A83: Re: Re: call question

To: <assembly-83@lists.ticalc.org>
Subject: A83: Re: Re: call question
From: "James Matthews" <matthews@tkb.att.ne.jp>
Date: Sun, 25 Oct 1998 13:07:42 +0900
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-83@lists.ticalc.org


If speed is not of the UTMOST importance:

ld	b,10	
ld	c,10	; Testing for (10,10)
ld	d,3
call	_ipoint
jr	z,on
jr	off

Later,

James Matthews (matthews@tkb.att.ne.jp)

ICQ: 7413754
http://home.att.ne.jp/gold/tomcat21/index.html
http://library.advanced.org/18242/

----------
> From: David Phillips <electrum@tfs.net>
> To: assembly-83@lists.ticalc.org
> Subject: A83: Re: call question
> Date: Sunday, October 25, 1998 7:14 AM
> 
> 
> You call your FindPixel function, then check to see if it is on or off:
> 
> FindPixel:
> ; IN: B,C = X,Y
> ; OUT: HL = pointer to pixel in video buffer, A = mask
> ...
> 
> ld bc,(37 << 8)+25        ; check pixel at (37, 25)
> call FindPixel            ; get address/mask
> and (hl)                  ; test pixel
> jr z,pixel_is_off         ; if zero, pixel is off
> pixel_is_on:              ; if not, it is on
> 
> 
> -----Original Message-----
> From: Heydude27@aol.com <Heydude27@aol.com>
> To: assembly-83@lists.ticalc.org <assembly-83@lists.ticalc.org>
> Date: Saturday, October 24, 1998 11:23 AM
> Subject: A83: call question
> 
> 
> >
> >Does anyone know how to detect if a pixel is on or off, and how to use it.
> >Thanks
>