad is connected")
} else {
input = portmidi.DeviceID(in)
output = portmidi.DeviceID(out)
}
return
}
func main() {
flag.Parse()
var err error
if err = portmidi.Initialize(); err != nil {
log.Fatal("error while initializing portmidi", err)
}
if out, err = portmidi.NewOutputStream(portmidi.DeviceID(*flagOutput), 1024, 0); err != nil {
log.Fatal("error while initializing connection to midi out stream")
}
if pad, err = launchpad.Open(); err != nil {
log.Fatal("error while initializing connection to launchpad", err)
}
grid = newGrid()
instruments = []int{
70, // maracas
38, // snare 1
40, // snare 2
51, // ride cymbal
42, // closed hi-hat
58, // vibra slap
46, // open hi-hat
81} // open triangle
// load an initial drum pattern
// hi-hats
grid[0][4] = true
grid[2][4] = true
grid[4][4] = true
grid[6][4] = true
// snares
grid[5][3] = true
grid[5][2] = true
grid[5][1] = true
// bells
grid[6][7] = true
grid[7][7] = true
grid[5][6] = true
// clear
pad.Reset()
// listen button toggles
ch := pad.Listen()
go func() {
for {
hit := <-ch
log.Println("drum toggled at", hit)
if hit.Y == -1 || hit.X > 7 {
// a controller button is hit
continue
}
grid[hit.X][hit.Y] = !grid[hit.X][hit.Y]
if !grid[hit.X][hit.Y] {
// turn off immediately
pad.Light(hit.X, hit.Y, 0, 0)
}
}
}()
for {
for x := 0; x < NumberofHGrids; x++ {
tick(x)
}
}
}