Implement Windows and Linux GPU Acceleration

Backend/src/lib.rs

@@ -9,7 +9,7 @@ use log::{error, warn};
 use std::sync::Arc;
 use tauri::path::BaseDirectory;
 use tauri::WindowEvent;
-use tauri::{Emitter, Manager};
+use tauri::{Emitter, Manager, WebviewUrl, WebviewWindowBuilder};
 use tauri_plugin_updater::UpdaterExt;
 
 use crate::core::BackendId;
@@ -147,11 +147,24 @@ fn try_reopen_last_repo<R: tauri::Runtime>(app_handle: &tauri::AppHandle<R>) {
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
     load_local_dotenv();
+    let initial_config = settings::AppConfig::load_or_default();
     workarounds::apply_linux_nvidia_workaround();
+    workarounds::apply_gpu_acceleration_preference(&initial_config.performance);
+    #[cfg(target_os = "windows")]
+    let main_window_browser_args =
+        workarounds::main_window_browser_args(&initial_config.performance);
 
     // Initialize logging after startup-only process environment adjustments.
     logging::init();
-    let app_state = state::AppState::new_with_config();
+    log::info!(
+        "performance: GPU acceleration {} at startup",
+        if initial_config.performance.gpu_accel {
+            "enabled"
+        } else {
+            "disabled"
+        }
+    );
+    let app_state = state::AppState::new_with_config(initial_config);
     monitoring::sync_backend_monitoring(&app_state.config());
 
     println!("Running OpenVCS...");
@@ -197,6 +210,39 @@ pub fn run() {
                     crate::plugin_paths::set_resource_dir(parent.to_path_buf());
                 }
             }
+
+            if app.get_webview_window("main").is_none() {
+                #[cfg(target_os = "windows")]
+                let builder = {
+                    let mut builder = WebviewWindowBuilder::new(
+                        app,
+                        "main",
+                        WebviewUrl::App("index.html".into()),
+                    )
+                    .title("OpenVCS")
+                    .inner_size(1100.0, 600.0)
+                    .min_inner_size(1100.0, 600.0)
+                    .resizable(true);
+                    if let Some(args) = main_window_browser_args.clone() {
+                        builder = builder.additional_browser_args(args);
+                    }
+                    builder
+                };
+                #[cfg(not(target_os = "windows"))]
+                let builder = WebviewWindowBuilder::new(
+                    app,
+                    "main",
+                    WebviewUrl::App("index.html".into()),
+                )
+                .title("OpenVCS")
+                .inner_size(1100.0, 600.0)
+                .min_inner_size(1100.0, 600.0)
+                .resizable(true);
+                if let Err(err) = builder.build() {
+                    log::error!("failed to create main window: {}", err);
+                }
+            }
+
             // Keep resource lookup state populated before resolving bundled Node
             // candidates. `bundled_node_candidate_paths()` uses both the generic
             // RESOURCE_DIR base and the exact Tauri-resolved `node-runtime`

Backend/src/settings.rs

@@ -285,7 +285,7 @@ impl Default for Lfs {
 pub struct Performance {
     #[serde(default)]
     pub progressive_render: bool,
-    #[serde(default)]
+    #[serde(default = "default_true")]
     pub gpu_accel: bool,
     #[serde(default = "default_true")]
     pub animations: bool,

Backend/src/state.rs

@@ -43,12 +43,11 @@ pub struct AppState {
 }
 
 impl AppState {
-    /// Creates app state by loading persisted settings and recent repositories.
+    /// Creates app state from a preloaded settings snapshot and recent repositories.
     ///
     /// # Returns
     /// - A fully initialized [`AppState`] with config and recent repositories loaded.
-    pub fn new_with_config() -> Self {
-        let cfg = AppConfig::load_or_default(); // reads ~/.config/openvcs/openvcs.conf
+    pub fn new_with_config(cfg: AppConfig) -> Self {
         let s = Self {
             config: RwLock::new(cfg),
             repo_config: RwLock::new(RepoConfig::default()),

Backend/src/workarounds.rs

@@ -1,5 +1,7 @@
 // Copyright © 2025-2026 OpenVCS Contributors
 // SPDX-License-Identifier: GPL-3.0-or-later
+use crate::settings::Performance;
+
 #[cfg(target_os = "linux")]
 /// Applies a runtime workaround for NVIDIA + Wayland rendering issues.
 ///
@@ -37,6 +39,38 @@ pub fn apply_linux_nvidia_workaround() {
     }
 }
 
+#[cfg(target_os = "linux")]
+/// Applies the stored GPU acceleration preference before the webview starts.
+///
+/// When disabled, this forces WebKitGTK into a software/compositing-off path.
+/// When enabled, any previously injected disable flags are removed so the host
+/// can use the default accelerated path.
+///
+/// # Parameters
+/// - `performance`: Persisted performance settings.
+///
+/// # Returns
+/// - `()`.
+pub fn apply_gpu_acceleration_preference(performance: &Performance) {
+    const COMPOSITING_KEY: &str = "WEBKIT_DISABLE_COMPOSITING_MODE";
+    const WEBGL_KEY: &str = "WEBKIT_DISABLE_WEBGL";
+
+    if performance.gpu_accel {
+        eprintln!("Clearing GPU-disable env vars where present");
+        unsafe {
+            std::env::remove_var(COMPOSITING_KEY);
+            std::env::remove_var(WEBGL_KEY);
+        }
+        return;
+    }
+
+    eprintln!("Applying GPU-disable env vars: {COMPOSITING_KEY}=1, {WEBGL_KEY}=1");
+    unsafe {
+        std::env::set_var(COMPOSITING_KEY, "1");
+        std::env::set_var(WEBGL_KEY, "1");
+    }
+}
+
 #[cfg(not(target_os = "linux"))]
 #[inline]
 /// No-op on non-Linux platforms.
@@ -46,3 +80,33 @@ pub fn apply_linux_nvidia_workaround() {
 pub fn apply_linux_nvidia_workaround() {
     // no-op on non-Linux
 }
+
+#[cfg(not(target_os = "linux"))]
+#[inline]
+/// No-op on non-Linux platforms.
+///
+/// # Parameters
+/// - `performance`: Persisted performance settings.
+///
+/// # Returns
+/// - `()`.
+pub fn apply_gpu_acceleration_preference(_performance: &Performance) {
+    // no-op on non-Linux
+}
+
+#[cfg(target_os = "windows")]
+/// Returns additional browser arguments for the main webview when GPU acceleration is disabled.
+///
+/// # Parameters
+/// - `performance`: Persisted performance settings.
+///
+/// # Returns
+/// - Browser argument string when GPU acceleration is disabled.
+/// - `None` when no override is needed.
+pub fn main_window_browser_args(performance: &Performance) -> Option<String> {
+    if performance.gpu_accel {
+        return None;
+    }
+
+    Some("--disable-gpu --disable-gpu-compositing".to_string())
+}

Backend/tauri.conf.json

@@ -16,16 +16,7 @@
   },
   "app": {
     "withGlobalTauri": true,
-    "windows": [
-      {
-        "title": "OpenVCS",
-        "width": 1100,
-        "height": 600,
-        "resizable": true,
-        "minWidth": 1100,
-        "minHeight": 600
-      }
-    ],
+    "windows": [],
     "security": {
       "csp": null
     }

Frontend/src/modals/settings.html

@@ -4,19 +4,19 @@
     <div class="dialog sheet" role="dialog" aria-modal="true" aria-labelledby="settings-title">
         <div class="sheet-head">
             <h3 id="settings-title" style="margin:0">Settings</h3>
-            <button class="icon close" data-close aria-label="Close">✕</button>
+            <button class="icon close" data-close type="button" aria-label="Close">✕</button>
         </div>
 
         <section class="sheet-body">
             <!-- Sidebar -->
             <nav class="list-scroll" aria-label="Settings sections">
                 <ul id="settings-nav" class="list">
-                    <li><button class="seg-btn active" data-section="general">General</button></li>
-                    <li><button class="seg-btn" data-section="diff">Diff &amp; Merge</button></li>
-                    <li><button class="seg-btn" data-section="performance">Performance</button></li>
-                    <li><button class="seg-btn" data-section="ux">UX</button></li>
-                    <li><button class="seg-btn" data-section="logging">Logging</button></li>
-                    <li><button class="seg-btn" data-section="plugins">Plugins</button></li>
+                    <li><button class="seg-btn active" type="button" data-section="general">General</button></li>
+                    <li><button class="seg-btn" type="button" data-section="diff">Diff &amp; Merge</button></li>
+                    <li><button class="seg-btn" type="button" data-section="performance">Performance</button></li>
+                    <li><button class="seg-btn" type="button" data-section="ux">UX</button></li>
+                    <li><button class="seg-btn" type="button" data-section="logging">Logging</button></li>
+                    <li><button class="seg-btn" type="button" data-section="plugins">Plugins</button></li>
                     <!-- You can add: integrations, advanced, experimental, logging, network later -->
                 </ul>
             </nav>
@@ -184,8 +184,8 @@ <h3 id="settings-title" style="margin:0">Settings</h3>
                         </label>
                     </div>
                     <div class="group">
-                        <label class="checkbox"><input type="checkbox" id="set-gpu-accel" disabled /> GPU acceleration
-                            <span class="help-tip" title="Use GPU acceleration when available for smoother rendering.">?</span>
+                        <label class="checkbox"><input type="checkbox" id="set-gpu-accel" /> GPU acceleration
+                            <span class="help-tip" title="Takes effect on next app restart; enables accelerated webview compositing where supported.">?</span>
                         </label>
                     </div>
 

Frontend/src/scripts/features/settings.ts

@@ -6,7 +6,7 @@ import { openModal, closeModal } from '../ui/modals';
 import { toKebab } from '../lib/dom';
 import { confirmBool } from '../lib/confirm';
 import { notify } from '../lib/notify';
-import { setTheme, applyCommitSummaryRestriction } from '../ui/layout';
+import { setTheme, applyCommitSummaryRestriction, applyGpuAccelerationPreference } from '../ui/layout';
 import { collectGeneralSettings, loadGeneralSettingsIntoForm } from './settingsGeneral';
 import { DEFAULT_DARK_THEME_ID, DEFAULT_LIGHT_THEME_ID, DEFAULT_THEME_ID, getActiveThemeId, getAvailableThemes, refreshAvailableThemes, selectThemePack } from '../themes';
 import { invokePluginAction, reloadPlugins } from '../plugins';
@@ -241,11 +241,17 @@ async function renderPluginMenus(modal: HTMLElement): Promise<void> {
     const panelsScroll = modal.querySelector('#settings-panels-scroll');
     if (!nav || !panelsScroll) return;
 
-    nav.querySelectorAll<HTMLElement>('[data-plugin-menu="true"]').forEach((node) => node.remove());
-    nav.querySelectorAll<HTMLElement>('[data-plugin-menus-wrap="true"]').forEach((node) => node.remove());
+    nav.querySelectorAll<HTMLElement>('[data-plugin-menu="true"]').forEach((node) => {
+        node.remove();
+    });
+    nav.querySelectorAll<HTMLElement>('[data-plugin-menus-wrap="true"]').forEach((node) => {
+        node.remove();
+    });
     panelsScroll
         .querySelectorAll<HTMLElement>('.panel-form[data-plugin-menu="true"]')
-        .forEach((node) => node.remove());
+        .forEach((node) => {
+            node.remove();
+        });
 
     let menus: PluginMenuPayload[] = [];
     let pluginSummaries: PluginSummary[] = [];
@@ -462,10 +468,10 @@ function activateSection(modal: HTMLElement, section: string) {
     })();
 
     const btn = nav.querySelector<HTMLElement>(`[data-section="${safeSection}"]`);
-    nav.querySelectorAll<HTMLElement>('.seg-btn').forEach(b => {
+    nav.querySelectorAll<HTMLElement>('.seg-btn').forEach((b) => {
         b.classList.toggle('active', b === btn);
     });
-    panels.querySelectorAll<HTMLElement>('.panel-form').forEach(p => {
+    panels.querySelectorAll<HTMLElement>('.panel-form').forEach((p) => {
         p.classList.toggle('hidden', p.getAttribute('data-panel') !== safeSection);
     });
 
@@ -575,7 +581,9 @@ export function wireSettings() {
         .filter((el): el is HTMLInputElement => !!el);
     const updateLfsDependentState = () => {
         const enabled = !!lfsToggle?.checked;
-        lfsDependents.forEach(input => input.disabled = !enabled);
+        lfsDependents.forEach((input) => {
+            input.disabled = !enabled;
+        });
     };
     updateLfsDependentState();
     lfsToggle?.addEventListener('change', updateLfsDependentState);
@@ -690,6 +698,14 @@ export function wireSettings() {
             }
 
             const next = collectSettingsFromForm(modal);
+            const previousCfg = (() => {
+                try {
+                    return JSON.parse(String(modal.dataset.currentCfg || '{}')) as GlobalSettings;
+                } catch {
+                    return {} as GlobalSettings;
+                }
+            })();
+            const gpuChanged = previousCfg.performance?.gpu_accel !== next.performance?.gpu_accel;
 
             await TAURI.invoke('set_global_settings', { cfg: next });
             await syncFrontendMonitoring(next);
@@ -710,10 +726,11 @@ export function wireSettings() {
                 if (mono) root.style.setProperty('--mono', mono);
                 else root.style.removeProperty('--mono');
                 applyAnimationPreference(next?.performance?.animations);
+                applyGpuAccelerationPreference(next?.performance?.gpu_accel);
                 applyCommitSummaryRestriction(next?.general?.restrict_commit_summary !== false);
             } catch {}
 
-            notify('Settings saved');
+            notify(gpuChanged ? 'Settings saved. GPU changes apply after restart.' : 'Settings saved');
             flashSavedState(settingsSave);
         } catch (e) {
             console.error('Failed to save settings:', e);
@@ -766,6 +783,7 @@ export function wireSettings() {
             await TAURI.invoke('set_global_settings', { cfg: cur });
             await syncFrontendMonitoring(cur);
             applyAnimationPreference(cur.performance?.animations);
+            applyGpuAccelerationPreference(cur.performance?.gpu_accel);
             applyCommitSummaryRestriction(cur.general?.restrict_commit_summary !== false);
             await loadSettingsIntoForm(modal);
             setTheme('system');

Frontend/src/scripts/main.ts

@@ -11,7 +11,7 @@ import { destroyOverlayScrollbarsFor, initOverlayScrollbarsFor, refreshOverlaySc
 import { prefs, state, hasRepo, resolveVcsActionLabel } from './state/state';
 import {
     bindTabs, initResizer, refreshRepoActions, setRepoHeader, resetRepoHeader, setTab, setTheme,
-    bindLayoutActionState, applyCommitSummaryRestriction
+    bindLayoutActionState, applyCommitSummaryRestriction, applyGpuAccelerationPreference
 } from './ui/layout';
 import { clearPluginMenubarMenus, initMenubar, refreshPluginMenubarMenus } from './ui/menubar';
 import { closeAllModals } from './ui/modals';
@@ -132,18 +132,21 @@ async function boot() {
                     const mono = String(cfg?.ux?.font_mono || '').trim();
                     if (mono) root.style.setProperty('--mono', mono);
                     applyAnimationPreference(cfg?.performance?.animations);
+                    applyGpuAccelerationPreference(cfg?.performance?.gpu_accel);
                     applyCommitSummaryRestriction(cfg?.general?.restrict_commit_summary !== false);
                 } catch { /* best-effort */ }
             } catch {
                 try { await selectThemePack(DEFAULT_LIGHT_THEME_ID, { silent: true, mode: 'system' }); } catch {}
                 setTheme(prefs.theme);
                 applyAnimationPreference(true);
+                applyGpuAccelerationPreference(true);
                 applyCommitSummaryRestriction(true);
             }
         })();
     } else {
         setTheme(prefs.theme);
         applyAnimationPreference(true);
+        applyGpuAccelerationPreference(true);
         applyCommitSummaryRestriction(true);
     }
     wireRenderListCallbacks();

Frontend/src/scripts/ui/layout.test.ts

@@ -70,6 +70,34 @@ describe('applyCommitSummaryRestriction', () => {
   });
 });
 
+describe('applyGpuAccelerationPreference', () => {
+  beforeEach(() => {
+    vi.resetModules();
+    Object.defineProperty(globalThis, 'matchMedia', {
+      value: createMatchMediaMock,
+      configurable: true,
+      writable: true,
+    });
+    mountLayoutDom();
+  });
+
+  it('stores the GPU acceleration preference on the document root', async () => {
+    const { applyGpuAccelerationPreference } = await import('./layout');
+
+    applyGpuAccelerationPreference(false);
+    expect(document.documentElement.dataset.gpuAcceleration).toBe('off');
+
+    applyGpuAccelerationPreference(true);
+    expect(document.documentElement.dataset.gpuAcceleration).toBe('on');
+
+    applyGpuAccelerationPreference(undefined);
+    expect(document.documentElement.dataset.gpuAcceleration).toBe('on');
+
+    applyGpuAccelerationPreference(null);
+    expect(document.documentElement.dataset.gpuAcceleration).toBe('on');
+  });
+});
+
 describe('refreshRepoActions', () => {
   beforeEach(() => {
     vi.resetModules();