> For 21% improvement (of the function's run time), get rid of the array
> introduced in Map.cpp:3889:
> /----
> --- Map.cpp.org 2007-09-04 05:20:41.000000000 +0200
> +++ Map.cpp.erk 2007-09-04 05:23:52.000000000 +0200
> @@ -3886,22 +3886,17 @@
> else
> xr=x+1;
>
> - Uint8 side[8];
> - side[0]=gradient[wyu+xl];
> - side[1]=gradient[wyu+x ];
> - side[2]=gradient[wyu+xr];
> -
> - side[3]=gradient[wy +xr];
> -
> - side[4]=gradient[wyd+xr];
> - side[5]=gradient[wyd+x ];
> - side[6]=gradient[wyd+xl];
> -
> - side[7]=gradient[wy +xl];
> -
> - for (int i=0; i<8; i++)
> - if (side[i]>max)
> - max=side[i];
> +#define UPDATE_MAX(xy) {Uint8 tmp = gradient[(xy)]; if (tmp>max) max=tmp;}
> + UPDATE_MAX(wyu+xl);
> + UPDATE_MAX(wyu+x );
> + UPDATE_MAX(wyu+xr);
> + UPDATE_MAX(wy +xr);
> + UPDATE_MAX(wyd+xr);
> + UPDATE_MAX(wyd+x );
> + UPDATE_MAX(wyd+xl);
> + UPDATE_MAX(wy +xl);
> +#undef UPDATE_MAX
> +
> assert(max);
> if (max==1)
> gradient[wy+x]=1;
> \----
>
> For further ~9% improvement, avoid copying a Case structure in
> Map.cpp:3369, still in updateLocalGradient():
> /----
> --- Map.cpp.org 2007-09-04 05:20:41.000000000 +0200
> +++ Map.cpp.erk 2007-09-04 05:28:23.000000000 +0200
> @@ -3366,7 +3366,7 @@
> for (int xl=0; xl<32; xl++)
> {
> int xg=(xl+posX-15)&wMask;
> - Case c=cases[wyg+xg];
> + Case& c=cases[wyg+xg];
> int addrl=wyl+xl;
> if (gradient[addrl]!=255)
> {
> \----
> (This happens at several other locations, by the way... the second-worst
> place in Map.cpp appears to be in Map::updateRessourcesGradient(), and
> it'might also be worth the attention :-)
Thank you, I have commited these fixes to the master branch.
> And another thing, now we're at reading code:
> A couple of places in Map::updateLocalGradient(), there is code like this:
> if (xxi<0)
> xxi=0;
> else if (xxi>31)
> xxi=31;
> if (yyi<0)
> yyi=0;
> else if (yyi>31)
> xxi=31; // <-- Shouldn't this be yyi??
> That last line does look like a typo (or more likely a copy'n'paste error?).
Looks like. nuage wrote them (rev 990 and 1093). Is he still around to comment?
-- marv
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