fire: maybe make a smaller, firmware version?

This commit is contained in:
Vince Weaver 2019-01-02 16:41:48 -05:00
parent bf2010398a
commit 95c6dde2e7
4 changed files with 227 additions and 4 deletions

View File

@ -6,10 +6,11 @@ PNG_TO_RLE = ../gr-utils/png2rle
all: fire.dsk
fire.dsk: FIRE FIRE_TINY HELLO COOL_EFFECT
fire.dsk: FIRE FIRE_TINY FIRE_FIRMWARE HELLO COOL_EFFECT
$(DOS33) -y fire.dsk SAVE A HELLO
$(DOS33) -y fire.dsk BSAVE -a 0x1000 FIRE
$(DOS33) -y fire.dsk BSAVE -a 0x70 FIRE_TINY
$(DOS33) -y fire.dsk BSAVE -a 0x70 FIRE_FIRMWARE
$(DOS33) -y fire.dsk BSAVE -a 0x70 COOL_EFFECT
####
@ -29,6 +30,15 @@ FIRE_TINY: fire_tiny.o
fire_tiny.o: fire_tiny.s
ca65 -o fire_tiny.o fire_tiny.s -l fire_tiny.lst
####
FIRE_FIRMWARE: fire_firmware.o
ld65 -o FIRE_FIRMWARE fire_firmware.o -C ../linker_scripts/apple2_70.inc
fire_firmware.o: fire_firmware.s
ca65 -o fire_firmware.o fire_firmware.s -l fire_firmware.lst
####
@ -49,6 +59,6 @@ HELLO: hello.bas
#####
clean:
rm -f *~ *.o *.lst FIRE FIRE_TINY COOL_EFFECT HELLO
rm -f *~ *.o *.lst FIRE FIRE_TINY FIRE_FIRMWARE COOL_EFFECT HELLO

203
fire/fire_firmware.s Normal file
View File

@ -0,0 +1,203 @@
; Lo-res fire animation, size-optimized
; by deater (Vince Weaver) <vince@deater.net>
; based on code described here http://fabiensanglard.net/doom_fire_psx/
; 611 bytes at first
; 601 bytes -- strip out some unused code
; 592 bytes -- don't init screen
; 443 bytes -- remove more dead code
; 206 bytes -- no need to clear screen
; 193 bytes -- un-cycle exact the random16 code
; 189 bytes -- more optimization of random16 code
; 161 bytes -- move to 8-bit RNG
; 152 bytes -- reduce lookup to top half colors (had to remove brown)
; also changed maroon to pink
; 149 bytes -- use monitor GR
; 149 bytes -- load into zero page
; 140 bytes -- start using zero-page addressing
; 139 bytes -- rotate instead of mask for low bit
; 138 bytes -- bcs instead of jmp
; 137 bytes -- BIT nop trick to get rid of jump
; 135 bytes -- push/pull instead of saving to zero page
; 134 bytes -- replace half of lookup table with math
; 119 bytes -- replace that half of lookup table with better math
; 134 bytes -- replace other half of lookup table with math
; 132 bytes -- replace stack with zp loads
; 129 bytes -- use Y instead of X
; 125 bytes -- optimize low byte generationw with branch
; 113 bytes -- make get_row a subroutine
; 112 bytes -- regrettable change to the low-byte code
; 109 bytes -- replace BIT/OR in low calc with an ADC
; 107 bytes -- replace self-modifying load/store absolute with Y-indirect
; 106 bytes -- assume bit 8 is as random as bit 0
; Zero Page
SEEDL = $4E
TEMP = $00
TEMPY = $01
OUTL = $02
OUTH = $03
INL = $04
INH = $05
; 100 = $64
; Soft Switches
SET_GR = $C050 ; Enable graphics
FULLGR = $C052 ; Full screen, no text
LORES = $C056 ; Enable LORES graphics
; monitor routines
GR = $F390
fire_demo:
; GR part
jsr GR ; 3
bit FULLGR ; 3
;==========
; 6
; Setup white line on bottom
lda #$ff ; 2
ldy #39 ; 2
white_loop:
sta $7d0,Y ; hline 24 (46+47) ; 3
dey ; 1
bpl white_loop ; 2
;============
; 10
fire_loop:
ldx #22 ; 22 ; 2
yloop:
stx TEMPY ; txa/pha not any better ; 2
; setup the load/store addresses
; using Y-indirect is smaller than self-modifying code
jsr get_row ; 3
sty OUTL ; 2
sta OUTH ; 2
inx ; 1
jsr get_row ; 3
sty INL ; 2
sta INH ; 2
ldy #39 ; 2
xloop:
;=============================
; random8
;=============================
; 8-bit 6502 Random Number Generator
; Linear feedback shift register PRNG by White Flame
; http://codebase64.org/doku.php?id=base:small_fast_8-bit_prng
random8:
lda SEEDL ; 2
beq doEor ; 2
asl ; 1
beq noEor ; if the input was $80, skip the EOR ; 2
bcc noEor ; 2
doEor: eor #$1d ; 2
noEor: sta SEEDL ; 2
; end inlined RNG
bmi no_change ; assume bit 8 is as random as bit 0 ; 2
lda (INL),Y ; load value at row+1 ; 2
and #$7 ; mask off ; 2
tax ; 1
lda <(color_progression),X ; 2
.byte $2c ; BIT trick, nops out next instruction ; 1
no_change:
lda (INL),Y ; load value at row+1 ; 2
smc_sta:
sta (OUTL),Y ; 2
dey ; 1
bpl xloop ; 2
ldx TEMPY ; 2
dex ; 1
bpl yloop ; 2
bmi fire_loop ; 2
color_progression:
.byte $00 ; 8->0 ; 1000 0000
.byte $bb ; 9->11 ; 1001 1011
.byte $00 ; 10->0 ; 1010 0000
.byte $aa ; 11->10 ; 1011 1010
.byte $00 ; 12->0 ; 1100 0000
.byte $99 ; 13->9 ; 1101 1001
.byte $00 ; 14->0 ; 1110 0000
.byte $dd ; 15->13 ; 1111 1101
; Take row X and convert to address A:Y
get_row:
; get low byte
; 000X X00O
; lsr
; 0000 XX00 O
; adc #1
; 0000 XXOx
; lsr
; 0000 0XXO
; lsr
; 0000 00XX O
; ror
txa ; 1
and #$19 ; 2
lsr ; 1
adc #1 ; 2
lsr ; 1
lsr ; 1
tay ; 1
lda <low_offsets,Y ; 2
ror ; 1
tay ; 1
;===========
; 13
; high byte of store address
txa ; 1
and #$7 ; 2
lsr ; 1
ora #$4 ; 2
;===========
; 6
rts ; 1
; 14+6 = 20, as opposed to full lookup table which would be
; at least 24
; down to 13+3 at the expense of readability
; these are shifted left by one due to the algorithm
low_offsets:
.byte $00,$50,$a0

View File

@ -1,4 +1,4 @@
5 HOME
10 PRINT "FIRE DEMO V1.0"
10 PRINT "FIRE DEMO V1.1"
40 PRINT:PRINT
105 PRINT CHR$ (4)"BRUN FIRE_TINY"
105 PRINT CHR$ (4)"BRUN FIRE_FIRMWARE"

View File

@ -1,3 +1,13 @@
total size:
Demo code: 5k
MUSIC.lz4: 1k
ball.img: 8k
merry.img.lz4: 3k
wreath.img.lz4: 4k
============
21k
Memory Map:
00 Zero Page