Wanted : Monty Mole: Routine at 8C3D

8C3D: Check what attributes are around Monty

Used by the routine at 8B90.
8C3D	LD IY,$8D54	Point IY at the movement table at 8D54.
8C41	LD B,$02
8C43	LD A,($5C7C)	Get the Y co-ordinate (5C7C).
8C46	LD C,A	Remember this in C.
8C47	LD A,$BF	Invert the bottom 6 bits.
8C49	SUB C	Invert the bottom 6 bits.
8C4A	PUSH AF	Remember this.
8C4B	AND $07	Get the lowest 3 bits.
8C4D	JR Z,$8C51	Jump forward if none are set.
8C4F	LD B,$03	Otherwise default to 3.
8C51	LD A,B	Set the Y offset (8D5B).
8C52	LD ($8D5B),A	Set the Y offset (8D5B).
8C55	LD C,$02	Default to 2.
8C57	LD A,($5C7B)	Get the X co-ordinate (5C7C);
8C5A	AND $07	Get the lowest 3 bits.
8C5C	JR Z,$8C60	Jump foward if none are set.
8C5E	LD C,$03	Otherwise default to 3.
8C60	LD A,C	Set the X offset (8D5C).
8C61	LD ($8D5C),A	Set the X offset (8D5C).
8C64	POP AF	Restore Y co-ordinate.
8C65	AND $F8	Shift the top 5 bits down and store in the Y co-ordinate (8D5E)
8C67	RRCA
8C68	RRCA
8C69	RRCA
8C6A	LD ($8D5E),A
8C6D	LD A,($5C7B)	Get the X co-ordinate.
8C70	AND $F8	Shift the top 5 bits down and store in the X co-ordinate (8D5D)
8C72	RRCA
8C73	RRCA
8C74	RRCA
8C75	LD ($8D5D),A
8C78	LD A,($8D5E)	Get the Y co-ordinate.
8C7B	LD L,A	Scale it up to a screen address.
8C7C	LD H,$00
8C7E	ADD HL,HL
8C7F	ADD HL,HL
8C80	ADD HL,HL
8C81	ADD HL,HL
8C82	ADD HL,HL
8C83	LD A,($8D5D)	Get the X co-ordinate.
8C86	LD D,$00	Add this to get the desired offset.
8C88	LD E,A
8C89	ADD HL,DE
8C8A	LD DE,$5800	Add the base address to get an attribute on screen.
8C8D	ADD HL,DE	Add the base address to get an attribute on screen.
8C8E	LD ($8D59),HL	Store this attribute.
8C91	LD A,($8D5C)	Get the X co-ordinate for the offset.
8C94	LD B,A	Store this in B.
8C95	LD (IY+$00),$00	Default to no movement in this direction.
8C99	PUSH IY	Remember IY.
8C9B	CALL $8D0F	Check the movement tables across.
8C9E	LD HL,($8D59)	Move back a row.
8CA1	LD DE,$0020
8CA4	LD A,($8D5B)
8CA7	DEC A
8CA8	LD B,A
8CA9	ADD HL,DE
8CAA	DJNZ $8CA9
8CAC	LD A,($8D5C)	Get the X co-ordinate for the offset.
8CAF	LD B,A	Store this in B.
8CB0	INC IY	Move to the next direction.
8CB2	LD (IY+$00),$00	Default to no movement.
8CB6	CALL $8D0F	Check movement tables across.
8CB9	LD HL,($8D59)
8CBC	LD A,($8D5B)
8CBF	LD B,A
8CC0	INC IY	Move to the next direction.
8CC2	LD (IY+$00),$00	Default to no movement.
8CC6	CALL $8D2E	Check movement tables down.
8CC9	LD HL,($8D59)
8CCC	LD A,($8D5C)
8CCF	DEC A
8CD0	LD B,A
8CD1	INC HL
8CD2	DJNZ $8CD1
8CD4	LD A,($8D5B)
8CD7	LD B,A
8CD8	INC IY	Move to the next direction.
8CDA	LD (IY+$00),$00	Default to no movement.
8CDE	CALL $8D2E	Check movement tables down.
8CE1	POP IY	Restore IY to the base position.
8CE3	LD A,(IY+$00)	If any direction flag was set to 3, set it to 0 instead.
8CE6	CP $03
8CE8	JR NZ,$8CEE
8CEA	LD (IY+$00),$00
8CEE	LD A,(IY+$01)
8CF1	CP $03
8CF3	JR NZ,$8CF9
8CF5	LD (IY+$01),$00
8CF9	LD A,(IY+$02)
8CFC	CP $03
8CFE	JR NZ,$8D04
8D00	LD (IY+$02),$00
8D04	LD A,(IY+$03)
8D07	CP $03
8D09	RET NZ
8D0A	LD (IY+$03),$00
8D0E	RET