[client] renderer: add ability to toggle the FPS display

Before, if you want to see the FPS, you need to close the client and
restart it with the -k switch to see the FPS. This is annoying.

This PR introduces a new keybind, ScrollLock+D, which, when pressed,
toggles the display of the FPS.

This is implemented for both EGL and OpenGL backends.

client/src/app.c

@@ -552,3 +552,11 @@ void app_showHelp(bool show)
   g_state.lgr->on_help(g_state.lgrData, help);
   free(help);
 }
+
+void app_showFPS(bool showFPS)
+{
+  if (!g_state.lgr)
+    return;
+
+  g_state.lgr->on_show_fps(g_state.lgrData, showFPS);
+}

client/src/keybind.c

@@ -47,6 +47,12 @@ static void bind_video(int sc, void * opaque)
     core_startFrameThread();
 }
 
+static void bind_showFPS(int sc, void * opaque)
+{
+  g_state.showFPS = !g_state.showFPS;
+  app_showFPS(g_state.showFPS);
+}
+
 static void bind_rotate(int sc, void * opaque)
 {
   if (g_params.winRotate == LG_ROTATE_MAX-1)
@@ -126,6 +132,7 @@ void keybind_register(void)
 {
   app_registerKeybind(KEY_F, bind_fullscreen, NULL, "Full screen toggle");
   app_registerKeybind(KEY_V, bind_video     , NULL, "Video stream toggle");
+  app_registerKeybind(KEY_D, bind_showFPS   , NULL, "FPS display toggle");
   app_registerKeybind(KEY_R, bind_rotate    , NULL, "Rotate the output clockwise by 90° increments");
   app_registerKeybind(KEY_Q, bind_quit      , NULL, "Quit");
 

client/src/main.c

@@ -104,6 +104,8 @@ static int renderThread(void * unused)
     return 1;
   }
 
+  g_state.lgr->on_show_fps(g_state.lgrData, g_state.showFPS);
+
   /* signal to other threads that the renderer is ready */
   lgSignalEvent(e_startup);
 
@@ -131,7 +133,7 @@ static int renderThread(void * unused)
     if (!g_state.lgr->render(g_state.lgrData, g_params.winRotate))
       break;
 
-    if (g_params.showFPS)
+    if (g_state.showFPS)
     {
       const uint64_t t    = nanotime();
       g_state.renderTime   += t - g_state.lastFrameTime;
@@ -629,6 +631,8 @@ static int lg_run(void)
        if (g_cursor.sens < -9) g_cursor.sens = -9;
   else if (g_cursor.sens >  9) g_cursor.sens =  9;
 
+  g_state.showFPS = g_params.showFPS;
+
   // search for the best displayserver ops to use
   for(int i = 0; i < LG_DISPLAYSERVER_COUNT; ++i)
     if (LG_DisplayServers[i]->probe())
@@ -693,7 +697,6 @@ static int lg_run(void)
   // select and init a renderer
   bool needsOpenGL;
   LG_RendererParams lgrParams;
-  lgrParams.showFPS     = g_params.showFPS;
   lgrParams.quickSplash = g_params.quickSplash;
 
   if (g_params.forceRenderer)

client/src/main.h

@@ -47,6 +47,7 @@ struct AppState
 
   bool                 stopVideo;
   bool                 ignoreInput;
+  bool                 showFPS;
   bool                 escapeActive;
   int                  escapeAction;
   KeybindHandle        bindings[KEY_MAX];