jacket/examples/jacket_simple_client.nim

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import std/[logging, math, os]
import signal
import jacket
var jclient: ClientTPtr
var out1: PortTPtr
var status: cint
var log = newConsoleLogger(when defined(release): lvlInfo else: lvlDebug)
type
SampleT = DefaultAudioSampleT
JackBufferPtr = ptr UncheckedArray[SampleT]
const
tableSize = 4096
sineFreq = 440.0
twoPi = Pi * 2.0
type
SineOsc = object
waveform: array[0..tableSize, float]
phase: float
idxInc: float
SineOscPtr = ref SineOsc
proc initSineOsc(sr: float, freq: float): SineOsc =
let phsInc = twoPi / tableSize
var phase = 0.0
for i in 0 ..< tableSize:
result.waveform[i] = sin(phase)
phase += phsInc
result.phase = 0.0
result.idxInc = tableSize / sr * freq
proc tick(osc: SineOscPtr): float =
result = osc.waveform[int(osc.phase)]
osc.phase += osc.idxInc;
if osc.phase >= tableSize:
osc.phase -= tableSize
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 cleanup(sig: cint = 0) {.noconv.} =
debug "Cleaning up..."
if jclient != nil:
discard jclient.deactivate()
discard jclient.clientClose()
jclient = nil
quit QuitSuccess
proc shutdownCb(arg: pointer = nil) {.cdecl.} =
debug "Server has shut down"
cleanup()
proc process(nFrames: NFramesT, arg: pointer): cint {.cdecl.} =
var outbuf = cast[JackBufferPtr](portGetBuffer(out1, nFrames))
let osc = cast[SineOscPtr](arg)
for i in 0 ..< nFrames:
outbuf[i] = osc.tick() * 0.2
return 0
addHandler(log)
# create JACK client
setErrorFunction(errorCb)
jclient = clientOpen("jacket_port_register", NoStartServer.ord or UseExactName.ord, status.addr)
debug "Server status: " & $status
if jclient == nil:
error getJackStatusErrorString(status)
quit 1
let sampleRate =(float) jclient.getSampleRate()
var osc = initSineOsc(sampleRate, sineFreq)
when defined(windows):
setSignalProc(cleanup, SIGABRT, SIGINT, SIGTERM)
else:
setSignalProc(cleanup, SIGABRT, SIGHUP, SIGINT, SIGQUIT, SIGTERM)
if jclient.setProcessCallback(process, osc.addr) != 0:
error "Could not set process callback function."
cleanup()
jclient.onShutdown(shutdownCb, nil)
out1 = jclient.portRegister("out_1", JACK_DEFAULT_AUDIO_TYPE, PortIsOutput.ord, 0)
if jclient.activate() == 0:
# keep running until the Ctrl+C
while true:
sleep(50)
cleanup() # normally not reached