present_mode: proper vsync implementation

src/gl/inject_glx.cpp

@@ -131,8 +131,19 @@ EXPORT_C_(int) glXMakeCurrent(void* dpy, void* drawable, void* ctx) {
     return ret;
 }
 
+#ifndef GLX_SWAP_INTERVAL_EXT
+#define GLX_SWAP_INTERVAL_EXT 0x20F1
+#endif
+
 static void do_imgui_swap(void *dpy, void *drawable)
 {
+    static auto last_time = std::chrono::steady_clock::now();
+    auto current_time = std::chrono::steady_clock::now();
+
+    std::chrono::duration<double> elapsed_seconds = current_time - last_time;
+    if (HUDElements.vsync == 10 || elapsed_seconds.count() > 5.0)
+        glx.QueryDrawable(dpy, drawable, GLX_SWAP_INTERVAL_EXT, &HUDElements.vsync);
+
     GLint vp[4];
     if (!is_blacklisted()) {
         imgui_create(glx.GetCurrentContext(), gl_wsi::GL_WSI_GLX);

src/hud_elements.h

@@ -52,6 +52,7 @@ class HudElements{
         uint32_t vendorID;
         int hdr_status = 0;
         int refresh = 0;
+        unsigned int vsync = 10;
         std::unique_ptr<WineSync> winesync_ptr = nullptr;
         std::unique_ptr<Net> net = nullptr;
 #ifdef __linux__
@@ -158,11 +159,8 @@ class HudElements{
         std::string get_present_mode(){
             if (is_vulkan)
                 return presentModeMap[cur_present_mode];
-            // TODO: the opengl side is probably not as solid.
-            // But it also might not be possible to figure out if vsync
-            // is on or off unless we specify it.
             else
-                return params->gl_vsync == 0 ? "OFF" : "ON";
+                return vsync == 0 ? "OFF" : "ON";
 
         }
 };