jacket/examples/jacket_midi_print.nim

90 lines
2.4 KiB
Nim

import std/[logging, os, strutils]
import signal
import jacket
var jclient: ClientP
var event: MidiEvent
var midiPort: PortP
var status: cint
var exitSignalled: bool = false
var log = newConsoleLogger(when defined(release): lvlInfo else: lvlDebug)
proc cleanup() =
debug "Cleaning up..."
if jclient != nil:
discard jclient.deactivate()
discard jclient.clientClose()
jclient = nil
proc errorCb(msg: cstring) {.cdecl.} =
# Suppress verbose JACK error messages when server is not available by
# default. Pass ``lvlAll`` when creating the logger to enable them.
debug "JACK error: " & $msg
proc signalCb(sig: cint) {.noconv.} =
info "Received signal: " & $sig
exitSignalled = true
proc shutdownCb(arg: pointer = nil) {.cdecl.} =
info "JACK server has shut down."
exitSignalled = true
proc printMidiEvent(event: var MidiEvent) =
if event.size <= 3:
for i in 0..<event.size:
stdout.write(event.buffer[i].toHex)
stdout.write("h ")
stdout.write("\n")
stdout.flushFile()
proc processCb*(nFrames: NFrames, arg: pointer): cint {.cdecl.} =
let inbuf = portGetBuffer(midiPort, nFrames)
let count = midiGetEventCount(inbuf)
for i in 0..<count:
if midiEventGet(event.addr, inbuf, i.uint32) == 0:
printMidiEvent(event)
proc main() =
addHandler(log)
# Create JACK client
setErrorFunction(errorCb)
jclient = clientOpen("jacket_midi_print", NoStartServer.ord or UseExactName.ord, status.addr)
debug "JACK server status: " & $status
if jclient == nil:
error getJackStatusErrorString(status)
quit QuitFailure
# Set up signal handlers to clean up on exit
when defined(windows):
setSignalProc(signalCb, SIGABRT, SIGINT, SIGTERM)
else:
setSignalProc(signalCb, SIGABRT, SIGHUP, SIGINT, SIGQUIT, SIGTERM)
# Register JACK callbacks
if jclient.setProcessCallback(processCb) != 0:
error "Could not set JACK process callback function."
cleanup()
quit QuitFailure
jclient.onShutdown(shutdownCb)
# Create output port
midiPort = jclient.portRegister("midi_in", JACK_DEFAULT_MIDI_TYPE, PortIsInput.ord, 0)
# Activate JACK client ...
if jclient.activate() == 0:
# ... and keep running until a signal is received
while not exitSignalled:
sleep(50)
cleanup()
when isMainModule:
main()