PSSST: Routine at 634F

Used by the routines at SpawnBonusItem and UpdateBonusItem.

The main game loop. The objects from State_Robbie_Active onwards are 08 bytes each, and the loop calls the update routine for the type of each object in turn (see JumpTable_Main). Every update routine returns to NewActor, which moves on to the next object.

A pass starts here with the flower object at State_Flower and carries on up to the last object (the explosion at State_Explosion), then the next pass is started here again. Whenever the frame counter has changed, FrameUpdate is called to update the first four objects (Robbie, the spray can and the two weapons) once. This means that these are updated on every frame no matter how long a pass through the other objects takes.

Used by the routines at SpawnBonusItem and UpdateBonusItem. The main game loop. The objects from State_Robbie_Active onwards are 08 bytes each, and the loop calls the update routine for the type of each object in turn (see JumpTable_Main). Every update routine returns to NewActor, which moves on to the next object. A pass starts here with the flower object at State_Flower and carries on up to the last object (the explosion at State_Explosion), then the next pass is started here again. Whenever the frame counter has changed, FrameUpdate is called to update the first four objects (Robbie, the spray can and the two weapons) once. This means that these are updated on every frame no matter how long a pass through the other objects takes.
Start a new pass through the objects.
MainLoop_NewPass	634F	LD SP,$5D00	SP=5D00.
	6352	EI	Enable interrupts.
	6353	LD IX,$5E8C	IX=State_Flower (the flower object).
	6357	XOR A	Write 00 to CurrentBug_ID to reset the enemy counter.
	6358	LD ($5E16),A	Write 00 to CurrentBug_ID to reset the enemy counter.
This entry point is used by the routines at FrameUpdate and NewActor. Check whether the frame counter has changed.
MainLoop	635B	LD A,($5C78)	Compare FRAMES and LastFrame.
	635E	LD C,A
	635F	LD A,($5E1F)
	6362	CP C	If they are not equal call FrameUpdate to update the fast objects.
	6363	CALL NZ,FrameUpdate
Every update routine returns to NewActor.
	6366	LD HL,$7130	HL=NewActor (the routine which moves onto the next object).
	6369	PUSH HL	Stash the return address on the stack.
Find the update routine for the type of the object.
	636A	LD HL,$637E	HL=JumpTable_Main.
	636D	LD A,(IX+$00)	A=*IX+00 (the object state).
	6370	RLCA	Rotate A left once.
	6371	AND %01111110	Keep only bits 1-6 (the object type, held in bits 0-5 of the state, multiplied by two).
PerformJump	6373	LD C,A	BC=the offset into the jump table.
	6374	LD B,$00	BC=the offset into the jump table.
	6376	ADD HL,BC	HL=the address of the entry in the jump table.
	6377	LD A,(HL)	HL=the address of the update routine from the jump table.
	6378	INC HL
	6379	LD H,(HL)
	637A	LD L,A
	637B	JP IndirectJump	Jump to IndirectJump which does an indirect jump to the jump address.