Better Outrun port for Amiga

[ReadOnlyCat]

Originally Posted by DisposableHero

Not sure how much memory having the full graphics implemented would take, but using a 14Mhz processor to emulate 2 10Mhz ones and a 3.54 (presumably) Z80 sounds like a big ask, even with fastram. Lotus 2 shows the limits of this type of game on the A500, and the scenery is nowhere near as complex as arcade OutRun.

It is definitely possible to improve upon what Lotus 3 does.
For example, it uses two bitplanes for the road + grass + stripes when it should be possible to use only one by taking advantage of the copper to change the background color at the grass/road boundaries.
(The game is 16 colors so the copper can be pixel precise.)

I am fairly sure that if you dig in other areas, you will find quite a bit more to improve upon.
There is no doubt that Shaun Southern was a very good Amiga coder but he was working under time pressure and probably did not have much room to experiment.

Update:

Originally Posted by saimon69

@vulture
that guy is me, and i remember Lotus III mountain level damn slow in my 500 1.2 1 meg (that i have in europe) so unless the version i had was a beta and then the final version did run smoother had no clue...

(should not be a factor but i also used to play with music on)

Actually, this is a good point to mention, music could indeed be an aggravating factor.

Even the best music routines will consume a few scanlines per VBL so if the game is barely managing to draw all elements under one frame then the added cost of a music routine could push it over the edge and cause the slowdowns you remember.

Playing a few motor or crash sound effects costs on the other hand costs much less in terms of CPU (a few scanlines every second at most).

I think I have a copy of Lotus III around, I will give it a try this week. I need to get my hands on a trainer though otherwise I will never see that stage.

[vulture]

Lotus 3 stage codes here:

http://www.lemonamiga.com/games/cheats.php?id=700

[ReadOnlyCat]

Originally Posted by vulture

Lotus 3 stage codes here:
http://www.lemonamiga.com/games/cheats.php?id=700

Thanks.

I just tried Lotus 3 on my 500+ and I could not see any difference in smoothness with the Mountain level when switching between sound effects and music. And in both cases, although the frame rate was not smooth it was about the same than in the other levels.

However, it was quite a while since I had last played Lotus 3 and I must admit that I was less than impressed overall by the game fluidity, so much that I actually had to try Lotus 1 and 2 in order to verify if my memory of the series was flawed or if it was indeed only Lotus 3 which was failing in the frame rate department.
And it is pretty clear that indeed it is failing, the 1 and 2 versions are much more smoother which clearly results in much more pleasant feeling of control when driving the car left and right across the track.

In any case, the conclusion is that I was not able to notice any slowdown on a regular A500+ on the mountain level. Maybe it occurs only when playing on NTSC machines? If the game was designed for PAL machines it is possible that in 60Hz mode it does not have enough time to render the mountain road before two 30Hz frames are elapsed. (I was running in PAL mode.)

However, I noticed is that the low frame rate of the game is visually more apparent in that particular level than in the others. I assume that the very large rocks on the mountain side of the road occupy such a large surface on the screen that their jerky update (because of the low frame rate) is much more visible than that of the smaller objects which are usually drawn on the sides of the road.

It is not very obvious to me why Magnetic Fields decided to go with a lower frame rate when overall the game does not really look that much different from the second opus of the series. Maybe they wanted to keep the frame rate constant across levels so they set it to that of the slowest level (the mountain road) but given that this has so much negative influence on the reactivity of the game and the smoothness of the experience this would not seem to be a very good idea.

Add to that the fact that the checkerboard pattern coupled with the low frame rate often causes the road to flicker rather than scroll toward the player and the reason why they opted for that frame rate becomes even more mysterious.

Also:

Originally Posted by ReadOnlyCat

It is definitely possible to improve upon what Lotus 3 does.
For example, it uses two bitplanes for the road + grass + stripes when it should be possible to use only one by taking advantage of the copper to change the background color at the grass/road boundaries.
(The game is 16 colors so the copper can be pixel precise.)

One important thing to note in addition to the fact that Lotus uses two bitplanes for the road + sides is that it does not use hardware scrolling to modify the curve of the road. Which means that it has to redraw that curve every frame when a hardware scrolling solution would require no redrawing of the road at all: only a bit of left/right scroll per line and some colour cycling.

Using hardware scrolling to modify the curve of the road forces to draw line by line all the bobs which overlap the road, at least for the two bitplanes used by the road and roadside, but this might be worth it.

[vulture]

@ReadOnlyCat

thx for taking the time to test it m8!

edit
iirc, on ntsc it runs smoother and faster, not only on my A1200, but on an A500 running it (jupiter stage) at an expo. Dunno how the mountain stage in particular would be affected though.

[vulture]

ok, so, I had some spare time today and brought a friend's A500 home. Now, he didn't have Lotus 3 to try and I no longer have games on floppies, but he had Jaguar. So, I searched for cheats to visit various stages and stumbled upon this:

"Faster scenery:
Enter the sound selection screen, select the sound effects option, and choose radio. The scenery will appear at twice the normal speed while your car remains at its normal speed. "

So, the friend's miggy also has a mod to switch between 50 and 60hz and sure enough we chose 60 hz. And we thought, after we finished the english tracks, let's get to the greek tracks. The result was rapid and the video doesn't really do it justice as it's an old mobile and makes it look choppy while it's perfectly smooth, not to mention that I play with one hand while recording with the other. I don't think I've seen anything like it on an Amiga game before and there are those tall rocks at both sides of the road and it still doesn't slow down or drop frames! The gfx art isn't quite as good as Lotus', but still!

So, here's my crappy vid of it:

[ Show youtube player ]

[Schlachtwerk]

http://www.extentofthejam.com/pseudo/

http://codeincomplete.com/posts/2012...ascript_racer/

[Toni Galvez]

Hello folks,

Outrun on arcade runs at 30 FPS (PAL is 25). Then, you have 2 VBlank time to do all the things.

I should focus on a Amiga 500 version, not to make the game exactly like the arcade, but much better than the USGold shit.

- I should use a 4 bitplanes (16 colors)+copperlist for the sky(ingame parts). There is some good 16 colors generic palettes out there http://wayofthepixel.net/index.php?topic=4306.10
- I should reduce the graphics to 80% size.
- I should use 32 or 64EHB for non ingame parts.
- For the sound, I should use 3 channels module+SFX(engine noise and crash sounds) on the free channel.

No one mentioned the Outrun Europe game for Amiga, I think is a very good game, there is a lot of road objects and moves very fast (much faster than AtariST version) [ Show youtube player ].

Well, that's my point of view.

[Amiga1992]

Outrun with smaller graphics might not be a bad idea. I always liked this port:
[ Show youtube player ]

[eXeler0]

Id like to think the A500 could do a little better than the Master System? ;-)

[Amiga1992]

Originally Posted by eXeler0

Id like to think the A500 could do a little better than the Master System? ;-)

That's a nice thought but we would need to see proof, which I really haven't

[eXeler0]

Originally Posted by Akira

That's a nice thought but we would need to see proof, which I really haven't

By looking at the original Amiga port, I'd tend to agree
Seriously though, the hardware in the Master System is basically the same tech used in ColecoVision in 1982. The Texas Instruments TMS9928A (Coleco used the 9918 variant) does not handle large sprites well.. Also, the MS has 16KB video RAM (and 8k RAM)..
From that perspective, the OutRun port was impressive, but as a remake that aims to prove that the Amiga can do better than the original port, I think we could handle "proper size" as seen in the Arcade version...

[ReadOnlyCat]

Originally Posted by Akira

Outrun with smaller graphics might not be a bad idea. I always liked this port:
[ Show youtube player ]

It is indeed a really nice port.
They made sure to take the limitations of the Master System into account and it shows because the game is first and foremost playable.
Note that the road is updated in a similar way to the arcade version (cf my further comments below): the frequency at which the stripes are scrolled is much higher than the one at which the road geometry and scenery objects are updated.

Originally Posted by Toni Galvez

Hello folks,
Outrun on arcade runs at 30 FPS (PAL is 25). Then, you have 2 VBlank time to do all the things.

To be more precise it runs both at 30 FPS and 60.
The road is updated at 60 FPS but the rest of the scenery and objects (essentially all sprites) are updated at 30 FPS.

This is probably what contributes most to create Outrun's great impression of speed.

The Saturn version has a full 60 FPS mode which can be activated by a cheat. I have to admit though that it is not always strikingly better, maybe it was my TV but although I can notice the difference when switching modes, it is not obvious to me which mode I am in if I come back to the game after a pause.

Originally Posted by Toni Galvez

- For the sound, I should use 3 channels module+SFX(engine noise and crash sounds) on the free channel.

A good engine sound requires more than one channel, I would not be surprised if the arcade used more than two. It is generally a good idea to allow sound fx to steal less important channels from the music (drums or bass for example but not the melody like Elite did on Space Harrier Amiga ).

[s2325]

New info with screenshots about unfinished Out Run game http://www.atarimania.com/game-atari...opa_30270.html

[saimon69]

@s2325

Just hope they were not going to use the same engine used on the first outrun,that was not too good even for ST standards :/

[saimon69]

However, was talking couple of days ago with someone on FB (forgot its nick here) and cultivating the feasibility of a mixed tesselate/sprite engine to accelerate things (purely brainstorming but if something can come out of this is not a bad thing) similar to the PC-engine version

[ReadOnlyCat]

Originally Posted by saimon69

However, was talking couple of days ago with someone on FB (forgot its nick here) and cultivating the feasibility of a mixed tesselate/sprite engine to accelerate things (purely brainstorming but if something can come out of this is not a bad thing) similar to the PC-engine version

What do you mean by "tesselate" engine?

[eXeler0]

Originally Posted by ReadOnlyCat

What do you mean by "tesselate" engine?

Probably means sprite scaling by 50% for each iteration..

[saimon69]

Actually i mean using the grid in a similar way c64 and other 8-bit machines uses characters on in example Space Harrier and Turbo Outrun for street and for big elements; might result a bit choppy but for sure faster than move sprites - that can be used for cars and closer instances

[kamelito]

It could be improved by using techniques found in Vroom and Unreal (flight level).
Kamelito

[ReadOnlyCat]

Originally Posted by saimon69

Actually i mean using the grid in a similar way c64 and other 8-bit machines uses characters on in example Space Harrier and Turbo Outrun for street and for big elements; might result a bit choppy but for sure faster than move sprites - that can be used for cars and closer instances

Ah, oki, you mean tiled graphics I suppose.

The C64 and 8/16/32 bits consoles (except the PS1) have tiled graphic modes but the Amiga does not so I'm not sure using tiles as the unit of display (I mean copying the road tile by tile) would help performance wise. I would not exclude it though but managing the road raster scanline by scanline seems more flexible and appealing to my inner kitten.