Files
alttpr-baserom/decompresseditemgraphics.asm
2024-02-23 11:11:59 -06:00

540 lines
8.8 KiB
NASM

;===================================================================================================
; Get the item's graphic from WRAM/ROM
; Bit 7 set indicates an explicit WRAM address
; Bit 7 reset indicates an offset into the ROM buffer
;===================================================================================================
;---------------------------------------------------------------------------------------------------
; Enters with A for parameter
;---------------------------------------------------------------------------------------------------
TransferItemReceiptToBuffer_using_GraphicsID:
PHP
PHB
REP #$30
PHX
PHY
SEP #$30
LDX.b #$00
.find_reverse
CMP.l ItemReceipts_graphics,X
BEQ .found
INX
BNE .find_reverse
.found
TXA
REP #$30
BRA ++
;===================================================================================================
TransferRupeesProperly:
PHP
PHB
REP #$31
PHX
PHY
AND.w #$00FF
SBC.w #$0023
XBA
LSR
LSR
LSR
ADC.w #BigDecompressionBuffer+$800
BRA TransferItemReceiptToBuffer_using_ExplicitBufferAddress
;===================================================================================================
TransferItemReceiptToBuffer_using_ReceiptID:
PHP : PHB
REP #$30
PHX : PHY
++ AND.w #$00FF
ASL : TAX
LDA.l BusyItem : BNE +
LDA.l StandingItemGraphicsOffsets,X
BRA .have_address
+
LDA.l ItemReceiptGraphicsOffsets,X
.have_address
BMI TransferItemReceiptToBuffer_using_ExplicitBufferAddress
.rom_address
ADC.w #ItemReceiptGraphicsROM
PHK
BRA .continue
#TransferItemReceiptToBuffer_using_ExplicitBufferAddress:
PEA.w $7F7F
PLB
.continue
PLB
TAY
LDX.w #62
.next_write
LDA.w $003E,Y
STA.l ItemGetGFX+$00,X
LDA.w $023E,Y
STA.l ItemGetGFX+$40,X
DEY
DEY
DEX
DEX
BPL .next_write
REP #$30
PLY
PLX
PLB
PLP
RTL
;===================================================================================================
TransferItemToVRAM:
REP #$21
SEP #$10
LDA.w ItemGFXPtr
BEQ .exit
BMI .wram_address
.rom_address
ADC.w #ItemReceiptGraphicsROM
LDX.b #ItemReceiptGraphicsROM>>16
.set_address
STA.w $4302
ADC.w #$0200
STA.w $4312
STX.w $4304
STX.w $4314
LDX.b #$80
STX.w $2115
LDA.w #$1801
STA.w $4300
STA.w $4310
LDA.w #$0040
STA.w $4305
STA.w $4315
LDA.w ItemGFXTarget
STA.w $2116
LDX.b #$01
STX.w $420B
ADC.w #$0100
STA.w $2116
INX
STX.w $420B
STZ.w ItemGFXPtr
STZ.w ItemGFXTarget
.exit
RTL
.wram_address
LDX.b #$7F
BRA .set_address
;===================================================================================================
; Decompress everything at the start of the game
;===================================================================================================
DecompBufferOffset = $18
DecompTestByte = $04
DecompCommand = $02
DecompSize = $00
DecompTileCount = $1A
DecompSaveY = $1A
Decomp3BPPScratch = $20
;===================================================================================================
DecompressAllItemGraphics:
PHP
PHB
PHD
REP #$38
; Stack change for safety
TSX
LDA.w #$1400
TCS
PHX
; direct page change for speed
LDA.w #$1200
TCD
STZ.b DecompBufferOffset
SEP #$34
STA.l $4200 ; already 0 from the LDA above
LDX.b #$5D+$73 : JSR FastSpriteDecomp
LDX.b #$5C+$73 : JSR FastSpriteDecomp
LDX.b #$5B+$73 : JSR FastSpriteDecomp
LDX.b #$5A+$73 : JSR FastSpriteDecomp
REP #$30
PLX
TXS
SEP #$20
LDA.b #$81
STA.l $4200
PLD
PLB
PLP
RTL
;===================================================================================================
; I normally hate macros like this... but I don't feel like constantly rewriting this
;===================================================================================================
macro GetNextByte()
LDA.w $0000,Y
INY
BNE ?++
; Y pulls more than it needs, but that's fine
; the high byte should only be affected if we somehow have FF as our bank
; and if that happens, we have other problems
PHB
PLY
INY
PHY
PLB
LDY.w #$8000
?++
endmacro
;===================================================================================================
; There's no long vanilla routine, and we're going to make heavy use of this
; so might as well rewrite it to be fast
;===================================================================================================
FastSpriteDecomp:
SEP #$30
LDA.l GFXSheetPointers_background_bank,X : PHA : PLB
LDA.l GFXSheetPointers_background_high,X : XBA
LDA.l GFXSheetPointers_background_low,X
REP #$10
TAY
LDX.w #$0000
.next_command
%GetNextByte()
CMP.b #$FF
BNE .continue
;---------------------------------------------------------------------------------------------------
JMP Unrolled3BPPConvert
;---------------------------------------------------------------------------------------------------
.continue
CMP.b #$E0
BCS .expanded
STA.b DecompTestByte
REP #$20
AND.w #$001F
BRA .normal
;---------------------------------------------------------------------------------------------------
; Putting some commands up here for branch distance
;---------------------------------------------------------------------------------------------------
.nonrepeating
REP #$21
TYA
ADC.b DecompSize
ORA.w #$8000
STA.b DecompSize
SEP #$20
.next_nonrepeating
%GetNextByte()
STA.l DecompBuffer2,X
INX
CPY.b DecompSize
BNE .next_nonrepeating
BRA .next_command
;---------------------------------------------------------------------------------------------------
.repeating
%GetNextByte()
STY.b DecompSaveY
LDY.b DecompSize
.next_repeating
STA.l DecompBuffer2,X
INX
DEY
BNE .next_repeating
LDY.b DecompSaveY
BRA .next_command
;---------------------------------------------------------------------------------------------------
; Rest of command handling
;---------------------------------------------------------------------------------------------------
.expanded
STA.b DecompCommand
ASL
ASL
ASL
STA.b DecompTestByte
LDA.b DecompCommand
AND.b #$03
XBA
%GetNextByte()
REP #$20
;---------------------------------------------------------------------------------------------------
.normal
INC
STA.b DecompSize
SEP #$20
LDA.b DecompTestByte
AND.b #$E0
BEQ .nonrepeating
BMI .copy
ASL
BPL .repeating
ASL
BPL .repeating_word
;---------------------------------------------------------------------------------------------------
.incremental
%GetNextByte()
STY.b DecompSaveY
LDY.b DecompSize
.next_incremental
STA.l DecompBuffer2,X
INC
INX
DEY
BNE .next_incremental
LDY.b DecompSaveY
JMP .next_command
;---------------------------------------------------------------------------------------------------
.repeating_word
JSR .get_next_word
REP #$20
STY.b DecompSaveY
LDY.b DecompSize
DEY
.next_word
STA.l DecompBuffer2,X
INX
INX
DEY
DEY
BPL .next_word
INY
BEQ .not_too_far
DEX
.not_too_far
SEP #$20
LDY.b DecompSaveY
JMP .next_command
;---------------------------------------------------------------------------------------------------
.copy
JSR .get_next_word
STY.b DecompSaveY
TAY
LDA.b DecompSize
BNE ++
DEC.b DecompSize+1
++ PHB
LDA.b #$7F
PHA
PLB
.next_copy
LDA.w DecompBuffer2,Y
STA.w DecompBuffer2,X
INX
INY
DEC.b DecompSize+0
BNE .next_copy
DEC.b DecompSize+1
BPL .next_copy
PLB
LDY.b DecompSaveY
JMP .next_command
;---------------------------------------------------------------------------------------------------
; These are only used once per command, so I'm fine with letting them be a JSR I guess
;---------------------------------------------------------------------------------------------------
.get_next_word
%GetNextByte()
XBA
%GetNextByte()
XBA
RTS
;===================================================================================================
; More macros, because lazy
;===================================================================================================
macro DoPlanesA(offset)
LDA.w DecompBuffer2+<offset>+<offset>,Y
STA.w BigDecompressionBuffer+<offset>+<offset>,X
ORA.w DecompBuffer2+<offset>+<offset>-1,Y
AND.w #$FF00
STA.b Decomp3BPPScratch
LDA.w DecompBuffer2+$10+<offset>,Y
AND.w #$00FF
TSB.b Decomp3BPPScratch
XBA
ORA.b Decomp3BPPScratch
STA.w BigDecompressionBuffer+$10+<offset>+<offset>,X
endmacro
;===================================================================================================
Unrolled3BPPConvert:
LDA.b #$7F
PHA
PLB
REP #$21
LDY.w #$0000
LDX.b DecompBufferOffset
.next_3bpp_tile
%DoPlanesA(0) ; 8 times
%DoPlanesA(1)
%DoPlanesA(2)
%DoPlanesA(3)
%DoPlanesA(4)
%DoPlanesA(5)
%DoPlanesA(6)
%DoPlanesA(7)
; carry will always be clear
; don't worry
TXA
ADC.w #32
TAX
; just trust me
TYA
ADC.w #24
TAY
CMP.w #24*64
BCS .done
JMP .next_3bpp_tile
.done
STX.b DecompBufferOffset
SEP #$30
RTS
;===================================================================================================