ys2-intro/loader/tools/exomizer-3.1/exodecrs/split/main.s
2025-11-13 19:07:39 +03:00

80 lines
2.1 KiB
ArmAsm

; -------------------------------------------------------------------
; this file is intended to be assembled and linked with the cc65 toolchain.
; It has not been tested with any other assemblers or linkers.
; -------------------------------------------------------------------
; -------------------------------------------------------------------
; example usage of the standard decruncher
; this program decrunches data to memory
; -------------------------------------------------------------------
; if decrunching forwards then the following line must be uncommented.
;DECRUNCH_FORWARDS = 1
.IFNDEF DECRUNCH_FORWARDS
DECRUNCH_FORWARDS = 0
.ENDIF
; -------------------------------------------------------------------
.import split_gentable
.import split_decrunch
.export get_crunched_byte
.byte $01,$08,$0b,$08,<2003,>2003,$9e,'2','0','6','1',0,0,0
; -------------------------------------------------------------------
; we begin here
; -------------------------------------------------------------------
lda $02
sta _ebyte_lo
lda $03
sta _ebyte_hi
jsr get_Emerge_byte
sta _byte_lo
jsr get_Emerge_byte
cmp #0
beq done
sta _byte_hi
jsr split_gentable
next_part:
jsr get_Emerge_byte
sta _byte_lo
jsr get_Emerge_byte
cmp #0
beq done
sta _byte_hi
jsr split_decrunch
jmp next_part
done:
rts
; -------------------------------------------------------------------
get_Emerge_byte:
_ebyte_lo = * + 1
_ebyte_hi = * + 2
lda $ffff
inc _ebyte_lo
bne _ebyte_skip_hi
inc _ebyte_hi
_ebyte_skip_hi:
rts
; -------------------------------------------------------------------
get_crunched_byte:
.IF DECRUNCH_FORWARDS = 0
lda _byte_lo
bne _byte_skip_hi
dec _byte_hi
_byte_skip_hi:
dec _byte_lo
.ENDIF
_byte_lo = * + 1
_byte_hi = * + 2
lda $ffff ; needs to be set correctly before
.IF DECRUNCH_FORWARDS <> 0
inc _byte_lo
bne _byte_skip_hi
inc _byte_hi
_byte_skip_hi:
.ENDIF
rts ; decrunch_file is called.
; -------------------------------------------------------------------