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⌂ ∞ Elite on the BBC Micro and NES

Save and load: MoveInRightColumn

[NES version, Bank 6]

       Name: MoveInRightColumn                                       [Show more]
       Type: Subroutine
   Category: Save and load
    Summary: Process moving the highlight when it's in the right column (the
             save slots)

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * MoveInLeftColumn calls MoveInRightColumn
             * MoveInMiddleColumn calls MoveInRightColumn




 Arguments:

   A                    The slot number in the right column containing the
                        highlight (0 to 7)



.MoveInRightColumn

 JSR HighlightSaveName  ; Highlight the name of the save slot in A, so the
                        ; highlight is shown in the correct slot in the right
                        ; column

 JSR UpdateSaveScreen   ; Update the screen

 JSR WaitForNoDirection ; Wait until the left and right buttons on controller 1
                        ; have been released and remain released for at least
                        ; four VBlanks

.mrig1

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

 LDX controller1Up      ; If the up button on controller 1 is not being pressed,
 BPL mrig2              ; jump to mrig2 to move on to the next button

                        ; If we get here then the up button is being pressed

 CMP #0                 ; If A = 0 then we are already in the top slot in the
 BEQ mrig2              ; column, so jump to mrig2 to move on to the next button
                        ; as we can't move beyond the top of the column

 JSR PrintSaveName      ; Print the name of the commander file saved in slot A
                        ; so that it reverts to the normal font, as we are about
                        ; to move the highlight elsewhere

 SEC                    ; Set A = A - 1
 SBC #1                 ;
                        ; So A is now the slot number of the slot above

 JSR HighlightSaveName  ; Highlight the name of the save slot in A, so the
                        ; highlight moves to the new position

 JSR UpdateSaveScreen   ; Update the screen

.mrig2

 LDX controller1Down    ; If the down button on controller 1 is not being
 BPL mrig3              ; pressed, jump to mrig3 to move on to the next button

                        ; If we get here then the down button is being pressed

 CMP #7                 ; If A >= 7 then we are already in the bottom slot in
 BCS mrig3              ; the column, so jump to mrig3 to move on to the next
                        ; button as we can't move beyond the bottom of the
                        ; column

 JSR PrintSaveName      ; Print the name of the commander file saved in slot A
                        ; so that it reverts to the normal font, as we are about
                        ; to move the highlight elsewhere

 CLC                    ; Set A = A + 1
 ADC #1                 ;
                        ; So A is now the slot number of the slot below

 JSR HighlightSaveName  ; Highlight the name of the save slot in A, so the
                        ; highlight moves to the new position

 JSR UpdateSaveScreen   ; Update the screen

.mrig3

 LDX controller1Left03  ; If the left button on controller 1 was not being held
 BPL mrig4              ; down four VBlanks ago, jump to mrig4 to move on to the
                        ; next button

                        ; If we get here then the left button is being pressed

 JSR PrintSaveName      ; Print the name of the commander file saved in slot A
                        ; so that it reverts to the normal font, as we are about
                        ; to move the highlight elsewhere

 JMP MoveInMiddleColumn ; Move the highlight left to the specified slot number
                        ; in the middle column and process any further button
                        ; presses accordingly

.mrig4

 LDX controller1Right03 ; If the right button on controller 1 was not being held
 BPL mrig5              ; down four VBlanks ago, jump to mrig5 to check the icon
                        ; bar buttons

                        ; If we get here then the right button is being pressed

 JSR PrintSaveName      ; Print the name of the commander file saved in slot A
                        ; so that it reverts to the normal font, as we are about
                        ; to move the highlight elsewhere

 LDA #4                 ; This instruction has no effect as the first thing that
                        ; MoveToLeftColumn does is to set A to 9, which is the
                        ; slot number for the current commander

 JMP MoveToLeftColumn   ; Move the highlight to the left column (the current
                        ; commander) and process any further button presses
                        ; accordingly

.mrig5

                        ; If we get here then neither of the left or right
                        ; buttons have been pressed, so we move on to checking
                        ; the icon bar buttons

 JSR CheckSaveLoadBar   ; Check the icon bar buttons to see if any of them have
                        ; been chosen

 BCS mrig1              ; The C flag will be set if we are to resume what we
                        ; were doing (so we pick up where we left off after
                        ; processing the pause menu, for example, or keep going
                        ; if no button was chosen), so loop back to mrig1 to
                        ; keep checking for left and right button presses

                        ; If we get here then the C flag is clear and we need to
                        ; return from the SVE routine and go back to the icon
                        ; bar processing routine in TT102, so the button choice
                        ; can be processed there

 RTS                    ; Return from the subroutine