[PATCH 11/20] dix: rename a bunch of variables to be more self-explanatory

[Simon Thum]

On 04/20/2011 08:28 AM, Peter Hutterer wrote:
> i → used_offset
> iveloc → initial_velocity
> res → result
> vdiff → velocity_diff
> vfac → velocity_factor
> tmp → tracker_velocity
> 
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
>  dix/ptrveloc.c |   42 +++++++++++++++++++++++-------------------
>  1 files changed, 23 insertions(+), 19 deletions(-)
> 
> diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
> index 6fef0ee..9e1cf87 100644
> --- a/dix/ptrveloc.c
> +++ b/dix/ptrveloc.c
> @@ -590,13 +590,14 @@ CalcTracker(const MotionTracker *tracker, int cur_t){
>   */
>  static float
>  QueryTrackers(DeviceVelocityPtr vel, int cur_t){
> -    int offset, dir = UNDEFINED, i = -1, age_ms;
> +    int offset, dir = UNDEFINED, used_offset = -1, age_ms;
>      /* initial velocity: a low-offset, valid velocity */
> -    float iveloc = 0, res = 0, tmp, vdiff;
> -    float vfac =  vel->corr_mul * vel->const_acceleration; /* premultiply */
> +    float initial_velocity = 0, result = 0, velocity_diff;
> +    float velocity_factor =  vel->corr_mul * vel->const_acceleration; /* premultiply */
>      /* loop from current to older data */
>      for(offset = 1; offset < vel->num_tracker; offset++){
>  	MotionTracker *tracker = TRACKER(vel, offset);
> +	float tracker_velocity;
>  
>  	age_ms = cur_t - tracker->time;
>  
> @@ -620,42 +621,45 @@ QueryTrackers(DeviceVelocityPtr vel, int cur_t){
>  	    break;
>  	}
>  
> -	tmp = CalcTracker(tracker, cur_t) * vfac;
> +	tracker_velocity = CalcTracker(tracker, cur_t) * velocity_factor;
>  
> -	if ((iveloc == 0 || offset <= vel->initial_range) && tmp != 0) {
> +	if (tracker_velocity == 0)
> +	    continue;
> +
> +	if (initial_velocity == 0 || offset <= vel->initial_range) {
>  	    /* set initial velocity and result */
> -	    res = iveloc = tmp;
> -	    i = offset;
> -	} else if (iveloc != 0 && tmp != 0) {
> -	    vdiff = fabs(iveloc - tmp);
> -	    if (vdiff <= vel->max_diff ||
> -		vdiff/(iveloc + tmp) < vel->max_rel_diff) {
> +	    result = initial_velocity = tracker_velocity;
> +	    used_offset = offset;
> +	} else if (initial_velocity != 0) {
> +	    velocity_diff = fabs(initial_velocity - tracker_velocity);
> +	    if (velocity_diff <= vel->max_diff ||
> +		velocity_diff/(initial_velocity + tracker_velocity) < vel->max_rel_diff) {
>  		/* we're in range with the initial velocity,
>  		 * so this result is likely better
>  		 * (it contains more information). */
> -		res = tmp;
> -		i = offset;
> +		result = tracker_velocity;
> +		used_offset = offset;
>  	    }else{
>  		/* we're not in range, quit - it won't get better. */
>  		DebugAccelF("(dix prtacc) query: tracker too different:"
>  		            " old %2.2f initial %2.2f diff: %2.2f\n",
> -		            tmp, iveloc, vdiff);
> +		            tracker_velocity, initial_velocity, velocity_diff);
>  		break;
>  	    }
>  	}
>      }
>      if(offset == vel->num_tracker){
>  	DebugAccelF("(dix prtacc) query: last tracker in effect\n");
> -	i = vel->num_tracker-1;
> +	used_offset = vel->num_tracker-1;
>      }
> -    if(i>=0){
> +    if(used_offset >= 0){
>  #ifdef PTRACCEL_DEBUGGING
> -	MotionTracker *tracker = TRACKER(vel, i);
> +	MotionTracker *tracker = TRACKER(vel, used_offset);
>  	DebugAccelF("(dix prtacc) result: offset %i [dx: %i dy: %i diff: %i]\n",
> -	            i, tracker->dx, tracker->dy, cur_t - tracker->time);
> +	            used_offset, tracker->dx, tracker->dy, cur_t - tracker->time);
>  #endif
>      }
> -    return res;
> +    return result;
>  }
>  
>  #undef TRACKER_INDEX
Reviewed-by: Simon Thum <simon.thum at gmx.de>

Cheers,

Simon