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Released: pulse

Posted: Fri Feb 28, 2014 5:46 am
by pixel
Hi,

the VIC has been my first computer. But I never really coded something for it. And I never coded a game, too. So, finally, here's another piece in the not–yet–finished department just to get it out of my system. To be continued with more spare time. I hope you enjoy it a bit.

http://hugbox.org/pixel/blog/2014/2/23/pulse.prg

love+respect
pixel

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 5:54 am
by orion70
Welcome to Denial. Really impressive! Smooth scrolling and fast gameplay... It reminded me of Stavros Fasoulas' Delta.
Thanks for this, hope you'll have A LOT of spare time :)
pixel wrote:love+respect
Absolutely, especially if you finish this :P

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 7:30 am
by pixel
Thanks a lot! Very encouraging. :) I'm in serious need for spare bytes there, too. Would love to keep it unexpanded.

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 10:02 am
by malcontent
Very impressive for an unexpanded game. I enjoyed it a lot. It would really be a wonder if you could cram more in there. My only complaint is that the collision box seems to extend in front of the ship a bit too much.

Also you perhaps mean horizontal scrolling....

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 10:32 am
by joshuadenmark
Super smooth and fast moving, like this a lot.

Welcome to Denial, hope to see more smooth scrolling skills from you in the future :-)

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 3:48 pm
by groepaz
pretty cool!

Re: pulse – a vertically scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 7:33 pm
by pixel
I never saw Delta before. It looks great! Thanks for that, too.

Oh, ermh, yes, it should read "horizontal". :oops:

I can't find the problem with the collision box in the code and I don't like the sprites popping out on the left which shouldn't happen as well. As usual it's the last tiny bugs that drive one crazy... :twisted:

Maybe those ~100 bytes left should at least go into a score/life counter before reaching for wonders? :wink:

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Fri Feb 28, 2014 8:07 pm
by pixel
The collision box has been corrected and there's now the number of lifes, a score and a hiscore. Just download it again from the same location.

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sat Mar 01, 2014 7:56 am
by rhurst
Love your retro use of red-yellow-blue in this game! 8)

Amazing what those "few more bytes" can mean to a game like this, eh? :wink:

When you got your stock VIC 20 boot-from-tape version in a place where you value, please consider the ROM cartridge space next; start with a 4kb version to see what that opens for you. And if you like that (and you find the time), make that 8kb cartridge, and tantalize us even more with your apparent talent for this stuff.

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sat Mar 01, 2014 2:55 pm
by FD22
Loving this. I'd concur that the collision detection is slightly inconsistent - I can skim the landscape with pixel-precision, but sometimes the oncoming enemy waves or a riserbomb will drift just ahead of the ship and ... blammo.

But that's just me being picky - this is a cracking game. Martian Raider was always a favourite, and this evokes that classic Scramble essence in a new, more frenzied, faster-paced way. 10/10.

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sat Mar 01, 2014 4:43 pm
by pixel
I'm blown away by you people. Thanks a lot for the super-positive feedback and for helping me to finally get this thing right. (love+respect)²

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sun Mar 02, 2014 4:44 am
by Mike
rhurst wrote:When you got your stock VIC 20 boot-from-tape version in a place where you value, please consider the ROM cartridge space next; start with a 4kb version to see what that opens for you. [...]
From what I've seen with a quick peek in the VICE monitor, the game already uses the full 4K of $1000 to $1FFF, and also $0200 to $03FF for code, and - of course - the zeropage. The interrupt vectors at $0314, $0316 and $0318 are overwritten, yet it survives a tap on the restore key.

I also like the 'intro' sequence. It somehow reminds me of the self test patterns on those arcade cabinets. 8)

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sun Mar 02, 2014 7:16 am
by tokra
Love it! Reminds me of Nemesis/Gradius. Hats off for the smooth scrolling. Am I the only one missing sound a little?

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sun Mar 02, 2014 7:22 am
by pixel
Mike wrote:From what I've seen with a quick peek in the VICE monitor, the game already uses the full 4K of $1000 to $1FFF, and also $0200 to $03FF for code, and - of course - the zeropage. The interrupt vectors at $0314, $0316 and $0318 are overwritten, yet it survives a tap on the restore key.

I also like the 'intro' sequence. It somehow reminds me of the self test patterns on those arcade cabinets. 8)
Just checked. There're still 203 bytes left. 26 bytes on the zero page, about 98 on the stack, 52 bytes below $400 and 27 right below screen memory. Writing $7f to $911e did the trick blocking the restore key NMIs. It's the first thing that happens when the program starts. But that part is overwritten with the generated charset, so you won't see it in the monitor. The intro is just a leftover speed test of a bresenham line drawing routine. Another nice coincidence. :)

Yes! Gradius! Exactly! That's the thing I really used no play once on the NES and it certainly had it's impact. They must have had similar problems or ideas for calculating the trajectory of the enemy bullets – no special planning involved to make it look similar.

Re: pulse – a horizontally scrolling shoot–'em–up

Posted: Sun Mar 02, 2014 8:09 am
by orion70
Please pixel, throw some basic sounds in the game! I am missing them, too. :);