Cyberun: Routine at 56697

Used by the routine at ScrollWorld.

Used while the world is scrolling in at the start of a life. If the flag at ScrollInFlag is 3 the scroll is finished (see FinishScrollIn). If not, the vertical scroll speed is set to 4. If the flag at ChequeredFloorFlag is zero the scroll lasts for the number of steps that are left in B. Otherwise it looks at the six bytes of the screen where the ship is, and at the row above them, and goes on scrolling until they are all blank. Then the flag is set to 3, the playfield is coloured and the tiles are made again.

Used by the routine at ScrollWorld. Used while the world is scrolling in at the start of a life. If the flag at ScrollInFlag is 3 the scroll is finished (see FinishScrollIn). If not, the vertical scroll speed is set to 4. If the flag at ChequeredFloorFlag is zero the scroll lasts for the number of steps that are left in B. Otherwise it looks at the six bytes of the screen where the ship is, and at the row above them, and goes on scrolling until they are all blank. Then the flag is set to 3, the playfield is coloured and the tiles are made again.
LookForGround	56697	LD A,(23612)	The scroll-in flag.
	56700	CP 3	Jump to FinishScrollIn if A is 3.
	56702	JP Z,FinishScrollIn	Jump to FinishScrollIn if A is 3.
	56705	LD A,4	A=4.
	56707	LD (52410),A	Update the vertical scroll speed.
	56710	LD A,(56818)	The chequered floor flag.
	56713	AND A	Jump to LookForGround_Count if A is zero.
	56714	JR Z,LookForGround_Count	Jump to LookForGround_Count if A is zero.
	56716	LD B,6	B=6.
	56718	LD HL,(51458)	Fetch the word at 51458 into HL.
	56721	CALL GetScreenAddress	Call GetScreenAddress.
LookForGround_Loop	56724	LD A,(HL)	Read HL.
	56725	AND A	Jump to LookForGround_Restore if A is not zero.
	56726	JR NZ,LookForGround_Restore	Jump to LookForGround_Restore if A is not zero.
	56728	DEC H	Step H back.
	56729	LD A,(HL)	Read HL.
	56730	AND A	Jump to LookForGround_Restore if A is not zero.
	56731	JR NZ,LookForGround_Restore	Jump to LookForGround_Restore if A is not zero.
	56733	INC H	Advance H.
	56734	INC L	Advance L.
	56735	DJNZ LookForGround_Loop	Decrease B and jump to LookForGround_Loop until none remain.
	56737	POP BC	Bring BC back off the stack.
	56738	JR LookForGround_Found	Jump to LookForGround_Found.
LookForGround_Restore	56740	POP BC	Bring BC back off the stack.
	56741	JR ScrollInWorld	Jump to ScrollInWorld.
LookForGround_Count	56743	POP BC	Bring BC back off the stack.
	56744	DJNZ ScrollInWorld	Decrease B and jump to ScrollInWorld until none remain.
LookForGround_Found	56746	CALL ColourPlayfield	Call ColourPlayfield.
	56749	XOR A	Clear A.
	56750	LD (52410),A	Update the vertical scroll speed.
	56753	LD A,3	A=3.
	56755	LD (23612),A	Update the scroll-in flag.
	56758	LD HL,(52823)	Fetch the word at MapPosition into HL.
	56761	CALL MakeTiles	Call MakeTiles.
	56764	JP ScrollInWorld	Jump to ScrollInWorld.