Merge pull request #100 from supermarsx/smx/implement-window-context-management-helpers-2025-11-02

Implement cross-platform GL context helpers for overlay

Author: supermarsx

src/app/main.cpp

@@ -312,6 +312,7 @@ int main(int argc, char **argv) {
   fullscreen_thread.request_stop();
   overlay_thread.request_stop();
   hook->stop();
+  overlay_thread.join();
   overlay.shutdown();
   engine.shutdown();
   lizard::platform::shutdown_tray();

src/overlay/overlay.cpp

@@ -45,10 +45,6 @@ void stbi_image_free(void *);
 #include <CoreGraphics/CoreGraphics.h>
 #endif
 
-#ifdef __APPLE__
-#include <objc/message.h>
-#endif
-
 #ifndef LIZARD_TEST
 #include "embedded.h"
 #endif
@@ -476,6 +472,8 @@ bool Overlay::init(const app::Config &cfg, std::optional<std::filesystem::path>
   glDeleteShader(vsId);
   glDeleteShader(fsId);
 
+  platform::clear_current_context(m_window);
+
 #endif
   m_running = true;
   return true;
@@ -728,29 +726,13 @@ void Overlay::apply_pending_config() {
 void Overlay::shutdown() {
 #ifndef LIZARD_TEST
   stop();
-  // Release GL resources after the render loop has stopped
-#ifdef _WIN32
-  if (m_window.device && m_window.glContext) {
-    wglMakeCurrent((HDC)m_window.device, (HGLRC)m_window.glContext);
-  }
-#elif defined(__linux__)
-  if (m_window.native && m_window.glContext) {
-    Display *dpy = glXGetCurrentDisplay();
-    if (dpy) {
-      glXMakeCurrent(dpy, (GLXDrawable)m_window.native, (GLXContext)m_window.glContext);
-    }
-  }
-#elif defined(__APPLE__)
-  if (m_window.glContext) {
-    auto makeCurrent = reinterpret_cast<void (*)(id, SEL)>(objc_msgSend);
-    makeCurrent((id)m_window.glContext, sel_getUid("makeCurrentContext"));
-  }
-#endif
+  platform::make_context_current(m_window);
   m_texture.reset();
   m_vbo.reset();
   m_instance.reset();
   m_vao.reset();
   m_program.reset();
+  platform::clear_current_context(m_window);
   platform::destroy_window(m_window);
 #endif
 }
@@ -927,12 +909,14 @@ void Overlay::render() {
   glBindVertexArray(m_vao.id);
   glBindTexture(GL_TEXTURE_2D, m_texture.id);
   glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, static_cast<GLsizei>(m_badges.size()));
+  platform::swap_buffers(m_window);
   platform::poll_events(m_window);
 #endif
 }
 
 void Overlay::run(std::stop_token st) {
 #ifndef LIZARD_TEST
+  platform::make_context_current(m_window);
   using clock = std::chrono::steady_clock;
   auto last = clock::now();
   while (m_running && !st.stop_requested()) {
@@ -958,6 +942,7 @@ void Overlay::run(std::stop_token st) {
       std::this_thread::sleep_for(frame - spend);
     }
   }
+  platform::clear_current_context(m_window);
   stop();
 #else
   (void)st;

src/platform/linux/window.cpp

@@ -250,4 +250,26 @@ bool fullscreen_window_present() {
   return full;
 }
 
+void make_context_current(Window &window) {
+  std::lock_guard<std::mutex> lock(g_display_mutex);
+  if (g_display && window.native && window.glContext) {
+    glXMakeCurrent(g_display, static_cast<GLXDrawable>(reinterpret_cast<::Window>(window.native)),
+                   window.glContext);
+  }
+}
+
+void clear_current_context(Window &) {
+  std::lock_guard<std::mutex> lock(g_display_mutex);
+  if (g_display) {
+    glXMakeCurrent(g_display, None, nullptr);
+  }
+}
+
+void swap_buffers(Window &window) {
+  std::lock_guard<std::mutex> lock(g_display_mutex);
+  if (g_display && window.native) {
+    glXSwapBuffers(g_display, static_cast<GLXDrawable>(reinterpret_cast<::Window>(window.native)));
+  }
+}
+
 } // namespace lizard::platform

src/platform/mac/window.mm

@@ -141,6 +141,26 @@ bool fullscreen_window_present() {
   }
 }
 
+void make_context_current(Window &window) {
+  @autoreleasepool {
+    if (window.glContext) {
+      [(NSOpenGLContext *)window.glContext makeCurrentContext];
+    }
+  }
+}
+
+void clear_current_context(Window &) {
+  @autoreleasepool { [NSOpenGLContext clearCurrentContext]; }
+}
+
+void swap_buffers(Window &window) {
+  @autoreleasepool {
+    if (window.glContext) {
+      [(NSOpenGLContext *)window.glContext flushBuffer];
+    }
+  }
+}
+
 } // namespace lizard::platform
 
 #endif

src/platform/win/window.cpp

@@ -162,6 +162,20 @@ bool fullscreen_window_present() {
   return data.full;
 }
 
+void make_context_current(Window &window) {
+  if (window.device && window.glContext) {
+    wglMakeCurrent(static_cast<HDC>(window.device), static_cast<HGLRC>(window.glContext));
+  }
+}
+
+void clear_current_context(Window &) { wglMakeCurrent(nullptr, nullptr); }
+
+void swap_buffers(Window &window) {
+  if (window.device) {
+    SwapBuffers(static_cast<HDC>(window.device));
+  }
+}
+
 } // namespace lizard::platform
 
 #endif

src/platform/window.hpp

@@ -38,6 +38,9 @@ void destroy_window(Window &window);
 void poll_events(Window &window);
 bool fullscreen_window_present();
 std::pair<float, float> cursor_pos();
+void make_context_current(Window &window);
+void clear_current_context(Window &window);
+void swap_buffers(Window &window);
 #if defined(__linux__)
 void init_xlib_threads();
 #endif