[A83] Re: moving sprites

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: moving sprites
From: "Ronald Teune" <rtwolf@gmx.net>
Date: Mon, 18 Mar 2002 16:57:01 +0100
References: <F104VNasmMPNBWbZ53q000240a6@hotmail.com>
Reply-To: assembly-83@lists.ticalc.org


Since nobody sees the error in this program: pushing/popping within calls is
not a good idea.
Please correct me if I'm wrong.


>
> Most sprite routines destroy the contents of the registers, so you need to
> push the registers, then pop them afterwards.  This little routine moves a
> sprite, and calls 'pushsprite', which pushes all the registers, then pops
> them after drawing the sprite.
>
>
> ld ix,sprite
> ld a,0
> ld l,32
> ld b,80
> SpriteMoveLoop:
> push bc
> inc a
> ld b,8
> call PushSprite
> call PushFastCopy
> call PushSprite
> pop bc
> djnz SpriteMoveLoop
>
> ret
>
> PushSprite:
> push af
> push bc
> push de
> push hl
> push ix
> call ionPutSprite
> popem:
> pop ix
> pop hl
> pop de
> pop bc
> pop af
>
> PushFastCopy:
> push af
> push bc
> push de
> push hl
> push ix
> call ionfastcopy
> jr Popem
>
> Sprite:
> ..db %00111100
> ..db %01000010
> ..db %10110001
> ..db %10100001
> ..db %10000001
> ..db %10000101
> ..db %01000010
> ..db %00111100
>
> I hope this works...
>
>
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References:

[A83] Re: moving sprites

From: "Dan Weiss" <dwedit@hotmail.com>