Robotron: 2084: Routine at 53074

53074: Step Wide Entity Approach

Per-entity frame handler for an approaching wide entity. Advances the scroll counter, moves the entity down by eight pixels per frame, and on the final frame installs Handle_Horizontal_Enemy_Entity as the entity's new handler. Called from Main_Game_Loop.
Step_Wide_Entity_Approach	53074	EX DE,HL	Copy the entity pointer to DE.
	53075	LD HL,(50485)	Advance the animation phase counter by 64.
	53078	LD BC,64
	53081	ADD HL,BC
	53082	LD (50485),HL
	53085	EX DE,HL	Copy the entity pointer back to HL.
	53086	LD A,D	Jump to Step_Wide_Entity_Approach_Wrap to wrap the approach at the screen boundary.
	53087	CP 15
	53089	JR Z,Step_Wide_Entity_Approach_Wrap
	53091	JR NC,Step_Wide_Entity_Approach_Advance_Six	Jump to Step_Wide_Entity_Approach_Advance_Six if the entity's approach descent is complete.
	53093	EXX	Load the entity draw colour.
	53094	LD B,A
	53095	INC B
	53096	EXX
	53097	PUSH HL	Draw the entity sprite.
	53098	CALL Draw_Wide_Entity_Sprite_Pixels_Only
	53101	POP HL
	53102	INC HL	Move the entity eight pixels down the screen.
	53103	LD A,(HL)
	53104	ADD A,8
	53106	LD (HL),A
	53107	DEC HL	Step back within the entity record.
	53108	LD A,(50486)	Skip spawning if this is not the final approach frame.
	53111	CP 1
	53113	JR NZ,Step_Wide_Entity_Approach_Draw
	53115	EXX	Switch to the entity arrival colour INK: GREEN, PAPER: BLACK (BRIGHT) .
	53116	LD B,68
	53118	EXX
	53119	PUSH HL	Draw the entity's arrival frame.
	53120	CALL Draw_Wide_Entity_Sprite
	53123	POP HL
	53124	DEC HL	Install Handle_Horizontal_Enemy_Entity as the entity handler to begin horizontal movement.
	53125	LD DE,57782
	53128	LD (HL),D
	53129	DEC HL
	53130	LD (HL),E
	53131	LD DE,8	Advance eight bytes to the next entity record.
	53134	JR Step_Wide_Entity_Approach_Advance	Advance eight bytes to the next entity record.
Step_Wide_Entity_Approach_Wrap	53136	INC HL	Reset the descent position to wrap the approach path.
	53137	LD A,(HL)
	53138	SUB 112
	53140	LD (HL),A
	53141	DEC HL	Step back and prepare the draw colour.
	53142	LD A,D	Step back and prepare the draw colour.
Step_Wide_Entity_Approach_Draw	53143	EXX	Load the draw colour.
	53144	LD B,A
	53145	EXX
	53146	PUSH HL	Draw the entity sprite.
	53147	CALL Draw_Wide_Entity_Sprite_Pixels_Only
	53150	POP HL
Step_Wide_Entity_Approach_Advance_Six	53151	LD DE,6	Prepare to advance past this entity record.
Step_Wide_Entity_Approach_Advance	53154	ADD HL,DE	Advance to the next entity record and return.
	53155	RET	Advance to the next entity record and return.