slASHer - new Vic-20 game

[kamaleon70]

Hi everybody, I would like to share a video regarding a new small game for Vic-20 (slASHer) developed using MPAGD. MPAGD (Multi Platform Arcade Game Designer - https://jonathan-cauldwell.itch.io/mult ... e-designer) is available since some time and allows the creation of games for multiple platforms (ZX Sinclair, BBC model B, ...), but just recently we have started to work on the support for Vic-20 as well (still in beta - but will be released soon). slASHer was created using the beta version of MPAGD. I will notify here when full support for Vic-20 will be released in MPAGD. The only limitation is that, to have the game designer tool to be generic for various type of games, the games generated with it will require the max RAM expansion of 35Kbytes...
Here is a small video of the game made using my Vic-20 and 1541 floppy drive (of course the digital version is available too for simulators or while using SD readers) https://www.youtube.com/watch?v=UAUj9lcx_YE
The itch.io page to download it is here:
https://zxamaze.itch.io/slasher-vic-20
Please let me know what you think about that. I will post some info in the next future with more games made with MPAGD for Vic-20 and also news about the release of official support for Vic-20 in MPAGD.

[mingle]

Quite nice, the character-movement is nice and fluid.

The colour-handling does look a little "Spectrum-like", but if this is only a beta-release, that's forgivable

Will the final-release of the dev-enviroment allow for 'custom' Vic-20 specific screen-modes?

[Mike]

Hi, kamaleon70,

is there a higher quality master of the title(?) screen available? I am asking because this picture ...



... does not do the graphics capabilities of the VIC-20 justice. It's mostly a tad bit too obvious colour clash that ruins the overall impression (... of course you could always attribute it to artistic licence, but ...).

With a good master I could make a stab at it - with MINIPAINT and its assorted tools -, to produce a nicer looking title screen.

Greetings,

Michael

[Rich]

Glad there will be support for the VIC20 !! nice little game thank you for sharing this one!

[kamaleon70]

Hi, thanks everyone for the comments. Just some notes:
- The resolution used is fixed for now and is 176x176. It uses "bitmap" mode that configures 22x11 unique characters (8x16 size each) to simulate actual bitmap mode full screen not present on Vic-20.
- The colors are the ones available in the high res mode but MPAGD allows to configure the game to use multicolor option (in this way we can have up to 4 colors for each "character" area but the horizontal resolution is reduced to 1/2).
- Regarding the bitmaps for title screen, they are high res mode as well so limited colors, but of course it is possible to use multicolor in this case as well to produce nicer images (at the cost of course of horizontal resolution).

[Mike]

Just for the record, I already had some exposure as to how bitmap graphics on the VIC-20 is done.

The resolution used is fixed for now and is 176x176. [...]

You should seriously reconsider that choice. A bitmap resolution of 176x176 effectively forces you to put the address generating text screen either at $0000 or $0200, neither of which is exactly OS friendly.

The resolution of 160x192 can be realised by using the upper 4K internal RAM alone, with the text screen at $1000..$10EF, the bitmap effectively in $1100..$1FFF by using $10 as first character in the top left position. A column-major arrangement of chars is much preferred for an easier address function.

To repeat: a meagre increase of resolution by just 0,8% is not worth any trouble if you need to debug stuff and the OS workspace had been written all over it.

[...] it is possible to use multicolor [...]

The choice of hires or multi-colour is not an all-or-nothing for the whole screen! Each attribute cell has its own multi-colour enable bit. This allows to use hires at places where colour clash is uncritical, and use multi-colour at other places where colour clash would be too apparent and multi-colour then allows to place more colours nearby. Here's a particularly nice example, which started out from monochrome line art and then was colourized. Where possible, hires was kept, but some parts of the picture use multi-colour instead:



Unlike some other paint programs for the VIC-20, MINIPAINT does not force that all-or-nothing choice between full hires or full multi-colour from the user. You really should add support to its graphics format in MPAGD.

[kamaleon70]

Thanks for you note about MINIPAINT. We will consider for sure the support of it. I did not think about bitmap screens with mixed multicolor, high res graphics... Very nice
Regarding the resolution, we are using for screen location $200 but, because we are actually using only 242 bytes (22x11) so $200 to $2F2, we are not touching the more critical area between $300-$3ff. Based on our tests this was not an issue while not using BASIC but only assembly for the games. We have chosen 22x22 characters because we needed a square screen for our needs. The other option using the screen memory you proposed was like 20x24 for example. We wanted to reach the max resolution with "square" resolution.

[kamaleon70]

Mike, just realized that you were the one previously providing to me this info on screen resolution (with a lot more details) in the programming channel.
viewtopic.php?p=121877#p121877

[Mike]

[...] that you were the one previously providing to me this info [...]

Not only that (... ...), MPAGD and its predecessor AGD were featured in two older threads from 2018 and 2022, respectively.

In the thread of 2018, the relative mismatch between the graphics capabilities of the (planned) supported platforms had already been highlighted. The different resolutions are really the minor issue, just that one easily leads to designs for the lowest common denominator. However, the attribute handling on the VIC-20 is an aspect that one can't willfully ignore; that's about the same as if any intended support of MPAGD for C64 would not include the VIC-II hardware sprites.

My offer still stands to do either a raw convert of any better defined original of the still images, or even put more some work into them and re-pixel them in MINIPAINT. In either case, the resolution will be 160x192 pixels (with any selection of the attribute cells in multi-colour where sensible).

[kamaleon70]

If you can help to redo the bitmaps it will be great and will be really appreciated. We will update the game with better graphics if available. We have looked at minipaint and there are no issues to support it. The resolution of the game and the bitmaps can be easily changed when required. The d64 of the game has two files called slasher1d and slasher1c containing the data and color that we just load in character and color memory. So as long as we have similar files (essentially just dump of memory) and we know the resolution there is no issue to support better graphics. Thanks a lot for the offer

[kamaleon70]

I have posted two new videos on youtube showing a game developed with MPAGD Vic 20 (work in progress) and a small demo showing multicolor mode with MPAGD Vic 20. More videos and games to come. As indicate previously MPAGD (https://jonathan-cauldwell.itch.io/mult ... e-designer) Vic 20 support is still in beta but almost completed. We are very close to release it.

Videos
https://www.youtube.com/watch?v=5pBPrKXLsQg
https://www.youtube.com/watch?v=st2Rj2B_5Uk

[Rich]

Looking very nice , I like the use of the colour palette

[kamaleon70]

Hi everybody, the game slasher has been updated with new splash screens thanks to the work of Mike and his MiniPaint (https://www.sleepingelephant.com/ipw-we ... php?t=3752).
You can find the updated game here (the youtube video has been updated - https://www.youtube.com/watch?v=YGBX4ah9mDE):
https://zxamaze.itch.io/slasher-vic-20
Thanks

[kamaleon70]

We are working on a conversion of slASHer game from a .d64 with multiple files to load, to a single .prg. We would like to allow to play it on browser in the itch.io page but I am not sure what browser emulator we could use for that (the game requires 35K expanded memory to run). In the page we currently use (https://zxamaze.itch.io/slasher-vic-20) the game can be downloaded but it would be nice to have it to run directly from browser as well. Thanks.

[Mike]

[W]hat browser emulator we could use for that[?]

You could try out nippur72's vic20-emu or matsondawson's JS Vic20.