GTIA Blast update

[José Pereira]

Please visit our friend YouTube channel, there's news there:

http://www.youtube.com/user/kiwilove007?feature=watch

[bfollett]

Too bad it's such a low quality video

[+playsoft]

Here are the files - it's now an Atarimax Maxflash 8Mbit cart image and in the zip you will find ab.bin (raw image), ab.car (image with CART header) and ab_atarimax_8mbit.atr (programming image). I have successfully tested on Maxflash 8Mbit, THE!CART, Altirra and Atari800WINPLus. Going the cart route means it now runs on a 16K machine.

 

Renamed ATARI BLAST! because it contains ANTIC modes too, a couple of the levels you may recognise as reworked versions of Harvey's HawkQuest designs. On the programming side there are now sound effects, a couple more background tracks, some new attack patterns and enemy missiles. Still a lot to do...

 

Keys 1..8 will jump to a level (at any time) and A will start auto-fire which you can cancel by pressing the fire button (this was added for the 5200 where fire buttons are not as robust as they are on the 8-bit joystick).

 

Paul

 

ab_070114.zip

[Goochman]

This is fantastic work - Nice job!

[kiwilove]

Too bad it's such a low quality video

The video quality is acceptable - the original video was scrunched down via Youtube and remains a fair representation of the graphics of the game.

I thought some sort of video should be easily viewable/accessible for newbies who may wonder what the fuss is about, regarding this project... and a quick way to compare it with the earlier version - for those others who like a quick look too..

The Atari 400/800 version is due to be released soon - which will also be runable via the Altirra emulator.

 

Harvey

[José Pereira]

Can't do that download that now.

Anyone can post here some screens of the GR.12/ANTIC4 version?

Just too curious to wait untill I can get into a computer to load it.

Thanks.

José Pereira.

[Mclaneinc]

All really looks nice, forget which level it was but it was like the arcade Slapfight..

 

Nice work to all involved..

[Tezz]

Well done guys, looking good. Great that you're using different modes in each level.

[pseudografx]

A really nice concept. I hope the final version will include some interaction with the background and, of course, POWERUPS! :-)

[Paul Westphal]

If it ever gets finished, it looks like it will be one of the prettiest shooters yet. Interactive backgrounds would be cool...hidden goodies like flying over a pic of mario and dropping bombs ( xevious style ) on his eyes or smallberries....or flying over a c64 and bombing ( spelling ) out words on the keyboard for power-ups. Just a thought...

[pps]

This looks very promising. Keep on working!

[José Pereira]

Many of the different levels:

http://www.youtube.com/watch?v=uAZK8TFUSx8

[Heaven/TQA]

looking good... as I am still interesting in a simple sprite multiplexor... how did you realsied yours? not the vertical splits via DLI but when more than 4 players are per scanline?

[Rybags]

Looking promising - but more interaction with the background would be good.

[Aking]

this is the best thing to arrive to the A8 world since project M ...

[popmilo]

looking good... as I am still interesting in a simple sprite multiplexor... how did you realsied yours? not the vertical splits via DLI but when more than 4 players are per scanline?

If I'm seeing it correctly: when you pause video on Youtube you can see that if two enemy sprites are in same line one of them disappears...

Bullets are probably software sprites.

 

No magic there imho, just a very good, high speed code

 

Great work Paul!

[+Philsan]

Awesome!

[José Pereira]

@Pop: All shots are Missiles in 5th Player Mode taking PF3 colour (then 4Missiles = 4shots).

Our ship its two Missiles and that's why it sometimes has diferent lines colours, when the PF3 register changes (this happens in GR.12/ANTIC4, the only Mode that uses PF3 on the gfxs) and enemys takes the the other 2.

The shots PF3 its always white less in some parts of the GR.12/ANTIC4 levels.

At least is what I get at the first time I saw those videos and right now running the Emulator Monitor.

The 5th Player is always enabled and how would you always have the enemys bullets as white also on the 4:1 GTIA and still have them moving in 2:1 ?

The only thing here done in software its the parallax scrolling.

 

 

P.s.- The only thing I would suggest is on the 1:1 level that has gfxs/PF1 in white but maybe also on GTIA Mode9 colour0 black/grays/white set the bullets/shots PF3 in same luminance E but other colour to better distinguish the gfxs 'vs' shots.

Just an idea...

All the others are really AMAZING, OUTSTANDING,... !

Edited January 9, 2014 by José Pereira

[+therealbountybob]

Looks great Paul

 

Will it eventually run from disk (1050!) or is it likely to be cartridge only due to size ?

[+playsoft]

looking good... as I am still interesting in a simple sprite multiplexor... how did you realsied yours? not the vertical splits via DLI but when more than 4 players are per scanline?

 

Each frame I process the player ship first*** so that it is always drawn. The remaining 16 sprites I process in a random order so that it's not always the same ones missing out on the multiplexer slots when there are horizontal clashes. For my random order I just use a table of 10 order sequences:

shuffles:
  .byte 0,10,1,4,9,13,15,6,7,3,12,5,8,2,14,11,16
  .byte 0,14,7,16,15,6,5,1,2,10,9,13,8,3,12,4,11
  ...<snip>
  .byte 0,6,2,12,1,10,16,15,14,7,5,13,3,8,4,9,11

*** Except in GTIA 10 where I can't modify the sprite colours as they are used in the playfield. If I always drew the player ship, the sprites using players 0 & 1 would always disappear when alongside the player ship.

[+playsoft]

If I'm seeing it correctly: when you pause video on Youtube you can see that if two enemy sprites are in same line one of them disappears...

Bullets are probably software sprites.

 

No magic there imho, just a very good, high speed code

 

Great work Paul!

 

Thanks Popmilo!

 

Yes, you only ever get 2 multicolour sprites in the same horizontal space in any one frame. The multiplexer divides the screen up so that every 8 scan lines there are two multiplexer slots available - one for the player 0/1 sprite, the other for the player 2/3 sprite. When an attempt is made to draw a sprite it first looks at the player 0/1 slots - if all the slots it needs are free then it books them and updates the sprite data. If the player 0/1 slots weren't available it then tries the player 2/3 slots.

 

The multiplexer interrupt is run from a POKEY timer and whenever it finds a booked slot it writes to the h/w registers. Everything is double buffered so that it can be preparing the next frame while displaying the current.

 

The bullets are all missiles. The players are missiles 0 & 1 and are simply multiplexed as they never clash. The enemy bullets are the remaining missiles and are not currently multiplexed. In modes with good missile visibility (GTIA 9, ANTIC 2) they are used independently, in other modes they are overlaid to get the OR colour from the sprite colours. In poor visibility modes the missiles also alternate each frame between normal player colours and fifth player colour as that seemed to give better results.

[+playsoft]

@Pop: All shots are Missiles in 5th Player Mode taking PF3 colour (then 4Missiles = 4shots).

Our ship its two Missiles and that's why it sometimes has diferent lines colours, when the PF3 register changes (this happens in GR.12/ANTIC4, the only Mode that uses PF3 on the gfxs) and enemys takes the the other 2.

The shots PF3 its always white less in some parts of the GR.12/ANTIC4 levels.

At least is what I get at the first time I saw those videos and right now running the Emulator Monitor.

The 5th Player is always enabled and how would you always have the enemys bullets as white also on the 4:1 GTIA and still have them moving in 2:1 ?

The only thing here done in software its the parallax scrolling.

 

 

P.s.- The only thing I would suggest is on the 1:1 level that has gfxs/PF1 in white but maybe also on GTIA Mode9 colour0 black/grays/white set the bullets/shots PF3 in same luminance E but other colour to better distinguish the gfxs 'vs' shots.

Just an idea...

All the others are really AMAZING, OUTSTANDING,... !

 

José - I had to check the code...

 

In GTIA 9 and ANTIC 2, the missiles use the fifth player colour only; the enemy missiles are not overlaid so there are two of them on screen simultaneously. I will try a different hue in GTIA 9.

 

In GTIA 11 and ANTIC 4, the missiles alternate each frame between fifth player colour and sprite colours; the enemy missiles are overlaid to get the OR sprite colour so there is only one on screen at any one time.

 

In GTIA 10, the missiles use the sprite colours only; both player and enemy missiles are overlaid to get the OR sprite colour so there is only one enemy missile and the player fires left/right.

[+playsoft]

Looks great Paul

 

Will it eventually run from disk (1050!) or is it likely to be cartridge only due to size ?

 

Thanks Jason. No it's too big now to run from a 1050. This was not an easy decision to make and we ummed and ahhed over it for a long time but eventually decided it would be more fun to go the big cartridge route.

[José Pereira]

Yes on GR.8 and 9 I was sure the shots were 5th Player so thats why I said they could be any colour. Only thing is that in GR.8 the gfxs pixels are in white that is luminance E and the reason why I said that you can use any colour but it must be in luminance E because it will always take the PF1 luminance.

But on GR.11 the best seems that you always use white for the shots in 5th Player mode.

 

Just some ideas...

As a side note I noticed that NTSC guys get the traditional Artifacting looking good and most of the time the parallax part is in a different colour than the main complex gfxs (this way the shots/PF3 are in solid white and different than the artifacted gfxs then no need to change).

For PAL guys there's some nice blending and even better in the ANTIC4 grounds with some new shades/colours.

[kiwilove]

 

Thanks Jason. No it's too big now to run from a 1050. This was not an easy decision to make and we ummed and ahhed over it for a long time but eventually decided it would be more fun to go the big cartridge route.

As seen in the very first demo release - the original intention was for it to be disk based for 48k Atari's - but it was changed because blank diskettes were not easily available and also that disk drives weren't used as much nowadays, in that flashdrives or rather flashcarts were in use more and more. The transfer going the cart route had the attraction that it can now run on 16k Atari's 400/800 machines. Also the 5200 option came up - which we never envisaged at the start of this project - which we never even considered. The reception of the 5200 version was even better received because obviously they have had fewer releases than the computer line. Now with adding the Antic modes 2 and 4 (which we never thought of using, at the very start...) the size is bigger than a disk as such..

 

This project has encompassed more and more things than we first imagined it will... and so far this is generally a good/better thing. This game was not to be some kind of Xevious like game (that Hawkquest tries to capture...) - and cannot be when it's original design and implementations were not headed in that direction. Though it may be (or not?) possible to add some elements of that game?

Various other conditions are attached - which I won't detail further. We anticipate a much slower progress with the game's development in future - and I hope you guys do appreciate seeing it's progress so far... It could have been kept 'top secret' until it's eventual release upon completion.

 

Harvey