Swift 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. Swift

func chilkatTest() {
    var success: Bool = false

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

    let json = CkoJsonObject()!
    json.updateString(jsonPath: "payload.text", value: "CHILKAT")
    json.updateBool(jsonPath: "output.includeModuleData", value: true)

    let fmt = CkoFormats()!
    let jsonOut = CkoJsonObject()!
    success = fmt.qrCode(op: "generate", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(fmt.lastErrorText!)")
        return
    }

    var width: Int = jsonOut.int(of: "symbols[0].moduleData.width").intValue
    var height: Int = jsonOut.int(of: "symbols[0].moduleData.height").intValue
    var rowBytes: Int = jsonOut.int(of: "symbols[0].moduleData.rowBytes").intValue
    print("kind: \(jsonOut.string(of: "symbols[0].moduleData.kind")!)")
    print("modules: \(width) x \(height), \(rowBytes) bytes per row")

    //  The matrix is height rows of rowBytes bytes.
    let bd = CkoBinData()!
    success = bd.appendEncoded(encData: jsonOut.string(of: "symbols[0].moduleData.bytesBase64"), encoding: "base64")
    if success == false {
        print("\(bd.lastErrorText!)")
        return
    }

    let sbRow = CkoStringBuilder()!
    var row: Int
    var col: Int
    var b: Int
    var mask: Int = 128
    for row = 0; row <= height - 1; row++ {
        sbRow.clear()
        for col = 0; col <= width - 1; col++ {
            //  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
            }

            b = bd.getByte(index: (row * rowBytes) + (col / 8)).intValue
            if ((b / mask) % 2) == 1 {
                sbRow.append(value: "##")
            }
            else {
                sbRow.append(value: "  ")
            }

            mask = mask / 2
        }

        print("\(sbRow.getAsString()!)")
    }

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

    //  

    //  Sample output:

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

}