dos33fsprogs/graphics/gr/mode7/rainbow_lookup.s
Vince Weaver e0febd1a90 demos: more work
keep making git mistakes urgh
2021-01-05 22:52:10 -05:00

25 lines
518 B
ArmAsm

;====================
; lookup_map
;====================
; finds value in space_x.i,space_y.i
; returns color in A
; CLOBBERS: A,Y
lda SPACEX_I ; 3
sta spacex_label+1 ; self modifying code, LAST_SPACEX_I ; 4
lda SPACEY_I ; 3
sta spacey_label+1 ; self modifying code, LAST_SPACEY_I ; 4
lda SPACEX_I
and #$f
sta TEMP
asl
asl
asl
asl
ora TEMP
eor SPACEY_I
sta map_color_label+1 ; self-modifying