4cade/src/glue.decompress.a
2021-11-17 00:25:17 -05:00

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;license:MIT
;(c) 2018-2020 by 4am & qkumba
;
; Exomizer glue functions
;
; Public functions
; - DecompressHGR
; - DecompressDHGR
; - DecompressSHR
;
DECRUNCH = $0314 ; decrunch entry point
;------------------------------------------------------------------------------
; DecompressSHR
;
; in: compressed SHR loaded to $1FF8+
; file size in sizelo2/sizehi2 as set by ProRWTS2
; out: decompressed SHR at $2000..$9FFF
; $00A7..$00A8 clobbered by decompressor
; $00AE..$00AF clobbered by decompressor
; $00FC..$00FF clobbered by decompressor
; $0200..$03CB clobbered by decompressor
;------------------------------------------------------------------------------
DecompressSHR
lda #$1F
+HIDE_NEXT_2_BYTES
; /!\ execution falls through here
;------------------------------------------------------------------------------
; DecompressHGR
;
; in: compressed HGR loaded to $3FF8+
; file size in sizelo2/sizehi2 as set by ProRWTS2
; out: decompressed HGR at $4000..$5FFF
; $00A7..$00A8 clobbered by decompressor
; $00AE..$00AF clobbered by decompressor
; $00FC..$00FF clobbered by decompressor
; $0200..$03CB clobbered by decompressor
;------------------------------------------------------------------------------
DecompressHGR
lda #$3F
pha
jsr SwitchToBank2
jsr EnableAccelerator
lda sizehi2
pha
lda sizelo2
pha
lda #>(@loaddecrunch - 1)
pha
lda #<(@loaddecrunch - 1)
pha
lda auxreq
bne +
jmp LoadIndexedFile ; load decompression code to $200
+ jmp LoadAuxIndexedFile ; load decompression code to $200/aux
@loaddecrunch
!word $200
!word kDecrunchRecord
ldx auxreq
sta READMAINMEM,x ; X = 0 or 1, so this will be READMAINMEM or READAUXMEM
sta WRITEMAINMEM,x ; X = 0 or 1, so this will be WRITEMAINMEM or WRITEAUXMEM
jsr DECRUNCH ; loaded from separate file
jsr SwitchToBank2
jmp DisableAcceleratorAndSwitchToBank1
;------------------------------------------------------------------------------
; DecompressDHGR
;
; in: compressed DHGR loaded to aux $3FF8+
; file size in sizelo2/sizehi2 as set by ProRWTS2
; out: decompressed HGR at $4000..$5FFF/main and $4000..$5FFF/aux
; $6000..$7FFF/aux clobbered by decompressor
; $00A7..$00A8 clobbered by decompressor
; $00AE..$00AF clobbered by decompressor
; $00FC..$00FF clobbered by decompressor
; $0200..$03CB clobbered by decompressor
;------------------------------------------------------------------------------
DecompressDHGR
jsr DecompressHGR
sta WRITEMAINMEM
lda #$60
sta PageFrom+2
lda #$40
jmp CopyHGR ; switches back to READMAINMEM on exit