mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-20 03:35:24 +00:00
113 lines
1.7 KiB
ArmAsm
113 lines
1.7 KiB
ArmAsm
;=================
|
|
; load RLE image
|
|
;=================
|
|
; Output is A:00 (assume page aligned)
|
|
; Input is in GBASH/GBASL
|
|
|
|
; format: first byte=xsize
|
|
; A0,X,Y means run of X bytes of Y color
|
|
; A1 means end of file
|
|
; A2-AF,X means run of low nibble, X color
|
|
; if high nibble not A: just display color
|
|
|
|
; CV = current Y
|
|
; CH = max xsize (usually 40)
|
|
; TEMP = page
|
|
; TEMPY= current X
|
|
|
|
|
|
load_rle_gr:
|
|
sec
|
|
sbc #4 ; adjust page to write to
|
|
; to match gr_offsets
|
|
sta TEMP
|
|
|
|
ldy #$0 ; init Y to 0
|
|
sty CV
|
|
|
|
jsr load_and_increment ; load xsize
|
|
sta CH
|
|
|
|
jsr unrle_new_y
|
|
|
|
|
|
rle_loop:
|
|
jsr load_and_increment
|
|
|
|
tax
|
|
|
|
cmp #$A1 ; if 0xa1
|
|
beq rle_done ; we are done
|
|
|
|
and #$f0 ; mask
|
|
cmp #$a0 ; see if special AX
|
|
beq decompress_special
|
|
|
|
; not special, just color
|
|
|
|
txa ; put color back in A
|
|
ldx #$1 ; only want to print 1
|
|
bne decompress_run
|
|
|
|
decompress_special:
|
|
txa ; put read value back in A
|
|
|
|
and #$0f ; check if was A0
|
|
|
|
bne decompress_color ; if A0 need to read run, color
|
|
|
|
decompress_large:
|
|
jsr load_and_increment ; run length now in A
|
|
|
|
decompress_color:
|
|
tax ; put runlen into X
|
|
jsr load_and_increment ; get color into A
|
|
|
|
decompress_run:
|
|
rle_run_loop:
|
|
sta (BASL),y ; write out the value
|
|
inc BASL
|
|
dec TEMPY
|
|
bne rle_not_eol ; if less then keep going
|
|
|
|
; if here, we are > max_X
|
|
|
|
inc CV
|
|
inc CV
|
|
pha
|
|
jsr unrle_new_y
|
|
pla
|
|
|
|
rle_not_eol:
|
|
dex
|
|
bne rle_run_loop ; if not zero, keep looping
|
|
|
|
beq rle_loop ; and branch always
|
|
|
|
rle_done:
|
|
lda #$15 ; move the cursor somewhere sane
|
|
sta CV
|
|
rts
|
|
|
|
|
|
load_and_increment:
|
|
lda (GBASL),Y
|
|
inc GBASL
|
|
bne lai_no_oflo
|
|
inc GBASH
|
|
lai_no_oflo:
|
|
rts
|
|
|
|
unrle_new_y:
|
|
ldy CV
|
|
lda gr_offsets,Y
|
|
sta BASL
|
|
lda gr_offsets+1,Y
|
|
clc
|
|
adc TEMP ; adjust for page
|
|
sta BASH
|
|
lda CH
|
|
sta TEMPY
|
|
ldy #0
|
|
rts
|