fix: make LV2 descriptor allocation static in examples

Signed-off-by: Christopher Arndt <chris@chrisarndt.de>

README.md

@@ -93,6 +93,8 @@ Required:
 
 * [Nim] >= 2.0
 
+Note: [LV2] C headers *need not* to be present to build nymph plugins.
+
 Optional:
 
 * [lv2bm] - For benchmarking and stress-testing plugins

examples/amp_plugin.nim

@@ -67,17 +67,21 @@ proc extensionData(uri: cstring): pointer {.cdecl.} =
 proc NimMain() {.cdecl, importc.}
 
 
+let descriptor = Lv2Descriptor(
+    uri: cstring(PluginUri),
+    instantiate: instantiate,
+    connectPort: connectPort,
+    activate: activate,
+    run: run,
+    deactivate: deactivate,
+    cleanup: cleanup,
+    extensionData: extensionData,
+)
+
 proc lv2Descriptor(index: cuint): ptr Lv2Descriptor {.
                    cdecl, exportc, dynlib, extern: "lv2_descriptor".} =
-    NimMain()
-
     if index == 0:
-        result = createShared(Lv2Descriptor)
-        result.uri = cstring(PluginUri)
-        result.instantiate = instantiate
-        result.connectPort = connectPort
-        result.activate = activate
-        result.run = run
-        result.deactivate = deactivate
-        result.cleanup = cleanup
-        result.extensionData = extensionData
+        NimMain()
+        return addr(descriptor)
+
+    return nil

examples/faustlpf_plugin.nim

@@ -16,8 +16,6 @@ type
         freq: ptr cfloat
         flt: ptr faustlpf
 
-proc NimMain() {.cdecl, importc.}
-
 
 proc instantiate(descriptor: ptr Lv2Descriptor; sampleRate: cdouble;
                  bundlePath: cstring; features: ptr UncheckedArray[ptr Lv2Feature]):
@@ -54,31 +52,30 @@ proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
     computefaustlpf(plug.flt, nSamples.cint, addr plug.input, addr plug.output)
 
 
-proc deactivate(instance: Lv2Handle) {.cdecl.} =
-    discard
-
-
 proc cleanup(instance: Lv2Handle) {.cdecl.} =
     let plug = cast[ptr FaustLPFPlugin](instance)
     deletefaustlpf(plug.flt)
     freeShared(plug)
 
 
-proc extensionData(uri: cstring): pointer {.cdecl.} =
-    return nil
+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".} =
-    NimMain()
-
     if index == 0:
-        result = createShared(Lv2Descriptor)
-        result.uri = cstring(PluginUri)
-        result.instantiate = instantiate
-        result.connectPort = connectPort
-        result.activate = activate
-        result.run = run
-        result.deactivate = deactivate
-        result.cleanup = cleanup
-        result.extensionData = extensionData
+        NimMain()
+        return addr(descriptor)
+
+    return nil

examples/miditranspose.lv2/miditranspose.ttl

@@ -6,7 +6,6 @@
 @prefix midi: <http://lv2plug.in/ns/ext/midi#> .
 @prefix opts: <http://lv2plug.in/ns/ext/options#> .
 @prefix params: <http://lv2plug.in/ns/ext/parameters#> .
-@prefix props: <http://lv2plug.in/ns/ext/port-props#> .
 @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
 @prefix units: <http://lv2plug.in/ns/extensions/units#> .
 @prefix urid: <http://lv2plug.in/ns/ext/urid#> .
@@ -49,7 +48,7 @@
         lv2:minimum -12 ;
         lv2:maximum 12 ;
         units:unit units:semitone12TET
-    ] ; 
+    ] ;
 
     rdfs:comment "A simple MIDI transposition LV2 plugin." ;
 

examples/miditranspose_plugin.nim

@@ -28,46 +28,42 @@ type
 proc instantiate(descriptor: ptr Lv2Descriptor; sampleRate: cdouble;
                  bundlePath: cstring; features: ptr UncheckedArray[ptr Lv2Feature]):
                  Lv2Handle {.cdecl.} =
-    let amp: ptr MidiTransposePlugin = createShared(MidiTransposePlugin)
-    amp.map = cast[ptr UridMap](lv2FeaturesData(features, lv2UridMap))
+    let plug: ptr MidiTransposePlugin = createShared(MidiTransposePlugin)
+    plug.map = cast[ptr UridMap](lv2FeaturesData(features, lv2UridMap))
 
-    if amp.map.isNil:
-        freeShared(amp)
+    if plug.map.isNil:
+        freeShared(plug)
         return nil
 
-    amp.midi_urid = amp.map.map(amp.map.handle, lv2MidiMidiEvent)
+    plug.midi_urid = plug.map.map(plug.map.handle, lv2MidiMidiEvent)
 
-    return cast[Lv2Handle](amp)
+    return cast[Lv2Handle](plug)
 
 
 proc connectPort(instance: Lv2Handle; port: cuint;
                  dataLocation: pointer) {.cdecl.} =
-    let amp = cast[ptr MidiTransposePlugin](instance)
+    let plug = cast[ptr MidiTransposePlugin](instance)
     case cast[PluginPort](port)
     of PluginPort.Input:
-        amp.input = cast[ptr AtomSequence](dataLocation)
+        plug.input = cast[ptr AtomSequence](dataLocation)
     of PluginPort.Output:
-        amp.output = cast[ptr AtomSequence](dataLocation)
+        plug.output = cast[ptr AtomSequence](dataLocation)
     of PluginPort.Transposition:
-        amp.transposition = cast[ptr cfloat](dataLocation)
-
-
-proc activate(instance: Lv2Handle) {.cdecl.} =
-    discard
+        plug.transposition = cast[ptr cfloat](dataLocation)
 
 
 proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
-    let amp = cast[ptr MidiTransposePlugin](instance)
-    let outCapacity = amp.output.atom.size
-    atomSequenceClear(amp.output)
-    amp.output.atom.type = amp.input.atom.type
+    let plug = cast[ptr MidiTransposePlugin](instance)
+    let outCapacity = plug.output.atom.size
+    atomSequenceClear(plug.output)
+    plug.output.atom.type = plug.input.atom.type
 
-    if not atomSequenceIsEmpty(amp.input):
-        #echo &"Event sequence size: {amp.input.atom.size}"
-        let noteOffset = clamp(floor(amp.transposition[] + 0.5), -12, 12).uint8
+    if not atomSequenceIsEmpty(plug.input):
+        #echo &"Event sequence size: {plug.input.atom.size}"
+        let noteOffset = clamp(floor(plug.transposition[] + 0.5), -12, 12).uint8
 
-        for ev in amp.input:
-            if ev.body.`type` == amp.midi_urid:
+        for ev in plug.input:
+            if ev.body.`type` == plug.midi_urid:
                 var msg = cast[ptr UncheckedArray[uint8]](atomContents(AtomEvent, ev))
                 #echo &"0x{toHex(msg[0], 2)} 0x{toHex(msg[1], 2)} 0x{toHex(msg[2], 2)}"
 
@@ -77,35 +73,31 @@ proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
                 else:
                     discard
 
-                discard atomSequenceAppendEvent(amp.output, outCapacity, ev)
-
-
-proc deactivate(instance: Lv2Handle) {.cdecl.} =
-    discard
+                discard atomSequenceAppendEvent(plug.output, outCapacity, ev)
 
 
 proc cleanup(instance: Lv2Handle) {.cdecl.} =
     freeShared(cast[ptr MidiTransposePlugin](instance))
 
 
-proc extensionData(uri: cstring): pointer {.cdecl.} =
-    return nil
-
-
 proc NimMain() {.cdecl, importc.}
 
 
+let descriptor = Lv2Descriptor(
+    uri: cstring(PluginUri),
+    instantiate: instantiate,
+    connectPort: connectPort,
+    activate: nil,
+    run: run,
+    deactivate: nil,
+    cleanup: cleanup,
+    extensionData: nil,
+)
+
 proc lv2Descriptor(index: cuint): ptr Lv2Descriptor {.
                    cdecl, exportc, dynlib, extern: "lv2_descriptor".} =
-    NimMain()
-
     if index == 0:
-        result = createShared(Lv2Descriptor)
-        result.uri = cstring(PluginUri)
-        result.instantiate = instantiate
-        result.connectPort = connectPort
-        result.activate = activate
-        result.run = run
-        result.deactivate = deactivate
-        result.cleanup = cleanup
-        result.extensionData = extensionData
+        NimMain()
+        return addr(descriptor)
+
+    return nil

examples/multimodefilter_plugin.nim

@@ -72,33 +72,29 @@ proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
         plug.output[pos] = plug.svf.process(plug.input[pos])
 
 
-proc deactivate(instance: Lv2Handle) {.cdecl.} =
-    discard
-
-
 proc cleanup(instance: Lv2Handle) {.cdecl.} =
     freeShared(cast[ptr SVFPlugin](instance))
 
 
-proc extensionData(uri: cstring): pointer {.cdecl.} =
-    return nil
-
-
 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".} =
-    NimMain()
-
     if index == 0:
-        result = createShared(Lv2Descriptor)
-        result.uri = cstring(PluginUri)
-        result.instantiate = instantiate
-        result.connectPort = connectPort
-        result.activate = activate
-        result.run = run
-        result.deactivate = deactivate
-        result.cleanup = cleanup
-        result.extensionData = extensionData
+        NimMain()
+        return addr(descriptor)
+
+    return nil
 

examples/tiltfilter_plugin.nim

@@ -72,33 +72,28 @@ proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
         plug.output[pos] = plug.flt.process(plug.input[pos])
 
 
-proc deactivate(instance: Lv2Handle) {.cdecl.} =
-    discard
-
-
 proc cleanup(instance: Lv2Handle) {.cdecl.} =
     freeShared(cast[ptr TiltFilterPlugin](instance))
 
 
-proc extensionData(uri: cstring): pointer {.cdecl.} =
-    return nil
-
-
 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".} =
-    NimMain()
-
     if index == 0:
-        result = createShared(Lv2Descriptor)
-        result.uri = cstring(PluginUri)
-        result.instantiate = instantiate
-        result.connectPort = connectPort
-        result.activate = activate
-        result.run = run
-        result.deactivate = deactivate
-        result.cleanup = cleanup
-        result.extensionData = extensionData
+        NimMain()
+        return addr(descriptor)
 
+    return nil

src/nymph/plugin.nim

@@ -1,8 +0,0 @@
-plugin:
-    urid: urn:foobar#v1
-    port_group:
-        name: "stereo"
-        audio_input:
-            "in_l"
-        audio_input:
-            "in_r"