Text: PrintFlightMessage

       Name: PrintFlightMessage                                      [Show more]
       Type: Subroutine
   Category: Text
    Summary: Print an in-flight message
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * FlightLoop4To16 calls PrintFlightMessage


.PrintFlightMessage

 LDA messYC             ; Set A to the current row for in-flight messages

 LDX QQ11               ; If this is the space view, jump to fmes1 to skip the
 BEQ fmes1              ; following and leave A with this value, so we print the
                        ; in-flight message on the row specified in messYC

 JSR CLYNS+8            ; Clear the bottom two text rows of the visible screen,
                        ; and move the text cursor to column 1 on row 21, i.e.
                        ; the start of the top row of the two bottom rows, but
                        ; without resetting the in-flight message timer

 LDA #23                ; Set A to 23, so we print the in-flight message on row
                        ; 23 for all views other than the space view

.fmes1

 STA YC                 ; Move the text cursor to the row in A

 LDX #0                 ; Set QQ17 = 0 to switch to ALL CAPS
 STX QQ17

 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 messXC             ; Move the text cursor to column messXC, which we set
 STA XC                 ; to the text column of the current in-flight message
                        ; when we called MESS to display it

 LDA messXC             ; This appears to be an unnecessary duplicate of the
 STA XC                 ; above

 LDY #0                 ; We now work through the message one character at a
                        ; time, so set a character counter in Y

.fmes2

 LDA messageBuffer,Y    ; Fetch the Y-th character from the message buffer

 JSR CHPR_b2            ; Print the character

 INY                    ; Increment the character counter in Y

 CPY messageLength      ; Loop back until we have printed all the characters in
 BNE fmes2              ; the buffer, whose size is in messageLength

 LDA QQ11               ; If this is the space view, jump to RTS5 to return from
 BEQ RTS5               ; the subroutine, as the NMI handler will take care of
                        ; updating the screen when we next flip bitplanes

 JMP DrawMessageInNMI   ; Configure the NMI to display the message that we just
                        ; printed, returning from the subroutine using a tail
                        ; call