Files
alttpr-baserom/doorrando/entrance_fixes.asm
aerinon 380f917e60 Fix for mirror portal in inverted
Yet another fix for blocked doors in Standard ER, minor alteration for the swamp entrance fix to work when blocked as well.
2023-03-08 08:26:34 -07:00

300 lines
8.4 KiB
NASM

;===================================================================================================
; The only specific concern to keep in mind with this code is that your databank will be $00
; Actually, it should be $80, if you're using my fastrom changes.
;
; Leave all your door data vanilla
; Do not try to adjust doors as I previously suggested (not worth the effort)
; We need a few hooks and some light hardcoding either way
; Might as well just do it in a brute, but reliable, way
;
; In brief, this is the hack we're making:
; 1) Let vanilla routines draw the door normally
; 2) Draw over what vanilla just drew
; 3) Hijack the door tile type routine
; and replace the vanilla value with that of solid collision
; For door dection free RAM at $19EE-$19FF has been co-opted to door each drawn doors position and type bytes
; 19EE is for the "current" door for the IdentifyBlockedEntrance routine
; The array at 19F0 is for the collision routine to retrieve that information as it is no longer
; available by that point
;===================================================================================================
pushpc
org $01B0E6
JSL StoreDoorInfo
org $01892F
DoorDrawJankMove:
JML PrepDoorDraw
.return
JSL AdjustEscapeDoorGraphics
RTS
; we don't want to overwrite the JMP ($000E) that's already there
; Well, we could, but we don't need to
warnpc $018939
org $01BF43
JSL AdjustEscapeDoorCollision
org $01C132 ; ADC.w #$0040 : TAX : LDA.b $00
JSL AdjustEscapeDoorCollision_LowEntrance : NOP #2
pullpc
;===================================================================================================
StoreDoorInfo:
STA.w $1980,X
LDA.b $00 : STA.w $19F0,X
TXA
RTL
PrepDoorDraw:
; first off, we need this routine to return to our jank hook
; otherwise, finding a reliable place to put the graphics change check will be a pin
; so push the address to return to the routine
; It's a lot to explain why this is necessary
; Much easier to just tell you to look at $01890D in the disassembly
; and you should understand the vanilla program flow we need to reject
PEA.w DoorDrawJankMove_return-1
LDA.b $00
STA.w $19EE ; for current routine
; copy vanilla code (but fast rom)
LDA.l $8186F0,X
STA.b $0E
LDX.b $02
LDA.b $04
; and to execute the jump, we'll use the JMP ($000E) we carefully avoided overwriting
JML.l $818939
;===================================================================================================
; Adjustment stage 1: graphics
AdjustEscapeDoorGraphics:
JSR IdentifyBlockedEntrance
BCS .replace_graphics
JSR IdentifySancEntrance
BCS .fix_sanctuary_entrance
JSR IdentifySwampEntrance
BCS .fix_swamp_entrance
; Do nothing
RTL
;---------------------------------------------------------------------------------------------------
.replace_graphics ; for blocked doors
; using the value in $19A0 should be fine for finding the graphics
; the only caveat is that this appears to locate the tile just above the north-west corner
; so below, I've indicated that offset with a +$xxx after the base tilemap buffer
; The only odd thing I notice with this position is that some bad hardcoded adjust for
; exploding walls that shouldn't affect how we use this value at all!
LDY.w $0460 ; get door index
LDX.w $19A0-2,Y ; get tilemap index
; hardcoded shutter door graphics tile replacement
; the horizontal flips could easily be explicit LDAs
; but it's probably best the door is symmetrical
; using ORA makes your intent more clear
; and gives you fewer values to change if you experiment with other graphics
; row 1
LDA.w #$8838
STA.l $7E2000+$080,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$086,X
; row 2
LDA.w #$8828
STA.l $7E2000+$100,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$106,X
LDA.w #$8829
STA.l $7E2000+$102,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$104,X
JSR IdentifySwampEntrance
BCS .fix_swamp_entrance_alternate
; the state of the A, X, and Y registers is irrelevant when we exit
; they're all subsequently loaded with new values
RTL
.fix_sanctuary_entrance
LDY.w $0460 ; get door index
LDX.w $19A0-2,Y ; get tilemap index
; row 0
LDA.w #$14C4
STA.l $7E2000+$000,X ; sanity check = should calculate to 7e3bbc
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$006,X
LDA.w #$14C5
STA.l $7E2000+$002,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$004,X
; row 1
LDA.w #$14E8
STA.l $7E2000+$082,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$084,X
; row 2
LDA.w #$14F8
STA.l $7E2000+$102,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$104,X
RTL
.fix_swamp_entrance
LDY.w $0460 ; get door index
LDX.w $19A0-2,Y ; get tilemap index
; row 1 - outer section
LDA.w #$0908
STA.l $7E2000+$080,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$086,X
; row 2
LDA.w #$0918
STA.l $7E2000+$100,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$106,X
LDA.w #$14F8
STA.l $7E2000+$102,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$104,X
.fix_swamp_entrance_alternate
; row 0
LDA.w #$9DFC
STA.l $7E2000+$000,X
STA.l $7E2000+$002,X
STA.l $7E2000+$004,X
STA.l $7E2000+$006,X
; row 1 - mid section
LDA.w #$14E8
STA.l $7E2000+$082,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$084,X
; row 3
LDA.w #$A82C
STA.l $7E2000+$180,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$186,X
LDA.w #$A82D
STA.l $7E2000+$182,X
ORA.w #$4000 ; horizontally flip
STA.l $7E2000+$184,X
RTL
IdentifySancEntrance:
LDA.b $A0 : CMP.w #$0012 : BNE +
LDA.b $0A : CMP.w #$0010 : BNE +
SEC : RTS
+ CLC : RTS
IdentifySwampEntrance:
LDA.b $A0 : CMP.w #$0036 : BNE +
LDA.b $0A : CMP.w #$0010 : BNE +
SEC : RTS
+ CLC : RTS
;===================================================================================================
; Leaving this here in case you desire a fully custom door later
; For now, we'll just hardcode the tiles, as I did above
; I put these in column order because that's how they're expected for the vanilla draw routines
; but I changed my mind on redefining things
; and am too lazy to change it to a row-wise listing
BlockedEntrance:
dw $8838, $8828, $A888 ; column 0
dw $14E8, $8829, $C888 ; column 1
dw $14E8, $8829, $A888 ; column 2
dw $C838, $C828, $C888 ; column 3
;===================================================================================================
; Adjustment stage 2: collision
AdjustEscapeDoorCollision:
LSR ; vanilla shift
AdjustEscapeDoorCollisionShared:
; save our parameters
; but one or both of these may not be necessary depending on how you detect these doors
; all that matters is that after identifying blockage, we have:
; Y is the same as what we entered with
; X has A>>1, for whatever A entered with
PHA
LDA.w $19F0, Y ; grab door info (type, position)
STA.w $19EE ; store in temporary variable
JSR IdentifyBlockedEntrance
PLX ; this is a TAX in vanilla, just have X pull A instead
BCS .block_entrance
; vanilla value
LDA.b $00
RTL
.block_entrance
LDA.w #$0101 ; load tile type for solid collision
RTL
AdjustEscapeDoorCollision_LowEntrance:
ADC.w #$0040 ; vanilla add
JMP AdjustEscapeDoorCollisionShared
;===================================================================================================
; Enter with:
; $19EE containing the door information: position and type bytes
; Exit with:
; carry clear - leave door alone
; carry set - block door
IdentifyBlockedEntrance:
LDA.l ProgressIndicator : AND.w #$00FF : CMP.w #$0002 : BCS .leave_alone ; only in rain states (0 or 1)
LDA.l ProgressFlags : AND.w #$0004 : BNE .leave_alone ; zelda's been rescued
LDA.l BlockSanctuaryDoorInRain : BEQ + ;flagged
LDA.b $A0 : CMP.w #$0012 : BNE +
; we're in the sanctuary
; this code could be removed because you can't reach sanc without zelda currently
; but that's enforced in the logic, so this is to catch that case in case some mode allows it
LDA.l FollowerIndicator : AND.w #$00FF : CMP.w #$0001 : BEQ .leave_alone ; zelda is following
LDA.b $0A
CMP.w #$000A : BCC .leave_alone
CMP.w #$0014 : BCS .leave_alone
.block_door
SEC : RTS
+ LDA.l BlockCastleDoorsInRain : AND.w #$00FF : BEQ .leave_alone
LDX #$FFFE
- INX #2
LDA.l RemoveRainDoorsRoom, X : CMP.w #$FFFF : BEQ .leave_alone
CMP $A0 : BNE -
LDA.l RainDoorMatch, X
CMP.w $19EE : BNE .leave_alone
BRA .block_door
.continue
BRA -
.leave_alone
CLC : RTS
;===================================================================================================