Main loop: Main flight loop (Part 10 of 16)

       Name: Main flight loop (Part 10 of 16)                        [Show more]
       Type: Subroutine
   Category: Main loop
    Summary: For each nearby ship: Remove if scooped, or process collisions
  Deep dive: Program flow of the main game loop
    Context: See this subroutine in context in the source code
 References: No direct references to this subroutine in this source file


 The main flight loop covers most of the flight-specific aspects of Elite. This
 section covers the following:

   * Continue looping through all the ships in the local bubble, and for each
     one:

     * Remove scooped item after both successful and failed scooping attempts

     * Process collisions


.MA59

                        ; If we get here then scooping failed

 JSR EXNO3              ; Make the sound of the cargo canister being destroyed
                        ; and fall through into MA60 to remove the canister
                        ; from our local bubble

.MA60

                        ; If we get here then scooping was successful

 ASL INWK+31            ; Set bit 7 of the scooped or destroyed item, to denote
 SEC                    ; that it has been killed and should be removed from
 ROR INWK+31            ; the local bubble

.MA61

 BNE MA26               ; Jump to MA26 to skip over the collision routines and
                        ; to move on to missile targeting (this BNE is
                        ; effectively a JMP as A will never be zero)

.MA67

                        ; If we get here then we have collided with something,
                        ; but not fatally

 LDA #1                 ; Set the speed in DELTA to 1 (i.e. a sudden stop)
 STA DELTA

 LDA #5                 ; Set the amount of damage in A to 5 (a small dent) and
 BNE MA63               ; jump down to MA63 to process the damage (this BNE is
                        ; effectively a JMP as A will never be zero)

.MA58

                        ; If we get here, we have collided with something in a
                        ; potentially fatal way

 ASL INWK+31            ; Set bit 7 of the ship we just collided with, to
 SEC                    ; denote that it has been killed and should be removed
 ROR INWK+31            ; from the local bubble

 LDA INWK+35            ; Load A with the energy level of the ship we just hit

 SEC                    ; Set the amount of damage in A to 128 + A / 2, so
 ROR A                  ; this is quite a big dent, and colliding with higher
                        ; energy ships will cause more damage

.MA63

 JSR OOPS               ; The amount of damage is in A, so call OOPS to reduce
                        ; our shields, and if the shields are gone, there's a
                        ; chance of cargo loss or even death

 JSR EXNO3              ; Make the sound of colliding with the other ship and
                        ; fall through into MA26 to try targeting a missile