Manuel wrote:
> What about limiting the number of tombstones per row?
> Let's say you've a max of four TS per row and you have tables like this:
>
> level1 .byte #<row1, #<row2, #<row3 ...
>
> ORG FX00
>
> row1 .byte pos3, pos6, pos12, empty
> row2 .byte pos1, pos5, empty, pos16
> ...
>
> Now in the kernel you'd access these tables like this:
>
> LDX level1,Y
>
> LDA FX00,X
> LDA FX00+1,X
> LDA FX00+2,X
> LDA FX00+3,X
That a very good approach, I really like it!
And by ORing two positions into ony byte (i.E. row1 .byte pos2|pos3, ...) it would be possible to put more than one tombstone into one PF variable.
As this happens inside the kernel, every cycle counts, so I have a little improvement:
Store the data for the (i.E. four) tombstones different and save the level1 table:
ORG FX00
NUMROWS = 20
first: .byte pos3, pos1, ...
second: .byte pos6, pos5, ...
third: .byte pos12, empty,...
fourth: .byte empty, pos16,...
The kernel could look like this:
ldy level
lda FX00+NUMROWS*0,y
lda FX00+NUMROWS*1,y
lda FX00+NUMROWS*2,y
lda FX00+NUMROWS*3,y
The problem is, that I don't know, if Glenn is generating random levels or not.
For predefined static levels this works perfect.
For somehow limited random levels, a small (NUMROWS bytes) RAM table (store offset into a bigger ROM table with predefined tombstone patterns) would be necessary.
If the tombstones should be totally random, this approach won't work. :(
> But I think you'll see only in practice which idea is best...
That's how coding for the 2600 works, sometimes a very little design change results in a totally different optimal solution.
Have fun!
Thomas
_______________________________________________________
Thomas Jentzsch | *** Every bit is sacred ! ***
tjentzsch at web dot de |
______________________________________________________________________________
Flug.de - 570.000 Nutzer, ein Ziel: der optimale Flug
http://flug.de/sb/?PP=0-5-100-105-12
-
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/
