2024-05-06 00:54:59 -04:00

442 lines
7.5 KiB
ArmAsm

; cosmic fish
; a variation on bubble universe tiny -- Apple II Lores
; what if you zoom into a bubble universe and it's full of
; space fish?
; by Vince `deater` Weaver
; this version based on fast c64 code by serato_fig
; as posted to the sizecoding discord
; based on his TIC-80 variant
; originally was working off the BASIC code posted on the pouet forum
; original effect by yuruyrau on twitter
; 578 bytes = original color
; 531 bytes = remove keyboard code
; 527 bytes = inline sine gen
; 523 bytes = optimize init a bit
; 301 bytes = generate color lookup table
; 297 bytes = optimize color lookup table
; 282 bytes = optimize color shift
; 266 bytes = reduce resolution of sine table x2
; 260 bytes = shave off some bytes with unneeded compares
; 255 bytes = reoptimize the sine doubler
; 264 bytes = add sound (urgh)
; 265 bytes = fix colors
; 263 bytes = waste a lot of time optimizing color lookup table
; 259 bytes = undo self modifying code
; 247 bytes = remove extra cosine table
; 245 bytes = minor fixes
; 268 bytes = back to 64 byte lookup
; 264 bytes = optimize sine/cosine init
; 262 bytes = optimize var init
; 259 bytes = use sine_base in place
; 262 bytes = add in movement, reduce sound
; 255 bytes = rediculous code that moved table setup to be overwritten
; and the linear parts and $59 of sine table generated
; 260 bytes = modify panning to be more interesting
; 258 bytes = make assumptions on value of Y
; 256 bytes = extend linear adjust of sine table
; soft-switches
SPEAKER = $C030
FULLGR = $C052
; ROM routines
PLOT = $F800 ; PLOT AT Y,A
SETGR = $FB40 ; enable lores 40x48 mode, split text screen
; and clear top of screen
; zero page
COLOR = $30 ; used by PLOT
;SINES_BASE = $C0
I = $D0
J = $D1
T = $D7
U = $D8
V = $D9
IS = $DA
IT = $DB
PAN = $DC
INL = $FC
INH = $FD
sines = sines_base-$1A ; overlaps some code
sines2 = sines+$100 ; duplicate so we can index cosine into it
cosines = sines+$c0
color_map = $1000
bubble_gr:
;=======================
; init graphics
;=======================
jsr SETGR
; can't rely on registers after this as different on IIe
; with 80 col card
bit FULLGR
;========================
;========================
; initialize lookup tables
;========================
;========================
; these moved to the end (at expense of 4 bytes)
; so we can over-write part of sine table on top of it
jsr init_code_to_be_destroyed
; X=0 here
;=========================
; reconstruct sine base
;=========================
; generate the linear $30..$42 part
; and also string of $59 on end
; removes 26 bytes from table
; at expense of 16+4 bytes of code
; (4 from jsr/rts of moving over-writable table code)
;sines:
; .byte $30,$31,$32,$33,$34,$35,$36,$37,$38,$39,$3A,$3B,$3C,$3D,$3E,$3F
; .byte $40,$41,$42
;
;old_sines_base:
; .byte $42,$43,$44,$45,$46,$47,$48,
;sines_base:
; .byte $48,$49,$4A,$4B,$4C,$4C
; .byte $4D,$4E,$4E,$4F,$50,$50,$51,$52,$52,$53,$53,$54,$54,$55,$55,$55
; .byte $56,$56,$57,$57,$57,$58,$58,$58,$58,$58
;fifty_nines:
; .byte $59,$59,$59,$59,$59,$59
; .byte $59
ldy #$19 ; offset
ldx #$48 ; want to write $48 downto $30
; with $42 doubled
looper:
txa
sta sines,Y ; sines+12 .... sines
lda #$59 ; also write $59 off the top
sta fifty_nines,Y
cpy #$13 ; we could save more bytes if we didn't
beq skipper ; bother trying to be exact
dex
skipper:
dey
bpl looper
;==========================
; make sine/cosine tables
;==========================
; floor(s*sin((x-96)*PI*2/256.0)+48.5);
;===================================
;
;
; final_sine[i]=quarter_sine[i]; // 0..64
; final_sine[128-i]=quarter_sine[i]; // 64..128
; final_sine[128+i]=0x60-quarter_sine[i]; // 128..192
; final_sine[256-i]=0x60-quarter_sine[i]; // 192..256
setup_sine_table:
ldx #64
ldy #64
setup_sine_loop:
lda sines,X
; sta sines,X
sta sines,Y
lda #$60
sec
sbc sines,X
sta sines+128,X
sta sines+128,Y
iny
dex
bpl setup_sine_loop
; X is $ff here
; Y is $81?
;=======================
; init variables
;=======================
; wipe all of zero page but $FF
; we only care about one value, the color at $30
; in theory we only need to clear/copy $00..$C0
; but not sure how to use to our advantage
; X is $FF
inx ; X=0
ldy #0 ; Y=0
init_loop:
; sta a:$D0,X ; force 16-bit so doesn't wrap
; because I guess it's bad to wipe zero page?
; maybe it isn't?
sty $D0,X ; clear zero page
lda sines,X ; duplicate sine table for cosine use
sta sines2,X
dex
bne init_loop
; lda #0
; stx U
; stx V
; stx T
; stx INL
; X = 0 here
; Y = 0 here
dex
stx COLOR ; $FF (color white)
;=========================
;=========================
; main loop
;=========================
;=========================
; in theory Y=0 from previous loop, and also from init?
next_frame:
; reset I*T
lda T
sta IT
; reset I*S
; Y should always be 0 at this point...
; lda #0
sty IS
i_smc:
lda #13 ; 13
sta I
i_loop:
j_smc:
lda #$18 ; 24
sta J
j_loop:
; bit SPEAKER ; click speaker
; where S=41 (approximately 1/6.28)
; calc: a=i*s+v;
; calc: b=i+t+u;
; u=sines[a]+sines[b];
; v=cosines[a]+cosines[b];
clc ; 2
lda IS
adc V
tay
clc
lda IT
adc U
tax
clc
lda cosines,Y ; 4+
adc cosines,X ; 4+
sta V
; max value for both is $60 so never sets carry
lda sines,Y ; 4+
adc sines,X ; 4+
sta U ; 3
; bit SPEAKER ; click speaker
;===========================================================
; original code is centered at 96,96 (on hypothetical 192x192 screen)
; we adjust to be 40x48 window centered at 48,48
; PLOT U-48,V-48
; U already in A
; sec
u_smc:
sbc #48
tay ; 2
cpy #40
bcs no_plot
; calculate Ypos
lda V
; sec
vsmc:
sbc #48
cmp #48
bcs no_plot
bit SPEAKER ; click speaker
jsr PLOT ; PLOT AT Y,A
no_plot:
dec J
bne j_loop
done_j:
clc
lda IS
adc #41 ; 1/6.28 = 0.16 = 0 0 1 0 1 0 0 0 = 0x28
sta IS
dec I
bne i_loop
done_i:
inc T
; no panning first 256 times
bne no_t_oflo
inc PAN
no_t_oflo:
clc
lda u_smc+1
adc PAN
sta u_smc+1
;=================
; cycle colors
;=================
cycle_colors:
ldy #$0 ; 2
lda #4 ; 2
sta INH ; 2
cycle_color_loop:
lda (INL),Y ; 2
tax ; 1
lda color_map,X ; 3
sta (INL),Y ; 2
iny ; 1
bne cycle_color_loop ; 2
; need to do this for pages 4-7
inc INH ; 2
lda INH ; 2
cmp #$8 ; 2
bne cycle_color_loop ; 2
beq next_frame ; bra ; 2
init_code_to_be_destroyed:
;========================
; color lookup
;========================
; 34 original
; 30 updated
; 31 fixed
; 29 improved
setup_color_lookup:
;================
; current best
ldx #0 ; init output pointer ; 2
first_loop:
ldy #$ff ; reset current value ; 2
loop1:
yloop:
iny ; current output value ; 1
yloop2:
tya ; 1
sta color_map,X ; values[y]=a; ; 3
iny ; 1
inx ; 1
beq done ; 2
cpx #16 ; 2
beq first_loop ; 2
txa ; 1
and #$f ; 2
beq yloop ; if nextcol==0, skip f->0 ; 2
lsr ; 1
bne yloop2 ; if nextcol!=1, y=y+1 ; 2
dey ; if nextcol==1, repeat y ; 1
jmp yloop2 ; 3
done:
rts
; .byte $30,$31,$32,$33,$34,$35,$36,$37,$38,$39,$3A,$3B,$3C,$3D,$3E,$3F
; .byte $40,$41,$42
;old_sines_base:
; .byte $42,$43,$44,$45,$46,$47,$48,
sines_base:
.byte $48,$49,$4A,$4B,$4C,$4C
.byte $4D,$4E,$4E,$4F,$50,$50,$51,$52,$52,$53,$53,$54,$54,$55,$55,$55
.byte $56,$56,$57,$57,$57,$58,$58,$58,$58,$58
fifty_nines:
; .byte $59,$59,$59,$59,$59,$59
; .byte $59
; floor(s*cos((x-96)*PI*2/256.0)+48.5);