Add a SysEx example plugin

Cargo.lock

@@ -4252,6 +4252,13 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "sysex"
+version = "0.1.0"
+dependencies = [
+ "nih_plug",
+]
+
 [[package]]
 name = "termcolor"
 version = "1.1.3"

Cargo.toml

@@ -29,6 +29,7 @@ members = [
   "plugins/examples/poly_mod_synth",
   "plugins/examples/sine",
   "plugins/examples/stft",
+  "plugins/examples/sysex",
 
   "plugins/buffr_glitch",
   "plugins/crisp",

README.md

@@ -207,6 +207,8 @@ examples.
   higher level helper features, such as an adapter to process audio with a
   short-term Fourier transform using the overlap-add method, all using the
   compositional `Buffer` interfaces.
+- [**sysex**](plugins/examples/sysex) is a simple example of how to send and
+  receive SysEx messages by defining custom message types.
 
 ## Licensing
 

plugins/examples/midi_inverter/src/lib.rs

@@ -40,12 +40,6 @@ impl Plugin for MidiInverter {
         self.params.clone()
     }
 
-    fn accepts_bus_config(&self, _config: &BusConfig) -> bool {
-        // This is a zero channel plugin, but the host can configure it to pass through audio as
-        // needed. Ableton Live for instance doesn't support note effects.
-        true
-    }
-
     fn process(
         &mut self,
         _buffer: &mut Buffer,

plugins/examples/sysex/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "sysex"
+version = "0.1.0"
+edition = "2021"
+authors = ["Robbert van der Helm <mail@robbertvanderhelm.nl>"]
+license = "ISC"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+nih_plug = { path = "../../../", features = ["assert_process_allocs"] }

plugins/examples/sysex/src/lib.rs

@@ -0,0 +1,109 @@
+use nih_plug::prelude::*;
+use std::sync::Arc;
+
+#[derive(Default)]
+struct SysEx {
+    params: Arc<SysExParams>,
+}
+
+#[derive(Default, Params)]
+struct SysExParams {}
+
+// This is a struct or enum describing all MIDI SysEx messages this plugin will send or receive
+#[derive(Debug, Clone, PartialEq)]
+enum CoolSysExMessage {
+    Foo(f32),
+    Bar { x: u8, y: u8 },
+}
+
+// This trait is used to convert between `CoolSysExMessage` and the raw MIDI SysEx messages. That
+// way the rest of the code doesn't need to bother with parsing or SysEx implementation details.
+impl SysExMessage for CoolSysExMessage {
+    // This is a byte array that is large enough to write all of the messages to
+    type Buffer = [u8; 6];
+
+    fn from_buffer(buffer: &[u8]) -> Option<Self> {
+        // `buffer` contains the entire buffer, including headers and the 0xf7 End Of system
+        // eXclusive byte
+        match buffer {
+            [0xf0, 0x69, 0x01, n, 0xf7] => Some(CoolSysExMessage::Foo(*n as f32 / 127.0)),
+            [0xf0, 0x69, 0x02, x, y, 0xf7] => Some(CoolSysExMessage::Bar { x: *x, y: *y }),
+            _ => None,
+        }
+    }
+
+    fn to_buffer(self) -> (Self::Buffer, usize) {
+        // `Self::Buffer` needs to have a fixed size, so the result needs to be padded, and we
+        // return the message's actual length in bytes alongside it so the caller can trim the
+        // excess padding
+        match self {
+            CoolSysExMessage::Foo(x) => ([0xf0, 0x69, 0x01, (x * 127.0).round() as u8, 0xf7, 0], 5),
+            CoolSysExMessage::Bar { x, y } => ([0xf0, 0x69, 0x02, x, y, 0xf7], 6),
+        }
+    }
+}
+
+impl Plugin for SysEx {
+    const NAME: &'static str = "SysEx Example";
+    const VENDOR: &'static str = "Moist Plugins GmbH";
+    const URL: &'static str = "https://youtu.be/dQw4w9WgXcQ";
+    const EMAIL: &'static str = "info@example.com";
+
+    const VERSION: &'static str = env!("CARGO_PKG_VERSION");
+
+    const DEFAULT_INPUT_CHANNELS: u32 = 0;
+    const DEFAULT_OUTPUT_CHANNELS: u32 = 0;
+
+    const SAMPLE_ACCURATE_AUTOMATION: bool = true;
+
+    type SysExMessage = CoolSysExMessage;
+    type BackgroundTask = ();
+
+    fn params(&self) -> Arc<dyn Params> {
+        self.params.clone()
+    }
+
+    fn process(
+        &mut self,
+        _buffer: &mut Buffer,
+        _aux: &mut AuxiliaryBuffers,
+        context: &mut impl ProcessContext<Self>,
+    ) -> ProcessStatus {
+        // This example converts one of the two messages into the other
+        while let Some(event) = context.next_event() {
+            if let NoteEvent::MidiSysEx { timing, message } = event {
+                let new_message = match message {
+                    CoolSysExMessage::Foo(x) => CoolSysExMessage::Bar {
+                        x: (x * 127.0).round() as u8,
+                        y: 69,
+                    },
+                    CoolSysExMessage::Bar { x, y: _ } => CoolSysExMessage::Foo(x as f32 / 127.0),
+                };
+
+                context.send_event(NoteEvent::MidiSysEx {
+                    timing,
+                    message: new_message,
+                });
+            }
+        }
+
+        ProcessStatus::Normal
+    }
+}
+
+impl ClapPlugin for SysEx {
+    const CLAP_ID: &'static str = "com.moist-plugins-gmbh.sysex";
+    const CLAP_DESCRIPTION: Option<&'static str> =
+        Some("An example plugin to demonstrate sending and receiving SysEx");
+    const CLAP_MANUAL_URL: Option<&'static str> = Some(Self::URL);
+    const CLAP_SUPPORT_URL: Option<&'static str> = None;
+    const CLAP_FEATURES: &'static [ClapFeature] = &[ClapFeature::NoteEffect, ClapFeature::Utility];
+}
+
+impl Vst3Plugin for SysEx {
+    const VST3_CLASS_ID: [u8; 16] = *b"SysExCoolPluginn";
+    const VST3_CATEGORIES: &'static str = "Fx|Instrument|Tools";
+}
+
+nih_export_clap!(SysEx);
+nih_export_vst3!(SysEx);