100 lines
2.7 KiB
Nim
100 lines
2.7 KiB
Nim
## A tilt EQ / filter LV2 plugin
|
|
|
|
import nymph
|
|
|
|
import paramsmooth
|
|
import tiltfilter
|
|
|
|
const
|
|
PluginUri = "urn:nymph:examples:tiltfilter"
|
|
minFreq = 20.0
|
|
maxFreq = 20_000.0
|
|
|
|
type
|
|
SampleBuffer = UncheckedArray[cfloat]
|
|
|
|
PluginPort {.pure.} = enum
|
|
Input, Output, Frequency, Steepness, Mode
|
|
|
|
TiltFilterPlugin = object
|
|
input: ptr SampleBuffer
|
|
output: ptr SampleBuffer
|
|
freq: ptr cfloat
|
|
steepness: ptr cfloat
|
|
mode: ptr cfloat
|
|
flt: TiltFilter
|
|
smoothFreq: ParamSmooth
|
|
|
|
|
|
proc instantiate(descriptor: ptr Lv2Descriptor; sampleRate: cdouble;
|
|
bundlePath: cstring; features: ptr UncheckedArray[ptr Lv2Feature]):
|
|
Lv2Handle {.cdecl.} =
|
|
try:
|
|
let plug = createShared(TiltFilterPlugin)
|
|
plug.flt = initTiltFilter(10_000.0, 1.0, fmLowPass, sampleRate)
|
|
plug.smoothFreq = initParamSmooth(20.0, sampleRate)
|
|
return cast[Lv2Handle](plug)
|
|
except OutOfMemDefect:
|
|
return nil
|
|
|
|
|
|
proc connectPort(instance: Lv2Handle; port: cuint;
|
|
dataLocation: pointer) {.cdecl.} =
|
|
let plug = cast[ptr TiltFilterPlugin](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)
|
|
of PluginPort.Steepness:
|
|
plug.steepness = cast[ptr cfloat](dataLocation)
|
|
of PluginPort.Mode:
|
|
plug.mode = cast[ptr cfloat](dataLocation)
|
|
|
|
|
|
proc activate(instance: Lv2Handle) {.cdecl.} =
|
|
let plug = cast[ptr TiltFilterPlugin](instance)
|
|
plug.flt.reset()
|
|
|
|
|
|
proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
|
|
let plug = cast[ptr TiltFilterPlugin](instance)
|
|
let freq = plug.freq[].clamp(minFreq, maxFreq)
|
|
|
|
plug.flt.setMode(plug.mode[].clamp(0.0, 2.0).FilterMode)
|
|
plug.flt.setSteepness(plug.steepness[])
|
|
|
|
for pos in 0 ..< nSamples:
|
|
plug.flt.setCenterFreq(plug.smoothFreq.process(freq))
|
|
plug.flt.update()
|
|
plug.output[pos] = plug.flt.process(plug.input[pos])
|
|
|
|
|
|
proc cleanup(instance: Lv2Handle) {.cdecl.} =
|
|
freeShared(cast[ptr TiltFilterPlugin](instance))
|
|
|
|
|
|
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
|