Underwurlde: Routine at E05F

Used by the routine at Run_Game.

Starts a bubble at the bottom of the room every now and then.

Nothing happens in a special room (a room y below 10), or when the type of Sabreman is 3C or more, which means that he is dying or being carried. The bubble takes one of the four bubble records that start at First_Bubble_Record, if one is free. A bubble is only made when the low byte of the frame counter plus 1A has its low six bits clear.

The record is a copy of the record of Sabreman, so the bubble is in his room. Its type is 58 its y position is BF (the bottom of the room), its attribute is 46 (yellow) and its x position is 40 or C0 depending on bit 7 of the tick counter. The handler is Handle_Bubble.

Used by the routine at Run_Game. Starts a bubble at the bottom of the room every now and then. Nothing happens in a special room (a room y below 10), or when the type of Sabreman is 3C or more, which means that he is dying or being carried. The bubble takes one of the four bubble records that start at First_Bubble_Record, if one is free. A bubble is only made when the low byte of the frame counter plus 1A has its low six bits clear. The record is a copy of the record of Sabreman, so the bubble is in his room. Its type is 58 its y position is BF (the bottom of the room), its attribute is 46 (yellow) and its x position is 40 or C0 depending on bit 7 of the tick counter. The handler is Handle_Bubble.
Spawn_Bubble	E05F	LD A,($8F1A)	Fetch the type of Sabreman.
	E062	CP $3C	Return if the type is 3C or more.
	E064	RET NC	Return if the type is 3C or more.
	E065	LD A,($8F1E)	Fetch the room y of Sabreman.
	E068	CP $10	Return if it is a special room.
	E06A	RET C	Return if it is a special room.
	E06B	LD HL,$8F5A	Point HL at First_Bubble_Record.
	E06E	LD DE,$0010	Set DE to the size of an object record.
	E071	LD B,$04	Set a counter in B for the four bubble records.
Spawn_Bubble_Find_Record	E073	LD A,(HL)	Fetch the type of the record.
	E074	AND A	Jump to Spawn_Bubble_Create if the record is free.
	E075	JR Z,Spawn_Bubble_Create	Jump to Spawn_Bubble_Create if the record is free.
	E077	ADD HL,DE	Move on to the next record.
	E078	DJNZ Spawn_Bubble_Find_Record	Decrease the record counter and loop back for the next record.
	E07A	RET	Return, as all four bubble records are in use.
Spawn_Bubble_Create	E07B	EX DE,HL	Point DE at the free record.
	E07C	LD HL,$8F1A	Point HL at Sabreman_Record.
	E07F	LD A,($5C78)	Fetch the low byte of the frame counter.
	E082	ADD A,L	Add the low byte of the address of the record of Sabreman.
	E083	AND %00111111	Keep only the low six bits.
	E085	RET NZ	Return unless they are zero.
	E086	LD BC,$000F	Set a counter of 0F bytes.
	E089	PUSH DE	Stash the address of the bubble record.
	E08A	LDIR	Copy the record of Sabreman to the bubble record, except for the redraw flags.
	E08C	POP HL	Restore the address of the bubble record to HL.
	E08D	LD A,$58	Set the type to 58.
	E08F	LD (HL),A	Set the type to 58.
	E090	LD A,($8ED6)	Fetch the tick counter.
	E093	AND %10000000	Keep only bit 7.
	E095	ADD A,$40	Add 40 which makes 40 or C0.
	E097	INC HL	Move to the x position.
	E098	LD (HL),A	Set the x position.
	E099	INC HL	Move to the y position.
	E09A	INC HL	Move to the y position.
	E09B	LD (HL),$BF	Set the y position to BF.
	E09D	INC HL	Move to the attribute.
	E09E	INC HL	Move to the attribute.
	E09F	LD (HL),$46	Set the attribute to 46 (yellow).
	E0A1	LD A,$01	A=01 (the value of the redraw flags).
	E0A3	LD DE,$000A	Set the offset from the attribute to the redraw flags of the record (0A).
	E0A6	ADD HL,DE	Move to the redraw flags.
	E0A7	LD (HL),A	Set the redraw flags to 01 so that the bubble is drawn without being erased first.
	E0A8	RET	Return.