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Save and load: MoveInLeftColumn

[NES version, Bank 6]

Name: MoveInLeftColumn [Show more] Type: Subroutine Category: Save and load Summary: Process moving the highlight when it's in the left column (the current commander)
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * MoveToLeftColumn calls MoveInLeftColumn

Arguments: A Must be set to 9, as that represents the slot number of the left column containing the current commander
.MoveInLeftColumn JSR SetupPPUForIconBar ; If the PPU has started drawing the icon bar, configure ; the PPU to use nametable 0 and pattern table 0 LDX controller1Left03 ; If the left button on controller 1 was not being held BPL mlef3 ; down four VBlanks ago or for the three VBlanks before ; that, jump to mlef3 to check the right button ; If we get here then the left button is being pressed, ; so we need to move the highlight left from its current ; position (which is given in A and is always 9) to the ; right column JSR PrintSaveName ; Print the name of the commander file in its current ; position in A, to remove the highlight CMP #9 ; If A = 9 then we have pressed the left button while BEQ mlef1 ; highlighting the current commander name on the left ; of the screen, so we need to move the highlight to the ; right column, so jump to mlef1 to do this ; ; This will always be the case as this routine is only ; called with A = 9 (as that's the slot number we use ; to represent the current commander in the left ; column), so presumably this logic is left over from a ; time when this routine was a bit more generic LDA #0 ; Otherwise the highlight must currently be in either ; the middle or right column, so set A = 0 so the ; highlight moves to the top of the new column (though ; again, this will never happen) JMP mlef2 ; Jump to mlef2 to move the highlight to the right ; column .mlef1 ; If we get here then we have pressed the left button ; while highlighting the current commander name on the ; left of the screen LDA #4 ; Set A = 4 so the call to MoveInRightColumn moves the ; highlight to slot 4 in the right column, which is at ; the same vertical position as the current commander ; name on the left .mlef2 JMP MoveInRightColumn ; Move the highlight left to the specified slot number ; in the right column and process any further button ; presses accordingly .mlef3 LDX controller1Right03 ; If the right button on controller 1 was not being held BPL mlef6 ; down four VBlanks ago or for the three VBlanks before ; that, jump to mlef6 to check the icon bar buttons ; If we get here then the right button is being pressed, ; so we need to move the highlight right from its ; current position (which is given in A and is always 9) ; to the middle column JSR PrintSaveName ; Print the name of the commander file in its current ; position in A, to remove the highlight CMP #9 ; If A = 9 then we have pressed the right button while BEQ mlef4 ; highlighting the current commander name on the left of ; the screen, so we need to move the highlight to the ; middle column, so jump to mlef4 to do this ; ; This will always be the case as this routine is only ; called with A = 9 (as that's the slot number we use ; to represent the current commander in the left ; column), so presumably this logic is left over from a ; time when this routine was a bit more generic LDA #0 ; Otherwise the highlight must currently be in either ; the middle or right column, so set A = 0 so the ; highlight moves to the top of the new column (though ; again, this will never happen) JMP mlef5 ; Jump to mlef5 to move the highlight to the middle ; column .mlef4 ; If we get here then we have pressed the right button ; while highlighting the current commander name on the ; left of the screen LDA #4 ; Set A = 4 so the call to MoveInMiddleColumn moves the ; highlight to slot 4 in the middle column, which is at ; the same vertical position as the current commander ; name on the left .mlef5 JMP MoveInMiddleColumn ; Move the highlight left to the specified slot number ; in the middle column and process any further button ; presses accordingly .mlef6 ; 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 MoveInLeftColumn ; 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), so loop back ; to the start of the routine 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 RTS ; Return from the subroutine