Routines
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E013: Cut a step in +U short at a box of a cell
Used by the routine at CLIP_PLUS_U.
As CUT_STEP_PLUS_V, for the step in U (+A) and the +U routine (CLIP_PLUS_U); the overlap in U comes from HIT_BOXES_U. The entry point CUT_STEP_U adds twice A to the step.
Input
D The column of the cell to test
H Its row
IX The object
Output
F Carry set if the step was cut
CUT_STEP_PLUS_U E013 CALL HIT_BOXES_U Test the cell's boxes; nothing in the way returns with carry clear
E016 RET NC
This entry point is used by the routine at CUT_STEP_MINUS_U.
CUT_STEP_U E017 ADD A,A CUT_STEP_U: twice minus the overlap added to the step in U; then mark the object stopped
E018 ADD A,(IX+$0A)
E01B LD (IX+$0A),A
E01E JR MARK_BLOCKED
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