PureBasic Forums - English

Demivec wrote: Sun Apr 25, 2021 4:33 pm The unicode codepoints are quite extensive and also still in a state of change.

Perhaps a link to the symbols would be better.

http://www.unicode.org/charts/

Sicro wrote: Sun Apr 25, 2021 5:59 pm PureBasic uses UCS-2 (2 bytes per character) and is therefore limited to the character codes from 0 to 65,535 (see PB help).

But even with this limitation the filling of the list takes some seconds (I tested it with the source code of the PureBasic IDE).

Maybe it would be better if not all characters are displayed at once. At the top of the window we could place several buttons with different character ranges or take a ComboBoxGadget for it, with which we could switch the displayed character ranges in the list.

Procedure handleError(value, text.s)
  If Not value
    MessageRequester("Error", text)
    End
  EndIf
EndProcedure

Procedure.s _Chr(v.i) ;return a proper surrogate pair for unicode values outside the BMP (Basic Multilingual Plane)
  Protected high, low
  If v < $10000
    ProcedureReturn Chr(v)
  Else
    ;calculate surrogate pair of unicode codepoints to represent value in UTF-16
    v - $10000
    high = v / $400 + $D800 ;high/lead surrogate value
    low = v % $400 + $DC00  ;low/tail surrogate value
    ProcedureReturn Chr(high) + Chr(low)
  EndIf
EndProcedure

#imageWidth = 310
#imageHeight = 310
handleError(LoadFont(0, "Courier", 200), "Can't load font.")
handleError(CreateImage(0, #imageWidth, #imageHeight), "Can't to create image.")

If StartDrawing(ImageOutput(0))
  DrawingFont(FontID(0))
  a$ = _Chr($1F600)
  DrawText(0, 0, a$)
  StopDrawing()
EndIf

handleError(OpenWindow(0, 0, 0, #imageWidth, #imageHeight + 20, a$ + "Unicode Test" + a$), "Can't open window.")
ImageGadget(0, 0, 0, 0, 0, ImageID(0))
TextGadget(1, 5, #imageHeight, #imageWidth, 20, ReplaceString(Space(25), " ", a$))

Repeat: Until WaitWindowEvent() = #PB_Event_CloseWindow

• If you see a smiling emoji "" after running the above code you can see that UTF-16 is being used by the DrawText() function and not UCS-2.
• If you see a line of smiling emoji in the TextGadget then you can see that UTF-16 is being used by the TextGadget() and not UCS-2.
• If you see a smiling emoji at the beginning and end of the Window's title then you can see that UTF-16 is being used by the OpenWindow() function and not UCS-2.
• If you see a smiling emoji in the debug window while debugging than you can see that the Debug command is using UTF-16 and that the font you are using in the Debug window also has a character for that codepoint.

Demivec wrote: Thu Apr 29, 2021 2:44 am @Sicro: PureBasic says it uses UCS-2 internally but I think that is a bit fiddly. I think the truth is that all of its string functions like Mid() , LSet() and so on simply operate on codepoints as if they were all two bytes long. Many functions that utilize strings actually make use of UTF-16. UTF-16 allows all of the Unicode codepoints to be written using either two or four bytes with a surrogate mechanism.

Here is a demonstration:
[...]

Len(one character string)

Demivec wrote: Thu Apr 29, 2021 2:44 am Also, as stated earlier the codepoint definitions are still in a process of change. UCS-2 is updated to keep it synchronized to changes in the BMP (Basic Multilingual Plane) of unicode.

Demivec wrote: Thu Apr 29, 2021 2:44 am Note: I verified that the forum update now allows Unicode characters outside the BMP to be posted in messages. The Smiley emoticon in this message is the test case. Here are a few more 🀁🀂🀃🀢🀣🀤🀥🀦🀧🀨🀩(mahjong tiles).

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