Space Invaders

[Havie]

Originally Posted by Coagulus

To get the transparency effect you could add an extra biplane and then use Bitplanesbitmap for the 1 bitplane the invaders etc would reside on. The top half of the colours could then be brightened versions of the first half. The invaders would look a little transparent then but still only be in 1 bitplane...

Not quite sure what you mean but I don't think this would work as I am using dual bitplane mode to put the background behind the invaders.

[Havie]

Originally Posted by DamienD

...and here's one that's "320x200" pixels:

I can play around with:

• The opacity of the sky.
• The opacity of the moon.
• The sky positioning i.e. higher or lower.
• The moon positioning i.e. higher or lower.

...and when you're happy, create 8 and 16 colour .IFF files

Examples:

8 colour .IFF:



16 colour .IFF:

320x200 is the correct size as I wanted everyone to be able to play the game. I just use a poke to switch all Amiga's to NTSC mode which has the added benefit of stretching the screen and creating a better aspect ratio.

As I seem to be collecting features, I will need to implement a menu with some graphic options so you could have colour overlays or not, background moon or not, PAL or NTSC.

Code needs a bit of a rewrite as I blit directly to the screen (no double buffering) and erase using a non-transparent black box around all the bobs but obviously this doesn't work with a background so having to recapture all the sprites without a black border. Luckily, Blitz Basic can easily set Blit modes so I can erase a bob using erase mode and then re-blit in cookie mode. Simples!

The only bit causing me a bit of a headache is when the invaders reach the side of the screen, I had a loop that aligned all the invaders from the 1st one when this happened (as the arcade does) before they all moved down but I can't do it this way now as I would need to erase up to 55 invaders and re-blit them in one loop which would definitely give some serious slow down so I now have to aligned them individually before moving them down - maybe I will do a row at a time so it only takes 5 loops (1/12 second) to align them? Or maybe there is a better way and I haven't thought of it yet...

[Coagulus]

Originally Posted by Havie

Not quite sure what you mean but I don't think this would work as I am using dual bitplane mode to put the background behind the invaders.

Ah yes the effect wouldn't work then. I was thinking 4 bitplanes for the background then a fifth for the game. The game would still be 1 bitplane then but be on a 5 bitplane screen.

[saimon69]

Originally Posted by S. Campbell

oh god please not copper effects.

When well made you could not even tell is copper...

[klx300r]

thanks so much! so cool I remember playing the original at an arcade with my big brother back in 78 ! Lots of quarters spend on that arcade box

[Havie]

Took a break over Christmas but have got back into this over the last week or so and implemented Damien's background (thanks mate). Looks pretty nice but if you don't like it you can turn it off!

So game is basically complete and you have a few additional hot keys:

zx and space = left right and fire (or joystick).
P=pause
B=background on/off
Change overlay on screen: 1=original 2=colour

My only concern is the speed as it seems ok in WinUae but not sure how it'll run on A500/600. I think the last version was slow on a 500 (comment about UFO sound which is fine on WinUae). Anyway, if you get a chance, have a test and let me know how it goes for you - could possibly look to optimise if needed...

Download from here: https://eab.abime.net/zone/Space%20Invaders.adf

[Havie]

Tried on my 1200 and speed was fine but noticed two bugs to fix.

1) You can shoot the ufo multiple times
2) Your bullet does strange things and disappears half way up the screen but as there are less invaders it's doesn't!

Still interested in how this runs on an A500.

1) Sorted
2) Possibly sorted with a subtle move of the vwait to near the beginning of the loop and the not the end?

Working download: https://eab.abime.net/zone/Space%20Invaders.adf

[Havie]

Tested it on A500 in WinUAE and seems to run fine and UFO making correct sound (fingers crossed)...

[Havie]

Had a bit of a bug squashing moment:

1) UFO still not working properly - fixed.
2) Sounds cutting out so gave each sound effect it's own channel - fixed.
3) Saved correct source code to floppy image

I know it takes a while to load as each shape is loaded individually and I could save all the shapes in one file which would speed up loading but I like the fact that anyone with DPaint, PPaint or other package can redo the graphics like Spade Invaders!

[DamienD]

Originally Posted by Havie

Took a break over Christmas but have got back into this over the last week or so and implemented Damien's background (thanks mate). Looks pretty nice but if you don't like it you can turn it off!

So game is basically complete and you have a few additional hot keys:

zx and space = left right and fire (or joystick).
P=pause
B=background on/off
Change overlay on screen: 1=original 2=colour

Heya Havie,

Firstly well done in getting all this working, I previously read your other thread: Spaces Invaders with a moon background

Regarding the background though; I'm surprised that this didn't come out like the sshots posted here, and the quality looks poor:

If you need me to try to optimise them then I can

[Havie]

Originally Posted by DamienD

Heya Havie,

Firstly well done in getting all this working, I previously read your other thread: Spaces Invaders with a moon background

Regarding the background though; I'm surprised that this didn't come out like the sshots posted here, and the quality looks poor:

If you need me to try to optimise them then I can

Thanks Damien - not sure if I messed it up? It would be great if your optimise for 8 colours then it should slot in easy enough as I load palette from background. Thanks.

Nearly there...

[DamienD]

Originally Posted by Havie

Thanks Damien - not sure if I messed it up? It would be great if your optimise for 8 colours then it should slot in easy enough as I load palette from background. Thanks.

Nearly there...

The below first example is 8 colours

Originally Posted by DamienD

...and here's one that's "320x200" pixels:

I can play around with:

• The opacity of the sky.
• The opacity of the moon.
• The sky positioning i.e. higher or lower.
• The moon positioning i.e. higher or lower.

...and when you're happy, create 8 and 16 colour .IFF files

Examples:

8 colour .IFF:



16 colour .IFF:

I can put the .IFF in The Zone! for you?

But do you want anyt optimisations i.e:

• The opacity of the sky.
• The opacity of the moon.
• The sky positioning i.e. higher or lower.
• The moon positioning i.e. higher or lower.

[Havie]

Now I remember why I fiddled with the 8 colour version - I wasn't keen on the blue craters on the moon.

Hang on a mo...

[Havie]

Right so when I use you 8 colour background it looks wrong and now I remember fiddling with it to make it look better. Also, I reduced the brightness to make the invaders and player standout more clearly.

So my version looks like this with the wrong colours?



Your 8 colour version comes out like this:




I must be doing something wrong? I even made a 16 colour palette with the correct colours but they still end up wrong and I get a black as colour 8. Must be something to do with the dual playfield? Or may be it's something to do wiht the copper commands on the front screen?

Help!

[jotd]

you could inspect your copperlist with winuae to debug (this is looking promising anyway)

[Havie]

I am now wondering if it is to do with the rgb values?

If I am targeting an OCS/ECS Amiga then the each colour component is in teh range 0-15 but if I am using an AGA Amiga then the ranges is 0-255. I think I am setting the paletter under AGA in PPaint rather than OCS/ECS? Does this make sense?

Or am I confusing myself?

If I do:

PalRGB 0,8,30,103,204 (set palette 0, colour 8, red,green,blue) I get an RGB out of range error.

[Havie]

Just tried using DPaint instead of PPaint and guess what - colours now display correctly? Have no idea what is going on...

[DamienD]

Hmmm, I have many iterations of this on my computer...

So you want it a little darker then?

I'll quickly save at 8 colours and as an .IFF file; then upload to The Zone!

Edit: ok, "Invaders_Backgrounds.zip" now in The Zone! that contains both these 8 colour .IFFs:

As mentioned though, tell me if you want any adjustments

[DamienD]

Originally Posted by Havie

Now I remember why I fiddled with the 8 colour version - I wasn't keen on the blue craters on the moon.

Ah, gotcha.

The craters were black but when reducing to 8 colours in "XNView NP" it changes them to blue for some reason

Let me see if I can work around this

[DamienD]

Hmmm, not sure why... but when I cut out a perfectly black moon:

Then paste onto any of the above images, it then gets slightly degraded

Too tired now, will do more investigation after work tomorrow evening...