docs: public void handleTouchEvent(MotionEvent ev){
          if(ev.getAction() == MotionEvent.ACTION_MOVE){
              // A finger is dragging about
              if(mTexHeight != 0 && mTexWidth != 0){
                  mSummedTouchPosition[0] += (2 * (ev.getX() - mLastTouchPosition[0])) / mTexWidth;
                  mSummedTouchPosition[1] += (2 * (ev.getY() - mLastTouchPosition[1])) / -mTexHeight;
                  mLastTouchPosition[0] = ev.getX();
                  mLastTouchPosition[1] = ev.getY();
              }
          }else if(ev.getAction() == MotionEvent.ACTION_DOWN){
              // The primary finger has landed
              mLastTouchPosition[0] = ev.getX();
              mLastTouchPosition[1] = ev.getY();
          }
      }