Gunfright: Routine at 42066

42066: Handle Sheriff Entrance

Type 26: the sheriff arriving back in the street. The vertical offset of the sprite in byte 13 grows by four every frame, with a rising sound, until it reaches 28. The object then becomes a sheriff (type 1) and is protected from harm for a short time.
Raise the sprite and play a rising tone.
HandleSheriffEntrance	42066	LD A,(IX+13)	Fetch the vertical offset of the sprite.
	42069	ADD A,4	Add 4 to the offset.
	42071	LD (IX+13),A	Store the new offset.
	42074	CALL PlayShortTone	Play a sound effect whose pitch depends on the offset.
	42077	LD A,(IX+13)	Fetch the offset again.
	42080	CP 28	Return if the offset is still below 28.
	42082	RET C	Return if the offset is still below 28.
The sheriff has arrived, so turn the object into a sheriff.
	42083	LD (IX+0),1	Turn the object into a sheriff.
	42087	LD (IX+13),0	Reset the vertical offset of the sprite to zero.
	42091	LD A,16	Write 16 to ProtectionTimer to make the sheriff invulnerable for a short time.
	42093	LD (41480),A
	42096	LD HL,41512	Point the sprite list of the object at SheriffSpriteList.
	42099	LD (IX+14),L
	42102	LD (IX+15),H
	42105	LD C,0	Clear C, so that no controls are being pressed.
	42107	JP HandleSheriff_Act	Carry on in the sheriff handler.