rough sdl2 backend

crates/egui_glow/Cargo.toml

@@ -34,14 +34,16 @@ clipboard = ["egui-winit?/clipboard"]
 
 ## For the `winit` integration:
 ## enable opening links in a browser when an egui hyperlink is clicked.
-links = ["egui-winit?/links"]
+links = ["egui-winit?/links", "webbrowser"]
 
 ## Enable profiling with the [`puffin`](https://docs.rs/puffin) crate.
 puffin = ["dep:puffin", "egui-winit?/puffin", "egui/puffin"]
 
 ## Enable [`winit`](https://docs.rs/winit) integration.
 winit = ["egui-winit"]
 
+## Enable [`sdl2`](https://docs.rs/sdl2) integration.
+sdl2 = ["dep:sdl2"]
 
 [dependencies]
 egui = { version = "0.22.0", path = "../egui", default-features = false, features = [
@@ -61,6 +63,11 @@ document-features = { version = "0.2", optional = true }
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 egui-winit = { version = "0.22.0", path = "../egui-winit", optional = true, default-features = false }
 puffin = { version = "0.16", optional = true }
+sdl2 = { git = "https://github.com/Rust-SDL2/rust-sdl2.git", features = [
+  "bundled",
+  "static-link",
+], optional = true }
+webbrowser = { version = "0.8.3", optional = true }
 
 # Web:
 [target.'cfg(target_arch = "wasm32")'.dependencies]
@@ -69,11 +76,17 @@ wasm-bindgen = { version = "0.2" }
 
 
 [dev-dependencies]
-glutin = "0.30"             # examples/pure_glow
-raw-window-handle = "0.5.0"
+# examples/pure_glow_winit
+glutin = "0.30"
 glutin-winit = "0.3.0"
-
+raw-window-handle = "0.5.0"
+# examples/pure_glow_sdl2
+env_logger = "0.10"
 
 [[example]]
-name = "pure_glow"
+name = "pure_glow_winit"
 required-features = ["winit", "egui/default_fonts"]
+
+[[example]]
+name = "pure_glow_sdl2"
+required-features = ["sdl2", "egui/default_fonts"]

crates/egui_glow/examples/pure_glow_sdl2.rs

@@ -0,0 +1,97 @@
+//! Example how to use pure `egui_glow` with `sdl2`.
+
+#![allow(unsafe_code)]
+
+fn main() {
+    env_logger::init();
+    let sdl = sdl2::init().unwrap();
+    let video = sdl.video().unwrap();
+    let gl_attr = video.gl_attr();
+    gl_attr.set_context_profile(sdl2::video::GLProfile::Core);
+    gl_attr.set_context_version(3, 0);
+    let window = video
+        .window("Hello egui sdl2!", 1024, 769)
+        .opengl()
+        .resizable()
+        .allow_highdpi()
+        .build()
+        .unwrap();
+    let gl_context = window.gl_create_context().unwrap();
+    window
+        .subsystem()
+        .gl_set_swap_interval(sdl2::video::SwapInterval::LateSwapTearing)
+        .or_else(|_| {
+            window
+                .subsystem()
+                .gl_set_swap_interval(sdl2::video::SwapInterval::VSync)
+        })
+        .expect("Could not gl_set_swap_interval(...)");
+
+    let (gl, window, mut events_loop, _gl_context) = {
+        let gl = unsafe {
+            glow::Context::from_loader_function(|s| video.gl_get_proc_address(s) as *const _)
+        };
+        let event_loop = sdl.event_pump().unwrap();
+        (gl, window, event_loop, gl_context)
+    };
+    let gl = std::sync::Arc::new(gl);
+    let mut egui_glow = egui_glow::sdl2::EguiGlow::new(&window, gl.clone(), None);
+
+    let clipboard = &mut sdl.video().unwrap().clipboard();
+
+    let mut clear_colour: [f32; 3] = [0.1, 0.1, 0.1];
+    let mut name = "Ted";
+    let mut age = 41;
+
+    'mainloop: loop {
+        let mut quit_clicked: bool = false;
+        egui_glow.run(&window, clipboard, |egui_ctx| {
+            egui::SidePanel::left("my_left_side_panel").show(egui_ctx, |ui| {
+                ui.heading("Hello World!");
+                if ui.button("Quit").clicked() {
+                    quit_clicked = true;
+                }
+                ui.color_edit_button_rgb(&mut clear_colour);
+                ui.hyperlink_to("here", "http://www.google.com");
+            });
+            egui::SidePanel::right("my_right_side_panel").show(egui_ctx, |ui| {
+                ui.heading("My egui Application");
+                ui.horizontal(|ui| {
+                    ui.label("Your name: ");
+                    ui.text_edit_singleline(&mut name);
+                });
+                ui.add(egui::Slider::new(&mut age, 0..=120).text("age"));
+                if ui.button("Click each year").clicked() {
+                    age += 1;
+                }
+                ui.label(format!("Hello '{name}', age {age}"));
+            });
+        });
+
+        if quit_clicked {
+            break 'mainloop;
+        }
+
+        unsafe {
+            use glow::HasContext as _;
+            gl.clear_color(clear_colour[0], clear_colour[1], clear_colour[2], 1.0);
+            gl.clear(glow::COLOR_BUFFER_BIT);
+        }
+
+        // draw things behind egui here
+
+        egui_glow.paint(&window);
+
+        // draw things on top of egui here
+        window.gl_swap_window();
+
+        for event in events_loop.poll_iter() {
+            //repaint_after = std::time::Duration::from_secs(0);
+            egui_glow.on_event(&event, &window);
+
+            if let sdl2::event::Event::Quit { .. } = event {
+                break 'mainloop;
+            }
+        }
+    }
+}

crates/egui_glow/examples/pure_glow_sdl2_resize_fix.rs

@@ -0,0 +1,126 @@
+//! Example how to use pure `egui_glow` with `sdl2`.
+
+#![allow(unsafe_code)]
+
+fn main() {
+    env_logger::init();
+    let sdl = sdl2::init().unwrap();
+    let video = sdl.video().unwrap();
+    let gl_attr = video.gl_attr();
+    gl_attr.set_context_profile(sdl2::video::GLProfile::Core);
+    gl_attr.set_context_version(3, 0);
+    let window = video
+        .window("Hello egui sdl2!", 1024, 769)
+        .opengl()
+        .resizable()
+        .allow_highdpi()
+        .build()
+        .unwrap();
+    let gl_context = window.gl_create_context().unwrap();
+    window
+        .subsystem()
+        .gl_set_swap_interval(sdl2::video::SwapInterval::LateSwapTearing)
+        .or_else(|_| {
+            window
+                .subsystem()
+                .gl_set_swap_interval(sdl2::video::SwapInterval::VSync)
+        })
+        .expect("Could not gl_set_swap_interval(...)");
+
+    let (gl, window, mut events_loop, _gl_context) = {
+        let gl = unsafe {
+            glow::Context::from_loader_function(|s| video.gl_get_proc_address(s) as *const _)
+        };
+        let event_loop = sdl.event_pump().unwrap();
+        (gl, window, event_loop, gl_context)
+    };
+    let gl = std::sync::Arc::new(gl);
+    let mut egui_glow = egui_glow::sdl2::EguiGlow::new(&window, gl.clone(), None);
+
+    let clipboard = &mut sdl.video().unwrap().clipboard();
+
+    let mut clear_colour: [f32; 3] = [0.1, 0.1, 0.1];
+    let mut name = "Ted";
+    let mut age = 41;
+
+    let handle_events = std::sync::Arc::new(std::sync::Mutex::new(
+        |event: Option<sdl2::event::Event>| {
+            let mut quit_clicked: bool = false;
+            egui_glow.run(&window, clipboard, |egui_ctx| {
+                egui::SidePanel::left("my_left_side_panel").show(egui_ctx, |ui| {
+                    ui.heading("Hello World!");
+                    if ui.button("Quit").clicked() {
+                        quit_clicked = true;
+                    }
+                    ui.color_edit_button_rgb(&mut clear_colour);
+                    ui.hyperlink_to("here", "http://www.google.com");
+                });
+                egui::SidePanel::right("my_right_side_panel").show(egui_ctx, |ui| {
+                    ui.heading("My egui Application");
+                    ui.horizontal(|ui| {
+                        ui.label("Your name: ");
+                        ui.text_edit_singleline(&mut name);
+                    });
+                    ui.add(egui::Slider::new(&mut age, 0..=120).text("age"));
+                    if ui.button("Click each year").clicked() {
+                        age += 1;
+                    }
+                    ui.label(format!("Hello '{name}', age {age}"));
+                });
+            });
+
+            if quit_clicked {
+                return false;
+            }
+
+            unsafe {
+                use glow::HasContext as _;
+                gl.clear_color(clear_colour[0], clear_colour[1], clear_colour[2], 1.0);
+                gl.clear(glow::COLOR_BUFFER_BIT);
+            }
+
+            // draw things behind egui here
+
+            egui_glow.paint(&window);
+
+            // draw things on top of egui here
+            window.gl_swap_window();
+
+            if let Some(event) = event {
+                //repaint_after = std::time::Duration::from_secs(0);
+                egui_glow.on_event(&event, &window);
+
+                if let sdl2::event::Event::Quit { .. } = event {
+                    return false;
+                }
+            }
+            return true;
+        },
+    ));
+
+    let try_handle = |event: Option<sdl2::event::Event>| -> bool {
+        if let Ok(handle) = &mut handle_events.try_lock() {
+            handle(event)
+        } else {
+            true
+        }
+    };
+
+    //Note: this is a workaround for https://stackoverflow.com/a/40693139
+    let _event_watch = sdl.event().unwrap().add_event_watch(|event| {
+        use sdl2::event::{Event, WindowEvent};
+        if let Event::Window {
+            win_event: WindowEvent::Resized(..) | WindowEvent::SizeChanged(..),
+            ..
+        } = event
+        {
+            try_handle(Some(event));
+        };
+    });
+
+    'mainloop: loop {
+        if !try_handle(events_loop.wait_event_timeout(5)) {
+            break 'mainloop;
+        }
+    }
+}

crates/egui_glow/examples/pure_glow.rs → crates/egui_glow/examples/pure_glow_winit.rs

@@ -149,7 +149,7 @@ fn main() {
     let (gl_window, gl) = create_display(&event_loop);
     let gl = std::sync::Arc::new(gl);
 
-    let mut egui_glow = egui_glow::EguiGlow::new(&event_loop, gl.clone(), None);
+    let mut egui_glow = egui_glow::winit::EguiGlow::new(&event_loop, gl.clone(), None);
 
     event_loop.run(move |event, _, control_flow| {
         let mut redraw = || {

crates/egui_glow/src/lib.rs

@@ -25,6 +25,11 @@ pub mod winit;
 #[cfg(all(not(target_arch = "wasm32"), feature = "winit"))]
 pub use winit::*;
 
+#[cfg(feature = "sdl2")]
+pub mod sdl2;
+#[cfg(feature = "sdl2")]
+pub use crate::sdl2::*;
+
 /// Check for OpenGL error and report it using `log::error`.
 ///
 /// Only active in debug builds!