Re: A83: pixel testing and ION
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Re: A83: pixel testing and ION
On Fri, 24 Sep 1999 19:10:27 -0400, Chris wrote:
>well again I ask how do you do a pixel test in ASM? With just the actual
>test and jp's but don't draw any pixels if it's on or off, cause that's
>what has been confusing me in all the source code I've looked at.
>
>About ion: Since I'm kind of new to 83 ASM I'm not too experianced but I
>would help in anyway possible. Just tell me how to port the code and i'll
>make all my games for 83 and +. But I don't have an 83 so I'm going to
>need someone who does to test it.
The _ipoint rom call can do this - do the following:
ld b,50 ; x coord
ld c,20 ; y coord
ld d,3 ; Tell rom call to test pixel
call _ipoint ; Test it!!
jr z,on ; If z, the point was on
off:
yadayadayada
on:
yadayadayada
The coord (0,0) is the bottom right of the screen. I hope this helps.
Check the proper TI documentation for more info.
James Vernon
jimbob_v@hotmail.com
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