add "bring your own gui" example plugins

This commit is contained in:
Billy Messenger
2024-12-14 17:10:03 -06:00
parent 400eb3156f
commit ac1caecd2d
11 changed files with 2343 additions and 14 deletions

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[package]
name = "byo_gui_wgpu"
version = "0.1.0"
edition = "2021"
authors = ["Billy Messenger <60663878+BillyDM@users.noreply.github.com>"]
license = "ISC"
description = "A simple example plugin with a raw WGPU context for rendering"
[lib]
# The `lib` artifact is needed for the standalone target
crate-type = ["cdylib", "lib"]
[dependencies]
nih_plug = { path = "../../../", features = ["assert_process_allocs", "standalone"] }
baseview = { git = "https://github.com/RustAudio/baseview.git", rev = "9a0b42c09d712777b2edb4c5e0cb6baf21e988f0" }
wgpu = "23"
raw-window-handle = "0.5"
raw-window-handle-06 = { package = "raw-window-handle", version = "0.6" }
pollster = "0.4.0"
crossbeam = "0.8"
atomic_float = "0.1"
# To make the state persistable
serde = { version = "1.0", features = ["derive"] }

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//! This plugin demonstrates how to "bring your own GUI toolkit" using a raw WGPU context.
use baseview::{WindowHandle, WindowOpenOptions, WindowScalePolicy};
use crossbeam::atomic::AtomicCell;
use nih_plug::params::persist::PersistentField;
use nih_plug::prelude::*;
use raw_window_handle::{HasRawWindowHandle, RawWindowHandle};
use serde::{Deserialize, Serialize};
use std::{
borrow::Cow,
num::NonZeroIsize,
ptr::NonNull,
sync::{
atomic::{AtomicBool, Ordering},
Arc,
},
};
use wgpu::SurfaceTargetUnsafe;
/// The time it takes for the peak meter to decay by 12 dB after switching to complete silence.
const PEAK_METER_DECAY_MS: f64 = 150.0;
pub struct CustomWgpuWindow {
gui_context: Arc<dyn GuiContext>,
device: wgpu::Device,
queue: wgpu::Queue,
pipeline: wgpu::RenderPipeline,
surface: wgpu::Surface<'static>,
surface_config: wgpu::SurfaceConfiguration,
#[allow(unused)]
params: Arc<MyPluginParams>,
#[allow(unused)]
peak_meter: Arc<AtomicF32>,
}
impl CustomWgpuWindow {
fn new(
window: &mut baseview::Window<'_>,
gui_context: Arc<dyn GuiContext>,
params: Arc<MyPluginParams>,
peak_meter: Arc<AtomicF32>,
scaling_factor: f32,
) -> Self {
let target = baseview_window_to_surface_target(window);
pollster::block_on(Self::create(
target,
gui_context,
params,
peak_meter,
scaling_factor,
))
}
async fn create(
target: SurfaceTargetUnsafe,
gui_context: Arc<dyn GuiContext>,
params: Arc<MyPluginParams>,
peak_meter: Arc<AtomicF32>,
scaling_factor: f32,
) -> Self {
let (unscaled_width, unscaled_height) = params.editor_state.size();
let width = (unscaled_width as f64 * scaling_factor as f64).round() as u32;
let height = (unscaled_height as f64 * scaling_factor as f64).round() as u32;
let instance = wgpu::Instance::new(wgpu::InstanceDescriptor::default());
let surface = unsafe { instance.create_surface_unsafe(target) }.unwrap();
let adapter = instance
.request_adapter(&wgpu::RequestAdapterOptions {
power_preference: wgpu::PowerPreference::LowPower,
force_fallback_adapter: false,
// Request an adapter which can render to our surface
compatible_surface: Some(&surface),
})
.await
.expect("Failed to find an appropriate adapter");
// Create the logical device and command queue
let (device, queue) = adapter
.request_device(
&wgpu::DeviceDescriptor {
label: None,
required_features: wgpu::Features::empty(),
required_limits: wgpu::Limits::downlevel_webgl2_defaults()
.using_resolution(adapter.limits()),
memory_hints: wgpu::MemoryHints::MemoryUsage,
},
None,
)
.await
.expect("Failed to create device");
const SHADER: &str = "
const VERTS = array(
vec2<f32>(0.5, 1.0),
vec2<f32>(0.0, 0.0),
vec2<f32>(1.0, 0.0)
);
struct VertexOutput {
@builtin(position) clip_position: vec4<f32>,
@location(0) position: vec2<f32>,
};
@vertex
fn vs_main(
@builtin(vertex_index) in_vertex_index: u32,
) -> VertexOutput {
var out: VertexOutput;
out.position = VERTS[in_vertex_index];
out.clip_position = vec4<f32>(out.position - 0.5, 0.0, 1.0);
return out;
}
@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
return vec4<f32>(in.position, 0.5, 1.0);
}
";
let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
label: None,
source: wgpu::ShaderSource::Wgsl(Cow::Borrowed(SHADER)),
});
let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
label: None,
bind_group_layouts: &[],
push_constant_ranges: &[],
});
let swapchain_capabilities = surface.get_capabilities(&adapter);
let swapchain_format = swapchain_capabilities.formats[0];
let pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: None,
layout: Some(&pipeline_layout),
vertex: wgpu::VertexState {
module: &shader,
entry_point: Some("vs_main"),
buffers: &[],
compilation_options: Default::default(),
},
fragment: Some(wgpu::FragmentState {
module: &shader,
entry_point: Some("fs_main"),
compilation_options: Default::default(),
targets: &[Some(swapchain_format.into())],
}),
primitive: wgpu::PrimitiveState::default(),
depth_stencil: None,
multisample: wgpu::MultisampleState::default(),
multiview: None,
cache: None,
});
let surface_config = surface.get_default_config(&adapter, width, height).unwrap();
surface.configure(&device, &surface_config);
Self {
gui_context,
device,
queue,
pipeline,
surface,
surface_config,
params,
peak_meter,
}
}
}
impl baseview::WindowHandler for CustomWgpuWindow {
fn on_frame(&mut self, _window: &mut baseview::Window) {
// Do rendering here.
let frame = self
.surface
.get_current_texture()
.expect("Failed to acquire next swap chain texture");
let view = frame
.texture
.create_view(&wgpu::TextureViewDescriptor::default());
let mut encoder = self
.device
.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
{
let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
label: None,
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: &view,
resolve_target: None,
ops: wgpu::Operations {
load: wgpu::LoadOp::Clear(wgpu::Color::BLACK),
store: wgpu::StoreOp::Store,
},
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
});
rpass.set_pipeline(&self.pipeline);
rpass.draw(0..3, 0..1);
}
self.queue.submit(Some(encoder.finish()));
frame.present();
}
fn on_event(
&mut self,
_window: &mut baseview::Window,
event: baseview::Event,
) -> baseview::EventStatus {
// Use this to set parameter values.
let _param_setter = ParamSetter::new(self.gui_context.as_ref());
match &event {
// Do event processing here.
baseview::Event::Window(event) => match event {
baseview::WindowEvent::Resized(window_info) => {
self.params.editor_state.size.store((
window_info.logical_size().width.round() as u32,
window_info.logical_size().height.round() as u32,
));
self.surface_config.width = window_info.physical_size().width;
self.surface_config.height = window_info.physical_size().height;
self.surface.configure(&self.device, &self.surface_config);
}
_ => {}
},
_ => {}
}
baseview::EventStatus::Captured
}
}
#[derive(Debug, Serialize, Deserialize)]
pub struct CustomWgpuEditorState {
/// The window's size in logical pixels before applying `scale_factor`.
#[serde(with = "nih_plug::params::persist::serialize_atomic_cell")]
size: AtomicCell<(u32, u32)>,
/// Whether the editor's window is currently open.
#[serde(skip)]
open: AtomicBool,
}
impl CustomWgpuEditorState {
pub fn from_size(size: (u32, u32)) -> Arc<Self> {
Arc::new(Self {
size: AtomicCell::new(size),
open: AtomicBool::new(false),
})
}
/// Returns a `(width, height)` pair for the current size of the GUI in logical pixels.
pub fn size(&self) -> (u32, u32) {
self.size.load()
}
/// Whether the GUI is currently visible.
// Called `is_open()` instead of `open()` to avoid the ambiguity.
pub fn is_open(&self) -> bool {
self.open.load(Ordering::Acquire)
}
}
impl<'a> PersistentField<'a, CustomWgpuEditorState> for Arc<CustomWgpuEditorState> {
fn set(&self, new_value: CustomWgpuEditorState) {
self.size.store(new_value.size.load());
}
fn map<F, R>(&self, f: F) -> R
where
F: Fn(&CustomWgpuEditorState) -> R,
{
f(self)
}
}
pub struct CustomWgpuEditor {
params: Arc<MyPluginParams>,
peak_meter: Arc<AtomicF32>,
/// The scaling factor reported by the host, if any. On macOS this will never be set and we
/// should use the system scaling factor instead.
scaling_factor: AtomicCell<Option<f32>>,
}
impl Editor for CustomWgpuEditor {
fn spawn(
&self,
parent: ParentWindowHandle,
context: Arc<dyn GuiContext>,
) -> Box<dyn std::any::Any + Send> {
let (unscaled_width, unscaled_height) = self.params.editor_state.size();
let scaling_factor = self.scaling_factor.load();
let gui_context = Arc::clone(&context);
let params = Arc::clone(&self.params);
let peak_meter = Arc::clone(&self.peak_meter);
let window = baseview::Window::open_parented(
&ParentWindowHandleAdapter(parent),
WindowOpenOptions {
title: String::from("WGPU Window"),
// Baseview should be doing the DPI scaling for us
size: baseview::Size::new(unscaled_width as f64, unscaled_height as f64),
// NOTE: For some reason passing 1.0 here causes the UI to be scaled on macOS but
// not the mouse events.
scale: scaling_factor
.map(|factor| WindowScalePolicy::ScaleFactor(factor as f64))
.unwrap_or(WindowScalePolicy::SystemScaleFactor),
},
move |window: &mut baseview::Window<'_>| -> CustomWgpuWindow {
CustomWgpuWindow::new(
window,
gui_context,
params,
peak_meter,
scaling_factor.unwrap_or(1.0),
)
},
);
self.params.editor_state.open.store(true, Ordering::Release);
Box::new(CustomWgpuEditorHandle {
state: self.params.editor_state.clone(),
window,
})
}
fn size(&self) -> (u32, u32) {
self.params.editor_state.size()
}
fn set_scale_factor(&self, factor: f32) -> bool {
// If the editor is currently open then the host must not change the current HiDPI scale as
// we don't have a way to handle that. Ableton Live does this.
if self.params.editor_state.is_open() {
return false;
}
self.scaling_factor.store(Some(factor));
true
}
fn param_value_changed(&self, _id: &str, _normalized_value: f32) {
// As mentioned above, for now we'll always force a redraw to allow meter widgets to work
// correctly. In the future we can use an `Arc<AtomicBool>` and only force a redraw when
// that boolean is set.
}
fn param_modulation_changed(&self, _id: &str, _modulation_offset: f32) {}
fn param_values_changed(&self) {
// Same
}
}
/// The window handle used for [`EguiEditor`].
struct CustomWgpuEditorHandle {
state: Arc<CustomWgpuEditorState>,
window: WindowHandle,
}
/// The window handle enum stored within 'WindowHandle' contains raw pointers. Is there a way around
/// having this requirement?
unsafe impl Send for CustomWgpuEditorHandle {}
impl Drop for CustomWgpuEditorHandle {
fn drop(&mut self) {
self.state.open.store(false, Ordering::Release);
// XXX: This should automatically happen when the handle gets dropped, but apparently not
self.window.close();
}
}
/// This version of `baseview` uses a different version of `raw_window_handle than NIH-plug, so we
/// need to adapt it ourselves.
struct ParentWindowHandleAdapter(nih_plug::editor::ParentWindowHandle);
unsafe impl HasRawWindowHandle for ParentWindowHandleAdapter {
fn raw_window_handle(&self) -> RawWindowHandle {
match self.0 {
ParentWindowHandle::X11Window(window) => {
let mut handle = raw_window_handle::XcbWindowHandle::empty();
handle.window = window;
RawWindowHandle::Xcb(handle)
}
ParentWindowHandle::AppKitNsView(ns_view) => {
let mut handle = raw_window_handle::AppKitWindowHandle::empty();
handle.ns_view = ns_view;
RawWindowHandle::AppKit(handle)
}
ParentWindowHandle::Win32Hwnd(hwnd) => {
let mut handle = raw_window_handle::Win32WindowHandle::empty();
handle.hwnd = hwnd;
RawWindowHandle::Win32(handle)
}
}
}
}
/// WGPU uses raw_window_handle v6, but baseview uses raw_window_handle v5, so manually convert it.
fn baseview_window_to_surface_target(window: &baseview::Window<'_>) -> wgpu::SurfaceTargetUnsafe {
use raw_window_handle::{HasRawDisplayHandle, HasRawWindowHandle};
let raw_display_handle = window.raw_display_handle();
let raw_window_handle = window.raw_window_handle();
wgpu::SurfaceTargetUnsafe::RawHandle {
raw_display_handle: match raw_display_handle {
raw_window_handle::RawDisplayHandle::AppKit(_) => {
raw_window_handle_06::RawDisplayHandle::AppKit(
raw_window_handle_06::AppKitDisplayHandle::new(),
)
}
raw_window_handle::RawDisplayHandle::Xlib(handle) => {
raw_window_handle_06::RawDisplayHandle::Xlib(
raw_window_handle_06::XlibDisplayHandle::new(
NonNull::new(handle.display),
handle.screen,
),
)
}
raw_window_handle::RawDisplayHandle::Xcb(handle) => {
raw_window_handle_06::RawDisplayHandle::Xcb(
raw_window_handle_06::XcbDisplayHandle::new(
NonNull::new(handle.connection),
handle.screen,
),
)
}
raw_window_handle::RawDisplayHandle::Windows(_) => {
raw_window_handle_06::RawDisplayHandle::Windows(
raw_window_handle_06::WindowsDisplayHandle::new(),
)
}
_ => todo!(),
},
raw_window_handle: match raw_window_handle {
raw_window_handle::RawWindowHandle::AppKit(handle) => {
raw_window_handle_06::RawWindowHandle::AppKit(
raw_window_handle_06::AppKitWindowHandle::new(
NonNull::new(handle.ns_view).unwrap(),
),
)
}
raw_window_handle::RawWindowHandle::Xlib(handle) => {
raw_window_handle_06::RawWindowHandle::Xlib(
raw_window_handle_06::XlibWindowHandle::new(handle.window),
)
}
raw_window_handle::RawWindowHandle::Xcb(handle) => {
raw_window_handle_06::RawWindowHandle::Xcb(
raw_window_handle_06::XcbWindowHandle::new(
NonZeroU32::new(handle.window).unwrap(),
),
)
}
raw_window_handle::RawWindowHandle::Win32(handle) => {
// will this work? i have no idea!
let mut raw_handle = raw_window_handle_06::Win32WindowHandle::new(
NonZeroIsize::new(handle.hwnd as isize).unwrap(),
);
raw_handle.hinstance = handle
.hinstance
.is_null()
.then(|| NonZeroIsize::new(handle.hinstance as isize).unwrap());
raw_window_handle_06::RawWindowHandle::Win32(raw_handle)
}
_ => todo!(),
},
}
}
/// This is mostly identical to the gain example, minus some fluff, and with a GUI.
pub struct MyPlugin {
params: Arc<MyPluginParams>,
/// Needed to normalize the peak meter's response based on the sample rate.
peak_meter_decay_weight: f32,
/// The current data for the peak meter. This is stored as an [`Arc`] so we can share it between
/// the GUI and the audio processing parts. If you have more state to share, then it's a good
/// idea to put all of that in a struct behind a single `Arc`.
///
/// This is stored as voltage gain.
peak_meter: Arc<AtomicF32>,
}
#[derive(Params)]
pub struct MyPluginParams {
/// The editor state, saved together with the parameter state so the custom scaling can be
/// restored.
#[persist = "editor-state"]
editor_state: Arc<CustomWgpuEditorState>,
#[id = "gain"]
pub gain: FloatParam,
#[id = "foobar"]
pub some_int: IntParam,
}
impl Default for MyPlugin {
fn default() -> Self {
Self {
params: Arc::new(MyPluginParams::default()),
peak_meter_decay_weight: 1.0,
peak_meter: Arc::new(AtomicF32::new(util::MINUS_INFINITY_DB)),
}
}
}
impl Default for MyPluginParams {
fn default() -> Self {
Self {
editor_state: CustomWgpuEditorState::from_size((400, 300)),
// See the main gain example for more details
gain: FloatParam::new(
"Gain",
util::db_to_gain(0.0),
FloatRange::Skewed {
min: util::db_to_gain(-30.0),
max: util::db_to_gain(30.0),
factor: FloatRange::gain_skew_factor(-30.0, 30.0),
},
)
.with_smoother(SmoothingStyle::Logarithmic(50.0))
.with_unit(" dB")
.with_value_to_string(formatters::v2s_f32_gain_to_db(2))
.with_string_to_value(formatters::s2v_f32_gain_to_db()),
some_int: IntParam::new("Something", 3, IntRange::Linear { min: 0, max: 3 }),
}
}
}
impl Plugin for MyPlugin {
const NAME: &'static str = "BYO GUI Example (WGPU)";
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 AUDIO_IO_LAYOUTS: &'static [AudioIOLayout] = &[
AudioIOLayout {
main_input_channels: NonZeroU32::new(2),
main_output_channels: NonZeroU32::new(2),
..AudioIOLayout::const_default()
},
AudioIOLayout {
main_input_channels: NonZeroU32::new(1),
main_output_channels: NonZeroU32::new(1),
..AudioIOLayout::const_default()
},
];
const SAMPLE_ACCURATE_AUTOMATION: bool = true;
type SysExMessage = ();
type BackgroundTask = ();
fn params(&self) -> Arc<dyn Params> {
self.params.clone()
}
fn editor(&mut self, _async_executor: AsyncExecutor<Self>) -> Option<Box<dyn Editor>> {
Some(Box::new(CustomWgpuEditor {
params: Arc::clone(&self.params),
peak_meter: Arc::clone(&self.peak_meter),
// TODO: We can't get the size of the window when baseview does its own scaling, so if the
// host does not set a scale factor on Windows or Linux we should just use a factor of
// 1. That may make the GUI tiny but it also prevents it from getting cut off.
#[cfg(target_os = "macos")]
scaling_factor: AtomicCell::new(None),
#[cfg(not(target_os = "macos"))]
scaling_factor: AtomicCell::new(Some(1.0)),
}))
}
fn initialize(
&mut self,
_audio_io_layout: &AudioIOLayout,
buffer_config: &BufferConfig,
_context: &mut impl InitContext<Self>,
) -> bool {
// TODO: Figure out a way to disable log spam from wgpu.
// After `PEAK_METER_DECAY_MS` milliseconds of pure silence, the peak meter's value should
// have dropped by 12 dB
self.peak_meter_decay_weight = 0.25f64
.powf((buffer_config.sample_rate as f64 * PEAK_METER_DECAY_MS / 1000.0).recip())
as f32;
true
}
fn process(
&mut self,
buffer: &mut Buffer,
_aux: &mut AuxiliaryBuffers,
_context: &mut impl ProcessContext<Self>,
) -> ProcessStatus {
for channel_samples in buffer.iter_samples() {
let mut amplitude = 0.0;
let num_samples = channel_samples.len();
let gain = self.params.gain.smoothed.next();
for sample in channel_samples {
*sample *= gain;
amplitude += *sample;
}
// To save resources, a plugin can (and probably should!) only perform expensive
// calculations that are only displayed on the GUI while the GUI is open
if self.params.editor_state.is_open() {
amplitude = (amplitude / num_samples as f32).abs();
let current_peak_meter = self.peak_meter.load(std::sync::atomic::Ordering::Relaxed);
let new_peak_meter = if amplitude > current_peak_meter {
amplitude
} else {
current_peak_meter * self.peak_meter_decay_weight
+ amplitude * (1.0 - self.peak_meter_decay_weight)
};
self.peak_meter
.store(new_peak_meter, std::sync::atomic::Ordering::Relaxed)
}
}
ProcessStatus::Normal
}
}
impl ClapPlugin for MyPlugin {
const CLAP_ID: &'static str = "com.moist-plugins-gmbh.byo-gui-wgpu";
const CLAP_DESCRIPTION: Option<&'static str> =
Some("A simple example plugin with a raw WGPU context for rendering");
const CLAP_MANUAL_URL: Option<&'static str> = Some(Self::URL);
const CLAP_SUPPORT_URL: Option<&'static str> = None;
const CLAP_FEATURES: &'static [ClapFeature] = &[
ClapFeature::AudioEffect,
ClapFeature::Stereo,
ClapFeature::Mono,
ClapFeature::Utility,
];
}
impl Vst3Plugin for MyPlugin {
const VST3_CLASS_ID: [u8; 16] = *b"ByoGuiWGPUWooooo";
const VST3_SUBCATEGORIES: &'static [Vst3SubCategory] =
&[Vst3SubCategory::Fx, Vst3SubCategory::Tools];
}
nih_export_clap!(MyPlugin);
nih_export_vst3!(MyPlugin);

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use nih_plug::prelude::*;
use byo_gui_wgpu::MyPlugin;
fn main() {
nih_export_standalone::<MyPlugin>();
}