alttpshuffleinput.asm

lorom

; $04CB is free ram, let use 12x2 bytes for our changes
!TABLE_ICHANGE = $04CB
!CPY_ORIGINAL_INPUT = $7C

; $80-81 copy of input
!CPY_INPUT = $80
!ROOM_COUNTER = $2B2

; - $82[0x1]: Copy of $10
; - $83[0x1]: Copy of $11
; $7C arg?
; $7E set to initialise once
!TAB_INIT = $7E


macro a8()
    SEP #$20
endmacro

macro a16()
    REP #$20
endmacro

macro i8()
    SEP #$10
endmacro

macro i16()
    REP #$10
endmacro

macro ai8()
    SEP #$30
endmacro

macro ai16()
    REP #$30
endmacro


; This is the readjoypad routine
org $0003D1

  STZ $4016 
  ; Storing the state of Joypad 1 to $00-$01
  LDA $4218 : STA $00
  STA $7D
  LDA $4219 : STA $01
  STA $7C
  
  ; added, we don't want to do stuff on empty input
  ORA $00 : BEQ .a
    JSL change_input
  .a
  
  ; $F2 has the pure joypad data
  LDA $00 : STA $F2 : TAY 
        
  ; $FA at this point contains the joypad data from the last frame.
  ; This is intended to avoid flooding in processing commands.
  ; Send this "button masked" reading here.
  ; Hence $F2 and $FA contain pure joypad readings from this frame now.
  EOR $FA : AND $F2 : STA $F6 : STY $FA
        
  ; Essentially the same procedure as above, but for the other half of JP1.
  LDA $01 : STA $F0 : TAY
  EOR $F8 : AND $F0 : STA $F4 : STY $F8
        
  RTS
  
  ;  J2 is skipped, hey free space code! it's here to have an idea of the extra size we can use here
        
  ;LDA $421A : STA $00
  ;LDA $421B : STA $01
        
  ;LDA $00 : STA $F3 : TAY
  ;EOR $FB : AND $F3 : STA $F7 : STY $FB
        
  ;LDA $01 : STA $F1 : TAY
  ;EOR $F9 : AND $F1 : STA $F5 : STY $F9
        
  ;RTS


org $008056
    JSL gamemode_hook


; == INPUT DISPLAY STUFF	
; Hook into subroutine that transfers hud tiles to vram
org $028068
    JSL load_tile_gfx_hook


	
	
; Game Mode hook
org $1BB1E0

; This change input according to the table of change
change_input:
    PHP
    %i16()
    %a8()
	LDA $00 : STA $8E
	LDA $01 : STA $8F
	%a16()
	LDA $8E
	PHB : PHK : PLB
	BEQ .end ; if input is 0 do nothing
	LDX #$0000
	STZ !CPY_INPUT
	.loop
	  LDA $8E
	  LDY.w table_input_bitmask, X ; debug stuff
	  SEP #$02
	  BIT.w table_input_bitmask, X : BEQ .endif
        LDA !TABLE_ICHANGE, X
		ADC !TABLE_ICHANGE, X
		TAY
		LDA table_input_bitmask, Y
	    ORA !CPY_INPUT
		STA !CPY_INPUT
      .endif
      INX
	  INX
	  CPX #$0018 : BNE .loop
	.afterloop
	  ; let's prevent up + down and left + right
	  LDA !CPY_INPUT
	  AND #$0C00 : CMP #$0C00 : BEQ .del_ud
	  LDA !CPY_INPUT
	  AND #$0300 : CMP #$0300 : BEQ .del_lr
	  JMP .hello
	  .del_ud
	    EOR #$0400
	    JMP .ch_i
	  .del_lr
	    EOR #$0100
	  .ch_i
	    STA !CPY_INPUT
	  .hello
	  %a8()
	  LDX #$0001
	  LDA !CPY_INPUT
	  STA $00
	  LDA !CPY_INPUT, X
	  STA $01
	.end
	PLB
	PLP
	%a8()
	%i8()
    RTL

; ==== GAME HOOK ===
gamemode_hook:
   PHP
   %i16()
   %a16()
   LDA #$0000
   CMP !TAB_INIT : BEQ .init_table
   JMP .normal
   .init_table
     STZ !ROOM_COUNTER
     LDA #$0000
	 STA $82
     LDX #$0000
	 LDY #$0000
	 .loop
	   TXA
	   STA !TABLE_ICHANGE, Y
	   INX
	   INY
	   INY
	   CPX #$000C : BNE .loop
	 LDA #$0001
	 STA !TAB_INIT
   .normal
	JSR transition_detection
	JSR input_display
    JMP end_of_gamemode_hook

end_of_gamemode_hook:
    PLP
    JSL $0080B5 ; GameModes
    RTL

shuffle_dpad:
    LDA #$0006
	STA $00
	LDA #$0009
	STA $02
	JSR shuffle_table_input
	RTS

shuffle_button_noSS:
    LDA #$0000
    STA $00
	LDA #$0005
	STA $02
	JSR shuffle_table_input
	RTS

shuffle_all_noSS:
   LDA #$0000
   STA $00
   LDA #$0009
   STA $02
   JSR shuffle_table_input
   RTS

; index are wrong here   

;$4204/4205 is the 16 bit dividend, $4206 is the 8bit divisor, the
;quotient will be put in $4214, and the remainder in $4216/4217.
	
; 00 02 table range
shuffle_table_input:
  LDX $02
  LDA $02
  SBC $00
  INA
  STA $04
  .loop
    STX $06
    LDA $0FA0 ; RNG value
	ADC $1A
	; modulo
	STA $4204
	LDA $04
	SBC $02
	ADC $06
	%a8()
	STA $4206 ; need to wait 8 cycles for the register to do its work
	%a16()
	NOP : NOP : NOP
	LDA $4216
	ADC $00
	STA $06 : ADC $06 : TAY; double this shit for index
	TXA : STA $06 :	ADC $06 : PHX : TAX ; double X
	LDA !TABLE_ICHANGE, X
	STA $06
	LDA !TABLE_ICHANGE, Y
	STA !TABLE_ICHANGE, X
	LDA $06
	STA !TABLE_ICHANGE, Y
	PLX
	DEX
	LDA $00
	DEA
	STA $06
    CPX $06 : BNE .loop
  RTS


table_input_bitmask:
  ; 	A		B	  Y      X        L      R      	>		<		v		^	Start	  select
  DW #$0080, #$8000, #$4000, #$0040, #$0020, #$0010, #$0100, #$0200, #$0400, #$0800, #$1000, #$2000,
  
  
  
;; From helg practice romhack  
transition_detection:
    ; Transition detection {{{

    %ai8()
    LDA $10 : CMP $82 : BNE .gamemode_changed
    LDA $11 : CMP $83 : BNE .submode_changed

    RTS

  .gamemode_changed
    LDA $82

    CMP #$05 : BEQ .gamemode_load_game
    CMP #$07 : BEQ .gamemode_dungeon
    CMP #$09 : BEQ .gamemode_overworld
    CMP #$0B : BEQ .gamemode_overworld ; "Special" overworld (?)
    CMP #$13 : BEQ .gamemode_victory ; LW?
    CMP #$16 : BEQ .gamemode_victory ; DW?

    JMP .end

  .gamemode_victory
    LDA $10

    ; Just killed a boss. Loading overworld.
    CMP #$08 : BEQ .shuffle_input

    JMP .end

  .gamemode_load_game
    LDA $10

    ; Link in bed
    CMP #$07 : BEQ .shuffle_input

    JMP .end

  .gamemode_dungeon
    LDA $10

    ; Dungeon -> Overworld
    CMP #$0F : BEQ .shuffle_input

    ; Caught by Wall Master
    CMP #$11 : BEQ .shuffle_input

    JMP .end

  .gamemode_overworld
    LDA $10

    ; OW (special) -> OW
    CMP #$09 : BEQ .shuffle_input

    ; OW -> OW (special)
    CMP #$0B : BEQ .shuffle_input

    ; Overworld -> Dungeon
    CMP #$0F : BEQ .shuffle_input

    ; Fall in hole
    CMP #$11 : BEQ .shuffle_input

    JMP .end

  .submode_changed
    LDA $10

    ; Dungeon
    CMP #$07 : BEQ .submode_dungeon

    ; Overworld
    CMP #$09 : BEQ .submode_overworld

    JMP .end

  .submode_overworld
    LDA $11

    ; Normal transition
    CMP #$01 : BEQ .room_or_map_changed

    ; Transition into Dark Woods
    CMP #$0D : BEQ .shuffle_input

    ; Mirror
    CMP #$23 : BEQ .shuffle_input

    ; Whirlpool
    CMP #$2E : BEQ .shuffle_input

    JMP .end

  .submode_dungeon
    LDA $11

    ; Normal transition intra-room
    CMP #$01 : BEQ .room_or_map_changed

    ; Normal transition inter-room
    CMP #$02 : BEQ .room_or_map_changed

    ; Transition upwards
    CMP #$06 : BEQ .shuffle_input

    ; Transition upwards
    CMP #$07 : BEQ .shuffle_input

    ; Walking up straight inter-room staircase
    CMP #$12 : BEQ .shuffle_input

    ; Walking down straight inter-room staircase
    CMP #$13 : BEQ .shuffle_input

    ; Transition inter-room staircase
    CMP #$0E : BEQ .shuffle_input

    JMP .end
  ; This is for shuffling input only every 3 normal transitions
  .shuffle_input
     STZ !ROOM_COUNTER
     ; difficulty are choosen from the file slot, it start at 02
     LDA $701FFE
	 CMP #$02 : BEQ .baby_shuffle
	 CMP #$04 : BEQ .normal_shuffle
	 CMP #$06 : BEQ .hard_shuffle
	 JMP .end 
	 .baby_shuffle
	    %ai16()
	    JSR shuffle_button_noSS
	    JMP .end
	 .normal_shuffle
	    %ai16()
	    JSR shuffle_dpad
	    JSR shuffle_button_noSS
		JMP .end
	 .hard_shuffle
       	%ai16()
		JSR shuffle_all_noSS
	    JMP .end
  .room_or_map_changed
     LDA !ROOM_COUNTER
	 INA
	 STA !ROOM_COUNTER
	 CMP #$03 : BNE .end
	 STZ !ROOM_COUNTER
	 JMP .shuffle_input
  .end
    %a8()
    ; Persist new game mode/submode.
    LDA $10 : STA $82
    LDA $11 : STA $83
    RTS
    ; }}}


print "1bb1e0 section ends at ", pc, ". Max is 1bb800"	
incsrc inputdisplay.asm
print "1bb1e0 section ends at ", pc, ". Max is 1bb800"	

inputdisplay.asm

!POS_MEM_INPUT_DISPLAY_TOP = $7EC7F0
!POS_MEM_INPUT_DISPLAY_BOT = $7EC830

;org $0FF4F0
	
input_display:
    ; Shamelessly stolen from Total's SM hack.
	PHP
	PHB : PHK : PLB
	%ai16()
    LDA !CPY_ORIGINAL_INPUT

    TAY
    LDX #$0000

-   TYA : AND ctrl_top_bit_table, X : BEQ +
    LDA ctrl_top_gfx_table, X
    JMP ++
+   LDA #$207F
++  STA !POS_MEM_INPUT_DISPLAY_TOP, X
    INX : INX : CPX #$00C : BNE -

    LDX #$0000

-   TYA : AND ctrl_bot_bit_table, X : BEQ +
    LDA ctrl_bot_gfx_table, X
    JMP ++
+   LDA #$207F
++  STA !POS_MEM_INPUT_DISPLAY_BOT, X
    INX : INX : CPX #$00C : BNE -
	
	PLB
	PLP
    RTS

load_tile_gfx_hook:
    JSL $00E310

    PHB : PHK : PLB

    %a16()
    ; dest address. #$7000 = $E000 in VRAM. (multiply by 2)
    LDA #$7000 : STA $2116

    LDX.b #00
    LDY.b #12 ; number of tiles

  .loop
    ; loop
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    LDA hud_table,x : STA $2118 : INX : INX
    DEY : BEQ .end
    JMP .loop

  .end
    PLB

    RTL

hud_table:
    DW #$0000,#$1800,#$3C00,#$6600,#$7E00,#$6600,#$6600,#$0000
    DW #$0000,#$7C00,#$6600,#$7C00,#$6600,#$6600,#$7C00,#$0000
    DW #$0000,#$6600,#$3C00,#$1800,#$1800,#$3C00,#$6600,#$0000
    DW #$0000,#$6600,#$6600,#$3C00,#$1800,#$1800,#$1800,#$0000
    DW #$0000,#$6000,#$6000,#$6000,#$6000,#$7E00,#$7E00,#$0000
    DW #$0000,#$7C00,#$6600,#$6600,#$7C00,#$6C00,#$6600,#$0000
    DW #$1000,#$3800,#$7C00,#$FE00,#$3800,#$3800,#$3800,#$0000
    DW #$3800,#$3800,#$3800,#$FE00,#$7C00,#$3800,#$1000,#$0000
    DW #$0800,#$0C00,#$7E00,#$7F00,#$7E00,#$0C00,#$0800,#$0000
    DW #$1000,#$3000,#$7E00,#$FE00,#$7E00,#$3000,#$1000,#$0000
    DW #$0000,#$0000,#$E800,#$8800,#$E800,#$2800,#$EE00,#$0000
    DW #$0000,#$0000,#$EE00,#$8400,#$E400,#$2400,#$E400,#$0000

	
; L, u, R, Y, X, SL
ctrl_top_bit_table:
    DW #$2000,#$0008,#$1000,#$0040,#$4000,#$0020
ctrl_top_gfx_table:
    DW #$2404,#$2406,#$2405,#$2403,#$2402,#$240A

; l, d, r, B, A, ST
ctrl_bot_bit_table:
    DW #$0002,#$0004,#$0001,#$0080,#$8000,#$0010
ctrl_bot_gfx_table:
    DW #$2409,#$2407,#$2408,#$2401,#$2400,#$240B