82 lines
2.2 KiB
Nim
82 lines
2.2 KiB
Nim
## A FAUST standard library 2-pole lowpass filter LV2 plugin
|
|
|
|
import nymph
|
|
import faustlpf
|
|
|
|
const
|
|
PluginUri = "urn:nymph:examples:faustlpf"
|
|
|
|
type
|
|
PluginPort {.pure.} = enum
|
|
Input, Output, Frequency
|
|
|
|
FaustLPFPlugin = object
|
|
input: ptr SampleBuffer
|
|
output: ptr SampleBuffer
|
|
freq: ptr cfloat
|
|
flt: ptr faustlpf
|
|
|
|
|
|
proc instantiate(descriptor: ptr Lv2Descriptor; sampleRate: cdouble;
|
|
bundlePath: cstring; features: ptr UncheckedArray[ptr Lv2Feature]):
|
|
Lv2Handle {.cdecl.} =
|
|
try:
|
|
let plug = cast[ptr FaustLPFPlugin](createShared(FaustLPFPlugin))
|
|
plug.flt = newfaustlpf()
|
|
initfaustlpf(plug.flt, sampleRate.cint)
|
|
return cast[Lv2Handle](plug)
|
|
except OutOfMemDefect:
|
|
return nil
|
|
|
|
|
|
proc connectPort(instance: Lv2Handle; port: cuint;
|
|
dataLocation: pointer) {.cdecl.} =
|
|
let plug = cast[ptr FaustLPFPlugin](instance)
|
|
case cast[PluginPort](port)
|
|
of PluginPort.Input:
|
|
plug.input = cast[ptr SampleBuffer](dataLocation)
|
|
of PluginPort.Output:
|
|
plug.output = cast[ptr SampleBuffer](dataLocation)
|
|
of PluginPort.Frequency:
|
|
plug.freq = cast[ptr cfloat](dataLocation)
|
|
|
|
|
|
proc activate(instance: Lv2Handle) {.cdecl.} =
|
|
let plug = cast[ptr FaustLPFPlugin](instance)
|
|
instanceClearfaustlpf(plug.flt)
|
|
|
|
|
|
proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
|
|
let plug = cast[ptr FaustLPFPlugin](instance)
|
|
plug.flt.set_cutoff(plug.freq[])
|
|
computefaustlpf(plug.flt, nSamples.cint, addr plug.input, addr plug.output)
|
|
|
|
|
|
proc cleanup(instance: Lv2Handle) {.cdecl.} =
|
|
let plug = cast[ptr FaustLPFPlugin](instance)
|
|
deletefaustlpf(plug.flt)
|
|
freeShared(plug)
|
|
|
|
|
|
proc NimMain() {.cdecl, importc.}
|
|
|
|
|
|
let descriptor = Lv2Descriptor(
|
|
uri: cstring(PluginUri),
|
|
instantiate: instantiate,
|
|
connectPort: connectPort,
|
|
activate: activate,
|
|
run: run,
|
|
deactivate: nil,
|
|
cleanup: cleanup,
|
|
extensionData: nil,
|
|
)
|
|
|
|
proc lv2Descriptor(index: cuint): ptr Lv2Descriptor {.
|
|
cdecl, exportc, dynlib, extern: "lv2_descriptor".} =
|
|
if index == 0:
|
|
NimMain()
|
|
return addr(descriptor)
|
|
|
|
return nil
|