xmas2023: some scrolling

This commit is contained in:
Vince Weaver 2023-12-20 00:48:41 -05:00
parent 04f628973c
commit 08a2f6dbf5

View File

@ -1,3 +1,9 @@
mod7_table = $1c00
div7_table = $1d00
hposn_low = $1e00
hposn_high = $1f00
;=============================
; draw the fireplace scene
;=============================
@ -6,6 +12,11 @@ fireplace:
sta FRAMEL
sta FRAMEH
lda #120
sta HGR_COPY_Y1
lda #160
sta HGR_COPY_Y2
bit SET_GR
bit LORES
bit FULLGR
@ -168,6 +179,46 @@ frame_inc_done:
;==================
; do the action
; 4 paths?
; nothing
; draw fire1
; draw fire2
; copy hgr line
do_action:
ldx HGR_COPY_Y1 ; 3
lda hposn_high,X ; 4
clc ; 2
adc #$20 ; 2
sta INH ; 3
lda hposn_low,X ; 4
sta INL ; 3
; 21
ldx HGR_COPY_Y2 ; 3
lda hposn_high,X ; 4
clc ; 2
adc #$20 ; 2
sta OUTH ; 3
lda hposn_low,X ; 4
sta OUTL ; 3
; 21
ldy #39 ; 2
copy_hgr_line_loop:
lda (INL),Y ; 5
sta (OUTL),Y ; 6
dey ; 2
bpl copy_hgr_line_loop ; 2/3
; 2+(40*16)-1 = 641
inc HGR_COPY_Y1 ; 5
inc HGR_COPY_Y2 ; 5
; do the lores screen, 160 lines
@ -175,15 +226,14 @@ frame_inc_done:
; -4 (bit LORES)
; -15 (inc FRAME)
; -3 (jmp)
; -693
;=======
;10378
; 9685
; Try X=17 Y=114 cycles=10375
; Try X=214 Y=9 cycles=9685
lda $0 ; nop3
ldy #114 ; 2
loop3: ldx #17 ; 2
ldy #9 ; 2
loop3: ldx #214 ; 2
loop4: dex ; 2
bne loop4 ; 2nt/3
dey ; 2