Icon bar: CheckForPause

       Name: CheckForPause                                           [Show more]
       Type: Subroutine
   Category: Icon bar
    Summary: Pause the game if the pause button (Start) is pressed
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * CheckForPause_b0 calls CheckForPause
             * EQSHP calls CheckForPause
             * RunDemoFlightLoop calls CheckForPause
             * TT102 calls CheckForPause
             * BuyAndSellCargo calls via CheckForPause-3
             * LAUN calls via CheckForPause-3


 Arguments:

   A                    The button number to check to see if it is the pause
                        button (a value of 80 indicates the pause button)


 Returns:

   C flag               The status of the pause button:

                          * Clear if the pause button is not being pressed

                          * Set if the pause button is being pressed, in which
                            case we return from the subroutine after pausing the
                            the game, processing any choices from the icon bar,
                            and unpausing the game when Start is pressed again


 Other entry points:

   CheckForPause-3      Set A to the number of the icon bar button in
                        iconBarChoice so we check whether the pause button is
                        being pressed


 LDA iconBarChoice      ; Set A to the number of the icon bar button that has
                        ; been chosen from the icon bar (for when this routine
                        ; is called via the CheckForPause-3 entry point)

.CheckForPause

 CMP #80                ; If iconBarChoice = 80 then the Start button has been
 BNE cpse1              ; pressed to pause the game, so if this is not the case,
                        ; jump to cpse1 to return from the subroutine with the
                        ; C flag clear and without pausing

 LDA #0                 ; Set iconBarChoice = 0 to clear the pause button press
 STA iconBarChoice      ; so we don't simply re-enter the pause menu when we
                        ; resume

 JSR PauseGame_b6       ; Pause the game and process choices from the pause menu
                        ; until the game is unpaused by another press of Start

 SEC                    ; Set the C flag to indicate that the game was paused

 RTS                    ; Return from the subroutine

.cpse1

 CLC                    ; Clear the C flag to indicate that the game was not
                        ; paused

 RTS                    ; Return from the subroutine