Take Glow context using Arc. (#1640)

This allows usage with a Glow context that is passed between threads.

Cargo.toml

@@ -37,3 +37,6 @@ opt-level = 2 # fast and small wasm, basically same as `opt-level = 's'`
 # opt-level = 3 # unecessarily large wasm for no performance gain
 
 # debug = true # include debug symbols, useful when profiling wasm
+
+[patch.crates-io]
+three-d = { git = "https://github.com/asny/three-d.git", rev = "7ac4f3e1e14335290e505a5799a0b88717474678" }

eframe/src/epi.rs

@@ -28,7 +28,7 @@ pub struct CreationContext<'s> {
     /// The [`glow::Context`] allows you to initialize OpenGL resources (e.g. shaders) that
     /// you might want to use later from a [`egui::PaintCallback`].
     #[cfg(feature = "glow")]
-    pub gl: Option<std::rc::Rc<glow::Context>>,
+    pub gl: Option<std::sync::Arc<glow::Context>>,
 }
 
 // ----------------------------------------------------------------------------
@@ -334,7 +334,7 @@ pub struct Frame {
     /// A reference to the underlying [`glow`] (OpenGL) context.
     #[cfg(feature = "glow")]
     #[doc(hidden)]
-    pub gl: Option<std::rc::Rc<glow::Context>>,
+    pub gl: Option<std::sync::Arc<glow::Context>>,
 }
 
 impl Frame {
@@ -371,7 +371,7 @@ impl Frame {
     /// To get a [`glow`] context you need to compile with the `glow` feature flag,
     /// and run eframe with the glow backend.
     #[cfg(feature = "glow")]
-    pub fn gl(&self) -> Option<&std::rc::Rc<glow::Context>> {
+    pub fn gl(&self) -> Option<&std::sync::Arc<glow::Context>> {
         self.gl.as_ref()
     }
 

eframe/src/native/epi_integration.rs

@@ -185,7 +185,7 @@ impl EpiIntegration {
         max_texture_side: usize,
         window: &winit::window::Window,
         storage: Option<Box<dyn epi::Storage>>,
-        #[cfg(feature = "glow")] gl: Option<std::rc::Rc<glow::Context>>,
+        #[cfg(feature = "glow")] gl: Option<std::sync::Arc<glow::Context>>,
     ) -> Self {
         let egui_ctx = egui::Context::default();
 

eframe/src/native/run.rs

@@ -51,7 +51,7 @@ pub fn run_glow(
     let window_builder =
         epi_integration::window_builder(native_options, &window_settings).with_title(app_name);
     let (gl_window, gl) = create_display(native_options, window_builder, &event_loop);
-    let gl = std::rc::Rc::new(gl);
+    let gl = std::sync::Arc::new(gl);
 
     let mut painter = egui_glow::Painter::new(gl.clone(), None, "")
         .unwrap_or_else(|error| panic!("some OpenGL error occurred {}\n", error));

eframe/src/web/glow_wrapping.rs

@@ -17,7 +17,7 @@ impl WrappedGlowPainter {
         let canvas = super::canvas_element_or_die(canvas_id);
 
         let (gl, shader_prefix) = init_glow_context_from_canvas(&canvas)?;
-        let gl = std::rc::Rc::new(gl);
+        let gl = std::sync::Arc::new(gl);
 
         let dimension = [canvas.width() as i32, canvas.height() as i32];
         let painter = egui_glow::Painter::new(gl, Some(dimension), shader_prefix)
@@ -32,7 +32,7 @@ impl WrappedGlowPainter {
 }
 
 impl WrappedGlowPainter {
-    pub fn gl(&self) -> &std::rc::Rc<glow::Context> {
+    pub fn gl(&self) -> &std::sync::Arc<glow::Context> {
         self.painter.gl()
     }
 

egui_glow/examples/pure_glow.rs

@@ -8,7 +8,7 @@ fn main() {
 
     let event_loop = glutin::event_loop::EventLoop::with_user_event();
     let (gl_window, gl) = create_display(&event_loop);
-    let gl = std::rc::Rc::new(gl);
+    let gl = std::sync::Arc::new(gl);
 
     let mut egui_glow = egui_glow::EguiGlow::new(gl_window.window(), gl.clone());
 

egui_glow/src/painter.rs

@@ -1,6 +1,6 @@
 #![allow(unsafe_code)]
 
-use std::{collections::HashMap, rc::Rc};
+use std::{collections::HashMap, sync::Arc};
 
 use egui::{
     emath::Rect,
@@ -42,7 +42,7 @@ impl TextureFilterExt for TextureFilter {
 /// This struct must be destroyed with [`Painter::destroy`] before dropping, to ensure OpenGL
 /// objects have been properly deleted and are not leaked.
 pub struct Painter {
-    gl: Rc<glow::Context>,
+    gl: Arc<glow::Context>,
 
     max_texture_side: usize,
 
@@ -82,7 +82,7 @@ impl Painter {
     /// * failed to create postprocess on webgl with `sRGB` support
     /// * failed to create buffer
     pub fn new(
-        gl: Rc<glow::Context>,
+        gl: Arc<glow::Context>,
         pp_fb_extent: Option<[i32; 2]>,
         shader_prefix: &str,
     ) -> Result<Painter, String> {
@@ -219,7 +219,7 @@ impl Painter {
     }
 
     /// Access the shared glow context.
-    pub fn gl(&self) -> &std::rc::Rc<glow::Context> {
+    pub fn gl(&self) -> &Arc<glow::Context> {
         &self.gl
     }
 

egui_glow/src/post_process.rs

@@ -7,7 +7,7 @@ use glow::HasContext as _;
 /// Uses a framebuffer to render everything in linear color space and convert it back to `sRGB`
 /// in a separate "post processing" step
 pub(crate) struct PostProcess {
-    gl: std::rc::Rc<glow::Context>,
+    gl: std::sync::Arc<glow::Context>,
     pos_buffer: glow::Buffer,
     index_buffer: glow::Buffer,
     vao: crate::vao::VertexArrayObject,
@@ -21,7 +21,7 @@ pub(crate) struct PostProcess {
 
 impl PostProcess {
     pub(crate) unsafe fn new(
-        gl: std::rc::Rc<glow::Context>,
+        gl: std::sync::Arc<glow::Context>,
         shader_prefix: &str,
         is_webgl_1: bool,
         [width, height]: [i32; 2],

egui_glow/src/winit.rs

@@ -12,7 +12,7 @@ pub struct EguiGlow {
 }
 
 impl EguiGlow {
-    pub fn new(window: &winit::window::Window, gl: std::rc::Rc<glow::Context>) -> Self {
+    pub fn new(window: &winit::window::Window, gl: std::sync::Arc<glow::Context>) -> Self {
         let painter = crate::Painter::new(gl, None, "")
             .map_err(|error| {
                 tracing::error!("error occurred in initializing painter:\n{}", error);

examples/custom_3d_three-d/Cargo.toml

@@ -12,4 +12,4 @@ publish = false
 eframe = { path = "../../eframe", features = ["glow"] }
 egui_glow = { path = "../../egui_glow" }
 glow = "0.11"
-three-d = { version = "0.11", default-features = false }
+three-d = { version = "0.12", default-features = false }

examples/custom_3d_three-d/src/main.rs

@@ -80,7 +80,7 @@ impl MyApp {
 /// to the [`egui::PaintCallback`] because [`three_d::Context`] isn't `Send+Sync`, which
 /// [`egui::PaintCallback`] is.
 fn with_three_d_context<R>(
-    gl: &std::rc::Rc<glow::Context>,
+    gl: &std::sync::Arc<glow::Context>,
     f: impl FnOnce(&three_d::Context) -> R,
 ) -> R {
     use std::cell::RefCell;
@@ -111,15 +111,12 @@ fn paint_with_three_d(three_d: &three_d::Context, info: &egui::PaintCallbackInfo
 
     // Respect the egui clip region (e.g. if we are inside an `egui::ScrollArea`).
     let clip_rect = info.clip_rect_in_pixels();
-    let render_states = RenderStates {
+    three_d.set_scissor(ScissorBox {
-        clip: Clip::Enabled {
+        x: clip_rect.left_px.round() as _,
-            x: clip_rect.left_px.round() as _,
+        y: clip_rect.from_bottom_px.round() as _,
-            y: clip_rect.from_bottom_px.round() as _,
+        width: clip_rect.width_px.round() as _,
-            width: clip_rect.width_px.round() as _,
+        height: clip_rect.height_px.round() as _,
-            height: clip_rect.height_px.round() as _,
+    });
-        },
-        ..Default::default()
-    };
 
     let camera = Camera::new_perspective(
         three_d,
@@ -150,11 +147,7 @@ fn paint_with_three_d(three_d: &three_d::Context, info: &egui::PaintCallbackInfo
         ..Default::default()
     };
 
-    let material = ColorMaterial {
+    let mut model = Model::new(three_d, &cpu_mesh).unwrap();
-        render_states,
-        ..Default::default()
-    };
-    let mut model = Model::new_with_material(three_d, &cpu_mesh, material).unwrap();
 
     // Set the current transformation of the triangle
     model.set_transformation(Mat4::from_angle_y(radians(angle)));