Routines
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6BF0: Check whether a character is beside a chair
Used by the routine at 6C7C. Returns with the zero flag set if the character is standing beside a chair. Returns with the carry flag set if the character should turn round.
Input
A Character's animatory state
DE Character's coordinates
H Character number (0x98-0xA9)
6BF0 BIT 7,A Set the zero flag if the character is facing left
This entry point is used by the routine at 6CAF with H=0xAC (ERIC).
6BF2 LD A,D A=character's y-coordinate
6BF3 JR NZ,$6C2E Jump if the character is facing right
6BF5 CP $9B Set the zero flag if the character is on the top floor
6BF7 LD A,E A=character's x-coordinate
6BF8 JR NZ,$6C12 Jump if the character's on the middle floor
6BFA CP $3A Is the character to the right of the Map Room wall?
6BFC JR NC,$6C0B Jump if so
6BFE CP $30 This is the x-coordinate of the leftmost chair in the Reading Room
6C00 RET C Return if the character is to the left of this
6C01 NOP
6C02 CP $38 This is the x-coordinate of the rightmost chair in the Reading Room
6C04 JR Z,$6C07 Jump if the character is beside the rightmost chair in the room
6C06 RET NC Return if the character is to the right of this chair
6C07 AND A
6C08 BIT 0,A Return with the zero flag set if the character is standing beside a chair
6C0A RET
The character is on the top floor to the right of the Map Room wall.
6C0B CP $40 This is the x-coordinate of the leftmost chair in the Map Room
6C0D RET C Return if the character is to the left of this
6C0E CP $48 This is the x-coordinate of the rightmost chair in the Map Room
6C10 JR $6C04
The character is somewhere on the middle floor.
6C12 CP $27 Is the character to the right of the Exam Room wall?
6C14 JR NC,$6C1E Jump if so
6C16 CP $1D This is the x-coordinate of the leftmost chair in the White Room
6C18 RET C Return if the character is to the left of this
6C19 INC A This is the x-coordinate (+1) of the rightmost chair in the White Room
6C1A CP $26
6C1C JR $6C04
The character is on the middle floor to the right of the Exam Room wall.
6C1E CP $2B This is the x-coordinate of the leftmost chair in the Exam Room
6C20 RET C Return if the character is to the left of this
6C21 CP $3C This is the x-coordinate of the left end of the first set of chairs in the Exam Room
6C23 JR C,$6C29 Jump if the character is to the left of this
6C25 CP $44 This is the x-coordinate of the rightmost chair in the Exam Room
6C27 JR $6C04
The character is in the Exam Room, to the left of the first set of chairs.
6C29 INC A This is the x-coordinate (+1) of the right end of the second set of chairs in the Exam Room
6C2A CP $36
6C2C JR $6C04
The character is facing right.
6C2E CP $9B Set the zero flag if the character is on the top floor
6C30 LD A,E A=character's x-coordinate
6C31 JR NZ,$6C42 Jump if the character is on the middle floor
6C33 CP $3A This is the x-coordinate of the wall between the Reading and Map Rooms
6C35 JR NC,$6C3E Jump if the character is to the right of this
6C37 CP $37 This is the x-coordinate of the spot between the two chairs at the right in the Reading Room; if this were 'CP $38' instead, kids would be able to find the rightmost seat in the room
6C39 CCF Clear the carry flag if the character is to the left of the rightmost chair in the room (i.e. he's still on his way there)
6C3A RET NZ Return unless the character is beside the rightmost chair in the room
6C3B AND A Reset the zero flag, and set the carry flag to indicate that the character should turn round
6C3C CCF
6C3D RET
6C3E CP $48 This is the x-coordinate of the rightmost seat in the Map Room
6C40 JR $6C39
6C42 CP $27 This is the x-coordinate of the wall between the White and Exam Rooms
6C44 JR NC,$6C4A Jump if the character is to the right of this
6C46 CP $25 This is the x-coordinate of the rightmost chair in the White Room
6C48 JR $6C39
6C4A CP $44 This is the x-coordinate of the rightmost chair in the Exam Room
6C4C JR $6C39
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