[Ohrrpgce] SVN: james/8832 A* Pathfinding now caches NPC locations in an NPCCollisionCache object

[Ralph Versteegen]

At this point, I'm having trouble speeding up pathfinding any further. The
main obvious remaining step I see is to split up AStarNode into two UDTs.
Profiling (see attachment) shows time is spent fairly evenly all over the
place, largely in functions where it's hard to see any alternative way to
write the function.

As for differences between different builds, here's a benchmark: I
commented out "npcmove_walk_ahead(npci)" in npcmove_pathfinding_chase after
calculating the path so the npcs never move, run with --runfast -z 1, and
then go to the 100 npc map and don't move. (Note that this means the NPCs
attempt to repath every tick, except those in the interior, which is most
of them.)

debug=2 gengcc=0: 34fps
debug=0 gengcc=0: 122fps
debug=0 gengcc=1: 195fps
debug=0 gengcc=1 arch=64: 245fps
(If I don't comment out that line, and instead run around with F11 enabled,
I get ~500fps)

On 9 June 2017 at 18:02, Ralph Versteegen <teeemcee at gmail.com> wrote:

> This makes a big difference!
> Amazingly pathfinding seems to be almost 10x faster if you compile with
> debug=0; the 100 NPC map only takes about 20% CPU time for me in that case,
> even without gengcc. I'm rather shocked that the difference is that much,
> since gengcc only adds overhead on each function call and pointer access,
> but there aren't that many of those.
>
> I found another profiling tool I'd installed on my system, oprofile. This
> one is very fancy indeed, it can simultaneously profile the whole system.
> Anyway, it shows that all the runtime is inside fb_TlsGetCtx and
> libpthread. I didn't realise that the -exx overhead when you call a
> function (calls to fb_ErrorSetFuncName and fb_ErrorSetFuncName) store the
> current function name in thread local storage.
>
> On 9 June 2017 at 07:34, James Paige <Bob at hamsterrepublic.com> wrote:
>
>> Now the 100 npc map runs *almost* completely smoothly on my computer.
>>
>> On Thu, Jun 8, 2017 at 12:33 PM, <subversion at hamsterrepublic.com> wrote:
>>
>>> james
>>> 2017-06-08 12:33:51 -0700 (Thu, 08 Jun 2017)
>>> 195
>>> A* Pathfinding now caches NPC locations in an NPCCollisionCache object
>>> which is used for the whole pathfinding operation, rather that looping
>>> over every npc on every pathfinding collision check.
>>> ---
>>> U   wip/game.bas
>>> U   wip/game.bi
>>> U   wip/game_udts.bi
>>> U   wip/pathfinding.bas
>>> U   wip/pathfinding.bi
>>> U   wip/testgame/a-star.hss
>>> U   wip/testgame/a-star.rpg
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>>
>>
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