;Eye Door Disassembly
;by Herald83

;Info {
;  Eye doors consist of three PLMs, the eye itself (center two tiles), the top spike and the bottom spike.
;  The Low byte is the door index, all three PLMs share the same index. The High byte is 00.
;  Standard "hits to open" is 0003.
;  The eye remains inactive when Samus is farther away, becomes active when within 6 horizontal tiles, goes inactive when Samus is too close. While active the eye opens, shoots three times, closes and cycles. The projectile deals 4 base damage (no suits) to Samus.
;  Shooting with missile or super causes eye to flash and dust puff to be drawn.
;  The spike PLMs wiggle while door is active and inflict spike damage if Samus touches them. You need to be in morph ball mode to actually hit them though, because the eye itself will prevent you from hitting it. }
;PLM Headers {
	;tile AD isn't part of the door PLM itself, it's the terrain around the door
	;AAE3 is shared with tons of other PLMs and just points an 86BC instruction. I'm not sure if/how it is used by the Top Spikes so I left it in for reference.
		;KEJ regarding AAE3: these PLMs simply run their setup and do nothing else.
;Dir	Part		PLM	 -> Header				Tile Table
;Left	Eye 		DB56 -> DA8C D81E
;		Top 		DB5A -> DAB9 D8E9 AAE3
;		Bottom		DB60 -> DAB9 D91F
;Right	Eye			DB48 -> DA8C D955			CA-CD (open, mid, closed, flash)
;		Top			DB4C -> DAB9 DA20 AAE3		AA-AC
;		Bottom		DB52 -> DAB9 DA56 }

;DB56 & DB52: Eye PLM {
;  Setup Routine {
org $84DA8C
	PHY
	LDA $1DC7,Y ;PLM Room argument
	JSR $80818E
	LDA $7ED8B0,X ;Opened door bit array. D0-EF are never used
	PLY
	AND $05E7 : BNE + ;Often used to check bits for completed tasks/picked up items
	LDX $1C87,Y ; PLM's location in the room (nth block * 2)
	LDA #$C044,Y
	JSR $82B4
	LDA $1DC7,Y : CLC : ADC $07A5 : ADC $07A5 : TAX ;Current room's width in blocks
	LDA #$D0FF
	JSR $82B4
+	RTS }
;  Shared Routines {
org $84D77A ;fire projectile!
	LDA $0000,Y
	PHY
	LDY #$B743 : JSR $868097 ;KEJ: spawns some kind of projectiles? Only used by gate PLMs, so far as I can see. Also used by some enemies.
	LDA #$004C : JSR $8090CB
	PLY
	INY : INY
	RTS
org $84D790 ;run once when hit, after checking for death, while eye is closed
	LDA $0000,Y
	PHY
	LDY #$B751 : JSR $868097 ;KEJ: spawns some kind of projectiles? Only used by gate PLMs, so far as I can see. Also used by some enemies.
	PLY
	INY : INY
	RTS
org $84D79F ;wildly guessing this animates the smoke? that seems to have 4 frames worth of animation. run twice when hit plus twice after checking for death (either result)
	PHY
	LDA #$030A : LDY #$E517 : JSR $868097 ;KEJ: spawns some kind of projectiles? Only used by gate PLMs, so far as I can see. Also used by some enemies.
	LDA #$030A : LDY #$E517 : JSR $868097 ;KEJ: spawns some kind of projectiles? Only used by gate PLMs, so far as I can see. Also used by some enemies.
	PLY
	RTS
org $84D7B6 ;run twice, only in death setup
	PHY
	LDA #$000B : LDY #$E517 : JSR $868097 ;KEJ: spawns some kind of projectiles? Only used by gate PLMs, so far as I can see. Also used by some enemies.
	PLY
	RTS
org $84D7DA ;change blue door to shootable blue door
	PHX
	LDA $1C87,x : SEC : SBC $07A5 : SBC $07A5 : STA $1C87,x : TAX
	LDA #$C040
	JSR $82B4 ;X must contain a block location in ram, and A has new status for it. High byte becomes the new block-prop (second nybble should be 0), and low byte becomes the new bts value.
	TXA : CLC : ADC $07A5 : ADC $07A5 : TAX
	LDA #$D0FF
	JSR $82B4
	TXA : CLC : ADC $07A5 : ADC $07A5 : TAX
	LDA #$D0FE
	JSR $82B4
	TXA : CLC : ADC $07A5 : ADC $07A5 : TAX
	LDA #$D0FD
	JSR $82B4
	PLX
	RTS }
;  DB56: Facing Left {
;    Tile Draws {
org $849BF7 ;eye closed + draw top/bot A
	db $04
	db $80
	db $AA,$84
	db $CC,$84
	db $CC,$8C
	db $AA,$8C
	dw $0000
org $849C03 ;eye closed
	db $02
	db $80
	db $CC,$84
	db $CC,$8C
	dw $0000
org $849C0B ;eye changing
	db $02
	db $80
	db $CB,$84
	db $CB,$8C
	dw $0000
org $849C13 ;eye open, shootable
	db $02
	db $80
	db $CA,$C4
	db $CA,$DC
	dw $0000
org $849C1B ;eye flash when shot
	db $02
	db $80
	db $CD,$84
	db $CD,$8C
	dw $0000
org $849C23 ;eye open, solid
	db $02
	db $80
	db $CA,$84
	db $CA,$8C
	dw $0000
org $84A9A7 ;blue door; dunno if this is distinct from the blue door's routines
	db $04
	db $80
	db $0C,$80
	db $2C,$D0
	db $2C,$D8
	db $0C,$D8
	dw $0000 }
;    Behavior {
org $84D81E
	dw $8A72,$D8E3 ;Load the room argument, and if positive, check that door bit. If set, use the argument as the next instruction.
	
	;$D822 - idle state: close eye if samus is out of range
	dw $0004,$9C03 ;draw eye closed
	dw $8D41 : db $06,$04 : dw $D830 ;detection of samus' proximity to the door, first argument is horizontal limit, second is vertical limit, execute program following if true
	dw $8724,$D822 ;Use the address given by the argument as the next instruction.
	
	;D830
	dw $8A24,$D880 ;Hit Animation, Store the argument as the target instruction for special routines. Stored in 7E:DEBC,X
	dw $86C1,$BD50 ;Projectile Detection (shared with Red Doors)
	dw $0008,$9C0B ;draw eye changing
	
	;$D83C - active state: shoot samus when she's in range, close eye if too close
	dw $8D41 : db $01,$04 : dw $D878 ;check proximity and close eye if samus is too close
	dw $0040,$9C13 ;draw eye open, shootable
	dw $D77A,$0000 ;fire projectile!
	dw $0020,$9C13 ;draw eye open, shootable
	dw $D77A,$0000 ;fire projectile!
	dw $0020,$9C13 ;draw eye open, shootable
	dw $D77A,$0000 ;fire projectile!
	dw $0040,$9C13 ;draw eye open, shootable
	dw $0006,$9C0B ;draw eye changing
	dw $0030,$9C03 ;draw eye closed
	dw $0030,$9C03 ;draw eye closed
	dw $0006,$9C0B ;draw eye changing
	dw $8D41 : db $06,$04 : dw $D83C ;check proximity, loop if she stays within range
	dw $8724,$D822 ;idle if she's too far away
	
	;D878 - close eye when samus is too close
	dw $0004,$9C03 ;draw eye closed
	dw $8724,$D83C ;return to active state
	
	;$D880 - take a hit, check for death, return to active state
	dw $8C10 : db $09 ;go to $80:90CB and play sound
	dw $D79F
	dw $D79F
	dw $8A91 : db $03 : db $D8C4 ;Increment hit counter. If at least as much as the argument (1 byte), set the door as opened, disable preplm code, and goto the second argument (2 bytes)
	dw $0002,$9C1B ;draw eye flash when hit
	dw $0002,$9C23 ;draw eye open, solid
	dw $D79F
	dw $0002,$9C1B ;draw eye flash when hit
	dw $0002,$9C23 ;draw eye open, solid
	dw $0002,$9C1B ;draw eye flash when hit
	dw $D79F
	dw $0002,$9C23 ;draw eye open, solid
	dw $0004,$9C0B ;draw eye changing
	dw $0008,$9C03 ;draw eye closed
	dw $D790,$0000
	dw $0038,$9C03 ;draw eye closed
	dw $0004,$9C0B ;draw eye changing
	dw $0004,$9C23 ;draw eye open, solid
	dw $8724,$D83C ;return to active state
	
	;D8C4 - death sequence part one - death set up
	dw $86CA ;Stores #$86D0 to 7E:1CD7,X (RTS). Effectively disables pre-PLM instructions.
	dw $D7B6
	dw $D7B6
	dw $D79F
	dw $D79F
	dw $D7DA ;change blue door to shootable blue door
	dw $874E : db $0A ;Set 7E:1D77,X to the argument (# of cycles for door to flash)
	
	;D8D3 - death sequence part two - death animation
	dw $0003,$9BF7 ;draw eye closed + top/bot A
	dw $0004,$A9A7 ;draw blue door
	dw $873F,$D8D3 ;Decrement 7E:1D77,X. loops through animation until zero.
	dw $8724,$C4B1 ;generate Blue Door facing left (External Pointer)	
	
	;D8E3 - Draw blue door if the door bit was set (door is already dead)
	dw $D7DA ;change blue door to shootable blue door
	dw $8724,$C4B1 ;generate Blue Door facing left (External Pointer) }
	}
;  DB52: Facing Right {
;    Tile Draws {
org $849C4F
	db $04
	db $80
	db $AA,$80
	db $CC,$80
	db $CC,$88
	db $AA,$88
	dw $0000
org $849C5B
	db $02
	db $80
	db $CC,$80
	db $CC,$88
	dw $0000
org $849C63
	db $02
	db $80
	db $CB,$80
	db $CB,$88
	dw $0000
org $849C6B
	db $02
	db $80
	db $CA,$C0
	db $CA,$D8
	dw $0000
org $849C73
	db $02
	db $80
	db $CD,$80
	db $CD,$88
	dw $0000
org $849C7B
	db $02
	db $80
	db $CA,$80
	db $CA,$88
	dw $0000
org $84A9E3
	db $04
	db $80
	db $0C,$84
	db $2C,$D4
	db $2C,$DC
	db $0C,$DC
	dw $0000 }
;    Behavior {
org $84D955
	dw $8A72,$DA1A
	
	dw $0004,$9C5B
	dw $8D41 : db $06,$04 : dw $D967
	dw $8724,$D959
	
	dw $8A24,$D9B7
	dw $86C1,$BD50
	dw $0008,$9C63
	
	dw $8D41 : db $01,$04 : dw $D9AF
	dw $0040,$9C6B
	dw $D77A,$0014
	dw $0020,$9C6B
	dw $D77A,$0014
	dw $0020,$9C6B
	dw $D77A,$0014
	dw $0040,$9C6B
	dw $0006,$9C63
	dw $0030,$9C5B
	dw $0030,$9C5B
	dw $0006,$9C63
	dw $8D41 : db $06,$04 : dw $D973
	dw $8724,$D959
	
	dw $0004,$9C5B
	dw $8724,$D973
	
	dw $8C10 : db $09
	dw $D79F
	dw $D79F
	dw $8A91 : db $03 : dw $D9FB
	dw $0002,$9C73
	dw $0002,$9C7B
	dw $D79F
	dw $0002,$9C73
	dw $0002,$9C7B
	dw $0002,$9C73
	dw $D79F
	dw $0002,$9C7B
	dw $0004,$9C63
	dw $0008,$9C5B
	dw $D790,$0004
	dw $0038,$9C5B
	dw $0004,$9C63
	dw $0004,$9C7B
	dw $8724,$D973
	
	dw $86CA
	dw $D7B6
	dw $D7B6
	dw $D79F
	dw $D79F
	dw $D7C3
	dw $874E : db $0A
	
	dw $0003,$9C4F
	dw $0004,$A9E3
	dw $873F,$DA0A
	dw $8724,$C4E2
	
	dw $D7C3
	dw $8724,$C4E2 }
	}
}

;DB5A, DB60, DB4C & DB52: Spike Tile PLMs {
;  Setup Routine {
org $84DAB9
	PHY
	LDA $1DC7,Y
	JSR $80818E
	LDA $7ED8B0,X
	PLY
	AND $05E7 : BNE +
	LDX $1C87,Y
	LDA #$A000
	JSR $82B4
+	RTS }
;  Projectile Detection { ;Used by both spike tiles. Unsure if it's shared with other stuff or not.
org $84D753
	TXY
	LDA $1DC7,x
	JSL $80818E
	LDA $7ED8B0,x : AND $05E7 : BEQ +
	TYX
	LDA #$D779 : STA $1CD7,x
	LDA $7EDEBC,x : STA $1D27,x
	LDA #$0001 : STA $7EDE1C,x
+	RTS }
;  DB5A: Left Top Tile { ;Animates the top wiggly spike block of the eye door if the door is still alive
;    Tile Draws {
org $849C2B ;
	db $01
	db $00
	db $AA,$A4
	dw $0000
org $849C31 ;
	db $01
	db $00
	db $AB,$A4
	dw $0000
org $849C37 ;
	db $01
	db $00
	db $AC,$A4
	dw $0000 }
;    Behavior {
org $84D8E9
	dw $8A72,$D91D ;Check if it still exists, else delete PLM
	;D8ED - off loop: samus out of range
	dw $8D41 : db $06,$10 : dw $D8FB ;proximity detection
	dw $0008,$9C2B ;first tile
	dw $8724,$D8ED ;loop
	;D8FB
	dw $8A24,$D91D ;Hit animation
	dw $86C1,$D753 ;Projectile Detection
	;D903 - on loop: samus in range
	dw $0008,$9C2B ;first tile
	dw $0008,$9C31 ;second tile
	dw $0008,$9C37 ;third tile
	dw $0008,$9C31 ;second tile
	dw $8D41 : db $06,$10 : dw $D903 ;proximity detection
	dw $8724,$D8ED ;else return to off loop
	;D91D - kill plm
	dw $86BC ;delete PLM }
	}
;  DB60: Left Bottom Tile { ;Upside-down version of the top tile
;    Tile Draws {
org $849C3D
	db $01
	db $00
	db $AA,$AC
	dw $0000
org $849C43
	db $01
	db $00
	db $AB,$AC
	dw $0000
org $849C49
	db $01
	db $00
	db $AC,$AC
	dw $0000 }
;    Behavior {
org $84D91F
	dw $8A72,$D953
	;off loop
	dw $8D41 : db $06,$10 : dw $D931
	dw $0008,$9C3D
	dw $8724,$D923
	;
	dw $8A24,$D953
	dw $86C1,$D753
	;on loop
	dw $0008,$9C3D
	dw $0008,$9C43
	dw $0008,$9C49
	dw $0008,$9C43
	dw $8D41 : db $06,$10 : dw $D939
	dw $8724,$D923
	;kill plm
	dw $86BC }
	}
;  DB4C: Right Top Tile {
;    Tile Draws {
org $849C83
	db $01
	db $00
	db $AA,$A0
	dw $0000
org $849C89
	db $01
	db $00
	db $AB,$A0
	dw $0000
org $849C8F
	db $01
	db $00
	db $AC,$A0
	dw $0000 }
;    Behavior {
org $84DA20	
	dw $8A72,$DA54
	;off loop
	dw $8D41 : db $06,$10 : dw $DA32
	dw $0008,$9C83
	dw $8724,$DA24
	;
	dw $8A24,$DA54
	dw $86C1,$D753
	;on loop
	dw $0006,$9C83
	dw $0006,$9C89
	dw $0006,$9C8F
	dw $0006,$9C89
	dw $8D41 : db $06,$10 : dw $DA3A
	dw $8724,$DA24
	;kill plm
	dw $86BC }
}
;  DB52: Right Bottom Tile {
;    Tile Draws {
org $849C95
	db $01
	db $00
	db $AA,$A8
	dw $0000
org $849C9B
	db $01
	db $00
	db $AB,$A8
	dw $0000
org $849CA1
	db $01
	db $00
	db $AC,$A8
	dw $0000
	}	
;    Behavior {
org $84DA56	
	dw $8A72,$DA8A
	;off loop
	dw $8D41 : db $06,$10 : dw $DA68
	dw $0008,$9C95
	dw $8724,$DA5A
	;
	dw $8A24,$DA8A
	dw $86C1,$D753
	;on loop
	dw $0006,$9C95
	dw $0006,$9C9B
	dw $0006,$9CA1
	dw $0006,$9C9B
	dw $8D41 : db $06,$10 : dw $DA70
	dw $8724,$DA5A
	;kill plm
	dw $86BC }
}
}