From 3fd5b09a9401ac6655578e18ff7db31a32fb6f74 Mon Sep 17 00:00:00 2001
From: reo <emre@reoco.de>
Date: Sat, 6 Sep 2025 11:52:49 +0300
Subject: [PATCH] Initial implementation of imgui support

---
 game/src/main.rs                      |  6 ++-
 glium_platform/Cargo.toml             |  5 +-
 glium_platform/src/lib.rs             |  2 +-
 glium_platform/src/platform.rs        |  7 ++-
 glium_platform/src/render/debug_ui.rs | 77 +++++++++++++++++++++++++++
 glium_platform/src/render/mod.rs      |  2 +
 6 files changed, 95 insertions(+), 4 deletions(-)
 create mode 100644 glium_platform/src/render/debug_ui.rs

diff --git a/game/src/main.rs b/game/src/main.rs
index fe810dd..e72db32 100644
--- a/game/src/main.rs
+++ b/game/src/main.rs
@@ -44,7 +44,11 @@ impl System for RenderingTestSystem {
         ));
     }
 
-    fn update(&mut self, ctx: &mut SystemContext) {}
+    fn update(&mut self, ctx: &mut SystemContext) {
+        // if let Some(mut debug_ui) = ctx.platform_context.imgui_ui.as_ref().map(|ui| ui.borrow_mut()) {
+        //     debug_ui.text("Hello World!");
+        // }
+    }
 }
 
 fn main() {
diff --git a/glium_platform/Cargo.toml b/glium_platform/Cargo.toml
index c206b4e..ebae599 100644
--- a/glium_platform/Cargo.toml
+++ b/glium_platform/Cargo.toml
@@ -13,4 +13,7 @@ raidillon_core = { path = "../core" }
 raidillon_assets = { path = "../asset" }
 raidillon_ecs = { path = "../ecs" }
 winit = "0.30.12"
-indexmap = "2.10.0"
\ No newline at end of file
+indexmap = "2.10.0"
+imgui = "0.12.0"
+imgui-winit-support = "0.13.0"
+imgui-glium-renderer = "0.13.0"
diff --git a/glium_platform/src/lib.rs b/glium_platform/src/lib.rs
index 7d91b4d..6fd924f 100644
--- a/glium_platform/src/lib.rs
+++ b/glium_platform/src/lib.rs
@@ -5,6 +5,6 @@ pub mod gltf_loader;
 pub mod system;
 mod render;
 
-pub use assets::{GliumAssetManager};
+pub use assets::GliumAssetManager;
 pub use platform::GliumPlatform;
 pub use system::RenderingSystem;
diff --git a/glium_platform/src/platform.rs b/glium_platform/src/platform.rs
index 478974f..bf1aeac 100644
--- a/glium_platform/src/platform.rs
+++ b/glium_platform/src/platform.rs
@@ -14,6 +14,7 @@ use winit::event::{Event, WindowEvent};
 use raidillon_assets::{ModelManager, ModelManagerRef};
 use raidillon_core::Engine;
 use crate::{GliumAssetManager};
+use crate::render::debug_ui::ImguiBridge;
 use crate::render::BasicMeshRenderingSystem;
 
 pub const MESH_RENDERER: &str = "mesh_renderer";
@@ -25,6 +26,7 @@ pub struct GliumPlatform {
     rendering_system_manager: RenderingSystemManager,
     asset_manager: ModelManagerRef,
     engine: Engine,
+    imgui_bridge: ImguiBridge,
 }
 
 impl Platform for GliumPlatform {
@@ -47,13 +49,16 @@ impl Platform for GliumPlatform {
             Box::new(BasicMeshRenderingSystem::initialize(&display))
         );
 
+        let imgui_bridge = ImguiBridge::new(&display, &window).unwrap();
+
         Self {
             event_loop,
             window,
             display,
             rendering_system_manager,
             asset_manager,
-            engine
+            engine,
+            imgui_bridge,
         }
     }
 
diff --git a/glium_platform/src/render/debug_ui.rs b/glium_platform/src/render/debug_ui.rs
new file mode 100644
index 0000000..796be6d
--- /dev/null
+++ b/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!()
+    }
+}
\ No newline at end of file
diff --git a/glium_platform/src/render/mod.rs b/glium_platform/src/render/mod.rs
index 01028df..e98554f 100644
--- a/glium_platform/src/render/mod.rs
+++ b/glium_platform/src/render/mod.rs
@@ -1,2 +1,4 @@
 mod basic;
+pub mod debug_ui;
+
 pub use basic::BasicMeshRenderingSystem;
\ No newline at end of file