mode7_demo: initial fading code

This commit is contained in:
Vince Weaver 2017-12-17 22:03:20 -05:00
parent 7d61a84afc
commit ca61c86a63

View File

@ -7,7 +7,7 @@
jsr clear_screens ; clear top/bottom of page 0/1
jsr set_gr_page0
lda #$0
lda #$4
sta DRAW_PAGE
lda #<demo_rle
@ -23,15 +23,53 @@
jsr load_rle_gr
loop_forever:
lda #<fade_lookup
sta GBASL
lda #>fade_lookup
sta GBASH
loop_forever:
jsr gr_fade
jsr page_flip
lda #200
jsr WAIT
lda #<(fade_lookup+16)
sta GBASL
lda #>(fade_lookup+16)
sta GBASH
jsr gr_fade
jsr page_flip
lda #200
jsr WAIT
lda #<(fade_lookup+32)
sta GBASL
lda #>(fade_lookup+32)
sta GBASH
jsr gr_fade
jsr page_flip
lda #200
jsr WAIT
lda #<(fade_lookup+48)
sta GBASL
lda #>(fade_lookup+48)
sta GBASH
jsr gr_fade
jsr page_flip
lda #200
jsr WAIT
jmp loop_forever
@ -47,17 +85,17 @@ gr_fade:
gr_copy_loop:
lda gr_offsets,X ; lookup low byte for line addr ; 4+
sta gr_copy_line+1 ; out and in are the same ; 4
sta gr_copy_line+4 ; 4
sta gr_copy_line1+1 ; out and in are the same ; 4
sta gr_copy_line2+1 ; 4
lda gr_offsets+1,X ; lookup high byte for line addr ; 4+
clc ; 2
adc DRAW_PAGE ; 3
sta gr_copy_line+5 ; 4
sta gr_copy_line2+2 ; 4
lda gr_offsets+1,X ; lookup high byte for line addr ; 4+
adc #$8 ; for now, fixed 0xc ; 2
sta gr_copy_line+2 ; 4
sta gr_copy_line1+2 ; 4
ldy #0 ; set xpos counter to 0 ; 2
@ -67,16 +105,44 @@ gr_copy_loop:
gr_copy_below4:
ldy #119 ; for early ones, copy 120 bytes ; 2
bcc gr_copy_line ; ; 3
bcc gr_copy_line1 ; ; 3
gr_copy_above4: ; for last four, just copy 80 bytes
ldy #79 ; 2
gr_copy_line:
gr_copy_line1:
lda $ffff,Y ; load a byte (self modified) ; 4+
pha
sty TEMPY ; save Y
; do high nibble
and #$f0
lsr
lsr
lsr
lsr
tay
lda (GBASL),Y
and #$f0
sta TEMP
; do low nibble
pla
and #$0f
tay
lda (GBASL),Y
and #$0f
ora TEMP
ldy TEMPY ; restore Y
gr_copy_line2:
sta $ffff,Y ; store a byte (self modified) ; 5
dey ; decrement pointer ; 2
bpl gr_copy_line ; ; 2nt/3
bpl gr_copy_line1 ; ; 2nt/3
gr_copy_line_done:
inx ; increment ypos value ; 2
@ -93,13 +159,14 @@ gr_copy_line_done:
.include "../asm_routines/gr_unrle.s"
.include "../asm_routines/hlin_clearscreen.s"
.include "../asm_routines/gr_setpage.s"
.include "../asm_routines/pageflip.s"
.include "mode7_demo_backgrounds.inc"
; Fade paramaters
fade_lookup:
.byte $0,$1,$2,$3,$4,$5,$6,$7, $8,$9,$a,$b,$c,$d,$e,$f
.byte $0,$0,$0,$2,$0,$0,$2,$5, $5,$8,$5,$3,$4,$8,$4,$7
.byte $0,$0,$0,$0,$0,$0,$5,$0, $0,$0,$0,$0,$8,$0,$0,$5
.byte $0,$0,$0,$0,$0,$0,$0,$0, $0,$0,$0,$0,$0,$0,$0,$0
.byte $00,$11,$22,$33,$44,$55,$66,$77, $88,$99,$aa,$bb,$cc,$dd,$ee,$ff
.byte $00,$00,$00,$22,$00,$00,$22,$55, $55,$88,$55,$33,$44,$88,$44,$77
.byte $00,$00,$00,$00,$00,$00,$55,$00, $00,$00,$00,$00,$88,$00,$00,$55
.byte $00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00,$00