Flight: wW

       Name: wW                                                      [Show more]
       Type: Subroutine
   Category: Flight
    Summary: Start a hyperspace countdown
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * Ghy calls wW


 Start the hyperspace countdown (for both inter-system hyperspace and the
 galactic hyperdrive).


.wW

 LDA #15                \ The hyperspace countdown starts from 15, so set A to
                        \ 15 so we can set the two hyperspace counters

 STA QQ22+1             \ Set the number in QQ22+1 to A, which is the number
                        \ that's shown on-screen during the hyperspace countdown

 STA QQ22               \ Set the number in QQ22 to 15, which is the internal
                        \ counter that counts down by 1 each iteration of the
                        \ main game loop, and each time it reaches zero, the
                        \ on-screen counter gets decremented, and QQ22 gets set
                        \ to 5, so setting QQ22 to 15 here makes the first tick
                        \ of the hyperspace counter longer than subsequent ticks

 TAX                    \ Print the 8-bit number in X (i.e. 15) at text location
 BNE ee3                \ (0, 1), padded to 5 digits, so it appears in the top
                        \ left corner of the screen, and return from the
                        \ subroutine using a tail call (the BNE is effectively a
                        \ JMP as A is never zero)