Robotron: 2084: Routine at 52959

Per-entity frame handler for an approaching narrow entity. Advances the animation phase counter, moves the entity down by six pixels per frame, and on the final frame installs Handle_Homing_Enemy as the entity's new handler. Called from Main_Game_Loop.

Per-entity frame handler for an approaching narrow entity. Advances the animation phase counter, moves the entity down by six pixels per frame, and on the final frame installs Handle_Homing_Enemy as the entity's new handler. Called from Main_Game_Loop.
Step_Narrow_Entity_Approach	52959	INC HL	Step past the entity type byte.
	52960	EX DE,HL	Copy the entity pointer to DE.
	52961	LD HL,(50485)	Advance the animation phase counter by 64.
	52964	LD BC,64
	52967	ADD HL,BC
	52968	LD (50485),HL
	52971	EX DE,HL	Copy the entity pointer back to HL.
	52972	LD A,D	Jump to Step_Narrow_Entity_Approach_Wrap to wrap the approach at the screen boundary.
	52973	CP 15
	52975	JR Z,Step_Narrow_Entity_Approach_Wrap
	52977	JR NC,Step_Narrow_Entity_Approach_Advance_Six	Jump to Step_Narrow_Entity_Approach_Advance_Six if the entity's approach descent is complete.
	52979	EXX	Load the entity draw colour.
	52980	LD B,A
	52981	INC B
	52982	EXX
	52983	PUSH HL	Draw the entity sprite.
	52984	CALL Draw_Clipped_Wide_Sprite
	52987	POP HL
	52988	INC HL	Move the entity six pixels down the screen.
	52989	LD A,(HL)
	52990	ADD A,6
	52992	LD (HL),A
	52993	DEC HL	Step back within the entity record.
	52994	LD A,(50486)	Skip spawning if this is not the final approach frame.
	52997	CP 1
	52999	JR NZ,Step_Narrow_Entity_Approach_Draw
	53001	EXX	Switch to the entity arrival colour INK: YELLOW, PAPER: BLACK (BRIGHT) .
	53002	LD B,70
	53004	EXX
	53005	PUSH HL	Draw the entity's arrival frame.
	53006	CALL Draw_Entity_Sprite
	53009	POP HL
	53010	DEC HL	Install Handle_Homing_Enemy as the entity's new handler to begin homing on the player.
	53011	DEC HL
	53012	LD DE,52560
	53015	LD (HL),D
	53016	DEC HL
	53017	LD (HL),E
	53018	LD DE,9	Advance nine bytes to the next entity record.
	53021	JR Step_Narrow_Entity_Approach_Advance	Advance nine bytes to the next entity record.
Step_Narrow_Entity_Approach_Wrap	53023	INC HL	Reset the descent position to wrap the approach path.
	53024	LD A,(HL)
	53025	SUB 84
	53027	LD (HL),A
	53028	DEC HL	Step back and prepare the draw colour.
	53029	LD A,D	Step back and prepare the draw colour.
Step_Narrow_Entity_Approach_Draw	53030	EXX	Load the draw colour.
	53031	LD B,A
	53032	EXX
	53033	PUSH HL	Draw the entity sprite.
	53034	CALL Draw_Clipped_Wide_Sprite
	53037	POP HL
Step_Narrow_Entity_Approach_Advance_Six	53038	LD DE,6	Prepare to advance past this entity record.
Step_Narrow_Entity_Approach_Advance	53041	ADD HL,DE	Advance to the next entity record and return.
	53042	RET	Advance to the next entity record and return.