Overview
The VstPlugin class handles the loading and management of VST2 plugins in Lumix. It provides functionality for MIDI event routing, plugin window management, and VST lifecycle operations.
Enumerations
VstType
public enum VstType
{
VST, // VST is an effect
VSTi // VST is an instrument
}
Properties
Unique identifier for this plugin instance.Automatically generated as a GUID when the plugin is instantiated.
The display name of the plugin, derived from the plugin file name.
The type of VST plugin - either VST (effect) or VSTi (instrument).Determined automatically based on the VST plugin’s capabilities.
The underlying VST plugin context from the Jacobi.Vst library.Provides low-level access to VST commands and plugin information.
The SDL2 window hosting the plugin’s editor interface.
Constructor
public VstPlugin(string pluginPath)
The file system path to the VST plugin DLL.
Example
try
{
var vstPlugin = new VstPlugin(@"C:\Program Files\VSTPlugins\MySynth.dll");
Console.WriteLine($"Loaded: {vstPlugin.PluginName}");
Console.WriteLine($"Type: {vstPlugin.PluginType}");
}
catch (Exception ex)
{
Console.WriteLine($"Failed to load plugin: {ex.Message}");
}
Methods
SendNoteOn
public void SendNoteOn(int channel, int note, int velocity)
The MIDI note number (0-127). Middle C is 60.
The note velocity (0-127). Higher values indicate louder notes.
Example
var vstPlugin = new VstPlugin(pluginPath);
// Play middle C with medium velocity
vstPlugin.SendNoteOn(channel: 0, note: 60, velocity: 80);
// Play higher notes
vstPlugin.SendNoteOn(0, 64, 90); // E
vstPlugin.SendNoteOn(0, 67, 85); // G
SendNoteOff
public void SendNoteOff(int channel, int note, int velocity)
The MIDI note number (0-127) to stop.
The release velocity (0-127). Some plugins use this for release characteristics.
Example
// Stop playing middle C
vstPlugin.SendNoteOff(channel: 0, note: 60, velocity: 64);
SendSustainPedal
public void SendSustainPedal(int channel, bool isPressed)
true to engage the sustain pedal, false to release it.
Example
// Press sustain pedal
vstPlugin.SendSustainPedal(channel: 0, isPressed: true);
// Play some notes while sustain is on
vstPlugin.SendNoteOn(0, 60, 80);
vstPlugin.SendNoteOff(0, 60, 64);
// Release sustain pedal
vstPlugin.SendSustainPedal(channel: 0, isPressed: false);
OpenPluginWindow
public void OpenPluginWindow()
Example
var vstPlugin = new VstPlugin(pluginPath);
// Open the plugin editor
vstPlugin.OpenPluginWindow();
// Window can be closed by user, then reopened
vstPlugin.OpenPluginWindow(); // Will reopen at previous position
Dispose
public void Dispose(bool closeWindow = true)
Whether to close the plugin window. Defaults to true.
Example
// Dispose and close window
vstPlugin.Dispose();
// Dispose but keep window open (for window handle reuse)
vstPlugin.Dispose(closeWindow: false);
Usage Example
using Lumix.Plugins.VST;
public class VstExample
{
private VstPlugin _synth;
public void LoadAndPlaySynth()
{
// Load VST instrument
_synth = new VstPlugin(@"C:\VSTPlugins\MySynth.dll");
if (_synth.PluginType == VstType.VSTi)
{
// Open the editor window
_synth.OpenPluginWindow();
// Play a chord
_synth.SendNoteOn(0, 60, 100); // C
_synth.SendNoteOn(0, 64, 100); // E
_synth.SendNoteOn(0, 67, 100); // G
await Task.Delay(2000);
// Stop the chord
_synth.SendNoteOff(0, 60, 64);
_synth.SendNoteOff(0, 64, 64);
_synth.SendNoteOff(0, 67, 64);
}
}
public void Cleanup()
{
_synth?.Dispose();
}
}
Implementation Notes
- The plugin window is created as an always-on-top, non-resizable window
- The editor UI updates at approximately 60 FPS via the
EditorIdle mechanism
- Window minimize and maximize buttons are removed to prevent UI issues
- The plugin type is automatically detected based on the
VstPluginFlags.IsSynth flag
- MIDI events are processed immediately through the plugin’s command stub
See Also