From 180f2b70fa1b1b922ea45ebf0092a20e87f48a99 Mon Sep 17 00:00:00 2001
From: Patrick Wuttke <mewin@mewin.de>
Date: Sun, 21 Sep 2025 15:18:02 +0200
Subject: [PATCH] Disable X11 on Wayland unless explicitly activated.

---
 private/raid/application.cpp |  6 +++---
 public/raid/raid.hpp         | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/private/raid/application.cpp b/private/raid/application.cpp
index cdc27e5..78594da 100644
--- a/private/raid/application.cpp
+++ b/private/raid/application.cpp
@@ -426,9 +426,9 @@ void Application::cleanup()
 bool Application::initSDL()
 {
 #if MIJIN_TARGET_OS == MIJIN_OS_LINUX
-    // prefer x11 over wayland, as ImGui viewports don't work with wayland
-    // TODO: this still doesn't work all the time, maybe there will be an update to ImGui in the future?
-    SDL_SetHint(SDL_HINT_VIDEO_DRIVER, "x11,wayland");
+    if (mConfig.flags.x11OnWayland) {
+        SDL_SetHint(SDL_HINT_VIDEO_DRIVER, "x11,wayland");
+    }
 #endif
     if (!SDL_Init(SDL_INIT_VIDEO))
     {
diff --git a/public/raid/raid.hpp b/public/raid/raid.hpp
index 5a1f54b..188f0ec 100644
--- a/public/raid/raid.hpp
+++ b/public/raid/raid.hpp
@@ -51,6 +51,21 @@ struct FontConfig
     FontFlags flags;
 };
 
+struct ApplicationFlags : mijin::BitFlags<ApplicationFlags>
+{
+    /**
+     * (Linux only) prefer X11 even when on Wayland. Required for multi-viewport support, but currently really buggy.
+     * \see https://github.com/ocornut/imgui/issues/8609
+     * \see https://github.com/ocornut/imgui/issues/8587
+     */
+    bool x11OnWayland : 1 = false;
+};
+
+struct ApplicationConfig
+{
+    ApplicationFlags flags = {};
+};
+
 class Application
 {
 private:
@@ -65,6 +80,7 @@ private:
     bool mRunning = true;
     ImGuiWindowFlags mMainWindowFlags = DEFAULT_MAIN_WINDOW_FLAGS;
     std::unordered_map<ImGuiStyleVar, std::variant<float, ImVec2>> mMainWindowStyles;
+    const ApplicationConfig mConfig;
 
     using GLbitfield = std::uint32_t;
     using GLint = std::int32_t;
@@ -91,8 +107,12 @@ private:
     glTexImage2D_fn_t glTexImage2D;
     glDeleteTextures_fn_t glDeleteTextures;
 public:
+    explicit Application(ApplicationConfig config = {}) noexcept : mConfig(config) {}
     virtual ~Application() = default;
 
+    [[nodiscard]]
+    const ApplicationConfig& getConfig() const noexcept { return mConfig; }
+
     [[nodiscard]]
     mijin::StackedFileSystemAdapter& getFS() { return mFS; }