113 lines
2.9 KiB
Nim
113 lines
2.9 KiB
Nim
import std/[logging, math, os]
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import signal
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import jacket
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var jclient: ClientP
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var outPort: PortP
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var status: cint
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var exitSignalled: bool = false
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var log = newConsoleLogger(when defined(release): lvlInfo else: lvlDebug)
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type
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Sample = DefaultAudioSample
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JackBufferP = ptr UncheckedArray[Sample]
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const
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tableSize = 4096
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sineFreq = 440.0
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twoPi = Pi * 2.0
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type
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SineOsc = object
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waveform: array[0..tableSize, float]
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phase: float
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idxInc: float
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SineOscP = ref SineOsc
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proc initSineOsc(sr: float, freq: float): SineOsc =
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let phsInc = twoPi / tableSize
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var phase = 0.0
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for i in 0 ..< tableSize:
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result.waveform[i] = sin(phase)
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phase += phsInc
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result.phase = 0.0
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result.idxInc = tableSize / sr * freq
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proc tick(osc: SineOscP): float =
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result = osc.waveform[int(osc.phase)]
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osc.phase += osc.idxInc;
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if osc.phase >= tableSize:
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osc.phase -= tableSize
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proc cleanup() =
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debug "Cleaning up..."
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if jclient != nil:
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discard jclient.deactivate()
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discard jclient.clientClose()
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jclient = nil
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proc errorCb(msg: cstring) {.cdecl.} =
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# Suppress verbose JACK error messages when server is not available by
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# default. Pass ``lvlAll`` when creating the logger to enable them.
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debug "JACK error: " & $msg
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proc signalCb(sig: cint) {.noconv.} =
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debug "Received signal: " & $sig
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exitSignalled = true
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proc shutdownCb(arg: pointer = nil) {.cdecl.} =
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warn "JACK server has shut down."
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exitSignalled = true
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proc processCb(nFrames: NFrames, arg: pointer): cint {.cdecl.} =
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var outbuf = cast[JackBufferP](portGetBuffer(outPort, nFrames))
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let osc = cast[SineOscP](arg)
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for i in 0 ..< nFrames:
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outbuf[i] = osc.tick() * 0.2
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return 0
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addHandler(log)
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# Create JACK client
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setErrorFunction(errorCb)
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jclient = clientOpen("jacket_sine", NoStartServer.ord or UseExactName.ord, status.addr)
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debug "JACK server status: " & $status
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if jclient == nil:
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error getJackStatusErrorString(status)
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quit QuitFailure
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# Create sine oscillator
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let sampleRate = jclient.getSampleRate.float
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debug "JACK sample rate: " & $sampleRate
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var osc = initSineOsc(sampleRate, sineFreq)
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# Set up signal handlers to clean up on exit
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when defined(windows):
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setSignalProc(signalCb, SIGABRT, SIGINT, SIGTERM)
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else:
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setSignalProc(signalCb, SIGABRT, SIGHUP, SIGINT, SIGQUIT, SIGTERM)
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# Register JACK callbacks
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if jclient.setProcessCallback(processCb, osc.addr) != 0:
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error "Could not set JACK process callback function."
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cleanup()
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quit QuitFailure
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jclient.onShutdown(shutdownCb)
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# Create output port
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outPort = jclient.portRegister("out_1", JACK_DEFAULT_AUDIO_TYPE, PortIsOutput.ord, 0)
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# Activate JACK client ...
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if jclient.activate() == 0:
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# ... and keep running until a signal is received
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while not exitSignalled:
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sleep(50)
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cleanup()
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