Yer, with limited tiles its not soo bad. The current thing im working on uses a 
change check for updates but that's not for scrolling.  Im just not sure any 
method would work for a mode 4 screen, its just too much data. 

 

Adrian

 

From: owner-sam-us...@nvg.ntnu.no [mailto:owner-sam-us...@nvg.ntnu.no] On 
Behalf Of Thomas Harte
Sent: 21 April 2012 18:31
To: sam-users@nvg.ntnu.no
Subject: Re: Musics

 

The best idea I've come up with is to use a very limited number of tiles and 
scroll like one of those infinite ball demos.

 

So, you have 8x8 tiles and 8 screen buffers. You scroll only either 1 or zero 
pixels at a time, only ever in one direction. Assuming it's a right to left 
scroll, for each movement you switch from one buffer to the next. Then run 
through each on-screen tile and paint only if that tile is not the same as the 
tile one position to its left.

 

With a small number of possible tiles and a normal sort of platform game layout 
(ie, lots of horizontal platforms) you shouldn't have to draw all that much. 
Level two of Super Mario Brothers would probably be an ideal usage case.

 

I guess that the next thing would be to store your tile map as the computed 
list of tile changes to draw per tile column, and to consider whether compiling 
your tiles so that you map from the combination of old tile and new to the code 
and draw only the changes gives a meaningful boost for the memory cost.

 

I'm not sure whether anybody else has done this sort of thing, but I really 
mean to give it a go sometime soon.


On Saturday, 21 April 2012, Adrian Brown wrote:

That's top, im a child of the electronic sound - don't think my wife is too 
impressed with it blasting out of the office though ;)  Im working on some 
other sam bits at the moment (when time allows)  For programmery people, 
scrolling on sam is what let it down imho.  Thinking of something like sanxion, 
who has some ideas on how to move that much data.  Im guessing it would have to 
be mode 2 to really be able to get a decent speed scroller.  Ive tried various 
things for a decent speed scroll mode 4, but it just doesn't seem possible if 
you want a lot of graphics on screen, even with compiled block data.

 

Adrian

 

From: owner-sam-us...@nvg.ntnu.no 
<javascript:_e(%7b%7d,%20'cvml',%20'owner-sam-us...@nvg.ntnu.no');>  
[mailto:owner-sam-us...@nvg.ntnu.no 
<javascript:_e(%7b%7d,%20'cvml',%20'owner-sam-us...@nvg.ntnu.no');> ] On Behalf 
Of David Sanders
Sent: 20 April 2012 11:16
To: sam-users@nvg.ntnu.no 
<javascript:_e(%7b%7d,%20'cvml',%20'sam-users@nvg.ntnu.no');> 
Subject: Musics

 

Hello List,

 

If anyone fancies a listen to the most fiendishly complicated piece of Sam 
music I've written, here it is:

 

http://dsanders.co.uk/sanxion.dsk

 

It's kind of a conversion of Rub Hubbard's Sanxion loader, but done from memory 
so probably quite different. I believe the effect at around 2:00 has never been 
done before on the Coupé! A first time for everything even on the Sam eh? So, 
why did I spend my morning writing this? Your guess is as good as mine, but I 
reckon someone now ought to make the effort to convert the actual game. Ahem.

 

Cheers

 

 

David

 

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