From d4e3f4cfdd84a97238016361c9b4d6436d8f387f Mon Sep 17 00:00:00 2001
From: wolfwood <transmethyl@gmail.com>
Date: Mon, 16 Mar 2026 20:55:00 -0500
Subject: [PATCH] Add an option to accept an X11 window id as an argument and
 draw in it rather than opening a new window.

---
 src/ProjectMSDLApplication.cpp |  5 +++++
 src/SDLRenderingWindow.cpp     | 18 ++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/ProjectMSDLApplication.cpp b/src/ProjectMSDLApplication.cpp
index 3d12e58..2ba4399 100644
--- a/src/ProjectMSDLApplication.cpp
+++ b/src/ProjectMSDLApplication.cpp
@@ -233,6 +233,11 @@ void ProjectMSDLApplication::defineOptions(Poco::Util::OptionSet& options)
     options.addOption(Option("beatSensitivity", "", "Beat sensitivity. Between 0.0 and 2.0. Default 1.0.",
                              false, "<number>", true)
                           .binding("projectM.beatSensitivity", _commandLineOverrides));
+#ifdef __linux__
+    options.addOption(Option("window_id", "wid", "Existing X11 window id to draw in.",
+                             false, "<number>", true)
+                          .binding("window.wid", _commandLineOverrides));
+#endif
 }
 
 int ProjectMSDLApplication::main(POCO_UNUSED const std::vector<std::string>& args)
diff --git a/src/SDLRenderingWindow.cpp b/src/SDLRenderingWindow.cpp
index efac35e..201bb44 100644
--- a/src/SDLRenderingWindow.cpp
+++ b/src/SDLRenderingWindow.cpp
@@ -204,6 +204,10 @@ void SDLRenderingWindow::CreateSDLWindow()
     int top{_config->getInt("top", 0)};
     bool positionOverridden = _config->getBool("overridePosition", false);
 
+#ifdef __linux__
+    uint64_t wid{_config->getUInt64("wid", 0)};
+#endif
+
     if (!positionOverridden)
     {
         left = SDL_WINDOWPOS_UNDEFINED;
@@ -249,8 +253,18 @@ void SDLRenderingWindow::CreateSDLWindow()
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
 #endif
 
-    _renderingWindow = SDL_CreateWindow("projectM", left, top, width, height,
-                                        SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+#ifdef __linux__
+    if (wid) {
+        SDL_SetHint(SDL_HINT_VIDEO_FOREIGN_WINDOW_OPENGL, "1");
+        _renderingWindow = SDL_CreateWindowFrom((void*)wid);
+    }
+    else
+#endif
+    {
+      _renderingWindow = SDL_CreateWindow("projectM", left, top, width, height,
+                                          SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    }
+
     if (!_renderingWindow)
     {
         auto errorMessage = "Could not create SDL rendering window. Error: " + std::string(SDL_GetError());