Re: A83: Re: Many Pixels... Routine? =P


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Re: A83: Re: Many Pixels... Routine? =P




In a message dated 11/02/98 9:57:27 PM, electrum@tfs.net writes:

>What exactly are you trying to do?

I want to be able to list the coordinates somewhere in the program like so...

X_Data:	.db 14, 28, 29, 32, 96, 4, 35, etc.  
Y_Data:	.db 63, 25, 78, 79, 22, 12, 61, etc.  (Just examples)

...and then load the labels into registers to point to that data, then specify
how many pixels for it to plot... 'ld b, 7' since there's seven values in that
example. 

These are all various points that I know I want to plot throughout the screen,
and have no order to use a large sprite routine for, so I want to be able to
just let it plot anything I list. Since it will be Many pixels, it should
write them to the Graph Buffer, and then I can copy the buffer to the
display...

>You can use or write your own FindPixel function, which is a
>function that you pass the X,Y coords (usually in BC or DE) that
>returns the address in the video buffer of the pixel and the

>bitmask of the pixel in A.  It would look like this:



>ld bc,(19<<8)+37    ; draw pixel at (19, 37)

>call FindPixel

>or (hl)             ; set the pixel in the video buffer

>ld (hl),a           ; and save it, because "or (hl)" saves it in A

Ok, I'm not quite familiar with all that yet, like using bitmasks and such, so
it would be very helpful if I could have a routine that carries out this
function, and I can learn off of that... I see your example will write this
individual point, but I need a routine that will go down this array of
coordinate data, looking up each point, then incrementing to the next location
of data in the series of '.db's...
																--Jason K.