Dual Playfield - Was it avoided because of speed or colors or something else?

[AestheticDebris]

Originally Posted by eXeler0

Can I go slightly off topic here. I can see that BC racers is using the new ”mode 7”-esque graphics mode that was only available on the Mega-CD add on and Later the 32X.
Market reception for those wasnt exactly great and also, the game was released before the 32x came out, so what was the marketing strategy there. Seems MegaCD wasnt a great large market to aim for?
Any memories of what was said at the time?

I think the appeal of CD games, at the time, was believed to be FMV games and so that's where a lot of the focus seemed to be. I don't remember much being made of the scaling and rotation capability, but then it probably seemed a bit "me too" seeming like you had to buy a whole add on just to be able to do what the SNES could out of the box. Not really an impression they'd have been keen on given the "Genesis does what Nintendon't" mentality.

Of course the general public looked at FMV games, gave a collective sigh and decided to spend their money elsewhere. Because existing games were a lot more fun than grainy, low resolution video full of bad actors and terrible dialog, made by games developers who thought they'd make great movie directors.

[lmimmfn]

Originally Posted by Tigerskunk

You are thinking too complicated, my friend..
With this little trick, you just blit into the background instead of the foreground layer, and use its colors. The trick is to make it look like the object is belonging to the foreground.
But if you watch my video, you will see that the blue enemies are always behind the other ones.

If you for instance only use 4 colors in the background, you have 4 independent colors for spare that way.
Can make a huge difference in a Dual Playfield game.

Maybe I'm just dumb mate , trying to understand, if you have 3 bit/8 colour bitplane in the background and another 3bit/8 colour in the foreground then that gives max of 16 colours, however the full 32 colours can be used if you blit, is that correct? And curious why wouldn't half brite be available in that scenario? Maybe it is but too slow to blit.

I'm still getting my head around your video as I'm just thinking in binary and hoe the planes are split, but I do understand you could get extra colours if e.g. all 3 planes in background are 1 and foreground planes are all 2 but the extra colours would only be available on colour overlap between background and foreground?

[AestheticDebris]

Originally Posted by lmimmfn

Maybe I'm just dumb mate , trying to understand, if you have 3 bit/8 colour bitplane in the background and another 3bit/8 colour in the foreground then that gives max of 16 colours, however the full 32 colours can be used if you blit, is that correct? And curious why wouldn't half brite be available in that scenario? Maybe it is but too slow to blit.

I'm still getting my head around your video as I'm just thinking in binary and hoe the planes are split, but I do understand you could get extra colours if e.g. all 3 planes in background are 1 and foreground planes are all 2 but the extra colours would only be available on colour overlap between background and foreground?

In dual playfield mode you can have 8 background colours and 8 foreground colours. But what you could do is draw some of the supposedly "foreground" enemies in the "background" layer, giving the impression of more foreground colours. That's what you see in the video. I suspect it is of dubious benefits though, you'd probably be better off without DP at all and just work with less bitplanes and more colours.

Blitting doesn't get you any extra colours, that's entirely determined by the number of bitplanes (copper changes notwithstanding). As to EHB, that's just a way of using the sixth bitplane since there are only 32 colour registers and 6 bitplanes gives 64 combinations, you don't need that in dual playfield mode since each playfield has at most 8 colours so you never need more than 16 colour registers.

[jotd]

if you don't use hardware sprites (possibly multiplexed) with a completely different set of colors in a DPF mode it really looks dull.

[DanScott]

Originally Posted by AestheticDebris

In dual playfield mode you can have 8 background colours and 8 foreground colours.

Effectively 7 colours per playfield, as colour 0 is transparent for each playfield.

Assuming you have a black background (you don't have to, but 99% of the time you probably will), then you effectively have 7 colours + black for your back playfield, and 7 for the foreground.

[Retro1234]

And that's why its not used - Unless you're some kind of Graphical Genius like Leander and KidChaos it will look like something from a Spectrum.

[aros-sg]

You can have 15 colors BOBs in dual playfield if you blit in both playfields. Needing to blit 3+3 = 6 planes for this maybe means you would not want to do this for each and every object, but only for some. Or maybe just parts of the objects. Like if object is 32x32 have an addtional 16x16 ~overlay ~sub bob in the front playfield to add a bit more color to it.

[AestheticDebris]

Originally Posted by aros-sg

You can have 15 colors BOBs in dual playfield if you blit in both playfields. Needing to blit 3+3 = 6 planes for this maybe means you would not want to do this for each and every object, but only for some. Or maybe just parts of the objects. Like if object is 32x32 have an addtional 16x16 ~overlay ~sub bob in the front playfield to add a bit more color to it.

At that point though you're largely undermining the benefits of dual playfield, because you're having to preserve backgrounds etc on both layers and blit to 6 bitplanes to get 5 bitplanes worth of colour.

[jotd]

I used that mode for my Scramble remake and it was damn good to work with.

I had to use some dynamic colors for status & fuel (were on the top and bottom so it was ok) but then background tiles completely independent from foreground bobs:

- brutal blits for foreground bobs
- scrolling only for background.

it went smooth, but it's from a 1981 game. I couldn't believe that they used that for Leander (basically for the same performance reason, this time on the collision level) and yet it looks so great (and that's also because the main character is a sprite with a different palette so it looks like 32 colors)

[sokolovic]

Originally Posted by Retro1234

And that's why its not used - Unless you're some kind of Graphical Genius like Leander and KidChaos it will look like something from a Spectrum.

Mmmm...
Au contraire, I remember this mode to be widely used. Lionheart, Shadow of the Beast, Worms, Mr Nutz, Shadow Fighter... There are many games graphically and technically praised that use it.

[jotd]

You're forgetting Jim Power

Really not sure about Shadow Fighter. There are really a lot of colors on the characters, and that's not possible/very difficult with dynamic color change, as opposed to the background where you can do whatever you want.

Fatal Noise uses EHB for instance. Isn't Shadow Fighter EHB as well?? got to check.

[sokolovic]

Originally Posted by jotd

You're forgetting Jim Power

Really not sure about Shadow Fighter. There are really a lot of colors on the characters, and that's not possible/very difficult with dynamic color change, as opposed to the background where you can do whatever you want.

Fatal Noise uses EHB for instance. Isn't Shadow Fighter EHB as well?? got to check.

That's why the "..." was here !

Shadow Fighter use dual playfield see here (pp24, 25, 26):
https://amr.abime.net/issue_359

[Retro1234]

Ok Ok, but it's not an easy task - Especially when it comes to something like a 16bit style Co-Op conversion. 7 colours! come on it's pants.

[saimon69]

Sometimes ago i did a proof of concept of conversion for the Street Fighter 1 port of msmalik681 from arcade asset to 7 colors, and i did reach a 6 fixed colors set-plus one changing according to the fighter (the bright green); i do expect Shadow Fighter OCS/ECS to act accordingly - or maybe to have a second set with a different color

[sokolovic]

Originally Posted by Retro1234

Ok Ok, but it's not an easy task - Especially when it comes to something like a 16bit style Co-Op conversion. 7 colours! come on it's pants.

That's why most of the best games that use dual playfield are Amiga exclusive (Lionheart, Kid Chaos, Shadow Fighter, Mr Nutz) or originals (Worms, Beast, Jim Power, Leander). They were designed from the ground around this limitation.

Saimon69, nice result. Check the amr link I've posted above, I believe the Shadow Fighter artist explain how he has done.

[7-Zark-7]

If you look up the earlier game diary entries for Uridium II in The One Amiga, Andrew Braybrook touches on early in it's development working on a dual playfield version, but ended up dropping the idea in favour of the released 32 colour version.

He has mentioned on twitter in the past had the A1200 been more successful (with the focus on OCS/ECS Amigas),it's an idea he'd liked to have tinkered more with some extra colours/CPU power to play with.

Might be wrong,but did Soccer Kid/Arabian Knights from Krisalis use dual playfield?

[lionagony]

Originally Posted by 7-Zark-7

Might be wrong,but did Soccer Kid/Arabian Knights from Krisalis use dual playfield?

Soccer Kid definitely does. Arabian Knights the first level doesn't and I haven't yet played past that so I don't want to check a longplay and spoil it for myself

[DanScott]

Looking at the long play, Arabian nights seems to use dual playfield (certainly on the levels with parallax... Not enough sprites for it to be done with those)

[Jobbo]

Arabian Nights was excellent! It's dual-playfield everywhere even without the parallax.

That lets the main sprite sit in-between foreground and background tiles. It also makes it faster to restore the dirty rectangles for blank areas of the foreground. You also don't need to store/handle all the unique combinations of foreground and background tiles when dual-playfield is doing it for you so it saves memory and/or time.

It's a really nice engine and the game is really fun!

[DanScott]

Yeah does look good, and defo looks like it's pulling a few tricks here and there (perhaps some foreground and background palettes combined with double blitting some objects to both playfields to give the impression of more colours on some objects) ?