LF: Testing a pixel

LF: Testing a pixel

• Subject: LF: Testing a pixel
• From: Kevin T. Huber <khuber@MR.Net>
• Date: Fri, 29 Nov 1996 13:39:23 GMT
• In-Reply-To: <1.5.4.32.19961129191328.006825b8@mail.geocities.com>

Try calling flib[find_pixel] with the point and then testing the bit
returned in D0 against the memory location pointed to by the address in A0.


Should look something like:
        move.w y,-(a7)
        move.w x,-(a7)
        jsr flib[find_pixel]
        lea 4(a7),a7               ;reset stack ptr
        btst d0,(a0)            
        beq yup_pixel_set
nope_pixel_clear:
        ...
yup_pixel_set:
        ...


This is untested and probably won't work, but that's the idea.


-Kevin
khuber@mr.net


warn@geocities.com writes:
 > Can anyone tell me how (or point me to some source where I can find out how)
 > to test a pixel.  Yes, I have read all the docs and I realized that it has
 > something to do with find_pixel in the flib library, but I have no clue as
 > to the specifics.
 > 
 > Thank you for any help you can offer,
 >                         Andrew

• LF: Testing a pixel
• From: Andrew <warn@geocities.com>

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