Subject: Re: [stella] GunFight 2600: Limit broken again! Now help needed! :-)|
From: Manuel Polik <manuel.polik@xxxxxxxxxxx>
Date: Thu, 15 Feb 2001 18:57:25 +0100
Manuel Polik wrote: > Hehe, you're right. At the moment it's just: If I don't do the two CLCs, > the sprites start to jump. Maybe it's worth to investigate WHY :-) Ok... the carry needs a defined state, that's all. Both the addition & the subtraction mess around with the carry, so when the sprites overlap vertically like this...: 0 ***** 1 0 ***** 1 0 ***** 1 ***** 1 ***** 1 ***** 1 0 ***** 1 0 ***** 1 0 SP1 C SP2 C ... the bottom of SP1 would clear the carry while SP2 is drawed and the top of SP2 would clear it for SP1. On these two positions I'd lose a line of the sprite, because of the jump. Now I just made a SEC replace a NOP in my skipdraw routines. The four won cycles now provide black 'guns' :-) It's now single again, since in a 2LK I'd have to do the color writes in the second line too, or? ARGH!!! ... with 4 color-writes per line, I win next to nothing in a 2LK. Any ideas around that problem? (I mean - besides buffering the player colors in the RAM and/or TXS&TSX... :-)) And: can someone give me a crash course in clever missile programming? I mean, do I really have to tweak ENAMx all the time? what about just making the missile invisible with the background color? I just thought I wouldn't need to determine _where_ the missile is, since it is aligned with the player, but with ENAMx I fear I need to know _exactly_ where it is... And another question: What all is delayed with VDEL? Just STA GRPx? What about STA NUSIZx? Greetings, Manuel P.S.: Just the binary this time, the delta in the source is < 5 lines and described in the mail.
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