Maths (Geometry): TAS6

       Name: TAS6                                                    [Show more]
       Type: Subroutine
   Category: Maths (Geometry)
    Summary: Negate the vector in XX15 so it points in the opposite direction
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * DOCKIT calls TAS6
             * TACTICS (Part 6 of 7) calls TAS6
             * TACTICS (Part 7 of 7) calls TAS6


.TAS6

 LDA XX15               ; Reverse the sign of the x-coordinate of the vector in
 EOR #%10000000         ; XX15
 STA XX15

 LDA XX15+1             ; Then reverse the sign of the y-coordinate
 EOR #%10000000
 STA XX15+1

 LDA XX15+2             ; And then the z-coordinate, so now the XX15 vector is
 EOR #%10000000         ; pointing in the opposite direction
 STA XX15+2

 RTS                    ; Return from the subroutine