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mirror of https://github.com/emilk/egui.git synced 2026-06-26 22:53:14 -04:00

Fill in DisplayHandle automatically on web painter just like it's done on winit (#8006)

* Closes https://github.com/emilk/egui/issues/8001
* Follow-up to https://github.com/emilk/egui/pull/7990

Also simplified/shortened the comments around display handle a bit. Lots
a repetition there made it hard to upgrade otherwise.
This commit is contained in:
Andreas Reich
2026-03-24 12:37:33 +01:00
committed by GitHub
parent b4f9cd7140
commit d985bf9b83
2 changed files with 64 additions and 63 deletions

View File

@@ -25,6 +25,24 @@ pub(crate) struct WebPainterWgpu {
needs_reconfigure: bool,
}
/// Owned web display handle that is `Send + Sync`.
///
/// `DisplayHandle` from `raw-window-handle` is `!Send`/`!Sync` because the enum
/// contains platform variants with raw pointers. On web the handle is always empty,
/// so this wrapper is safe.
#[cfg(target_arch = "wasm32")]
#[derive(Clone, Debug)]
struct WebDisplay;
#[cfg(target_arch = "wasm32")]
impl egui_wgpu::wgpu::rwh::HasDisplayHandle for WebDisplay {
fn display_handle(
&self,
) -> Result<egui_wgpu::wgpu::rwh::DisplayHandle<'_>, egui_wgpu::wgpu::rwh::HandleError> {
Ok(egui_wgpu::wgpu::rwh::DisplayHandle::web())
}
}
impl WebPainterWgpu {
pub fn render_state(&self) -> Option<RenderState> {
self.render_state.clone()
@@ -64,7 +82,17 @@ impl WebPainterWgpu {
) -> Result<Self, String> {
log::debug!("Creating wgpu painter");
let instance = options.wgpu_options.wgpu_setup.new_instance().await;
// Inject the display handle into the wgpu setup so that wgpu can create surfaces on WebGL.
let mut wgpu_options = options.wgpu_options.clone();
if let egui_wgpu::WgpuSetup::CreateNew(ref mut create_new) = wgpu_options.wgpu_setup
&& create_new.display_handle.is_none()
{
// Force WebGL, useful for quick & dirty testing:
//create_new.instance_descriptor.backends = wgpu::Backends::GL;
create_new.display_handle = Some(Box::new(WebDisplay));
}
let instance = wgpu_options.wgpu_setup.new_instance().await;
let surface = instance
.create_surface(wgpu::SurfaceTarget::Canvas(canvas.clone()))
.map_err(|err| format!("failed to create wgpu surface: {err}"))?;
@@ -72,7 +100,7 @@ impl WebPainterWgpu {
let depth_stencil_format = egui_wgpu::depth_format_from_bits(options.depth_buffer, 0);
let render_state = RenderState::create(
&options.wgpu_options,
&wgpu_options,
&instance,
Some(&surface),
egui_wgpu::RendererOptions {
@@ -90,7 +118,7 @@ impl WebPainterWgpu {
let surface_configuration = wgpu::SurfaceConfiguration {
format: render_state.target_format,
present_mode: options.wgpu_options.present_mode,
present_mode: wgpu_options.present_mode,
view_formats: vec![render_state.target_format],
..default_configuration
};
@@ -106,7 +134,7 @@ impl WebPainterWgpu {
surface_configuration,
depth_stencil_format,
depth_texture_view: None,
on_surface_status: Arc::clone(&options.wgpu_options.on_surface_status) as _,
on_surface_status: Arc::clone(&wgpu_options.on_surface_status) as _,
screen_capture_state: None,
capture_tx,
capture_rx,

View File

@@ -2,24 +2,19 @@ use std::sync::Arc;
/// A cloneable display handle for use with [`wgpu::InstanceDescriptor`].
///
/// This trait exists so that a [`winit::event_loop::OwnedDisplayHandle`] (or similar platform
/// display handle) can be stored, cloned, and later passed to wgpu.
/// [`wgpu::InstanceDescriptor`] stores its display handle as a non-cloneable
/// `Box<dyn WgpuHasDisplayHandle>`. This trait wraps it so it can be cloned
/// alongside the rest of the egui wgpu configuration.
///
/// wgpu requires an explicit display handle for GLES on some platforms (notably Wayland).
/// Because [`wgpu::InstanceDescriptor`] contains a `Box<dyn WgpuHasDisplayHandle>` which is
/// not cloneable, we wrap the handle in this trait so it can be cloned alongside the rest of
/// the egui wgpu configuration.
///
/// This is automatically implemented for all types that satisfy the bounds (including
/// [`winit::event_loop::OwnedDisplayHandle`]).
/// Automatically implemented for all types that satisfy the bounds
/// (including [`winit::event_loop::OwnedDisplayHandle`]).
pub trait EguiDisplayHandle:
wgpu::rwh::HasDisplayHandle + std::fmt::Debug + Send + Sync + 'static
{
/// Clone this handle into a `Box<dyn WgpuHasDisplayHandle>` suitable for setting on
/// [`wgpu::InstanceDescriptor::display`].
/// Clone into a `Box<dyn WgpuHasDisplayHandle>` for [`wgpu::InstanceDescriptor::display`].
fn clone_for_wgpu(&self) -> Box<dyn wgpu::wgt::WgpuHasDisplayHandle>;
/// Clone this handle into a new `Box<dyn EguiDisplayHandle>`.
/// Clone into a new `Box<dyn EguiDisplayHandle>`.
fn clone_display_handle(&self) -> Box<dyn EguiDisplayHandle>;
}
@@ -68,27 +63,14 @@ pub enum WgpuSetup {
impl WgpuSetup {
/// Creates a new [`WgpuSetup::CreateNew`] with the given display handle.
///
/// This is the recommended constructor. Most platforms (Windows, macOS/iOS, Android, web)
/// work fine without a display handle, but some (e.g. Wayland on Linux with GLES) require
/// one. Providing it unconditionally ensures your app works everywhere.
///
/// If you don't have a display handle available, use [`Self::without_display_handle`]
/// instead — it will still work on the majority of platforms.
///
/// With winit, pass [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
/// See [`WgpuSetupCreateNew::from_display_handle`] for details.
pub fn from_display_handle(display_handle: impl EguiDisplayHandle) -> Self {
Self::CreateNew(WgpuSetupCreateNew::from_display_handle(display_handle))
}
/// Creates a new [`WgpuSetup::CreateNew`] without a display handle.
///
/// A display handle is not required for headless operation (offscreen rendering, tests,
/// compute-only workloads). It also isn't needed on most platforms even when presenting
/// to a window — only some configurations (e.g. Wayland on Linux with GLES) require one.
///
/// If you do have a display handle available, prefer [`Self::from_display_handle`] for
/// maximum compatibility. With winit you can obtain one via
/// [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
/// See [`WgpuSetupCreateNew::without_display_handle`] for details.
pub fn without_display_handle() -> Self {
Self::CreateNew(WgpuSetupCreateNew::without_display_handle())
}
@@ -175,44 +157,32 @@ pub type NativeAdapterSelectorMethod = Arc<
///
/// Used for [`WgpuSetup::CreateNew`].
///
/// Use [`Self::from_display_handle`] when you have a display handle available — this is the
/// recommended constructor. With winit you can obtain one via
/// [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
/// Most platforms (Windows, macOS/iOS, Android, web) work fine without one, but some
/// (e.g. Wayland on Linux with GLES) require it. Providing it unconditionally ensures your
/// app works everywhere.
/// Prefer [`Self::from_display_handle`] when you have a display handle available.
/// Most platforms work without one, but some (e.g. Wayland with GLES, or WebGL)
/// require it, so providing one ensures maximum compatibility.
/// With winit, pass [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
///
/// If you don't have a display handle, use [`Self::without_display_handle`] — it will still
/// work on the majority of platforms, and is appropriate for headless rendering, tests, or
/// web targets.
///
/// Note: The [`wgpu::InstanceDescriptor::display`] field is always stored as `None` in
/// [`Self::instance_descriptor`]. The display handle is stored separately so it can be cloned
/// (since [`wgpu::InstanceDescriptor`] itself does not implement `Clone`), and is injected
/// into the descriptor at instance creation time.
/// Note: The display handle is stored in [`Self::display_handle`] rather than in
/// [`Self::instance_descriptor`] so the config can be cloned
/// ([`wgpu::InstanceDescriptor`] is not `Clone`). It is injected at instance creation time.
pub struct WgpuSetupCreateNew {
/// Instance descriptor for creating a wgpu instance.
/// Descriptor for the wgpu instance.
///
/// The [`wgpu::InstanceDescriptor::display`] field should be left as `None`; use the
/// [`Self::display_handle`] field instead (it will be injected when the instance is created).
/// Leave [`wgpu::InstanceDescriptor::display`] as `None` use [`Self::display_handle`]
/// instead (injected at instance creation time).
///
/// The most important field is [`wgpu::InstanceDescriptor::backends`], which
/// controls which backends are supported (wgpu will pick one of these).
/// If you only want to support WebGL (and not WebGPU),
/// you can set this to [`wgpu::Backends::GL`].
/// By default on web, WebGPU will be used if available.
/// WebGL will only be used as a fallback,
/// and only if you have enabled the `webgl` feature of crate `wgpu`.
/// The most important field is [`wgpu::InstanceDescriptor::backends`], which controls
/// which backends are supported (wgpu will pick one of these). For example, set it to
/// [`wgpu::Backends::GL`] to use only WebGL. By default on web, WebGPU is preferred
/// with WebGL as a fallback (requires the `webgl` feature of crate `wgpu`).
pub instance_descriptor: wgpu::InstanceDescriptor,
/// The display handle to pass to wgpu when creating the instance.
/// Display handle passed to wgpu at instance creation time.
///
/// Most platforms (Windows, macOS/iOS, Android, web) work without this, but some
/// (e.g. Wayland on Linux with GLES) require it. If you have a display handle
/// available, providing it ensures maximum compatibility.
/// Required on some platforms (e.g. Wayland with GLES, WebGL); optional elsewhere.
/// With winit, use [`winit::event_loop::OwnedDisplayHandle`].
///
/// When using winit, this is typically the
/// [`winit::event_loop::OwnedDisplayHandle`] obtained from the event loop.
/// `eframe` 's winit & web integrations will attempt to fill the display handle automatically if it is left empty.
pub display_handle: Option<Box<dyn EguiDisplayHandle>>,
/// Power preference for the adapter if [`Self::native_adapter_selector`] is not set or targeting web.
@@ -258,8 +228,11 @@ impl WgpuSetupCreateNew {
/// to a window — only some configurations (e.g. Wayland on Linux with GLES) require one.
///
/// If you do have a display handle available, prefer [`Self::from_display_handle`] for
/// maximum compatibility. With winit you can obtain one via
/// [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
/// maximum compatibility.
///
/// With winit you can obtain one via [`EventLoop::owned_display_handle`](winit::event_loop::EventLoop::owned_display_handle).
///
/// `eframe` 's winit & web integrations will attempt to fill the display handle automatically if it is left empty.
pub fn without_display_handle() -> Self {
Self {
instance_descriptor: wgpu::InstanceDescriptor {