Disable X11 compositor bypass

Compositor bypass is meant for fullscreen games consuming lots of GPU
resources. For a light app that will usually be windowed, this only
causes unnecessary compositor suspends, especially visible (and
annoying) with complying window manager like KWin.

Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/compat.h

@@ -43,4 +43,9 @@
 # define SCRCPY_SDL_HAS_WINDOW_ALWAYS_ON_TOP
 #endif
 
+#if SDL_VERSION_ATLEAST(2, 0, 8)
+// <https://hg.libsdl.org/SDL/rev/dfde5d3f9781>
+# define SCRCPY_SDL_HAS_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR
+#endif
+
 #endif

app/src/scrcpy.c

@@ -69,6 +69,13 @@ sdl_init_and_configure(bool display) {
     }
 #endif
 
+#ifdef SCRCPY_SDL_HAS_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR
+    // Disable compositor bypassing on X11
+    if (!SDL_SetHint(SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR, "0")) {
+        LOGW("Could not disable X11 compositor bypass");
+    }
+#endif
+
     // Do not disable the screensaver when scrcpy is running
     SDL_EnableScreenSaver();