destroy all textures on window destruction and restore OpenGL objects when Android resumes the app

engine/log.cpp

@@ -12,6 +12,9 @@ static size_t data_handler(void *contents, size_t size, size_t nmemb, void *user
 
 void LogRemote::start()
 {
+    if (m_running)
+        return; // already running
+
     m_running = true;
     m_thread = std::thread([&] {
         net_init();