Booty: Routine at 43224

43224: Clear Room Buffer

Used by the routine at DrawRoom.
First off, blank the screen.
ClearRoomBuffer	43224	LD B,24	Clear the bottom 24 lines using CL_LINE.
	43226	CALL 3652	Clear the bottom 24 lines using CL_LINE.
Clear the room buffer.
	43229	LD BC,800	Point HL at BufferRoom and count 800 bytes.
	43232	LD HL,41412	Point HL at BufferRoom and count 800 bytes.
ClearRoomBuffer_Loop	43235	LD A,0	Write 0 to the next byte and loop back until the room buffer is clear.
	43237	LD (HL),A
	43238	INC HL
	43239	DEC BC
	43240	LD A,B
	43241	OR C
	43242	JR NZ,ClearRoomBuffer_Loop
Clear the room attribute buffer. Setting each value to the INK value of the PAPER colour (?)
	43244	LD BC,800	BC=Counter; the length of the room attribute buffer (800).
ClearRoomAttributeBuffer_Loop	43247	LD A,(23505)	A=*ActiveRoom_PaperColour.
	43250	SLA A	Convert a PAPER value (using bits 3, 4 and 5) to an INK value (shifted left to bits 0, 1 and 2).
	43252	SLA A
	43254	SLA A
	43256	LD (HL),A	Write A to *HL.
	43257	INC HL	Increment the room attribute buffer pointer by one.
	43258	DEC BC	Decrease the room attribute buffer counter by one.
	43259	LD A,B	Jump to ClearRoomAttributeBuffer_Loop until the room attribute buffer counter is zero.
	43260	OR C
	43261	JR NZ,ClearRoomAttributeBuffer_Loop
	43263	RET	Return.