Lunar Jetman: Routine at 40492

40492: Animate: Laser Beam


LaserBeam_Animate	40492	CALL 42902	Call 42902.
	40495	LD D,(IX+1)	Laser Y position.
	40498	LD A,(IX+2)	Laser X position: pulse #1.
	40501	BIT 2,A	Jump to LaserBeam_Animate_1 if bit 2 is reset.
	40503	JR Z,LaserBeam_Animate_1	Jump to LaserBeam_Animate_1 if bit 2 is reset.
	40505	LD L,A	L=X position: pulse #1.
	40506	LD A,8
	40508	BIT 0,L
	40510	JR Z,LaserBeam_Animate_0
	40512	NEG
LaserBeam_Animate_0	40514	ADD A,L
	40515	LD E,A
	40516	LD H,D
	40517	PUSH HL
	40518	CALL ScreenAddress	Call ScreenAddress.
	40521	LD (IX+2),E
	40524	LD A,255
	40526	XOR (HL)
	40527	LD (HL),A
	40528	POP HL
	40529	CALL AttributeAddress	Call AttributeAddress.
	40532	LD A,(IX+7)
	40535	LD (HL),A
	40536	LD A,(IX+6)
	40539	SUB 8
	40541	LD (IX+6),A
	40544	AND %11111000	Keep only bits 3-7.
	40546	JR NZ,LaserBeam_Animate_1
	40548	RES 2,(IX+2)
LaserBeam_Animate_1	40552	EXX
	40553	LD BC,796	BC=796.
	40556	LD E,224	E=224.
	40558	EXX
Loop counter (to process pulses #2, #3, #4).
	40559	LD E,3	E=3.
	40561	PUSH IX
	40563	POP BC
	40564	INC BC
	40565	INC BC
	40566	INC BC
LaserBeam_Animate_2	40567	LD A,(BC)
	40568	XOR (IX+2)
	40571	AND %11111000	Keep only bits 3-7.
	40573	JR NZ,LaserBeam_Animate_3
	40575	EXX
	40576	LD A,B
	40577	LD B,C
	40578	LD C,E
	40579	EXX
	40580	INC BC
	40581	DEC E
	40582	JR NZ,LaserBeam_Animate_2
	40584	LD (IX+0),0
	40588	RET	Return.
LaserBeam_Animate_3	40589	LD A,(BC)
	40590	BIT 2,A
	40592	JR NZ,LaserBeam_Animate_4
	40594	DEC (IX+6)
	40597	LD A,(IX+6)
	40600	AND %00000111	Keep only bits 0-2.
	40602	RET NZ
	40603	LD A,(24128)	A=24128.
	40606	AND %00000011	Keep only bits 0-1.
	40608	OR %00000100	Set bit 2.
	40610	OR (IX+6)
	40613	LD (IX+6),A
	40616	LD A,(BC)
	40617	OR %00000100	Set bit 2.
	40619	LD (BC),A
	40620	RET	Return.
LaserBeam_Animate_4	40621	LD A,(BC)
	40622	LD L,A
	40623	LD A,8
	40625	BIT 0,L
	40627	JR Z,LaserBeam_Animate_5
	40629	NEG
LaserBeam_Animate_5	40631	ADD A,L
	40632	LD (BC),A
	40633	LD H,D
	40634	CALL ScreenAddress
	40637	EXX
	40638	LD A,B
	40639	LD B,C
	40640	LD C,E
	40641	EXX
	40642	XOR (HL)
	40643	LD (HL),A
	40644	INC BC
	40645	DEC E
	40646	JP NZ,LaserBeam_Animate_2
	40649	RET	Return.