Use EGL_VENDOR instead of NV-CONTROL for Nvidia detection

The latter will still match on a hybrid system when the iGPU's EGL
implementation is in use. This scenario works properly with EGL
rendering in Qt and SDL, so we want to allow that.

app/main.cpp

@@ -476,11 +476,7 @@ int main(int argc, char *argv[])
 #endif
     }
 
-    // Nvidia's proprietary driver has broken EGL support on X11, so don't use it.
+    if (WMUtils::isEGLSafe()) {
-    // This will break the EGLRenderer, but that's fine on Nvidia because they
-    // support both VDPAU and Vulkan renderers instead.
-    // https://github.com/moonlight-stream/moonlight-qt/issues/1751
-    if (!WMUtils::isRunningX11NvidiaProprietaryDriver()) {
         // Some ARM and RISC-V embedded devices don't have working GLX which can cause
         // SDL to fail to find a working OpenGL implementation at all. Let's force EGL
         // on all platforms for both SDL and Qt. This also avoids GLX-EGL interop issues

app/streaming/video/ffmpeg-renderers/eglvid.cpp

@@ -2,6 +2,7 @@
 #include "eglvid.h"
 
 #include "path.h"
+#include "utils.h"
 #include "streaming/session.h"
 #include "streaming/streamutils.h"
 
@@ -436,8 +437,7 @@ bool EGLRenderer::initialize(PDECODER_PARAMETERS params)
 
     // If we're using X11 GLX (both in SDL and Qt), don't use this renderer.
     // Switching between EGL and GLX can cause interoperability issues.
-    if (strcmp(SDL_GetCurrentVideoDriver(), "x11") == 0 &&
+    if (!WMUtils::isEGLSafe()) {
-            !SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_FORCE_EGL, SDL_FALSE)) {
         EGL_LOG(Warn, "Disabled due to use of GLX");
         return false;
     }

app/utils.h

@@ -7,9 +7,10 @@
 
 namespace WMUtils {
     bool isRunningX11();
-    bool isRunningX11NvidiaProprietaryDriver();
+    bool isRunningNvidiaProprietaryDriver();
     bool isRunningWayland();
     bool isRunningWindowManager();
     bool isRunningDesktopEnvironment();
+    bool isEGLSafe();
     QString getDrmCardOverride();
 }

app/wm.cpp

@@ -18,6 +18,10 @@
 #include <xf86drmMode.h>
 #endif
 
+#ifdef HAVE_EGL
+#include <EGL/egl.h>
+#endif
+
 #define VALUE_SET 0x01
 #define VALUE_TRUE 0x02
 
@@ -42,43 +46,39 @@ bool WMUtils::isRunningX11()
     }
 
     return !!(val & VALUE_TRUE);
-#endif
+#else
-
     return false;
+#endif
 }
 
-bool WMUtils::isRunningX11NvidiaProprietaryDriver()
+bool WMUtils::isRunningNvidiaProprietaryDriver()
 {
-#ifdef HAS_X11
+#ifdef HAVE_EGL
-    static SDL_atomic_t isRunningOnX11NvidiaDriver;
+    static SDL_atomic_t isRunningOnNvidiaDriver;
 
     // If the value is not set yet, populate it now.
-    int val = SDL_AtomicGet(&isRunningOnX11NvidiaDriver);
+    int val = SDL_AtomicGet(&isRunningOnNvidiaDriver);
     if (!(val & VALUE_SET)) {
-        Display* display = XOpenDisplay(nullptr);
         bool nvidiaDriver = false;
 
-        if (display != nullptr) {
+        EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-            int opcode, event, error;
+        if (display != EGL_NO_DISPLAY && eglInitialize(display, nullptr, nullptr)) {
-
+            const char* vendorString = eglQueryString(display, EGL_VENDOR);
-            // We use the presence of the NV-CONTROL extension to indicate
+            nvidiaDriver = vendorString && strstr(vendorString, "NVIDIA") != NULL;
-            // that the Nvidia proprietary driver is in use on native X11
+            eglTerminate(display);
-            nvidiaDriver = XQueryExtension(display, "NV-CONTROL", &opcode, &event, &error);
-
-            XCloseDisplay(display);
         }
 
         // Populate the value to return and have for next time.
         // This can race with another thread populating the same data,
         // but that's no big deal.
         val = VALUE_SET | (nvidiaDriver ? VALUE_TRUE : 0);
-        SDL_AtomicSet(&isRunningOnX11NvidiaDriver, val);
+        SDL_AtomicSet(&isRunningOnNvidiaDriver, val);
     }
 
     return !!(val & VALUE_TRUE);
-#endif
+#else
-
     return false;
+#endif
 }
 
 bool WMUtils::isRunningWayland()
@@ -102,9 +102,9 @@ bool WMUtils::isRunningWayland()
     }
 
     return !!(val & VALUE_TRUE);
-#endif
+#else
-
     return false;
+#endif
 }
 
 bool WMUtils::isRunningWindowManager()
@@ -176,3 +176,14 @@ QString WMUtils::getDrmCardOverride()
 
     return QString();
 }
+
+bool WMUtils::isEGLSafe()
+{
+    // We can use EGL if:
+    // a) We're not using X11/Wayland (EGLFS requires it)
+    // b) We're using Wayland (even XWayland is fine)
+    // c) We're using X11 but not the Nvidia proprietary driver
+    //
+    // https://github.com/moonlight-stream/moonlight-qt/issues/1751
+    return !WMUtils::isRunningWindowManager() || WMUtils::isRunningWayland() || !WMUtils::isRunningNvidiaProprietaryDriver();
+}