PureBasic Requires Chilkat v11.7.0+

Get the Modules of a QR Code (Bit Matrix)

See more QR Code Examples

Demonstrates getting the QR code itself, as a grid of dark and light modules, to draw with something other than the built-in PNG and SVG output: on a canvas, in a PDF, on a display, or with a label printer language. With output.includeModuleData the response has symbols[0].moduleData, a bit matrix with one bit per module, each row starting on a new byte, most significant bit first, 1 for dark. The quiet zone is not part of the matrix. The example prints the symbol using two characters per module. PureBasic

IncludeFile "CkBinData.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkFormats.pb"

Procedure ChilkatExample()

    success.i = 0

    ;  This example requires the Chilkat API to have been previously unlocked.
    ;  See Global Unlock Sample for sample code.

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(json,"payload.text","CHILKAT")
    CkJsonObject::ckUpdateBool(json,"output.includeModuleData",1)

    fmt.i = CkFormats::ckCreate()
    If fmt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    jsonOut.i = CkJsonObject::ckCreate()
    If jsonOut.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkFormats::ckQrCode(fmt,"generate",json,jsonOut)
    If success = 0
        Debug CkFormats::ckLastErrorText(fmt)
        CkJsonObject::ckDispose(json)
        CkFormats::ckDispose(fmt)
        CkJsonObject::ckDispose(jsonOut)
        ProcedureReturn
    EndIf

    width.i = CkJsonObject::ckIntOf(jsonOut,"symbols[0].moduleData.width")
    height.i = CkJsonObject::ckIntOf(jsonOut,"symbols[0].moduleData.height")
    rowBytes.i = CkJsonObject::ckIntOf(jsonOut,"symbols[0].moduleData.rowBytes")
    Debug "kind: " + CkJsonObject::ckStringOf(jsonOut,"symbols[0].moduleData.kind")
    Debug "modules: " + Str(width) + " x " + Str(height) + ", " + Str(rowBytes) + " bytes per row"

    ;  The matrix is height rows of rowBytes bytes.
    bd.i = CkBinData::ckCreate()
    If bd.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkBinData::ckAppendEncoded(bd,CkJsonObject::ckStringOf(jsonOut,"symbols[0].moduleData.bytesBase64"),"base64")
    If success = 0
        Debug CkBinData::ckLastErrorText(bd)
        CkJsonObject::ckDispose(json)
        CkFormats::ckDispose(fmt)
        CkJsonObject::ckDispose(jsonOut)
        CkBinData::ckDispose(bd)
        ProcedureReturn
    EndIf

    sbRow.i = CkStringBuilder::ckCreate()
    If sbRow.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    row.i
    col.i
    b.i
    mask.i = 128
    For row = 0 To height - 1
        CkStringBuilder::ckClear(sbRow)
        For col = 0 To width - 1
            ;  The module at (col,row) is a bit of the byte at (row * rowBytes) + (col / 8).
            ;  The leftmost module of each byte is its most significant bit.
            If (col % 8) = 0
                mask = 128
            EndIf

            b = CkBinData::ckGetByte(bd,(row * rowBytes) + (col / 8))
            If ((b / mask) % 2) = 1
                CkStringBuilder::ckAppend(sbRow,"##")
            Else
                CkStringBuilder::ckAppend(sbRow,"  ")
            EndIf

            mask = mask / 2
        Next
        Debug CkStringBuilder::ckGetAsString(sbRow)
    Next

    ;  The same symbol as the PNG that the call also returned:

    ;  

    ;  Sample output:

    ;  kind: bitMatrix
    ;  modules: 21 x 21, 3 bytes per row
    ;  ##############              ##############
    ;  ##          ##      ####    ##          ##
    ;  ##  ######  ##  ##  ####    ##  ######  ##
    ;  ##  ######  ##  ##          ##  ######  ##
    ;  ##  ######  ##  ##  ##  ##  ##  ######  ##
    ;  ##          ##  ####  ##    ##          ##
    ;  ##############  ##  ##  ##  ##############
    ;                  ####
    ;  ##  ##########      ####    ##########
    ;      ####          ##  ########    ######
    ;  ####  ########    ####  ##  ####      ####
    ;        ##  ##      ############    ####  ##
    ;    ######  ####  ######  ##    ##  ##
    ;                  ##  ##  ##    ##  ##    ##
    ;  ##############        ##  ##    ##      ##
    ;  ##          ##  ##  ##        ######  ####
    ;  ##  ######  ##  ####  ##  ##    ##
    ;  ##  ######  ##  ##  ############    ##
    ;  ##  ######  ##  ##      ##  ####  ##
    ;  ##          ##    ##  ########          ##
    ;  ##############  ##      ##      ######


    CkJsonObject::ckDispose(json)
    CkFormats::ckDispose(fmt)
    CkJsonObject::ckDispose(jsonOut)
    CkBinData::ckDispose(bd)
    CkStringBuilder::ckDispose(sbRow)


    ProcedureReturn
EndProcedure