At 03.03.2002, 01:15, Glenn Saunders wrote:
> The way I do it is to store a set of sprite graphics address pointers for
> each of the 15 unique sprite rotation settings (the 16th being the same as
> the 1st). Then I have a simple greater-than less-than check to determine
> whether to use the reflection bit or not. In other words, rotations 1-7
> (right) don't reflect, and 8-15 (left) do.
> I guess there is more than one way to do this sort of thing... It just
> seems like my way is the most straightforward.
> Thomas, how did you handle this in Thrust?
I have only 9 sprite graphics address pointers and do the reflection
with a simple compare, like you do. Here is the code:
MAXDIR = 32
;*** setup routine ***
lda P1dir
cmp #MAXDIR/2+1
bcc .noReflection
eor #$ff
adc #MAXDIR
.noReflection:
tax
lda ShipPatTab,x
...
;*** start of kernel ***
lda #MAXDIR/2-1 ; bit 3 is enabled here
cmp P1dir
bcs .noReflect
sta REFP1 ; enable bit 3
.noReflect:
Have fun!
Thomas
_______________________________________________________
Thomas Jentzsch | *** Every bit is sacred ! ***
tjentzsch at web dot de |
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