mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-06-17 13:29:39 +00:00
203 lines
3.5 KiB
ArmAsm
203 lines
3.5 KiB
ArmAsm
; do a (hopefully fast) plasma type demo
|
|
|
|
; 151 -- original
|
|
; 137 -- optimize generation
|
|
; 136 -- align lookup table so we can index it easier
|
|
; 130 -- optimize indexing of lookup
|
|
; 126 -- run loops backaward
|
|
; 124 -- notice X already 0 before plot
|
|
; 131 -- use GBASCALC. much faster, but 7 bytes larger
|
|
; 129 -- run loop backwards
|
|
; 128 -- set color ourselves
|
|
; 127 -- overlap color lookup with sine table
|
|
; 119 -- forgot to comment out unused
|
|
; 121 -- make it use full screen (40x48)
|
|
|
|
; 149 -- add page flipping
|
|
; 144 -- optimize a bit
|
|
; 141 -- smc DRAW_PAGE
|
|
|
|
; goal=135
|
|
|
|
.include "zp.inc"
|
|
.include "hardware.inc"
|
|
|
|
CTEMP = $FC
|
|
SAVEOFF = $FD
|
|
SAVEX = $FE
|
|
SAVEY = $FF
|
|
|
|
;================================
|
|
; Clear screen and setup graphics
|
|
;================================
|
|
plasma:
|
|
|
|
jsr SETGR ; set lo-res 40x40 mode
|
|
bit FULLGR ; make it 40x48
|
|
|
|
|
|
|
|
; color = ( 8.0 + 8*sin(x) + 8.0 + 8*sin(y) )/2
|
|
; becomes
|
|
; color = ( 16 + (sintable[xx&0xf]) + (sintable[yy&0xf])) / 2;
|
|
|
|
; we only create a 16x16 texture, which we pattern across 40x48 screen
|
|
|
|
create_lookup:
|
|
ldy #15
|
|
create_yloop:
|
|
ldx #15
|
|
create_xloop:
|
|
clc
|
|
lda #15 ; 8+8 (but 15 works better)
|
|
adc sinetable,X
|
|
adc sinetable,Y
|
|
lsr
|
|
lookup_smc:
|
|
sta lookup ; always starts at $d00
|
|
|
|
inc lookup_smc+1
|
|
|
|
dex
|
|
bpl create_xloop
|
|
|
|
dey
|
|
bpl create_yloop
|
|
|
|
; X and Y both $FF
|
|
|
|
create_lookup_done:
|
|
|
|
forever_loop:
|
|
|
|
cycle_colors:
|
|
; cycle colors
|
|
|
|
; can't do palette rotate on Apple II so faking it here
|
|
; just incrementing every entry in texture by 1
|
|
|
|
; X if $FF when arriving here
|
|
; ldx #0
|
|
inx ; make X 0
|
|
cycle_loop:
|
|
inc lookup,X
|
|
inx
|
|
bne cycle_loop
|
|
|
|
|
|
|
|
|
|
; set/flip pages
|
|
; we want to flip pages and then draw to the offscreen one
|
|
|
|
flip_pages:
|
|
|
|
; ldx #0 ; x already 0
|
|
|
|
lda draw_page_smc+1 ; DRAW_PAGE
|
|
beq done_page
|
|
inx
|
|
done_page:
|
|
ldy PAGE0,X ; set display page to PAGE1 or PAGE2
|
|
|
|
eor #$4 ; flip draw page between $400/$800
|
|
sta draw_page_smc+1 ; DRAW_PAGE
|
|
|
|
|
|
; plot current frame
|
|
; scan whole 40x48 screen and plot each point based on
|
|
; lookup table colors
|
|
plot_frame:
|
|
|
|
ldx #47 ; YY=47 (count backwards)
|
|
|
|
plot_yloop:
|
|
|
|
txa ; get (y&0xf)<<4
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
sta CTEMP ; save for later
|
|
|
|
txa ; get Y in accumulator
|
|
lsr ; call actually wants Ycoord/2
|
|
|
|
php ; save shifted-off low bit in C for later
|
|
|
|
jsr GBASCALC ; point GBASL/H to address in (A is ycoord/2)
|
|
; after, A is GBASL, C is clear
|
|
|
|
lda GBASH ; adjust to be PAGE1/PAGE2 ($400 or $800)
|
|
draw_page_smc:
|
|
adc #0
|
|
sta GBASH
|
|
|
|
plp ; restore C, indicating odd/even row
|
|
|
|
lda #$0f ; setup mask for odd/even line
|
|
bcc plot_mask
|
|
adc #$e0 ; needlessly clever, from monitor rom src
|
|
plot_mask:
|
|
sta MASK
|
|
|
|
;==========
|
|
|
|
ldy #39 ; XX = 39 (countdown)
|
|
|
|
plot_xloop:
|
|
|
|
stx SAVEX ; SAVE YY
|
|
|
|
tya ; get x&0xf
|
|
and #$f
|
|
ora CTEMP ; combine with val from earlier
|
|
; get ((y&0xf)*16)+x
|
|
|
|
tax
|
|
|
|
plot_lookup:
|
|
|
|
; sta plot_lookup_smc+1
|
|
|
|
plot_lookup_smc:
|
|
lda lookup,X ; load lookup, (y*16)+x
|
|
; lda lookup ; load lookup, (y*16)+x
|
|
|
|
and #$f
|
|
lsr ; we actually only have 8 colors
|
|
|
|
tax
|
|
lda colorlookup,X ; lookup color
|
|
sta COLOR ; each nibble should be same
|
|
|
|
jsr PLOT1 ; plot at GBASL,Y (x co-ord goes in Y)
|
|
|
|
ldx SAVEX ; restore YY
|
|
|
|
dey
|
|
bpl plot_xloop
|
|
|
|
dex
|
|
bpl plot_yloop
|
|
bmi forever_loop
|
|
|
|
colorlookup:
|
|
bw_color_lookup:
|
|
.byte $55,$22,$66,$77,$ff,$77,$55 ; ,$00 shared w sin table
|
|
|
|
; this is actually 8*sin(x)
|
|
sinetable:
|
|
.byte $00,$03,$05,$07,$08,$07,$05,$03
|
|
.byte $00,$FD,$FB,$F9,$F8,$F9,$FB,$FD
|
|
|
|
;colorlookup:
|
|
;.byte $00,$00,$05,$05,$07,$07,$0f,$0f
|
|
;.byte $07,$07,$06,$06,$02,$02,$05,$05
|
|
;.byte $00,$55,$77,$ff,$77,$66,$22,$55
|
|
|
|
; make lookup happen at page boundary
|
|
|
|
.org $d00
|
|
lookup:
|