Re: A82: Side-Scrolling


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Re: A82: Side-Scrolling




could you not just back the old screen up to the apdbuf, then simply scroll 
one, write a verticle line(use a hacked 8byX routine), scroll again, 
write..... till the whole thing is on the screen. this would take up verry 
little room, and if its not possible to back it up to the apdbuf and must 
remain on the graphmem, simply back it up, and hack the bufcopy routine to 
point to the apdbuf, it would be much more logical than using a sprite 
routine to do the work, much faster too



----Original Message Follows----
From: "Sam Heald" <evil_sam@hotmail.com>
Reply-To: assembly-82@lists.ticalc.org
To: assembly-82@lists.ticalc.org
Subject: A82: Side-Scrolling
Date: Sun, 12 Dec 1999 19:15:02 PST


Does anyone have any ideas on how to smooth scroll (pixel by pixel) a
picture onto the screen horizontally? The only minor snag is that the
current contents of GRAPH_MEM cannot be deleted as the new data scrolls onto
the screen (the old data scrolls off as the new scrolls on, and that is
easily accomplished). The technique I'm using now treats the entire picture
as one gigantic sprite. The current screen is GRAPH_MEM, the new screen is
APD_BUF. It scrolls APD_BUF by changing the x coord and using a hacked
version of CrASH_Man's PutSprClip that'll automask and work for an entire
screen. The GRAPH_MEM scrolls off of the screen using a simple routine
similar to CrASH_Man's Scrolling routines. My technique works, but the
hacked sprite routine and utility routines take up too much room(~250 bytes)
for such a trivial effect. Zelda will be a pretty tight budget of space, so
I really can't afford to waste space unneccessarily. Any thoughts?
   Sam

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