;This code will apply the horizontal shaking when ram address
;$7E:1887 is non-zero, causing the shaking effect to both
;shake vertically and horizontally.

!freeram_Xoffset_lo	= $1923		;\Layer 1 image relative X position, these two address
!freeram_Xoffset_hi	= $1924		;/don't have to be adjacent to each other.


org $00A2CB			;>hijack part of earthquake routine.
autoclean JML maincode		;>jump to a new code going to be inserted.
freecode			;>search freeram.
nop #2				;>get rid of extra bytes after the jump code.


maincode:
	LDA #$00			;\compatable with long addresses.
	STA !freeram_Xoffset_lo		;|
	STA !freeram_Xoffset_hi		;/

	LDA $1887			;\limit value to 0-3 values (4 different values).
	AND #$03			;/
	TAY				;>use for table.
	LDA lo_x_table,y		;\load values from table and store to x position
	STA !freeram_Xoffset_lo		;/low byte.
	CLC : ADC $1A			;\adjust x position.
	STA $1A				;|
	LDA hi_x_table,y		;|
	STA !freeram_Xoffset_hi		;|
	ADC $1B				;|
	STA $1B				;/



;restore_smw_code:
	LDA.W GrndShakeDispYHi,Y	;\restore a part of the earthquake effect.
	STA.W $1889			;/
	JML $00A2D1			;>and return back to the code the game left off.


lo_x_table:
	db $FE,$00,$02,$00
hi_x_table:
	db $FF,$00,$00,$00



GrndShakeDispYHi:
	db $FF,$00,$00,$00