Routines
Prev: CF35 Up: Map Next: CF50
CF48: Check Wall Vertical Reverse
Used by the routine at TestMoveDown.
Checks whether an object that is moving in the direction of heading two touches a wall in the cell containing a point. If it does, the depth is made positive and the object is pushed back by CheckWallVertical_PushBack.
Input
DE The horizontal position of the point
HL The vertical position of the point
IX The address of the object
Output
F The carry flag is set if the object hit a wall
Check the walls, then push the object back if it is touching one.
CheckWallVerticalReverse CF48 CALL CheckWallsHorizontalFirst Call CheckWallsHorizontalFirst.
CF4B RET NC Return if the object is not touching a wall.
CF4C NEG Make the depth positive, and jump to CheckWallVertical_PushBack.
CF4E JR CheckWallVertical_PushBack
View the equivalent code in;
Prev: CF35 Up: Map Next: CF50