Open a basic baseview window for standalone target

Cargo.lock

@@ -2008,6 +2008,7 @@ dependencies = [
  "assert_no_alloc",
  "atomic_float",
  "atomic_refcell",
+ "baseview 0.1.0 (git+https://github.com/robbert-vdh/baseview.git?branch=feature/resize)",
  "bitflags",
  "cfg-if 1.0.0",
  "clap-sys",

Cargo.toml

@@ -44,7 +44,7 @@ assert_process_allocs = ["dep:assert_no_alloc"]
 # Enables an export target for standalone binaries through the
 # `nih_export_standalone()` function. Disabled by default, as this requires
 # building additional dependencies for audio and MIDI handling.
-standalone = []
+standalone = ["dep:baseview"]
 # Enables the `nih_export_vst3!()` macro. Enabled by default. This feature
 # exists mostly for GPL-compliance reasons, since even if you don't use the VST3
 # wrapper you might otherwise still include a couple (unused) symbols from the
@@ -75,11 +75,17 @@ raw-window-handle = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 simplelog = "0.12"
-vst3-sys = { git = "https://github.com/robbert-vdh/vst3-sys.git", branch = "fix/note-off-event", optional = true }
 widestring = "1.0.0-beta.1"
 
+# Used for the `assert_process_allocs` feature
 assert_no_alloc = { version = "1.1", optional = true }
 
+# Used for the `standalone` feature
+baseview = { git = "https://github.com/robbert-vdh/baseview.git", branch = "feature/resize", optional = true }
+
+# Used for the `vst3` feature
+vst3-sys = { git = "https://github.com/robbert-vdh/vst3-sys.git", branch = "fix/note-off-event", optional = true }
+
 [target.'cfg(all(target_family = "unix", not(target_os = "macos")))'.dependencies]
 libc = "0.2.124"
 

src/plugin.rs

@@ -226,6 +226,8 @@ pub trait Editor: Send + Sync {
     //       otherwise be basically impossible to have this still be GUI-framework agnostic. Any
     //       callback that deos involve actual GUI operations will still be spooled to the IRunLoop
     //       instance.
+    // TODO: This function should return an `Option` instead. Right now window opening failures are
+    //       always fatal. This would need to be fixed in basevie first.
     fn spawn(
         &self,
         parent: ParentWindowHandle,

src/wrapper/standalone.rs

@@ -65,6 +65,9 @@ pub fn nih_export_standalone_with_args<P: Plugin, Args: IntoIterator<Item = Stri
         sample_rate: 44100.0,
         period_size: 512,
 
+        // TODO: When adding command line options, ignore this option on macOS
+        dpi_scale: 1.0,
+
         tempo: 120.0,
         timesig_num: 4,
         timesig_denom: 4,

src/wrapper/standalone/context.rs

@@ -1,8 +1,18 @@
+use std::sync::Arc;
+
 use super::wrapper::Wrapper;
-use crate::context::{PluginApi, ProcessContext, Transport};
+use crate::context::{GuiContext, PluginApi, ProcessContext, Transport};
 use crate::midi::NoteEvent;
+use crate::param::internals::ParamPtr;
 use crate::plugin::Plugin;
 
+/// A [`GuiContext`] implementation for the wrapper. This is passed to the plugin in
+/// [`Editor::spawn()`][crate::prelude::Editor::spawn()] so it can interact with the rest of the plugin and
+/// with the host for things like setting parameters.
+pub(crate) struct WrapperGuiContext<P: Plugin> {
+    pub(super) wrapper: Arc<Wrapper<P>>,
+}
+
 /// A [`ProcessContext`] implementation for the standalone wrapper. This is a separate object so it
 /// can hold on to lock guards for event queues. Otherwise reading these events would require
 /// constant unnecessary atomic operations to lock the uncontested RwLocks.
@@ -14,6 +24,40 @@ pub(crate) struct WrapperProcessContext<'a, P: Plugin> {
     pub(super) transport: Transport,
 }
 
+impl<P: Plugin> GuiContext for WrapperGuiContext<P> {
+    fn plugin_api(&self) -> PluginApi {
+        PluginApi::Standalone
+    }
+
+    fn request_resize(&self) -> bool {
+        nih_debug_assert_failure!("TODO: WrapperGuiContext::request_resize()");
+
+        true
+    }
+
+    // All of these functions are supposed to be called from the main thread, so we'll put some
+    // trust in the caller and assume that this is indeed the case
+    unsafe fn raw_begin_set_parameter(&self, param: ParamPtr) {
+        nih_debug_assert_failure!("TODO: WrapperGuiContext::raw_begin_set_parameter()");
+    }
+
+    unsafe fn raw_set_parameter_normalized(&self, param: ParamPtr, normalized: f32) {
+        nih_debug_assert_failure!("TODO: WrapperGuiContext::raw_set_parameter_normalized()");
+    }
+
+    unsafe fn raw_end_set_parameter(&self, param: ParamPtr) {
+        nih_debug_assert_failure!("TODO: WrapperGuiContext::raw_end_set_parameter()");
+    }
+
+    fn get_state(&self) -> crate::wrapper::state::PluginState {
+        todo!("WrapperGuiContext::get_state()");
+    }
+
+    fn set_state(&self, state: crate::wrapper::state::PluginState) {
+        nih_debug_assert_failure!("TODO: WrapperGuiContext::set_state()");
+    }
+}
+
 impl<P: Plugin> ProcessContext for WrapperProcessContext<'_, P> {
     fn plugin_api(&self) -> PluginApi {
         PluginApi::Standalone

src/wrapper/standalone/wrapper.rs

@@ -1,9 +1,12 @@
+use baseview::{EventStatus, Window, WindowHandler, WindowOpenOptions};
 use parking_lot::RwLock;
+use raw_window_handle::HasRawWindowHandle;
+use std::any::Any;
 use std::sync::Arc;
 
-use super::context::WrapperProcessContext;
+use super::context::{WrapperGuiContext, WrapperProcessContext};
 use crate::context::Transport;
-use crate::plugin::{BufferConfig, BusConfig, Editor, Plugin};
+use crate::plugin::{BufferConfig, BusConfig, Editor, ParentWindowHandle, Plugin};
 
 /// Configuration for a standalone plugin that would normally be provided by the DAW.
 #[derive(Debug, Clone)]
@@ -17,6 +20,12 @@ pub struct WrapperConfig {
     /// The audio backend's period size.
     pub period_size: u32,
 
+    /// The editor's DPI scaling factor. Currently baseview has no way to report this to us, so
+    /// we'll expose it as a command line option instead.
+    ///
+    /// This option is ignored on macOS.
+    pub dpi_scale: f32,
+
     /// The current tempo.
     pub tempo: f32,
     /// The time signature's numerator.
@@ -31,7 +40,7 @@ pub struct Wrapper<P: Plugin> {
     /// The plugin's editor, if it has one. This object does not do anything on its own, but we need
     /// to instantiate this in advance so we don't need to lock the entire [`Plugin`] object when
     /// creating an editor.
-    editor: Option<Box<dyn Editor>>,
+    editor: Option<Arc<dyn Editor>>,
 
     config: WrapperConfig,
 
@@ -49,12 +58,28 @@ pub enum WrapperError {
     InitializationFailed,
 }
 
+/// We need a window handler for baseview, but since we only create a window to report the plugin in
+/// this won't do much.
+struct WrapperWindowHandler {
+    /// The editor handle for the plugin's open editor. The editor should clean itself up when it
+    /// gets dropped.
+    _editor_handle: Box<dyn Any>,
+}
+
+impl WindowHandler for WrapperWindowHandler {
+    fn on_frame(&mut self, _window: &mut Window) {}
+
+    fn on_event(&mut self, _window: &mut Window, _event: baseview::Event) -> EventStatus {
+        EventStatus::Ignored
+    }
+}
+
 impl<P: Plugin> Wrapper<P> {
     /// Instantiate a new instance of the standalone wrapper. Returns an error if the plugin does
     /// not accept the IO configuration from the wrapper config.
     pub fn new(config: WrapperConfig) -> Result<Arc<Self>, WrapperError> {
         let plugin = P::default();
-        let editor = plugin.editor();
+        let editor = plugin.editor().map(Arc::from);
 
         let wrapper = Arc::new(Wrapper {
             plugin: RwLock::new(plugin),
@@ -97,13 +122,63 @@ impl<P: Plugin> Wrapper<P> {
     /// Will return an error if the plugin threw an error during audio processing or if the editor
     /// could not be opened.
     pub fn run(self: Arc<Self>) -> Result<(), WrapperError> {
-        // TODO: Open the editor and block until it is closed
-        // TODO: Do IO things
-        // TODO: Block until SIGINT is received if the plugin does not have an editor
+        // TODO: Do IO things, kinda important
+
+        match self.editor.clone() {
+            Some(editor) => {
+                let context = self.clone().make_gui_context();
+                let (width, height) = editor.size();
+
+                // DPI scaling should not be used on macOS since the OS handles it there
+                #[cfg(target_os = "macos")]
+                let scaling_policy = baseview::WindowScalePolicy::SystemScaleFactor;
+                #[cfg(not(target_os = "macos"))]
+                let scaling_policy = {
+                    editor.set_scale_factor(self.config.dpi_scale);
+                    baseview::WindowScalePolicy::ScaleFactor(self.config.dpi_scale as f64)
+                };
+
+                Window::open_blocking(
+                    WindowOpenOptions {
+                        title: String::from(P::NAME),
+                        size: baseview::Size {
+                            width: width as f64,
+                            height: height as f64,
+                        },
+                        scale: scaling_policy,
+                        gl_config: None,
+                    },
+                    move |window| {
+                        // TODO: This spawn function should be able to fail and return an error, but
+                        //       baseview does not support this yet. Once this is added, we should
+                        //       immediately close the parent window when this happens so the loop
+                        //       can exit.
+                        let editor_handle = editor.spawn(
+                            ParentWindowHandle {
+                                handle: window.raw_window_handle(),
+                            },
+                            context,
+                        );
+
+                        WrapperWindowHandler {
+                            _editor_handle: editor_handle,
+                        }
+                    },
+                )
+            }
+            None => {
+                // TODO: Block until SIGINT is received if the plugin does not have an editor
+                todo!("Support standalone plugins without editors");
+            }
+        }
 
         Ok(())
     }
 
+    fn make_gui_context(self: Arc<Self>) -> Arc<WrapperGuiContext<P>> {
+        Arc::new(WrapperGuiContext { wrapper: self })
+    }
+
     fn make_process_context(&self, transport: Transport) -> WrapperProcessContext<'_, P> {
         WrapperProcessContext {
             wrapper: self,