What does this code do, and is there anything wrong with it?

unsigned char somebody_elses_function(void)
{
  static unsigned int max_fast_vrect = 0;
  static unsigned int min_fast_vrect = 0;
  static unsigned int last_fast_vrect = 0;
  static signed char slope = 0;
  unsigned int fast_vrect = get_adc( VRECT_FAST );

  if(slope > 0)
  {
  if(fast_vrect <= last_fast_vrect)
  {
  if(slope++ > VRECT_SLOPE_DEBOUNCE)
  {
  slope = -1;
  max_fast_vrect = last_fast_vrect;
  }
  }
  else
  {
  last_fast_vrect = fast_vrect;
  }
  }
  else if(slope < 0)
  {
  if(fast_vrect >= last_fast_vrect)
  {
  if(slope-- < -VRECT_SLOPE_DEBOUNCE)
  {
  slope = 1;
  min_fast_vrect = last_fast_vrect;
  }
  }
  else
  {
  last_fast_vrect = fast_vrect;
  }
  }
  else
  {
  slope = 1;
  }

  if((min_fast_vrect >= max_fast_vrect) ||
  (max_fast_vrect < MIN_V_RECT) ||
  ((max_fast_vrect - min_fast_vrect) <= (max_fast_vrect + min_fast_vrect) >> (1+2))
  )
  {
  return TRUE;
  }

  return FALSE;
 
 
 

我没看懂，请高手指点一下啊！