New game: SolarGun 1.0

Sol_HSA

(that gif capture bugs a bit, but anyhoo..)
iki.fi/sol/zip/solargun10.tap - tap file
https://github.com/jarikomppa/speccy - sources

Timmy

Looks nice for a first game. Congrats. :)

Alessandro Grussu

I like the smooth movement of the spaceship, but unfortunately the background is not easy on my eyes...

MatGubbins

Looks good, any chance of removing that invisible wall in the middle so that the player can risk everything to save the world.

ZXSPIRITS

Hey, is good, is psicodelic shoot ´em up, but more shots :-O

Morkin

Nice shoot 'em up. I reckon it would make a nice game for a high score challenge (492 BTW :D ) . I like the way you've done the ship movement.

Occasionally it feels like my shots don't have any effect on some of the asteroids. Are some of them indestructible/multi-shot targets? Or could it be that there two rocks in the same place and it's only destroying one of them?

JasonUK

Very smooth but I'll +1 issue with background which doesn't lessens experience!

JasonUK

lol just read my last post which makes zero sense ~ should have read "which lessens experience"

Lethargeek

good to see a "demo effect" in a game, but the background pattern looks too repetitive / loop too short

joefish

Sorry, but I find the rippling background far too distracting.

It's a nice effect that the sprites leave decaying trails; that's not a problem since the lead sprite is re-drawn and clearly masked each time. But the changes in the background as it scrolls are too flickery, and draw attention away from the target objects.

If the issue is how much data can be re-drawn each frame, then perhaps the background could move in sine-wave like ripples, such that a different pattern of rows are updated each frame?

R-Tape

Good brewtime fun - 762.

I'd prefer a starfield, but can live with the background and scrolling text, though they do give it a bit of a tech demo feel. I was going to suggest a bonus for 3 at once, but as the screen fills up that tends to be a given!

Morkin

R-Tape wrote: »

Good brewtime fun - 762.

:((

Sol_HSA

Hi, and thanks for all the feedback!

If I end up making a 2.0, I'll take these all into account. I have some ideas of how to make this more like an "actual" game, with less random elements, but we'll see if I pick up on it. In the meantime, the sources are available for anyone to hack if they wish.

A little bit of background: I've been making some "base tech" for some time and figured that I need to make a "whole game" next in order to get forward. A simple shmup seemed like the way to go, and while making it over the weekend (I'd estimate under 8 hours of actual work for the whole game), it did expose a few holes in my routines, like input, including joystick support.

Audio remains to be a problem, although I could ditch the unnecessary scroller and spend all that time just playing sound every frame =)

Sol_HSA

I've blogged a bit about the making-of and what kinds of "cheats" I used to make the game run at 50Hz, http://sol.gfxile.net/#SPECCYVOL7:SOLARGUN

DaRkHoRaCe

Whoa, I thought it was a new lightgun game :D

spud

Brilliant mini game.

Scored 844

R-Tape

spud wrote: »

Brilliant mini game.

Scored 844

Shite!

RMartins

Nice dev posts on your blog.
Nice hacking :)

R-Tape

855.

R-Tape

1072.

Sol_HSA

R-Tape wrote: »

1072.

o_O

spud

R-Tape wrote: »

1072.

Right, it's on.

RMartins

I was reading your blog, and noticed something that I believe will not work as suggested.

ld a, #0x39 ; 0x39xx is a rom address with lots of ff's in 48k speccy
ld i, a ; set i
ld hl, #0xffff
ld (hl), #0xc9 ; 'ret'. Should be reti, but that's 2 bytes, and we aint got room for that.
im 2 ; interrupt mode 2, which should now hop to 0xffff which has our ret instruction.

This will not work, because according to Z80 Manual, you have to re-enable interrupts inside the interrupt handler routine. So a simple RET (or RETI) won't cut it.

From Z80 Manual, Page 18
Section "Interrupt Response"
sub-section "Interrupt Enable/Disable"

The EI instruction sets both IFF1 and IFF2 to the enable state. When the CPU accepts a maskable interrupt, both IFF1 and IFF2 are automatically reset, inhibiting further interrupts until the programmer issues a new El instruction.

If you don't ever use HALT instruction, it will "appear" that it's working, but it's not, because interrupts will remain disabled after the first time the handler runs.

If you use a HALT instruction (to sync with the screen refresh), it will lockup forever, since interrupt handler never enabled interrupts (EI) before returning, hence HALT will wait forever for interrupts to be enabled again.

Sol_HSA

RMartins wrote: »

If you use a HALT instruction (to sync with the screen refresh), it will lockup forever, since interrupt handler never enabled interrupts (EI) before returning, hence HALT will wait forever for interrupts to be enabled again.

I EI just before HALT, otherwise keep the interrupts disabled.

Kio

I think the main programme will do something like this:

a:  call domywork
    ei
    halt
    jr a

... Kio !

RMartins

Sol_HSA wrote: »

RMartins wrote: »

If you use a HALT instruction (to sync with the screen refresh), it will lockup forever, since interrupt handler never enabled interrupts (EI) before returning, hence HALT will wait forever for interrupts to be enabled again.

I EI just before HALT, otherwise keep the interrupts disabled.

Ok, with that extra condition it will work.

However, if you are managing 50Hz frames, it should be exactly the same, so enable (EI) inside interrupt handler, or just before HALT. But this way you can use the #FF address table and RET hack.

R-Tape

RMartins - it's after 5pm in every time zone, which officially means you're 'talking shop' - the forfeit for which is that you have to participate in the HI-SCORE CHALLENGE

:-p

MatGubbins

R-Tape wrote: »

RMartins - it's after 5pm in every time zone, which officially means you're 'talking shop' - the forfeit for which is that you have to participate in the HI-SCORE CHALLENGE

HeHeHe......with screenshots.. otherwise a random number could be typed in and annoy the competitors....

spud

1029 so far.

RMartins

I tried it, but I can't participate in a Hi-Score contest.
I have to finish my own game in time for the ZX-DEV-2015 contest deadline.

spud