Re: [stella] Asymmetrical Reflected Playfield

Subject: Re: [stella] Asymmetrical Reflected Playfield
From: Glenn Saunders <cybpunks2@xxxxxxxxxxxxx>
Date: Fri, 21 Sep 2001 22:34:51 -0700
At 10:33 PM 9/21/2001 -0400, you wrote:
Have you given thought to stealing from Centipede?

If someone posts a disassembly I'll take a look at it.

What I don't like about that approach is that it forces spaces between the bricks. Sure, the spaces wind up being small enough that you couldn't drive a car through them, but it would result in a different play pattern having them alternated like that.

Also, the tombstones are taller than the mushrooms so the alternating pattern will be more obvious.

Even if the tombstones are striped I might need two scanlines between rows, one to increment the PF Ram pointers and the other to keep up with what's going on with the sprites.

I don't think striping the tombstones will look too bad. It could be considered a form of dithering to make them more grey. Congo Bongo attempts something like that for dithering. I might even try doing a closed venetian blind flicker, or would that drive people insane?

If I need to do a proper PF write on the same scanlines I'm doing the sprite logic I don't see myself having enough cycles.

As I outlined in an earlier email, I need to perform quite a bit of conditional evaluation on the sprite scanlines:

1) Do I display P0? If so, how far into the table do I index? Do I need to turn VDELP0 on?
2) Do I display P1? If so, how far into the table do I index? Do I need to turn VDELP1 on?
3) Do I display M0? If so, how far into the M0 width/fine-control table do I index?
3) Do I display M1? If so, how far into the M1 width/fine-control table do I index?

THEN I get to write the registers and I need to issue an HMOVE as well for the missile fine control adjustments to take.

Also, if I want full vertical res for the pedestrian motion I'm going to have to do have enough time to do the missile routines in the playfield scanline since there is no VDEL for the missiles.

(Centipede and Millipede compromise vertical motion. Smooth movement is more important than cosmetics to me.)

Or I could do something even wackier. If I do flicker the venitian blind, though, I can intelligently determine whether to do odd or even scanlines to avoid having to change the missiles on a playfield scanline. That would be pretty sneaky. Or I could just not do the playfield on that one scanline, have it drop out.

It's too early to tell how it's going to wind up in the end, I guess.

I'll just tackle features one at a time.

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