dos33fsprogs/xmas_2019/snow_slow.s

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2019-12-11 13:35:56 +00:00
; Display falling snow
; by deater (Vince Weaver) <vince@deater.net>
; Zero Page
FRAMEBUFFER = $00 ; $00 - $0F
YPOS = $10
YPOS_SIN = $11
CH = $24
CV = $25
GBASL = $26
GBASH = $27
BASL = $28
BASH = $29
FRAME = $60
WAITING = $62
LETTERL = $63
LETTERH = $64
LETTERX = $65
LETTERY = $66
LETTERD = $67
LETTER = $68
BLARGH = $69
HGR_COLOR = $E4
STATE = $ED
DRAW_PAGE = $EE
LASTKEY = $F1
PADDLE_STATUS = $F2
TEMP = $FA
SNOWX = $F0
.include "hardware.inc"
;==================================
;==================================
jsr hgr
bit PAGE0
bit SET_GR
bit FULLGR
bit HIRES
display_loop:
;=========================
; erase old snow
ldx #0
jsr hcolor_equals
ldx #0
erase_loop:
stx SNOWX
ldx SNOWX
ldy snow_xhs,X
lda snow_ys,X
pha
lda snow_xls,X
tax
pla
jsr hplot0
inc SNOWX
ldx SNOWX
cpx #8
bne erase_loop
;=========================
; draw new snow
ldx #3
jsr hcolor_equals
ldx #0
draw_loop:
stx SNOWX
ldx SNOWX
inc snow_ys,X
lda snow_ys,X
cmp #192
bne snow_done
lda #0
sta snow_ys,X
snow_done:
ldy snow_xhs,X
lda snow_ys,X
pha
lda snow_xls,X
tax
pla
jsr hplot0
inc SNOWX
ldx SNOWX
cpx #8
bne draw_loop
jmp display_loop ; 3
snow_xls:
.byte 10,30,50,70,90,110,0,10
snow_xhs:
.byte 0,0,0,0,0,0,1,1
snow_ys:
.byte 0,0,0,0,0,0,0,0
;.include "state_machine.s"
;.include "gr_hline.s"
;.include "../asm_routines/keypress.s"
;.include "gr_copy.s"
;.include "random16.s"
;.include "fw.s"
.include "hgr.s"