Text-centring subs

[PhilOfPerth]

I write mostly text-based programmes, and often need to change the content of one or more lines during run-time, so I wrote these two subs to make it simple to do this.
Nothing Earth-shattering, but they may be useful to someone:

Code: (Select All)

'    This is a demo of two Subs I find useful in text-based progs, where lines of text need to be changed frequently

Screen _NewImage(1120, 768, 32)
Common Shared CPR
CPR = 1120 / _PrintWidth("X") '                         chars per row - used for centring text (change 1120 to your NewImage width)
_ScreenMove (_DesktopWidth - 1120) / 2, 100

yellow
WP "XXX", "101213" '                                    clear rows 10,12,13 and print centred string on each of them
Sleep 1
WP "YYY", "11" '                                        clear row 11 and print centred string on it
Sleep 1
red
WP "OOO", "11" '                                        clear row 11 and print centred red string on it
Sleep 1
white
CP "This Text", "15" '                                  clear row 15 and centre text on it
Sleep 1
red
WP "Finally, this", "1011121315" '                      clears row 10 to 15 and centres text on each of them
Sleep 1
WP "", "11"
Sleep 1
yellow
CP Space$(20) + "Change position with Spaces", "16" '      add spaces to change text position
CP "Left or Right" + Space$(20), "17"
Sleep

' ------------------------------------------------------------------------ THESE TWO SUBS ---------------------------------------------------

Sub WP (Txt$, RN$) '                                     Wipe (clear) row(s) named in RN$ (2-digit line numbers), then centre the string on each
    If RN$ = "" Then GoTo Place '                        if RN$ is given as empty string, jump to centring
    If Len(Txt$) < 1 Then Txt$ = Space$(CPR)
    For a = 1 To Len(RN$) - 1 Step 2 '                   for each pair of chars in RN$ (change to Step 3 for 3-digit line numbers)
        CL = Val(Mid$(RN$, a, 2)) '                      line to be cleaned
        Locate CL, 1: Print Space$(CPL) '                write row of spaces to the line
        Place:
        Ctr = Int(CPR / 2 - Len(Txt$) / 2) + 1 '         find centred start position for text string
        Locate CL, Ctr
        Print Txt$ '                                     print text string there (if string is empty, line remains cleared)
    Next
End Sub

Sub CP (txt$, RN$) '                                     Centre and Print text
    If RN$ = "" Then Exit Sub
    Ctr = Int(CPR / 2 - Len(txt$) / 2) + 1
    Locate Val(RN$), Ctr
    Print txt$
End Sub

' ----------------------------------------------------------------------------------------------------------------------------------------------

Sub white
    Color _RGB(255, 255, 255)
End Sub

Sub yellow
    Color _RGB(255, 255, 0)
End Sub

Sub red
    Color _RGB(255, 0, 0)
End Sub

You can also use Tab(n) in lieu of the Space$(n) for positioning the text