Add touch support

To handle touch input events, read the array motionEvents in your game loop. These contain events that have happened since the last time these arrays were cleared. The number of events contained is stored in motionEventsCount.

1. Iterate and handle each event in your game loop. In this example, the following code iterates motionEvents and handles them via handle_event:

   for(size_t i = 0; i < mApp->motionEventsCount; ++i) {
     GameActivityMotionEvent* motionEvent = mApp->motionEvents[i];
   
     int action = motionEvent->action;
     int actionMasked = action & AMOTION_EVENT_ACTION_MASK;
     int ptrIndex = (action & AMOTION_EVENT_ACTION_POINTER_INDEX_MASK) >>
       AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
   
     struct CookedEvent ev;
     memset(&ev, 0, sizeof(ev));
   
     if (actionMasked == AMOTION_EVENT_ACTION_DOWN ||
       actionMasked == AMOTION_EVENT_ACTION_POINTER_DOWN) {
         ev.type = COOKED_EVENT_TYPE_POINTER_DOWN;
     } else if (actionMasked == AMOTION_EVENT_ACTION_UP ||
       actionMasked == AMOTION_EVENT_ACTION_POINTER_UP) {
         ev.type = COOKED_EVENT_TYPE_POINTER_UP;
     } else {
         ev.type = COOKED_EVENT_TYPE_POINTER_MOVE;
     }
   
     ev.motionPointerId = motionEvent->pointers[ptrIndex].id;
     ev.motionIsOnScreen = motionEvent->source == AINPUT_SOURCE_TOUCHSCREEN;
     ev.motionX = GameActivityPointerInfo_getX(
       &motionEvent->pointers[ptrIndex]);
     ev.motionY = GameActivityPointerInfo_getY(
       &motionEvent->pointers[ptrIndex]);
   
     if (ev.motionIsOnScreen) {
       // Use screen size as the motion range.
       ev.motionMinX = 0.0f;
       ev.motionMaxX = SceneManager::GetInstance()->GetScreenWidth();
       ev.motionMinY = 0.0f;
       ev.motionMaxY = SceneManager::GetInstance()->GetScreenHeight();
     }
   
     handle_event(&ev);
   }
   

2. When you are done, remember to clear the queue of events that you have just handled:

   android_app_clear_motion_events(mApp);