Routines
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52955: Note Wall Contact
Used by the routine at NextStep.
Used when the ship has touched the side of a segment. For a segment that has a horizontal step the remaining length is limited to two steps if the slope goes the way that the tile is facing. If the ship has not touched a segment already the routine finds the screen address of the start with FindSegmentAddress and clears the first byte of the record. It carries on at FinishStep_Count.
NoteWallContact 52955 LD A,(52825) The horizontal step copy.
52958 AND A Jump to NoteWallContact_Check if A is zero.
52959 JR Z,NoteWallContact_Check
52961 LD A,(23581) The tile number.
52964 BIT 1,A Jump to NoteWallContact_Right if bit 1 of A is set.
52966 JR NZ,NoteWallContact_Right
52968 LD A,(58395) The slope direction.
52971 CP 1 Jump to NoteWallContact_Check if A is not 1.
52973 JR NZ,NoteWallContact_Check
NoteWallContact_Limit 52975 LD A,C A=C.
52976 CP 2 Jump to NoteWallContact_Check if A is less than 2.
52978 JR C,NoteWallContact_Check
52980 LD C,2 C=2.
52982 JR NoteWallContact_Check Jump to NoteWallContact_Check.
NoteWallContact_Right 52984 LD A,(58395) The slope direction.
52987 CP 255 Jump to NoteWallContact_Check if A is not 255.
52989 JR NZ,NoteWallContact_Check
52991 JR NoteWallContact_Limit Jump to NoteWallContact_Limit.
NoteWallContact_Check 52993 LD A,(23599) The flagged steps.
52996 AND A Jump to FinishStep_Count if A is not zero.
52997 JP NZ,FinishStep_Count
53000 EXX Switch to the alternate registers.
53001 CALL FindSegmentAddress Call FindSegmentAddress.
53004 XOR A Clear A.
53005 LD (IX+1),A Write A to offset 1 of IX.
53008 EXX Switch to the alternate registers.
53009 JP FinishStep_Count Jump to FinishStep_Count.
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