Tactics: SFRMIS

       Name: SFRMIS                                                  [Show more]
       Type: Subroutine
   Category: Tactics
    Summary: Add an enemy missile to our local bubble of universe
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * TACTICS (Part 5 of 7) calls SFRMIS


 An enemy has fired a missile, so add the missile to our universe if there is
 room, and if there is, make the appropriate warnings and noises.


.SFRMIS

 LDX #MSL               ; Set X to the ship type of a missile, and call SFS1-2
 JSR SFS1-2             ; to add a missile to our universe that has AI (bit 7
                        ; set), is hostile (bit 6 set) and has been launched
                        ; (bit 0 clear); the target slot number is set to 31,
                        ; but this is ignored as the hostile flags means we
                        ; are the target

 BCC sfrm1              ; The C flag will be set if the call to SFS1-2 was a
                        ; success, so if it's clear, jump to sfrm1 to return
                        ; from the subroutine

 LDA #120               ; Print recursive token 120 ("INCOMING MISSILE") as an
 JSR MESS               ; in-flight message

 LDY #9                 ; Call the NOISE routine with Y = 9 to make the sound
 JMP NOISE              ; of the missile being launched and return from the
                        ; subroutine using a tail call

.sfrm1

 RTS                    ; Return from the subroutine