Working on UI improvement

src/Game.h

@@ -87,6 +87,11 @@ namespace ZL {
 		float pinchStartDistance = 0.0f;
 		float pinchStartZoom = 0.0f;
 
+		// Tutorial: azimuth and inclination captured at the start of each camera drag,
+		// used to measure how far the user has rotated before advancing the tutorial step.
+		float dragStartAzimuth = 0.0f;
+		float dragStartInclination = 0.0f;
+
 		std::unique_ptr<AudioPlayerAsync> audioPlayer;
 
 		int64_t getSyncTimeMs();