Classic Amiga: Cool back layer trick in AMOS 

Amos is really easy to use and was phenomenally ahead of its time, but it's slow, even when compiled. A shame they never made Amos 3.0 with an updated compiler that translated to more optimised assembly. Blitz was quite a bit faster, but it was harder to use, so if Amos could have closed that gap between speed and convenience it would have been the best!

Yes, AMOS Pro was my first real IDE (after AmigaBASIC) to learn programming ;)

@@tomaszx7760 same here! Still using it for hobby projects.

@@nebularain3338 Even I could use it , did a half done Dungeon master like game which I feel sad I never completed because the the Harddrive died on me. (20 MB HD lol).

I started with GWBasic and then EasyAMOS followed by AMOS Pro and then finally Bitz Basic.

Thanks very much. :)

@@bitbeamcannon2468 always man. I’m actually a past Atari programmer who’s made 8 Atari games.

WHat are you talking about??? of course they were, with even more colors and tricks. Have you played: LionHeart, ElfMania, Ruff n Tumble????

I agree with both of you. There were games with great background effects on Amiga, but it's true that there could be more games using Amiga's capabilities. Unfortunately only few developers back in the day knew how to use Amiga's custom chips which were years ahead of anything else back then. Sometimes floppy medium was a bottleneck that required much more memory for the games compared to cartridge based consoles. That's why some ports of arcade and console games were rushed and mediocre. Some games needed optimizations in the engine to use Amiga's capabilities and optimizations for floppy medium. In most cases teams assigned to port games lacked time and knowledge about Amiga hardware to make a proper port.

Thank you and best of luck with your projects. Please subscribe if you've not already, because the next AMOS video will explain all the translucent effects in depth.

thanks.

You are not alone and I have a feeling this is a somewhat common tale. Fortunately now coding is great fun!

Thanks very much.

Thanks very much!

Thanks very much. :)

Thanks very much.

Thanks for watching!

Thanks very much. Have you seen our more recent videos about the game we started using Scorpion Engine? With much easier use (for non-programmers like us), more hardware banging features readily available for cool parallax and translucent effects, and the ability to make games for Megadrive as well, Scorpion Engine is now our de facto retro game authoring tool of choice.

It can not. This sample is just a "trick", unusable for a real game

Thanks very much for watching. We're glad you liked it!

Thanks very much!

Thanks very much.

Thanks very much

Your welcome :)@@bitbeamcannon2468 I love pixel art over any other form of art in the world, I have dabble in some myself but I am only learning.

I forgot to mention that there is also a memory cost: the mask is the exact same size as the background image so this would double the background memory requirements. Again, in some levels this may be an acceptable compromise. Cheers!

Some emulator settings are able to compensate for that, including by forcing a black border or making the low res screen take up the full screen instead of having a border, BUT the copper color changes only show up on the external borders of the screen if you are changing color zero, as you see in the video, I'm not changing color zero, so even on a real Amiga the borders stay nice and black. However, there was a programming trick that ECS Amiga's was capable of that could revert the color back to black on the edges, but I don't think AMOS was capable of that.

@@bitbeamcannon2468 Thanks Mike!.

@@AmitenTV You're very welcome.

Hi, The Amiga had a co-processor they called the copper chip which could do many things including change the RGB value of color indexes "during a vertical blanking gap" (basically each time the computer was done drawing each row of pixels and ready to move onto the next row of pixels to create the screen image). In this way you could trick the Amiga to display things like gradients using only one color index, by changing the color it displays at any give full row of pixels. AMOS has a "Rainbow" command which lets you control what RGB value any given color index displays at any vertical coordinate. I created a separate too program in AMOS to analyze a guide image I made and reproduce the gradient (with horizontal lines and all) as AMOS compliant Rainbow instructions... in other words I made code in Amos which generates more code in Amos ;) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VMADU2BVihY.html&ab_channel=BitBeamCannon

@@bitbeamcannon2468 thanks a lot for your very fast and detailed response!

There are ongoing efforts by different people and groups to make branch versions of Amos for full AGA support, editor/UI improvements, and making a windows executable that automatically opens Amos Pro on your PC in an emulated Amiga environment. Aside from that, if you don't care so much about specific ties to Amiga specifically (or Amos), there are incredible and easy to learn authoring systems out there ranging from Construct3 to Unreal Engine. I remember there had been people trying to make a literal port of Amos Basic to work and run and export for modern systems, but I'm not sure if they are still working on it, succeeded, or if it's abandonware. -Mike

Sorry, I don't know enough bout the SNES hardware, but presumablu the roadblock there would be blit speeds. While the SNEs has fantastic hardware for sprites and its existing tile based layers, I've never heard of it having anytihng dedidicated to blitting (drawing) to bit planes so if the main processor of the SNES had to it it, it would likely be extremely slow. The Amiga was specifically designed for fast blitting and planar graphics (full control of each bitplan independantly if desired) But I suggest talking to an experienced SNES developer. My guess is though you'd just be better off using the SNES's default hardware power as intended with I think up to 3 playfields whih would could independantly line scroll, and combined with some sprites, create the illusion of a great many layers of scrolling. You could also add in animated tiles to simulate other layers of scrolling.

@@bitbeamcannon2468 Yeah, it's up to four standard full-screen fully-overlapping layers that can all row/line scroll independently with varying colour depths depending on the background mode (four 2bpp layers with 24 visible colours per layer and 96 colours total for all backgrounds in Mode 0 for example), plus the standard up to 128 4bpp sprites with their own additional 120 visible colours as per usual (32 max sprites per scanline and 272 max sprite pixels per scanline). And there's some extra tricks that are possible by exploiting the high/low per-tile priority of each layer as well as the main/sub screens too for additional layering and parallax. So there's still plenty of scope there. But I was just curious about the bit-plane blitting thing as that sounded interesting too. Didn't think it would be an option on SNES to be honest, else I probably would have seen it mentioned elsewhere, but figured it was worth asking anyway just in case. :)

No, this does not use normal dual playfield mode. this is a single 16 color layer, using the blitter to blit the background layer in on every screen update. This puts some strong color limitations on the back layer and some on the front, but allows for some of the foreground and all objects to be 16 color bobs instead of 7 maximum which would be the case for OCS/ECS dual playfield mode.

This demo was made with Amos, and I had also made a SHMUP demo in AMOS, but the real DaemonClaw is currently not yet being developed for Amiga, BUT when it is made for Amiga we'll be using the same code base (and programmer) who's currently working with us to make Metro Siege, but the engine will be enhanced to support AGA specific hardware etc for DaemonClaw

A crazy amount, especially with a really strong programmer. Take a look at Metro Siege for example, which is a combination of C and Assembly, and runs great on OCS/ECS amigas.

I only used Brilliance in modern times to convert 256 color IFF images down to the proper IFF formats I needed for Amos. For making the pixel art in the first place I'd switched to Pro Motion NG on Windows based systems well over a decade ago. Back in the day I had originally used Dpaint for a couple of years before getting Brilliance and I just liked the interface and tool-set of Brilliance more.

@@bitbeamcannon2468 Ha ok cool. Thanks for your info. Can I ask other detail ? I ´m creating a very simple game with Amos Pro on Amiga 600. THe game is like Sorcery from cpc (I´m sure you know it) The fact is when I create a iff with deluxe paint, with the default palette, then I create the bob with DP4 also.. After this I go to Amos edit object and grab the iff to convert as Bob, and when I load iff and load Abk one of them lose colors... If I use get bob palette bobis correct but the background color change, if I don´t use get bob palette then bob is Ko and background Ok.. I think it´s because I have to use the same colors in both but it´s already the case (default both) What do you think ?

@@LuisDiaz-uu7xg They do indeed need to use the same exact color palette. Using the same colors is not enough, the colors must all be arranged in the same exact order in the palette, such as black for index zero etc.

@@bitbeamcannon2468 Wow ok, thanks for your help on this,I´ll try. have a nice week end

Not with Amos, as it does not support that at all... someone would have to completely replace the copper and sprite handling in Amos, likely with Assembly code for that, but with Scorpion Engine it's absolutely possible, but even with scorpion engine I think it's currently limited to using 3 color sprites for t he back layer. The great thing is though, due to Scorpion Engine's great use of the copper, you can have 4 totally unique colors per scan-line in the repeating sprite background and you can slice it up into segments which scroll at different speeds for some really AAA quality parallax effects. Have you seen our other project canned Aeon's Legend (AKA Scorpion Boy)?

@@bitbeamcannon2468 I'll check that out 👍

Emulator, but it was also tested on a Real Amiga.

No, not at all. it runs well on a standard A500 for example. You can download the demo and load it in Amos professional etc. bitbeamcannon.com/amiga/

Not yet. Our goal with the first few games is classic OCS.ECS compatibility. I think the progress being made on the AGA version of AMOS is awesome though, and I personally would love to eventually make an arcade style game which really shows off what AGA was really capable of, and in general I'm super glad the authoring systems are being developed and improved to empower people to make more and better games for Amiga. -Mike

you can use it in combination with dual playfield if that's what you mean, but since OCS/.ECS dual playfield is only 8 indexes per playfield it's a very big price to pay.

@@bitbeamcannon2468 So, one could use 2 colors for the fixed "BOB" background, 6 colors for the background playfield, 7 colors for the foreground playfield (that could be used exclusively for drawing enemies) and 16 colors for sprites, right?

@@ProfenixStudio Yes, BUT there is another severe color limit to the method, and that is, anywhere the BOB simulated back layer is drawn, you can't use half of the available colors in that portion of the layer or it will ruin the effect. I can't remember if it's the odd or even indexes you can't use, but only every other color index will properly seem opaque over the simulated back layer made with the special bob.

@@bitbeamcannon2468 you mean all the colors of the dual playfield or only the colors of the background playfield (where I draw the bob)? In other words, as in agony, in that portion I use one of the 3 bitplanes available for the background playfield, right?

@@ProfenixStudio The colors of the back playfield. The front playfiend would not be effected in any way.

I don't plan on building on top of this engine at the time. I made it public and open-source in hopes the community will build on top of it, optimize it, and continue to share it with others. I am and will be working on additional tools and examples. Have you watched our 'rainbow ripper tool' video yet?

You have a few options, but I highly recommend looking into Scorpion engine by Erik Hogan, which let's you develop a real retro game once and with some additional effort, export that game to real Megadrive, Amiga, Neo Geo, and the CD versions of those systems. You can also "wrap" those exported games in an emulator so to the actual end-user/player it just seems like any other windows .exe

@@bitbeamcannon2468 😮 so i could technically do this and put it in my own cabinet? wow. i have all that im just working in ue5.4... thanks for that info i use batocera and have used most of the frontend and emulators across the board. (pun intended) currently running a custom batocera plus build so i can play KI1 and 2 etc.. but also gotta have kodi and a full GUI ( i use that neonflash one)

@@Ready_Fire_Aim Yes, absolutely you could use it in any emulator or real consoles and NeoGeo arcade cabinet systems as well.

Thanks very much. Blitz is awesome but it was just all a matter of timing and convenience for me. I had already learned and began projects with Amos back then before I became aware of Blitz Basic. In other words, I greatly respect Blitz, but I'm not the right person to make any videos or tutorials about it.

AMOS had already garnered a massive following by the time Blitz was released.

OCS/ECS, but it would work the same if you used it on an AGA system. It should also be compatible with higher color-count AGA modes, but I've never tested it with any AGA extensions on AMOS,

Puoi scaricare il vero progetto Amos per questo dalla nostra pagina Amiga su bitbeamcannon.com/amiga/ Per assicurarci che potesse funzionare senza problemi con nemici ed effetti, ecc. abbiamo limitato gli aggiornamenti dello schermo (FPS) alla metà (quindi 25 per PAL e 30 per NTSC). Lo strato posteriore non è un doppio campo di gioco, utilizza una speciale modalità blitter per incollare un BOB a 2 colori sullo sfondo e il primo piano estremo è un altro schermo davanti allo schermo di gioco reale per il motivo dell'erba e gli sprite per gli alberi. To make sure it could run smoothly with enemies and effects etc. we capped the screen updates (FPS) to half (so 25 for PAL and 30 for NTSC). The back layer is not dual playfield, it's using a special blitter mode to paste a 2 color BOB into the background, and the extreme foreground is another screen in front of the real playing screen for the grass pattern and sprites for the trees. You can download the actual Amos project for this from our Amiga page at bitbeamcannon.com/amiga/ To make sure it could run smoothly with enemies and effects etc. we capped the screen updates (FPS) to half (so 25 for PAL and 30 for NTSC). The back layer is not dual playfield, it's using a special blitter mode to paste a 2 color BOB into the background, and the extreme foreground is another screen in front of the real playing screen for the grass pattern and sprites for the trees.

Yup. Made in Amos.. it runs smoothly at 25 FPS if I recall... It could likely run at 50/60 FPS if codded in Assembly

The mountain is actually blitted after the foreground is (right on top of it all) but before any characters or items, but because the the special blit setting telling it to only blit certain bit-planes, the mountain art doesn't effect the specific color registers that are used in that part of the foreground art. BTW, I picked up the terminology color indexes as a pixel artist, and not a PC programmer. I grew up with first an Adam Computer, them a C64, then Amigas, then finally Windows based PC. -cheers Mike

When spelling was artisanal.

Art is anal

Thanks. You can download the actual Amos project here: bitbeamcannon.com/amiga/ You can reuse the code however you'd like, but no one can use these graphics, so please replace them if you want to make your own game or demo.

Thanks for taking the time to comment, but how do you propose this wouldn't work in a real game? The foreground could be any kind of robust evolving tile map, and regarding the background being static, I wouldn't call that a 'cheat', but a compromise to get get a parallax effect within what is possible in AMOS. Mountains in the far distance actually would appear static unless you traveled very far horizontally in a level, so that only poses a problem if you want a different type of background like a stone wall that's also close to the player, in which case the repeating sprite trick (which AMOS can't do) would be a far better method for achieving that kind of parallax on OCS/ECS Amiga.

​@@bitbeamcannon2468 For the foreground (the forest), you open a 572-pixel-wide screen, within which you scroll using a "screen offset" function, that is fast because it change only the coper positioning of view in the memory. But to make a game with a real level design made up of dozens of screens to scroll through, you can't open a screen thousands of pixels wide, in particular with the 512Ko Chip Ram of the A500. This kind of scrolling use blitter operations, and it's not possible in Amos. To be perfectly honest, it's possible to do this kind of scrolling with a simple "screen offset", and a single screen twice the size of the screen, as some shoot 'em ups do, but it's rather limited in terms of scrolling possibilities. The idea is to prepare the playing field on the non-visible part of the screen on the left, little by little as the player moves to the right, copying next vertical offset lines as he goes on right, then returning to the first half of the screen in one go when the player reaches the far right. But this technique dont let you move in two directions (or more), and is also very difficult to do in AMOS.

@@plopparici3110 The next step of the demo was going to be to try to make it work using an actual tile map scrolling routine, but we had to move onto other things before we could try. Indeed AMOS forces lots of limitations on the programmer and on performance than the Amiga hardware was capible of.

Have you seen the game lately? It should make you happy: bitbeamcannon.com/daemonclaw/