I'm experimenting zint library for generating barcodes.
So far it seems quite easy to interface with thinBasic.

I will consider to create a specific thinBasic module and incorporate the library into it.
Any interest?

References

web site: http://www.zint.org.uk
api manual: http://www.zint.org.uk/Manual.aspx?type=p&page=5


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A preliminary VERY LOW level example. You need to have zint.dll downloadable from https://sourceforge.net/projects/zin...?source=navbar

  Type zint_render_line
      x       as single
      y       as single
      length  as single
      width   as single
      pNext   as DWord
    end type
    
    Type zint_render_string
      x       as single
      y       as single
      fsize   as single
      width   as single
      length  as Long
      pText   as Byte
      pNext   as DWord
    end type
    
    Type zint_render_ring
      x           as single
      y           as single
      radius      as single
      line_width  as single
      pNext       as DWord
    end type


    Type zint_render_hexagon
      x           as single
      y           as single
      height      as single
      pNext       as DWord
    end type


    Type zint_render
      width       as DWord
      height      as DWord
      pLines      as DWord  'struct zint_render_line *lines; /* Pointer to first line */
      pStrings    as dword  'struct zint_render_string *strings; /* Pointer to first string */
      pRings      as DWord  'struct zint_render_ring *rings; /* Pointer to first ring */
      phexagons   as DWord  'struct zint_render_hexagon *hexagons; /* Pointer to first hexagon */
    end type


'    struct zint_symbol {
'        int symbology;
'        int height;
'        int whitespace_width;
'        int border_width;
'        int output_options;
'        char fgcolour[10];
'        char bgcolour[10];
'        char outfile[256];
'        float scale;
'        int option_1;
'        int option_2;
'        int option_3;
'        int show_hrt;
'        int input_mode;
'        int eci;
'        unsigned char text[128];
'        int rows;
'        int width;
'        char primary[128];
'        unsigned char encoded_data[200][143];
'        int row_height[200]; /* Largest symbol is 189 x 189 Han Xin */
'        char errtxt[100];
'        char *bitmap;
'        int bitmap_width;
'        int bitmap_height;
'        unsigned int bitmap_byte_length;
'        float dot_size;
'        struct zint_render *rendered;
'        int debug;
'    };
'
    Type zint_symbol
      symbology         as Long
      height            as Long
      whitespace_width  as Long
      border_width      as Long
      output_options    as long
      fgcolour(10)      as Byte
      bgcolour(10)      as byte
      outfile           as string * 256
      scale             as single
      option_1          as Long
      option_2          as Long
      option_3          as Long
      show_hrt          as Long
      input_mode        as Long
      eci               as Long
      stext             as string * 128
      rows              as Long
      width             as Long
      primary           as string * 128
      encoded_data(200,143) as Byte
      row_height(200)   as Long
      errtxt            as string * 100
      pbitmap           as dword
      bitmap_width      as Long
      bitmap_height     as Long
      bitmap_byte_length  as Long
      dot_size          as single
      pRendered         as dword  'struct zint_render *rendered;
      debug             as Long
    end type




'ZINT_EXTERN struct zint_symbol *ZBarcode_Create(void);
DECLARE FUNCTION ZBarcode_Create LIB "zint.dll" ALIAS "ZBarcode_Create" () AS DWord


'ZINT_EXTERN void ZBarcode_Clear(struct zint_symbol *symbol);
DECLARE sub ZBarcode_Clear LIB "zint.dll" ALIAS "ZBarcode_Clear" (byval lSymbol as DWord)


'ZINT_EXTERN void ZBarcode_Delete(struct zint_symbol *symbol);
DECLARE sub ZBarcode_Delete LIB "zint.dll" ALIAS "ZBarcode_Delete" (byval lSymbol as DWord)
'
'ZINT_EXTERN int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int in_length);
DECLARE FUNCTION ZBarcode_Encode LIB "zint.dll" ALIAS "ZBarcode_Encode" (byval lSymbol as DWord, byval zSource as asciiz ptr, byval in_length as Long) AS long


'ZINT_EXTERN int ZBarcode_Encode_File(struct zint_symbol *symbol, char *filename);


'ZINT_EXTERN int ZBarcode_Print(struct zint_symbol *symbol, int rotate_angle);
DECLARE FUNCTION ZBarcode_Print LIB "zint.dll" ALIAS "ZBarcode_Print" (byval lSymbol as DWord, byval rotate_angle as Long) AS Long


'ZINT_EXTERN int ZBarcode_Encode_and_Print(struct zint_symbol *symbol, unsigned char *input, int length, int rotate_angle);
'ZINT_EXTERN int ZBarcode_Encode_File_and_Print(struct zint_symbol *symbol, char *filename, int rotate_angle);
'
'ZINT_EXTERN int ZBarcode_Render(struct zint_symbol *symbol, const float width, const float height);
'
'ZINT_EXTERN int ZBarcode_Buffer(struct zint_symbol *symbol, int rotate_angle);
DECLARE FUNCTION ZBarcode_Buffer LIB "zint.dll" ALIAS "ZBarcode_Buffer" (byval lSymbol as DWord, byval rotate_angle as Long) AS Long


'ZINT_EXTERN int ZBarcode_Encode_and_Buffer(struct zint_symbol *symbol, unsigned char *input, int length, int rotate_angle);
'ZINT_EXTERN int ZBarcode_Encode_File_and_Buffer(struct zint_symbol *symbol, char *filename, int rotate_angle);
'
'ZINT_EXTERN int ZBarcode_ValidID(int symbol_id);
DECLARE FUNCTION ZBarcode_ValidID LIB "zint.dll" ALIAS "ZBarcode_ValidID" (ByVal SymbolID as Long) AS Long


'ZINT_EXTERN int ZBarcode_Version();
DECLARE FUNCTION ZBarcode_Version LIB "zint.dll" ALIAS "ZBarcode_Version" () AS long




' http://zint.org.uk/Manual.aspx?type=p&page=5




Uses "UI"
uses "console"




' -- ID numbers of controls
Begin ControlID
  %cCanvasDB 
  %bBarCode
  %bClose 
End ControlID


Type BGRA
  B As Byte
  G As Byte
  R As Byte
  A As Byte
End Type


' -- Create dialog here
FUNCTION TBMAIN()
  LOCAL hDlg AS DWORD


  Dialog NEW pixels, 0, "thinBasic and zint lib",-1,-1, 640, 300, _
                                    %WS_POPUP Or %WS_VISIBLE Or _
                                     %WS_CLIPCHILDREN Or %WS_CAPTION OR _
                                     %WS_SYSMENU Or %WS_MINIMIZEBOX, 0 To hDlg
  
  ' -- Place controls here
  dim cx, cy as long
  'dialog pixels hDlg, 400, 400 to units cx, cy
  Control ADD CANVAS, hDlg, %cCanvasDB, "", 0, 0, 640, 200
  
  Control ADD BUTTON, hDlg, %bBarCode , "Redraw"  ,  10, 250, 50, 25, Call bModifyBitmapProc    
  Control ADD BUTTON, hDlg, %bClose   , "Close"   , 100, 250, 50, 25, Call bCloseProc
 
  DIALOG SHOW MODAL hDlg, CALL dlgProc


END FUNCTION


' -- Callback for dialog
CALLBACK FUNCTION dlgProc()


  ' -- Test for messages
  SELECT CASE CBMSG
    Case %WM_INITDIALOG
        DrawBarCode(CBHNDL)
     
    CASE %WM_CLOSE
    ' -- Put code to be executed before dialog end here


  END SELECT


END FUNCTION
 
' -- Callback for close button
CallBack Function bCloseProc()


  If CBMSG = %WM_COMMAND Then       
    If CBCTLMSG = %BN_CLICKED Then
      ' -- Closes the dialog 
      DIALOG END CBHNDL
    END IF
  END IF


End Function


CallBack Function bModifyBitmapProc()


  If CBMSG = %WM_COMMAND Then       
    If CBCTLMSG = %BN_CLICKED Then


      DrawBarCode(CBHNDL)


      Dialog SET TEXT CBHNDL, "OK " & Timer


    End If
  End If


End Function






function DrawBarCode(byval hWnd as Long) as Long
  dim pSymbol as zint_symbol ptr
  DWord   lSymbol
  string  sText   = "thinBASIC & zint rocks!" & $NUL


  printl "Version:", ZBarcode_Version
  lSymbol = ZBarcode_Create
  PrintL "Symbol:", lSymbol
  pSymbol = lSymbol
  
  pSymbol.symbology = 20 'Code 128
  'pSymbol.symbology = 58 'QR Code
  'pSymbol.symbology = 71 'Data MATRIX
  
  pSymbol.outfile     = "xxx.bmp"
  pSymbol.input_mode  = 0 'DATA_MODE
  'pSymbol.scale  = 0.8 


  'printl "BARCODE_CODE128 :", ZBarcode_ValidID(20)
  printl "Current pSymbol.symbology", pSymbol.symbology
  printl "ZBarcode_Encode :", ZBarcode_Encode(lSymbol, sText, 0)


  printl "ZBarcode_Buffer :", ZBarcode_Buffer(lSymbol, 0)
  'printl "ZBarcode_Print  :", ZBarcode_Print(lSymbol, 0)
  printl "pSymbol.bitmap_width", pSymbol.bitmap_width
  printl "pSymbol.bitmap_height", pSymbol.bitmap_height


  CANVAS_Attach(hWnd, %cCanvasDB, %TRUE)
  canvas_clear(rgb(255, 255, 255))
  CANVAS_Redraw
  
    long y, x, i
    Long red, blue, green
    dim nPixels = (pSymbol.bitmap_width) * (pSymbol.bitmap_height) * 4
    dim lColors(nPixels) as byte at pSymbol.pbitmap
    i = 1
    for y = 1 to pSymbol.bitmap_height
      for x = 1 to pSymbol.bitmap_width
            red   = lColors(i)
            green = lColors(i + 1)
            blue  = lColors(i + 2)
            Canvas_SetPixel(x, y, rgb(red, green, blue) )
            i += 3
        Next
    Next
    ZBarcode_Delete(lSymbol)


  CANVAS_Redraw


end Function