added isInitialized

src/glow/glow.cc

@@ -91,3 +91,5 @@ void glow::checkValidGLOW()
         glow::error() << "ERROR: GLOW is not initialized OR called from wrong thread.";
 }
 #endif
+
+bool glow::isInitialized() { return _isGlowInitialized; }

src/glow/glow.hh

@@ -22,6 +22,9 @@ extern struct _glowGLVersion
  */
 bool initGLOW();
 
+/// returns true if glow is initialized in this thread
+bool isInitialized();
+
 /// Asserts that glow is initialized
 /// Fails if not initialized OR wrong thread
 #ifdef GLOW_PERFORM_VALIDATION