[Ongoing] Powerglove

[Lazycow]

Hello EAB!

After stumbling over Codetapper's (excellent) sprite-tricks articles, I wanted to do a game with some sprite parallax effects, too. Seems like I have successfully revived parts of my 20 years old low level code...

development status: finished / released

trailer:
[ Show youtube player ]

boxed version available from: rgcd.bigcartel.com
download available from: rgcddev.itch.io
homepage: www.lazycow.de/powerglove

System requirements: Amiga A500 with 1 MB (or better)
It has been tested on Amigas with/without AGA and/or turbo boards. (PAL and NTSC!)

[Toni Wilen]

NTSC has 241 visible lines if max overscan. First NTSC line is 21, last is 262.

[Lazycow]

Yes, ok... but what's the overscan of 90% of all NTSC Amigas that are actually in use? Anyway... continuing with 320x224 for now.



Horizontal scrolling is working, but with graphics from the NES version for now. Amiga could have better graphics, of course. (At least if you find someone with good pixel skills...)

Next up: Time to include the parallax effect with sprites... uh oh...

[Lazycow]

Ok, copperlist, scrolling, blitting and audio is working now. Only a few minor problems: the playfield is off by one pixel.



But the scroll registers seems to be filled with $0000. Is this the correct behavior; do I have to adjust the scroll register or is there a bug somewhere?
copperlist segment:

dc.l    $008E2c81    ; diwstrt (PAL) 
dc.l    $00900cc1    ; diwstop (PAL) 
dc.l    $01005200    ; bplcon0, enable 5 bitplanes 
dc.l    $01040000    ; bplcon2, playfield priority 
;dc.l    $01060C61    ; bplcon3, color bank/spr res (AGA?) 
dc.l    $00920030    ; ddfstrt 
dc.l    $009400d0    ; ddfstop 
dc.l    $01020000    ; bplcon1, scroll register 
dc.l    $010800ee    ; bpl1mod, modulo 
dc.l    $010A00ee    ; bpl2mod

[wXR]

This is exciting. Any chance to share your work on GitHub or something, as you go?

[Lazycow]

Ok, the Amiga scroll register works as expected, but my code writes wrong values in there. (no big surprise, right?)

This means that Tubular Worlds has the same bug (embarrassing), because I am using an improved version of its scrolling code.


Almost playable now, but the graphics are missing. Here are some tests, 3 Monsters and 3 tests for the player. (still needs some tweaking)

@wXR: Maybe, but currently it's a big mess. Any plans for it or just curious?

[nobody]

I have uploaded a tileset maybe that could match this game in 16 colors.
check out, "metroid like" and "hostile planet"

http://opengameart.org/users/chipmunk

[Gzegzolka]

Cool

[Lazycow]

@Nobody: Oh, I like chipmunk's style. His open game art tileset would match, indeed. Thanks for the hint. But my own tileset is already 50% finished. (preview will be posted when "it's done") Stand by...

[nobody]

nice, let's see what you've got then. (This art in opengame art is mine, not "his" :P)

[Amiga1992]

OH man I love Powerglove! LAzycow, am glad you are into Amiga game making. Can't wait to see what original games you come up with for the platform

(and collaborate with nobody/chipmunk, he makes some awesome gfx!)

[Lazycow]

Cyborgjeff's Amiga version of the Powerglove ingame music: (wip)
https://soundcloud.com/cyborg-jeff/p...side-amiga-wip

@nobody: nice work!
@Akira: I made the Amiga low-level code compatible to my c64 low-level code, so I can just cross-compile my c64 games now. (That might give you a hint about another potential game)

[Amiga1992]

That's great to know! Looking forward!
And as I said I hope you embark into the adventure of making an Amiga-first (or exclusive) title next/soon!

[Lonewolf10]

LazyCow, any news? It's looking and sounding great so far

[Lazycow]

Ok, update time: The copper list displays a 2nd parallax layer now, build out of sprites. (yes, more than 8 sprites in a row on a 32 color screen) Still test-graphics only, the red and blue graphics are build out of sprites here. This was quite tricky, because I did not know very much about the copper commands and I needed all of them.

[ReadOnlyCat]

Really nice one!

But with 32 colors that must mean that copper and display eat almost all the available DMA, so do you still have enough time left to blit moving objects and for game logic on top of it?

[Amiga1992]

Looking beautiful!

[Lazycow]

@ReadOnlyCat: The copperlist currently "only" uses half of the available copper DMA slots, but you're right, this is a significant additional load. I haven't made a test with a 68000, yet. But with a 68020 it is fast enough. We will see...

[Lazycow]

Here's a first sneak peek for the 32 color graphics. (it's still a draft, they definitely need some polish)
Also, I made some speed tests: A500, 512k chipmem, 512k slowmem, NTSC
- in 32 color mode without multiplexed sprites, the game engine can move 9 robots in 60 fps
- when the copper fills the background with multiplexed sprites in 32 color mode, only 5 robots can be moved by the game engine with 60 fps

This is slightly too slow, because the scrolling needs some bandwith, too.

With real fastmem or on an A1200, the heavy copperlist is no longer a problem. So one idea would be to make the parallax effect optional for faster Amigas.

But maybe this is not necessary, because the whole background is never fully visible in scrolling rooms. (no sprites are needed below floor and ceiling) I made a test with a slightly smaller copperlist and everything was fast enough. Barely.

[Retro-Nerd]

Wow, that looks nice.