Games that didn't scroll smoothly - why not?

[Retro-Nerd]

Originally Posted by oneshotdead

many games for me like that Ruff'n'Tumble game were / are unplayable to me due to choppy scrolling that makes me so nauseous that I need a bucket to vomit in like I'm sea-sick, regardless of any other accomplishment of the game.

It is a major turnoff, choppy scrolling - along with slowdowns.

Yeah, but Ruff'n Tumble, Gods, Wolfchild... are different. They have not really a jerky scrolling but a motion blur, caused by the 25 FPS. The human eye really needs 50 FPS in 2D games to prevent a sea-sickness.

[oneshotdead]

OK... but Bitmap Bros. games do not make me sea sick, like SB2, X2, Gods... I can play them all right.

I think the wavy scrolling in Ruff'n'Tumble is just awful, a wanna-be Neo Geo game.
Very overrated, by the way.

[Retro-Nerd]

Ruff'n Tumble has a much faster scrolling than Gods, that's the reason for your sea sickness. The faster the worser in 25 FPS.

[Calgor]

The intro of Dragons Breath does not scroll smoothly when it shows the castle while moving horizontally, despite it appearing quite simple. Am taking a pot shot it may be due to being coded in C - although I thought even screen size bitmaps could be scrolled smoothly in 16 colours lores in C on OCS. Maybe Galahad who did the 100% version can confirm if it was indeed coded in C?

[Galahad/FLT]

Originally Posted by Calgor

The intro of Dragons Breath does not scroll smoothly when it shows the castle while moving horizontally, despite it appearing quite simple. Am taking a pot shot it may be due to being coded in C - although I thought even screen size bitmaps could be scrolled smoothly in 16 colours lores in C on OCS. Maybe Galahad who did the 100% version can confirm if it was indeed coded in C?

Manx C

[dlfrsilver]

C pile of crap.... pffff the only interest to code in C is that it's hard to crack....
it's too slow...

[crabfists]

So, taking Ruff'n'Tumble as an example. On an A500 I imagine the game is running in 2 frames (?) so you've got n clock cycles free at each vertical blank. For argument lets imagine the game update loop takes 35ms. Running this on a 68030 at 50Mhz surely you'd be able to do the game update loop in well under 20ms (ie 1 frame)? In that case couldn't the game be fixed up to run flat out and fix the scrolling? I understand there may be lots of things to fix up like speed of objects in the game world would expect the game was updated at a certain interval. Would this be impossible? Has anybody tried this before?

[Codetapper]

The vertical blank interrupt is most likely using the blitter a lot and waiting for it to finish. The blitter is no faster on an 030 (in fact the code can run so fast that it ends up waiting a lot more eating up precious DMA cycles), so you will generally not see much of an improvement.

If Ruff'n'Tumble ran at a constant 25fps I doubt it would appear as jerky as it does, hence it's probably dropping a frame regularly or scrolling too many pixels at slow screen updates.

[crabfists]

Thought that it's possible it might be the something like that... I suppose it's that whole GPU vs CPU thing (to use modern terminology). If, like you describe, your game is "GPU bound" then I imagine that's not so simple to fix.

Theoretically though, if you used standard memory operations instead of the blitter wouldn't that help? Running on a 68030 with a faster clock rate would mean faster memory access wouldnt it?

[IFW]

Only if accessing for example on board memory.
chipram and rga bus use the same timing.

[alphonsus]

Forgive me for being dumb or missing the point, but why are people concerned with frame rates over 25FPS?
Movies, DVDs and TV's (PAL anyway) run at 25FPS and no-one complains about them being jerky.
The human eye's persistence of vision (hence POVray) is 24FPS, anything faster is processed by the brain to seem like fluid motion.
So faster framerates shouldn't matter, but lower ones definately will.

(and I know that the edges of peception can manage 30FPS, but who plays their games out of the corner of their eyes?)

[Retro-Nerd]

You can trick the human eye with a motion blur in movies, you consider the image as fluid with 18-25 FPS. But it annoys in 2D Computer games, full 50 FPS are smooth AND crisp in motion.

I'm no expert, but a movie uses two 25 FPS interlaced half-images in even/odd lines to show one second of film. How does it work in Computer games? The same way?

What's exactly the difference between 50 FPS games like Turrican and 25 FPS games like Gods or Wolfchild, in a technical/programmer aspect? Or use these games simply 2x12,5 FPS half-images to show 25 FPS?

[Toni Wilen]

Originally Posted by alphonsus

The human eye's persistence of vision (hence POVray) is 24FPS, anything faster is processed by the brain to seem like fluid motion.

False. Unfortunately this myth always pops up when talking about frame rates

(Difference between 25fps and 50fps is huge, just try any games listed above..)

I'm no expert, but a movie uses two 25 FPS interlaced half-images in even/odd lines to show one second of film. How does it work in Computer games? The same way?

What's exactly the difference between 50 FPS games like Turrican and 25 FPS games like Gods or Wolfchild, in a technical/programmer aspect? Or use these games simply 2x12,5 FPS half-images to show 25 FPS?

50 fps game: update screen, wait for vblank (if screen updating took too long = 25fps temporarily)

25 fps game: update screen, wait until 2 vblanks have passed since screen updating started.

= No difference except waiting method.. (of course this was very minimal example, doublebuffering, AI etc.. not included)

50FPS on PAL is basically "312p". It is "interlaced" but both odd and even frames have exactly same position and length.

C pile of crap.... pffff the only interest to code in C is that it's hard to crack....
it's too slow...

C isn't much slower than assembler if you know what are you doing and don't need special assembly tricks.

I am quite sure you can do 50fps Xenon 2 even in C. That was lazy coding..

[oneshotdead]

Xenon 2 at 50 FPS would be glorious.
But could a stock-standard A500 do that, what with the sprite sizes, sprite numbers, no. of colours on sprites etc.?

My intuition tells me "no." Maybe your rational brain tells you "yes".

If so, please cite a shmup that looks that good, has wave numbers like that, and runs at 50 FPS - on A500, and at that time.

I would like to play it.

[s2325]

Battle Squadron?

[Galahad/FLT]

Originally Posted by s2325

Battle Squadron?

I think the scrolling is 50 frames, but the enemies are 25 frames

[oneshotdead]

Didn't Battle Squadron come out like 3 years after X2?

[s2325]

no, both games are from 1989

[oneshotdead]

regardless, it does not look as good as X2. And it has slowdown issues, if I remember rightly.

[s2325]

Xenon 2 have not slowdown issues because it was always slow game