Paul Slocum wrote:
> Without a HUGE improvement in the speed of the map generation, I
> don't know of a way to fix it. And rewriting the map generation
> system is not something I'm too excited about. It is pretty
> complicated, and there's not a lot of memory to spare.
Have you calculated how much time (worst case) you need in total for
scrolling and generating a new line?
The are some chances for optimization, but I don't know how much time
you have to save. E.g.
>From scrollRight:
lda levelDataA+4,y ;4
and #$F0 ;2
sta temp ;3
ldx levelDataA,y ;4
lda swap,x ;4
and #$0F ;2
ora temp ;3
sta levelDataA+4,y ;4 = 26
This can be replaced by:
lda levelDataA+4,y ;4
ldx levelDataA,y ;4
eor swap,x ;4
and #$F0 ;2
eor swap,x ;4
sta levelDataA+4,y ;4 = 22
There are many more places in the code, where this EOR trick can be
used. And if you have enough space (256 bytes) you could replace 4xLSR
with a large table and *maybe* save one blank line between the tiles.
How about generating the new line into an invisible buffer first and
then scroll and copy within one frame?
BTW: Why are you using BCD during map generation? Any clever trick I
am missing?
Have fun!
Thomas
_______________________________________________________
Thomas Jentzsch | *** Every bit is sacred ! ***
tjentzsch at web dot de |
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