Initial implementation of imgui support

glium_platform/src/render/debug_ui.rs

@@ -0,0 +1,77 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::time::Instant;
+use glium::Display;
+use glium::glutin::surface::WindowSurface;
+use imgui::{Context as ImguiContext};
+use imgui_winit_support::{HiDpiMode, WinitPlatform};
+use imgui_glium_renderer::Renderer as ImguiGliumRenderer;
+use winit::raw_window_handle::DisplayHandle;
+use winit::window::Window;
+use anyhow::Result;
+use crate::RenderingSystem;
+use crate::system::RenderingContext;
+use glium::Frame;
+
+pub struct ImguiBridge {
+    imgui: ImguiContext,
+    platform: WinitPlatform,
+    renderer: ImguiGliumRenderer,
+}
+
+impl ImguiBridge {
+    pub fn new(display: &Display<WindowSurface>, window: &Window) -> Result<Self> {
+        let mut imgui = ImguiContext::create();
+        imgui.set_ini_filename(None);
+        let mut platform = WinitPlatform::new(&mut imgui);
+        platform.attach_window(imgui.io_mut(), window, HiDpiMode::Default);
+        imgui.fonts().add_font(&[imgui::FontSource::DefaultFontData { config: None }]);
+        let renderer = ImguiGliumRenderer::new(&mut imgui, display)?;
+
+        Ok(Self {
+            imgui,
+            platform,
+            renderer,
+        })
+    }
+
+    pub fn render<F>(&mut self, target: &mut Frame, window: &Window, build_ui: F)
+    where
+        F: FnOnce(&imgui::Ui),
+    {
+        let ui = self.imgui.frame();
+
+        build_ui(&ui);
+
+        self.platform.prepare_render(ui, window);
+        let draw_data = self.imgui.render();
+
+        self
+            .renderer
+            .render(target, draw_data)
+            .expect("imgui rendering failed");
+    }
+
+    pub fn initialize_frame(&mut self) -> &mut imgui::Ui {
+        self.imgui.frame()
+    }
+
+    pub fn finish_frame(&mut self, target: &mut Frame, window: &Window, ui: imgui::Ui) {
+        self.platform.prepare_render(&ui, window);
+        let draw_data = self.imgui.render();
+        self.renderer.render(target, draw_data).expect("imgui rendering failed");
+    }
+}
+
+impl RenderingSystem for ImguiBridge {
+    fn render(&mut self, ctx: &mut RenderingContext) {
+        todo!()
+    }
+
+    fn initialize(display: &Display<WindowSurface>) -> Self
+    where
+        Self: Sized,
+    {
+        todo!()
+    }
+}