.SPS4 LDX #8 \ First we need to copy the space station's coordinates \ into K3, so set a counter to copy the first 9 bytes \ (the 3-byte x, y and z coordinates) from the station's \ data block at K% + NI% into K3 .SPL1 LDA K%+NI%,X \ Copy the X-th byte from the station's data block at STA K3,X \ K% + NI% to the X-th byte of K3 DEX \ Decrement the loop counter BPL SPL1 \ Loop back to SPL1 until we have copied all 9 bytes JMP TAS2 \ Call TAS2 to build XX15 from K3, returning from the \ subroutine using a tail callName: SPS4 [View in context] Type: Subroutine Category: Maths (Geometry) Summary: Calculate the vector to the space station
Calculate the vector between our ship and the space station and store it in XX15.
Ship data blocks and ship line heaps
Configuration variable: NI% = 36
The number of bytes in each ship's data block (as stored in INWK and K%)
Label SPL1 is local to this routine
Normalise the three-coordinate vector in K3