layer2control

by noahx42

Game:

Description:

;========================
;uberASM
;========================
;Version 1.3
;========================
;This ASM scrolls layer 2
;up and down depending on
;the button you pressed.
;========================
;It was completely
;built from scratch.
;========================
;Created by badummzi
;========================


;Customizable

!freeram = $13E6	;1-Byte. Only used, when SpeedType = $00

!Direction = $1468	;Which 'direction' layer two should scroll ($1466 = left/right, $1468 = up/down)

!U = #%10000000		;Which button causes layer 2 to scroll up/left (Format: axlr---- (Only when adress is $17. For other formats, please refer to the SMWC Ram-Map)
!D = #%10000000		;Which button causes layer 2 to scroll down/right

!UAddr = $15		;Ram-Adress of the button that makes layer 2 scroll up/left
!DAddr = $16		;Ram-Adress of the button that makes layer 2 scroll down/right

!ULock = #$00FF		;How much layer 2 can scroll up/left (16-Bit/Little-Endian!)
!DLock = #$0000		;How much layer 2 can scroll down/right (16-Bit/Little-Endian!)

!SpeedType = $01	;How fast the speed-values below are. ($01 = Default / Gets faster the higher the value, $00 = Slower than default (uses the freeram adress) / gets slower, the higher the value)

; > If set to $FF, when SpeedType = $01/$00, the layer won't move in the certain direction.
!SpeedUp = $01		;What speed the layer scrolls up/left
!SpeedDown = $01	;What speed the layer scrolls down/right

;End of defines

;===Code begins below===

main:
	;STZ $1411	; Remove the ; , if you're in a vertical level and want to disable the horizontal scroll (also makes layer 2 not move with the player (in vertical levels)) ;)
	LDA #!SpeedType
	BNE .check
	LDA !freeram
	BNE .SpeedSlow
	JSL .check
	RTL

.SpeedSlow:
	DEC !freeram
	RTL

.check:
	LDA $1493		;Just comment this out by adding a ; before it, if you want the player to still be able to scroll, after he hit the goaltape/ orb, etc.
	BNE .end		;/
	LDA $9D
	BNE .end
	LDA !UAddr
	AND !U
if !SpeedType == $00
	BNE .upSlow
else
	BNE .up
endif
	LDA !DAddr
	AND !D
if !SpeedType == $00
	BNE .downSlow
else
	BNE .down
endif
	RTL

.up:
if !SpeedUp != $FF
	REP #$20
	LDX #!SpeedUp
	.increase
		LDA !Direction
		CMP !ULock
		BEQ .end
		INC !Direction
		DEX
		BPL .increase
	SEP #$20
endif
	RTL

.down:
if !SpeedDown != $FF
	REP #$20
	LDX #!SpeedDown
	.decrease
		LDA !Direction
		CMP !DLock
		BEQ .end
		DEC !Direction
		DEX
		BPL .decrease
	SEP #$20
endif
	RTL

.end:
	SEP #$20
	RTL

.upSlow:
if !SpeedUp != $FF
	LDA #!SpeedUp
	STA !freeram
	REP #$20
	LDA !Direction
	CMP !ULock
	BEQ .end
	INC !Direction
	SEP #$20
endif
	RTL

.downSlow:
if !SpeedDown != $FF
	LDA #!SpeedDown
	STA !freeram
	REP #$20
	LDA !Direction
	CMP !DLock
	BEQ .end
	DEC !Direction
	SEP #$20
endif
	RTL
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