Sprite Invaders

rhurst · Post by **rhurst** » Sun Nov 21, 2010 5:03 pm

A functional version of this game and its source code is included in the VIC-SSS archive found here. A screenshot follows:

nbla000 · Post by **nbla000** » Mon Nov 22, 2010 5:28 am

Wow, another nice arcade conversion made in USA

Kweepa · Post by **Kweepa** » Mon Nov 22, 2010 9:08 am

Looks perfect!
I tried playing it here:
http://robert.hurst-ri.us/files/vic20/j ... aders.html
But it didn't start.

[EDIT] Hmm, looks like JarVIC doesn't work with the latest version of Java... either a parameter passing issue or a timing issue... Even bigger

orion70 · Post by **orion70** » Mon Nov 22, 2010 9:32 am

Me too

. Wouldn't it be possible to have a prg file of the game? TIA

.

rhurst · Post by **rhurst** » Mon Nov 22, 2010 1:59 pm

Hmmm, the JarVIC page link works fine for me, even through our enterprise firewall. I am using Linux Firefox with Java 1.6.18 and all 64-bit, too.

But your comments made me realize I did not post any PRG download url here at Denial.

Please click here for the PRG image only. Sorry.

orion70 · Post by **orion70** » Mon Nov 22, 2010 2:14 pm

Thanks! Very nice version of the game, graphically accurate and smooth - although, is it me or it's a bit slow compared to the original?

rhurst · Post by **rhurst** » Mon Nov 22, 2010 5:17 pm

Hmmm, a result of PAL timing perhaps? It may also play a bit slower upfront, especially in VIC 20 mode, from a larger object screen refresh ... however, this variant does not flicker any, and the animated movement is solid -- not a "rippled" water effect -- to make up for slower screen refreshes as the bit-mapped version in VIC Avenger does (which I include its cartridge ROM for such comparison purposes).

Just for the record, I think VIC Avenger is an excellent, complete clone of the arcade original -- in which I was in no way attempting to 'compete' or 'replace' its place as one of the best Space Invaders clone ever crafted -- and it is MUCH better (albeit ~3 years later) over the Atari VCS home version. Sprite Invaders was titled that way to infer that objective and distinction! But if it were in my ego, I'd wager I could make a better clone.

I do decrease VSYNC by one for PAL machines as a weak attempt to make up for its less frequent screen refreshes. I thought the game played too hard (and sometimes a little erratic especially in PAL mode) with VSYNC off entirely. Fortunately, I can tweak to increase its speed, but I'll have to play some more games in PAL mode and see how it feels... I don't like video games that make it impossible to conquer a level whereas the computer simply out-clocks the (aging) humanoid.

Obviously, this is a variant and not a clone of Space Invaders. I consciously decided to take this direction to meet my objective of providing an overall working example of VIC SSS in a video game that everyone understands. I'd like to make another game, megaVICmania, that exploits the use of repeating sprites. And possibly a Pitfall adventure and/or slot car and/or racing car scroller, too... love playing them all at arcades and on Atari VCS, but VIC versions left something to desire . . .

For you arcade geeks out there, can you identify ALL of the visible differences between this game in CLASSIC mode versus the original? I think I know them all, but maybe someone else can find something I would have missed if I went the clone route . . .

Progra · Post by **Progra** » Tue Nov 23, 2010 10:30 am

Lovely! Thank you!

Ghislain · Post by **Ghislain** » Wed Nov 24, 2010 4:51 am

I think that all the VIC-20 homebrew developers should really consider releasing their collection of games with Psytronik who put out the releases in a nice jewel case, instructions and color disk and sleeve labels.

Especially in the case of rhurst who is like a modern day Tom Griner, pushing the limits of the VIC-20 graphics capabilities.

Spectrum · Post by **Spectrum** » Sat Oct 22, 2011 3:46 am

I'm having some troubles with Sprite Invaders.
Everytime I die, all the fleet re-appears as a whole.
In other words, the game doesn't let me continue if I die. When my ship is destroyed, I've to re-start against the whole invader's fleet.

Am I the only one that is having such a trouble?

I hope to fix it because I am really loving how the sprites enhanced the game.

I am playing it on VICE.

matsondawson · Post by **matsondawson** » Sat Oct 22, 2011 4:13 am

I had the same issue playing on my emulator:

http://www.mdawson.net/vic20chrome/vic2 ... vaders.prg

rhurst · Post by **rhurst** » Sat Oct 22, 2011 7:31 am

Heh, that's simply how it is.

It is a simple game, that a potential programmer can identify with and perhaps have an easier time understanding its coding, that implements every feature the VIC Software Sprite Stack has to offer... it was never meant to be a clone. You have VIC Avenger for that.

For the gamer out there wanting to add this feature, there is a jump-point after death that could be re-tooled to continue the game. Or in the case of 1 or 2 player mode, the current NME state will need to be buffered for swapping. Not unlike managing the bricks in Break-Out!.

OT: Matt, your JS VIC emulator and page for running projects is of excellent quality. BTW, how is the "inline" version any different?

matsondawson · Post by **matsondawson** » Sun Oct 23, 2011 6:06 pm

The inline version is the old version which is JIT compiled to Javascript, it doesn't do cycle wise emulation, and hacks in support for interrupts.
The new one is meant to be a more exact emulation.
At some point I'll update the old one, though I wonder if I should just change it so that rather than inline, it replaces the .prg links with links to the emulator page.

matsondawson · Post by **matsondawson** » Sun Oct 23, 2011 6:10 pm

I wonder if sampled sounds from the original space invaders could be added to this?

Spectrum · Post by **Spectrum** » Mon Oct 24, 2011 3:23 am

rhurst wrote:Heh, that's simply how it is.

It is a simple game, that a potential programmer can identify with and perhaps have an easier time understanding its coding, that implements every feature the VIC Software Sprite Stack has to offer... it was never meant to be a clone. You have VIC Avenger for that.

OK! Thank you very much for your explanation! I thought it was a problem of my VICE settings on the iMac.