Status: IncreaseTally

       Name: IncreaseTally                                           [Show more]
       Type: Subroutine
   Category: Status
    Summary: Add the kill count to the fractional and low bytes of our combat
             rank tally following a kill
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * EXNO2 calls IncreaseTally


 Arguments:

   X                    The type of the ship that was killed


 Returns:

   C flag               If set, the addition overflowed


.IncreaseTally

 SETUP_PPU_FOR_ICON_BAR ; If the PPU has started drawing the icon bar, configure
                        ; the PPU to use nametable 0 and pattern table 0

 LDA currentBank        ; Fetch the number of the ROM bank that is currently
 PHA                    ; paged into memory at $8000 and store it on the stack

 LDA #1                 ; Page ROM bank 1 into memory at $8000
 JSR SetBank

                        ; The fractional kill count is taken from the KWL%
                        ; table, according to the ship's type (we look up the
                        ; X-1-th value from KWL% because ship types start at 1
                        ; rather than 0)

 LDA KWL%-1,X           ; Double the fractional kill count and push the low byte
 ASL A                  ; onto the stack
 PHA

 LDA KWH%-1,X           ; Double the integer kill count and put the high byte
 ROL A                  ; in Y
 TAY

 PLA                    ; Add the doubled fractional kill count to our tally,
 ADC TALLYL             ; starting by adding the fractional bytes:
 STA TALLYL             ;
                        ;   TALLYL = TALLYL + fractional kill count

 TYA                    ; And then we add the low byte of TALLY(1 0):
 ADC TALLY              ;
 STA TALLY              ;   TALLY = TALLY + carry + integer kill count

                        ; Fall through into ResetBankP to reset the ROM bank to
                        ; the value we stored on the stack