Opened 22 years ago

Closed 18 years ago

#215 closed defect (fixed)

FOA: Jerky movement in car chase

Reported by: SF/jbergstrom Owned by: Kirben
Priority: low Component: Engine: SCUMM
Version: Keywords:
Cc: Game: Indiana Jones 4

Description

ver. 0.2.0 devel(042002) English CD-talkie, Win32

When Indy rides a camel the camel doesn't move very smoothly, but with noticeably long steps. The same happens in the Monte Carlo car chase.

Ticket imported from: #551715. Ticket imported from: bugs/215.

Attachments (2)

atlantis.s11 (74.9 KB ) - added by eriktorbjorn 21 years ago.
Saved game right before the camel ride
atlantis.s12 (76.9 KB ) - added by eriktorbjorn 21 years ago.
Saved game right before the car chase

Download all attachments as: .zip

Change History (20)

comment:1 by SF/jackburton, 22 years ago

This is as the original worked, AFAIR.

comment:2 by SF/jbergstrom, 22 years ago

OK, the camel might be intended to move in steps but the cars really should move smoothly. In my original they do, at least.

comment:3 by fingolfin, 22 years ago

Summary: Jerky movement in overhead view actionsFOA: Jerky movement in overhead view actions

comment:4 by fingolfin, 22 years ago

Priority: normallow

comment:5 by fingolfin, 21 years ago

A late happy birthday to this bug report ;-)

comment:6 by fingolfin, 21 years ago

If you provide me with a save game just before the car race, I'll try to look into it.

by eriktorbjorn, 21 years ago

Attachment: atlantis.s11 added

Saved game right before the camel ride

by eriktorbjorn, 21 years ago

Attachment: atlantis.s12 added

Saved game right before the car chase

comment:7 by eriktorbjorn, 21 years ago

I made these two savegames with the latest CVS snapshot. Will they do?

comment:8 by fingolfin, 21 years ago

Just to clarify this: the camel ride is working perfectly fine. The scripts that control it only work on a very low resolution, and that's why the movement is jerky.

Sadly I can't load the car crash save game :-(

comment:9 by fingolfin, 21 years ago

Summary: FOA: Jerky movement in overhead view actionsFOA: Jerky movement in car chase

comment:10 by fingolfin, 21 years ago

Sadly, that second savegame does *not* work for me. It dies with an assertion: scumm/script.cpp:1185: failed assertion `idx < 5'

comment:11 by eriktorbjorn, 21 years ago

At least in the CD version, the car chase is in room 70. What happens if you skip to there with the debugger?

comment:12 by fingolfin, 21 years ago

That works quite well, thanks erik. Hm, the "walk speed" of the "indy car" is set to (10,5). Otherwise, the code looks pretty similiar to the desert chase (that is, there are some huge strings which essentially contain a description of the allowed paths for the car/camel, and the scripts parse those strings). It's a pity I can't use the original, it would be very nice to be able to exactly compare its behaviour to what we get.

comment:13 by SF/ender, 20 years ago

This is getting on to be a two year old bug. Has anybody managed to confirm that there actually IS a problem here, yet? :P

comment:14 by fingolfin, 20 years ago

Well, so far we mostly have what jbergstrom said. I have no way currently to check this with the original. So I dunno.

comment:15 by Kirben, 20 years ago

The problem still occurs, the cars are much more smoother in the original game. If you want to compare, use boot param 8888 in original game and ScummVM. To activate debug mode of original FOA: Skip introduction. Type 'shinymetal' without quotes Use 'CTRL d' to activate debug mode. Use 'CTRL l" to choose boot param. Enter 8888 Skip LA logo.

comment:16 by fingolfin, 20 years ago

AH thanks Kirben, very useful! That information combined with dosbox allowed me to experience the scene with the original engine and compare it directly to ScummVM (although dosbox isn't quite running FOA at 100% on my machine, but it's good enough).

Looking at this, it seems to me that our actor movement is actually OK -- the original is just as jerky. Only that in ScummVm this is far more noticable. That is, after each movement phase, there is a relatively long "standing" phase; so we have a small pause between each step, causing the jerky look & feel.

Not sure what is causing this... maybe our timing code needs some tweaking. <shrug>

comment:17 by fingolfin, 19 years ago

Another idea: Maybe a subtle difference with the walking code, in particular the _moving field and the waitForActor opcode is the cause.

Also, everything becomes smooth if I change the value "15" in ScummEngine::go to something a lot smaller. Of course then the rest of the game becomes faster (too fast; the 15 is an approximation for 1000/60, I think, turning jiffies/ticks, 1/60th of a second, into milliseconds).

Or if VAR_TIMER_NEXT had a smaller value (instead of the default 6) during the car chase scene, things would be smoother. But nothing in the scripts attempts such a thing.

comment:18 by Kirben, 18 years ago

Owner: set to Kirben
Resolution: fixed
Status: newclosed
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