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Player/Missiles as Overlays for software sprites

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What I hate about many games that have been ported to the

800 are the 1-colored players.


I'm working on some stuff using players as overlays for

software sprites (Graphics 12), that way with GPRIOR=0

you can have objects with 6 colors. Combined players

and missiles are 10 pixels wide. Not as good as the

the C64's multicolor sprites, but better than single-colored



The idea is to have 4 of these objects in a line. Vertical

multiplexing is simple on the ATARI and very colorful

games should be doable.


I will make a minigame using that technique first, I can't

do animations there, but it should be quite colorful.


This does also work in HiRes, although you have less

extra colors there. In theory, colorful HiRes sprites

are possible. Something like "Starquake" just with

colorful sprites.



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Cool - I am messing around with some stuff in Gr.12 too. Don't expect to see anything from me anytime soon though. Just tinkering at the moment. Good luck with your project! Colored hi-res is always a good thing on the A8.


Stephen Anderson

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Software sprites are somewhat time consuming, especially in character mode.


I wrote an engine to do 12x24 pixel sprites - which effectively means defining 4x3 characters. I calculated that it could probably move 8 sprites per frame.


Doing it in bitmap mode would yield faster results but then you lose a colour.


Elsewhere, Heaven started a thread on strip sprites - they use self-modifying code, a routine that uses about 2.5 K or so, but it is probably the fastest method of displaying sprites.


There's also the method some games use (e.g. Donkey Kong ) of just EORing the data with the background, although that produces colour changes which can be undesired, plus probably wouldn't look so great with underlays.


Animations aren't really much extra effort - all you are doing is changing the source data location. But for speed it is imperative to have pre-shifted sprite and mask data already stored.


As such, to calculate the memory usage for a single animation, you may as well multiply each frame's worth of data by 8, minus (8 * the height of the sprite in chrs).

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yeah. i messed around while looking to donkey kong and zone ranger. and the zone ranger sprite routine is the fastes i have seen at the moment and it is written very fast but not too complicated as far as i remember. i had a discussion with TMR about soft sprites and i come to conclusion that unfortunatly on atari it takes a lot of ram and cpu time in gr.12 or you are doing it like in dropzone. but "real" softsprites are very timeconsuming neverless what others say.


so if i would do a game with softsprites i would first try to preshift the stuff and use fonts like done in dropzone f.e. but if i want to have "real sprites" with background masking etc i would go the zone ranger way unless i figure a nice and fast routine for a "bubble bobble" c64 soft sprite routine (the bubbles are chars if i am right).


nice that Rybags remembers my researching... i was doing that long time ago...

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