[PATCH 08/20] dix: use single return statement in DoGetDirection

[Peter Hutterer]

On Wed, Apr 20, 2011 at 11:26:54AM -0700, Jamey Sharp wrote:
> This code mixes spaces and tabs, which you might consider making
> consistent as long as you're changing almost every line of the function
> anyway.

I'll fix it up, thanks

> Also, it isn't obvious to me why you're so excited about using a single
> return statement in several of these patches. :-)

I think I got a bit overexcited :) But debugging code is a lot simpler when
there's only one line to put a printf in or break point on, not several.

Cheers,
  Peter

> On Wed, Apr 20, 2011 at 04:28:17PM +1000, Peter Hutterer wrote:
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> >  dix/ptrveloc.c |   87 ++++++++++++++++++++++++++++++-------------------------
> >  1 files changed, 47 insertions(+), 40 deletions(-)
> > 
> > diff --git a/dix/ptrveloc.c b/dix/ptrveloc.c
> > index c23d513..12c4067 100644
> > --- a/dix/ptrveloc.c
> > +++ b/dix/ptrveloc.c
> > @@ -453,54 +453,61 @@ enum directions {
> >   */
> >  static int
> >  DoGetDirection(int dx, int dy){
> > -    float r;
> > -    int i1, i2;
> > +    int dir = 0;
> > +
> >      /* on insignificant mickeys, flag 135 degrees */
> >      if(abs(dx) < 2 && abs(dy) < 2){
> >  	/* first check diagonal cases */
> >  	if(dx > 0 && dy > 0)
> > -	    return E | SE | S;
> > -	if(dx > 0 && dy < 0)
> > -	    return N | NE | E;
> > -	if(dx < 0 && dy < 0)
> > -	    return W | NW | N;
> > -	if(dx < 0 && dy > 0)
> > -	    return W | SW | S;
> > +	    dir = E | SE | S;
> > +	else if(dx > 0 && dy < 0)
> > +	    dir =  N | NE | E;
> > +	else if(dx < 0 && dy < 0)
> > +	    dir =  W | NW | N;
> > +	else if(dx < 0 && dy > 0)
> > +	    dir =  W | SW | S;
> >          /* check axis-aligned directions */
> > -	if(dx > 0)
> > -            return NE | E | SE;
> > -        if(dx < 0)
> > -            return NW | W | SW;
> > -        if(dy > 0)
> > -            return SE | S | SW;
> > -        if(dy < 0)
> > -            return NE | N | NW;
> > -        return UNDEFINED; /* shouldn't happen */
> > -    }
> > -    /* else, compute angle and set appropriate flags */
> > +	else if(dx > 0)
> > +            dir =  NE | E | SE;
> > +        else if(dx < 0)
> > +            dir =  NW | W | SW;
> > +        else if(dy > 0)
> > +            dir =  SE | S | SW;
> > +        else if(dy < 0)
> > +            dir =  NE | N | NW;
> > +        else
> > +            dir = UNDEFINED; /* shouldn't happen */
> > +    } else { /* compute angle and set appropriate flags */
> > +        float r;
> > +        int i1, i2;
> > +
> >  #ifdef _ISOC99_SOURCE
> > -    r = atan2f(dy, dx);
> > +        r = atan2f(dy, dx);
> >  #else
> > -    r = atan2(dy, dx);
> > +        r = atan2(dy, dx);
> >  #endif
> > -    /* find direction.
> > -     *
> > -     * Add 360° to avoid r become negative since C has no well-defined
> > -     * modulo for such cases. Then divide by 45° to get the octant number,
> > -     * e.g.     0 <= r <= 1 is [0-45]°
> > -     *          1 <= r <= 2 is [45-90]°
> > -     *          etc.
> > -     * But we add extra 90° to match up with our N, S, etc. defines up
> > -     * there, rest stays the same.
> > -     */
> > -    r = (r+(M_PI*2.5))/(M_PI/4);
> > -    /* this intends to flag 2 directions (45 degrees),
> > -     * except on very well-aligned mickeys. */
> > -    i1 = (int)(r+0.1) % 8;
> > -    i2 = (int)(r+0.9) % 8;
> > -    if(i1 < 0 || i1 > 7 || i2 < 0 || i2 > 7)
> > -	return UNDEFINED; /* shouldn't happen */
> > -    return 1 << i1 | 1 << i2;
> > +        /* find direction.
> > +         *
> > +         * Add 360° to avoid r become negative since C has no well-defined
> > +         * modulo for such cases. Then divide by 45° to get the octant
> > +         * number,  e.g.
> > +         *          0 <= r <= 1 is [0-45]°
> > +         *          1 <= r <= 2 is [45-90]°
> > +         *          etc.
> > +         * But we add extra 90° to match up with our N, S, etc. defines up
> > +         * there, rest stays the same.
> > +         */
> > +        r = (r+(M_PI*2.5))/(M_PI/4);
> > +        /* this intends to flag 2 directions (45 degrees),
> > +         * except on very well-aligned mickeys. */
> > +        i1 = (int)(r+0.1) % 8;
> > +        i2 = (int)(r+0.9) % 8;
> > +        if(i1 < 0 || i1 > 7 || i2 < 0 || i2 > 7)
> > +            dir = UNDEFINED; /* shouldn't happen */
> > +        else
> > +            dir = (1 << i1 | 1 << i2);
> > +    }
> > +    return dir;
> >  }
> >  
> >  #define DIRECTION_CACHE_RANGE 5
> > -- 
> > 1.7.4.4
> > 
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