Re: [stella] Collaboration

Subject: Re: [stella] Collaboration
From: Glenn Saunders <cybpunks2@xxxxxxxxxxxxx>
Date: Sun, 12 Jan 2003 17:45:16 -0800
At 08:59 PM 1/12/2003 +0100, you wrote:
I have attached a very preliminary working demo. It only contains two of
the four needed kernels and still has some minimal flaws at the right
border. I rewrote it from scratch, but I tried to use Glenns variable
and constant names.

Wow! This is like a dream come true to see these guys moving finally after all this time. Thank you so much!

But you can already see both cars and one zombie moving smoothly, plus
another zombie that is jumping by one line (because the correct kernels
is still missing).

Let's modify the requirements a bit, or maybe debate them some to come up with a final featureset for the kernel (rubbing hands together with glee).

Although it looks like the ultimate ideal of full 1-scanline res movement accuracy on all object IS doable, it's at the cost of an opaque HMOVE comb on the left hand side of the screen. I was originally thinking that this would only have to be every other line (which would allow the sprites underneath to show up enough to allow them to move around in that area). Maybe that's impossible even when interlacing the missile updates?

Assuming that's necessary, the safe zone can't really extend completely to the left and I really have to constrain the zombies to the 2-playfield--pixel strip on either end (that I see you've widened, probably thinking the same thing I am.) So for the sake of symmetry, we don't need the zombies to be able to go to the far right of the screen either. Maybe that makes the timing a little easier?? Marginally?

Also, is there a way we can wrap the cars horizontally so they emerge bit by bit from the right hand side of the screen (like a vertical letterboxing effect)? The left would be taken care of by virtue of the HMOVE comb, but the right would naturally pop.

If the zombies only needed even/odd scanline positioning ala Super Challenge Football, what would that open up?

Also what are the chances of using the ball anywhere in the active part of the screen, assuming that all we may need is a single scanline brick shape?

Gaining the 5th sprite could enable that grenade idea I was talking about.

If the number of sub-kernels you had to do was doubled maybe you could hardcode all the ball position and width writes so that the Super Death Chase ghost could fade in and out and maybe shuffle left and right but not move vertically. It could then be a Wizard of War Wizard sort of character.

Also, how hard would it be to pull a Gunfight trick and make the zombie colors independent of the cars? The only thing I might want from this is to be able to do the Super Death Chase ghost, which should be white, not red or green. I could make it green and deliberately flicker it to black, I guess. The cool thing about that is I could flicker the green missile and flicker the other missile back and forth to generate red eyes.

The only thing that is NOT possible is a zombie pattern with a
completely empty line. Therefore I had to adjust the Ped1_1 pattern very
slightly at the neck.

That doesn't sound like too terrible a limitation although it will make my shapes for skeletons impossible. If I just do these generic guys and nothing else, I'll be more than happy.

I'm now very positive that Death Derby will be possible. :-)
And I hope this will encourage Glenn to continue his work.

I'm encouraged all right. You ARE going to go ahead and finish the kernel, right? How much time did you spend on this? You did it so fast!

If you get the "hard" stuff done I'll jump back in and restore the controller code and write some initial AI for the zombies (in the coin-op they move only in 4 directions but they are almost always moving in a fake-diagonal stagger-step pattern.).

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