JS 條形碼插件--JsBarcode 在小程序中使用

 

在小程序中的使用：

utils文件夾下 barcode.js 粘粘以下代碼

var CHAR_TILDE = 126
var CODE_FNC1 = 102

var SET_STARTA = 103
var SET_STARTB = 104
var SET_STARTC = 105
var SET_SHIFT = 98
var SET_CODEA = 101
var SET_CODEB = 100
var SET_STOP = 106

var REPLACE_CODES = {
  CHAR_TILDE: CODE_FNC1 // ~ corresponds to FNC1 in GS1-128 standard
}

var CODESET = {
  ANY: 1,
  AB: 2,
  A: 3,
  B: 4,
  C: 5
}

function getBytes (str) {
  var bytes = []
  for (var i = 0; i < str.length; i++) {
    bytes.push(str.charCodeAt(i))
  }
  return bytes
}

exports.code128 = function (ctx, text, width, height) {
  width = parseInt(width)

  height = parseInt(height)

  var codes = stringToCode128(text)

  var g = new Graphics(ctx, width, height)

  var barWeight = g.area.width / ((codes.length - 3) * 11 + 35)

  var x = g.area.left
  var y = g.area.top
  for (var i = 0; i < codes.length; i++) {
    var c = codes[i]
    // two bars at a time: 1 black and 1 white
    for (var bar = 0; bar < 8; bar += 2) {
      var barW = PATTERNS[c][bar] * barWeight
      // var barH = height - y - this.border;
      var barH = height - y
      var spcW = PATTERNS[c][bar + 1] * barWeight

      // no need to draw if 0 width
      if (barW > 0) {
        g.fillFgRect(x, y, barW, barH)
      }

      x += barW + spcW
    }
  }

  ctx.draw()
}

function stringToCode128 (text) {
  var barc = {
    currcs: CODESET.C
  }

  var bytes = getBytes(text)
  // decide starting codeset
  var index = bytes[0] === CHAR_TILDE ? 1 : 0

  var csa1 = bytes.length > 0 ? codeSetAllowedFor(bytes[index++]) : CODESET.AB
  var csa2 = bytes.length > 0 ? codeSetAllowedFor(bytes[index++]) : CODESET.AB
  barc.currcs = getBestStartSet(csa1, csa2)
  barc.currcs = perhapsCodeC(bytes, barc.currcs)

  // if no codeset changes this will end up with bytes.length+3
  // start, checksum and stop
  var codes = []

  switch (barc.currcs) {
    case CODESET.A:
      codes.push(SET_STARTA)
      break
    case CODESET.B:
      codes.push(SET_STARTB)
      break
    default:
      codes.push(SET_STARTC)
      break
  }

  for (var i = 0; i < bytes.length; i++) {
    var b1 = bytes[i] // get the first of a pair
    // should we translate/replace
    if (b1 in REPLACE_CODES) {
      codes.push(REPLACE_CODES[b1])
      i++ // jump to next
      b1 = bytes[i]
    }

    // get the next in the pair if possible
    var b2 = bytes.length > (i + 1) ? bytes[i + 1] : -1

    codes = codes.concat(codesForChar(b1, b2, barc.currcs))
    // code C takes 2 chars each time
    if (barc.currcs === CODESET.C) i++
  }

  // calculate checksum according to Code 128 standards
  var checksum = codes[0]
  for (var weight = 1; weight < codes.length; weight++) {
    checksum += (weight * codes[weight])
  }
  codes.push(checksum % 103)

  codes.push(SET_STOP)

  // encoding should now be complete
  return codes

  function getBestStartSet (csa1, csa2) {
    // tries to figure out the best codeset
    // to start with to get the most compact code
    var vote = 0
    vote += csa1 === CODESET.A ? 1 : 0
    vote += csa1 === CODESET.B ? -1 : 0
    vote += csa2 === CODESET.A ? 1 : 0
    vote += csa2 === CODESET.B ? -1 : 0
    // tie goes to B due to my own predudices
    return vote > 0 ? CODESET.A : CODESET.B
  }

  function perhapsCodeC (bytes, codeset) {
    for (var i = 0; i < bytes.length; i++) {
      var b = bytes[i]
      if ((b < 48 || b > 57) && b !== CHAR_TILDE) { return codeset }
    }
    return CODESET.C
  }

  // chr1 is current byte
  // chr2 is the next byte to process. looks ahead.
  function codesForChar (chr1, chr2, currcs) {
    var result = []
    var shifter = -1

    if (charCompatible(chr1, currcs)) {
      if (currcs === CODESET.C) {
        if (chr2 === -1) {
          shifter = SET_CODEB
          currcs = CODESET.B
        } else if ((chr2 !== -1) && !charCompatible(chr2, currcs)) {
          // need to check ahead as well
          if (charCompatible(chr2, CODESET.A)) {
            shifter = SET_CODEA
            currcs = CODESET.A
          } else {
            shifter = SET_CODEB
            currcs = CODESET.B
          }
        }
      }
    } else {
      // if there is a next char AND that next char is also not compatible
      if ((chr2 !== -1) && !charCompatible(chr2, currcs)) {
        // need to switch code sets
        switch (currcs) {
          case CODESET.A:
            shifter = SET_CODEB
            currcs = CODESET.B
            break
          case CODESET.B:
            shifter = SET_CODEA
            currcs = CODESET.A
            break
        }
      } else {
        // no need to shift code sets, a temporary SHIFT will suffice
        shifter = SET_SHIFT
      }
    }

    // ok some type of shift is nessecary
    if (shifter !== -1) {
      result.push(shifter)
      result.push(codeValue(chr1))
    } else {
      if (currcs === CODESET.C) {
        // include next as well
        result.push(codeValue(chr1, chr2))
      } else {
        result.push(codeValue(chr1))
      }
    }
    barc.currcs = currcs

    return result
  }
}

// reduce the ascii code to fit into the Code128 char table
function codeValue (chr1, chr2) {
  if (typeof chr2 === 'undefined') {
    return chr1 >= 32 ? chr1 - 32 : chr1 + 64
  } else {
    return parseInt(String.fromCharCode(chr1) + String.fromCharCode(chr2))
  }
}

function charCompatible (chr, codeset) {
  var csa = codeSetAllowedFor(chr)
  if (csa === CODESET.ANY) return true
  // if we need to change from current
  if (csa === CODESET.AB) return true
  if (csa === CODESET.A && codeset === CODESET.A) return true
  if (csa === CODESET.B && codeset === CODESET.B) return true
  return false
}

function codeSetAllowedFor (chr) {
  if (chr >= 48 && chr <= 57) {
    // 0-9
    return CODESET.ANY
  } else if (chr >= 32 && chr <= 95) {
    // 0-9 A-Z
    return CODESET.AB
  } else {
    // if non printable
    return chr < 32 ? CODESET.A : CODESET.B
  }
}

var Graphics = function (ctx, width, height) {
  this.width = width
  this.height = height
  this.quiet = Math.round(this.width / 40)

  this.border_size = 0
  this.padding_width = 0

  this.area = {
    width: width - this.padding_width * 2 - this.quiet * 2,
    height: height - this.border_size * 2,
    top: this.border_size - 4,
    left: this.padding_width + this.quiet
  }

  this.ctx = ctx
  this.fg = '#000000'
  this.bg = '#ffffff'

  // fill background
  this.fillBgRect(0, 0, width, height)

  // fill center to create border
  this.fillBgRect(0, this.border_size, width, height - this.border_size * 2)
}

// use native color
Graphics.prototype._fillRect = function (x, y, width, height, color) {
  this.ctx.setFillStyle(color)
  this.ctx.fillRect(x, y, width, height)
}

Graphics.prototype.fillFgRect = function (x, y, width, height) {
  this._fillRect(x, y, width, height, this.fg)
}

Graphics.prototype.fillBgRect = function (x, y, width, height) {
  this._fillRect(x, y, width, height, this.bg)
}

var PATTERNS = [
  [2, 1, 2, 2, 2, 2, 0, 0], // 0
  [2, 2, 2, 1, 2, 2, 0, 0], // 1
  [2, 2, 2, 2, 2, 1, 0, 0], // 2
  [1, 2, 1, 2, 2, 3, 0, 0], // 3
  [1, 2, 1, 3, 2, 2, 0, 0], // 4
  [1, 3, 1, 2, 2, 2, 0, 0], // 5
  [1, 2, 2, 2, 1, 3, 0, 0], // 6
  [1, 2, 2, 3, 1, 2, 0, 0], // 7
  [1, 3, 2, 2, 1, 2, 0, 0], // 8
  [2, 2, 1, 2, 1, 3, 0, 0], // 9
  [2, 2, 1, 3, 1, 2, 0, 0], // 10
  [2, 3, 1, 2, 1, 2, 0, 0], // 11
  [1, 1, 2, 2, 3, 2, 0, 0], // 12
  [1, 2, 2, 1, 3, 2, 0, 0], // 13
  [1, 2, 2, 2, 3, 1, 0, 0], // 14
  [1, 1, 3, 2, 2, 2, 0, 0], // 15
  [1, 2, 3, 1, 2, 2, 0, 0], // 16
  [1, 2, 3, 2, 2, 1, 0, 0], // 17
  [2, 2, 3, 2, 1, 1, 0, 0], // 18
  [2, 2, 1, 1, 3, 2, 0, 0], // 19
  [2, 2, 1, 2, 3, 1, 0, 0], // 20
  [2, 1, 3, 2, 1, 2, 0, 0], // 21
  [2, 2, 3, 1, 1, 2, 0, 0], // 22
  [3, 1, 2, 1, 3, 1, 0, 0], // 23
  [3, 1, 1, 2, 2, 2, 0, 0], // 24
  [3, 2, 1, 1, 2, 2, 0, 0], // 25
  [3, 2, 1, 2, 2, 1, 0, 0], // 26
  [3, 1, 2, 2, 1, 2, 0, 0], // 27
  [3, 2, 2, 1, 1, 2, 0, 0], // 28
  [3, 2, 2, 2, 1, 1, 0, 0], // 29
  [2, 1, 2, 1, 2, 3, 0, 0], // 30
  [2, 1, 2, 3, 2, 1, 0, 0], // 31
  [2, 3, 2, 1, 2, 1, 0, 0], // 32
  [1, 1, 1, 3, 2, 3, 0, 0], // 33
  [1, 3, 1, 1, 2, 3, 0, 0], // 34
  [1, 3, 1, 3, 2, 1, 0, 0], // 35
  [1, 1, 2, 3, 1, 3, 0, 0], // 36
  [1, 3, 2, 1, 1, 3, 0, 0], // 37
  [1, 3, 2, 3, 1, 1, 0, 0], // 38
  [2, 1, 1, 3, 1, 3, 0, 0], // 39
  [2, 3, 1, 1, 1, 3, 0, 0], // 40
  [2, 3, 1, 3, 1, 1, 0, 0], // 41
  [1, 1, 2, 1, 3, 3, 0, 0], // 42
  [1, 1, 2, 3, 3, 1, 0, 0], // 43
  [1, 3, 2, 1, 3, 1, 0, 0], // 44
  [1, 1, 3, 1, 2, 3, 0, 0], // 45
  [1, 1, 3, 3, 2, 1, 0, 0], // 46
  [1, 3, 3, 1, 2, 1, 0, 0], // 47
  [3, 1, 3, 1, 2, 1, 0, 0], // 48
  [2, 1, 1, 3, 3, 1, 0, 0], // 49
  [2, 3, 1, 1, 3, 1, 0, 0], // 50
  [2, 1, 3, 1, 1, 3, 0, 0], // 51
  [2, 1, 3, 3, 1, 1, 0, 0], // 52
  [2, 1, 3, 1, 3, 1, 0, 0], // 53
  [3, 1, 1, 1, 2, 3, 0, 0], // 54
  [3, 1, 1, 3, 2, 1, 0, 0], // 55
  [3, 3, 1, 1, 2, 1, 0, 0], // 56
  [3, 1, 2, 1, 1, 3, 0, 0], // 57
  [3, 1, 2, 3, 1, 1, 0, 0], // 58
  [3, 3, 2, 1, 1, 1, 0, 0], // 59
  [3, 1, 4, 1, 1, 1, 0, 0], // 60
  [2, 2, 1, 4, 1, 1, 0, 0], // 61
  [4, 3, 1, 1, 1, 1, 0, 0], // 62
  [1, 1, 1, 2, 2, 4, 0, 0], // 63
  [1, 1, 1, 4, 2, 2, 0, 0], // 64
  [1, 2, 1, 1, 2, 4, 0, 0], // 65
  [1, 2, 1, 4, 2, 1, 0, 0], // 66
  [1, 4, 1, 1, 2, 2, 0, 0], // 67
  [1, 4, 1, 2, 2, 1, 0, 0], // 68
  [1, 1, 2, 2, 1, 4, 0, 0], // 69
  [1, 1, 2, 4, 1, 2, 0, 0], // 70
  [1, 2, 2, 1, 1, 4, 0, 0], // 71
  [1, 2, 2, 4, 1, 1, 0, 0], // 72
  [1, 4, 2, 1, 1, 2, 0, 0], // 73
  [1, 4, 2, 2, 1, 1, 0, 0], // 74
  [2, 4, 1, 2, 1, 1, 0, 0], // 75
  [2, 2, 1, 1, 1, 4, 0, 0], // 76
  [4, 1, 3, 1, 1, 1, 0, 0], // 77
  [2, 4, 1, 1, 1, 2, 0, 0], // 78
  [1, 3, 4, 1, 1, 1, 0, 0], // 79
  [1, 1, 1, 2, 4, 2, 0, 0], // 80
  [1, 2, 1, 1, 4, 2, 0, 0], // 81
  [1, 2, 1, 2, 4, 1, 0, 0], // 82
  [1, 1, 4, 2, 1, 2, 0, 0], // 83
  [1, 2, 4, 1, 1, 2, 0, 0], // 84
  [1, 2, 4, 2, 1, 1, 0, 0], // 85
  [4, 1, 1, 2, 1, 2, 0, 0], // 86
  [4, 2, 1, 1, 1, 2, 0, 0], // 87
  [4, 2, 1, 2, 1, 1, 0, 0], // 88
  [2, 1, 2, 1, 4, 1, 0, 0], // 89
  [2, 1, 4, 1, 2, 1, 0, 0], // 90
  [4, 1, 2, 1, 2, 1, 0, 0], // 91
  [1, 1, 1, 1, 4, 3, 0, 0], // 92
  [1, 1, 1, 3, 4, 1, 0, 0], // 93
  [1, 3, 1, 1, 4, 1, 0, 0], // 94
  [1, 1, 4, 1, 1, 3, 0, 0], // 95
  [1, 1, 4, 3, 1, 1, 0, 0], // 96
  [4, 1, 1, 1, 1, 3, 0, 0], // 97
  [4, 1, 1, 3, 1, 1, 0, 0], // 98
  [1, 1, 3, 1, 4, 1, 0, 0], // 99
  [1, 1, 4, 1, 3, 1, 0, 0], // 100
  [3, 1, 1, 1, 4, 1, 0, 0], // 101
  [4, 1, 1, 1, 3, 1, 0, 0], // 102
  [2, 1, 1, 4, 1, 2, 0, 0], // 103
  [2, 1, 1, 2, 1, 4, 0, 0], // 104
  [2, 1, 1, 2, 3, 2, 0, 0], // 105
  [2, 3, 3, 1, 1, 1, 2, 0] // 106
]

utils文件夾下 index.js 放以下代碼

var barcode = require('./barcode')
function convertlength (length) {
  return Math.round(wx.getSystemInfoSync().windowWidth * length / 750)
}
function barc (id, code, width, height) {
  barcode.code128(wx.createCanvasContext(id), code, convertlength(width), convertlength(height))
}
module.exports = {
  barcode: barc
}

 

然后在小程序或mpvue中

<canvas canvas-id="barcode"></canvas>


var barcode = require('@/utils/index')

barcode.barcode('barcode', 'JsBarcode',  500, 350)

 配置：

JsBarcode("#barcode", "123", {
  format: "CODE39",//選擇要使用的條形碼類型
  width:3,//設置條之間的寬度
  height:100,//高度
  displayValue:true,//是否在條形碼下方顯示文字
  text:"456",//覆蓋顯示的文本
  fontOptions:"bold italic",//使文字加粗體或變斜體
  font:"fantasy",//設置文本的字體
  textAlign:"left",//設置文本的水平對齊方式
  textPosition:"top",//設置文本的垂直位置
  textMargin:5,//設置條形碼和文本之間的間距
  fontSize:15,//設置文本的大小
  background:"#eee",//設置條形碼的背景
  lineColor:"#2196f3",//設置條和文本的顏色。
  margin:15//設置條形碼周圍的空白邊距
});

 

官方：

https://github.com/lindell/JsBarcode/wiki/Options

 參考： https://blog.csdn.net/huangpb123/article/details/82527344

 

如用到二維碼：

下為：qrcode.js

(function () {
  // alignment pattern
  var adelta = [
    0, 11, 15, 19, 23, 27, 31, // force 1 pat
    16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 24, 26, 28, 28, 22, 24, 24,
    26, 26, 28, 28, 24, 24, 26, 26, 26, 28, 28, 24, 26, 26, 26, 28, 28
  ]

  // version block
  var vpat = [
    0xc94, 0x5bc, 0xa99, 0x4d3, 0xbf6, 0x762, 0x847, 0x60d,
    0x928, 0xb78, 0x45d, 0xa17, 0x532, 0x9a6, 0x683, 0x8c9,
    0x7ec, 0xec4, 0x1e1, 0xfab, 0x08e, 0xc1a, 0x33f, 0xd75,
    0x250, 0x9d5, 0x6f0, 0x8ba, 0x79f, 0xb0b, 0x42e, 0xa64,
    0x541, 0xc69
  ]

  // final format bits with mask: level << 3 | mask
  var fmtword = [
    0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976, // L
    0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0, // M
    0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed, // Q
    0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b // H
  ]

  // 4 per version: number of blocks 1,2; data width; ecc width
  var eccblocks = [
    1, 0, 19, 7, 1, 0, 16, 10, 1, 0, 13, 13, 1, 0, 9, 17,
    1, 0, 34, 10, 1, 0, 28, 16, 1, 0, 22, 22, 1, 0, 16, 28,
    1, 0, 55, 15, 1, 0, 44, 26, 2, 0, 17, 18, 2, 0, 13, 22,
    1, 0, 80, 20, 2, 0, 32, 18, 2, 0, 24, 26, 4, 0, 9, 16,
    1, 0, 108, 26, 2, 0, 43, 24, 2, 2, 15, 18, 2, 2, 11, 22,
    2, 0, 68, 18, 4, 0, 27, 16, 4, 0, 19, 24, 4, 0, 15, 28,
    2, 0, 78, 20, 4, 0, 31, 18, 2, 4, 14, 18, 4, 1, 13, 26,
    2, 0, 97, 24, 2, 2, 38, 22, 4, 2, 18, 22, 4, 2, 14, 26,
    2, 0, 116, 30, 3, 2, 36, 22, 4, 4, 16, 20, 4, 4, 12, 24,
    2, 2, 68, 18, 4, 1, 43, 26, 6, 2, 19, 24, 6, 2, 15, 28,
    4, 0, 81, 20, 1, 4, 50, 30, 4, 4, 22, 28, 3, 8, 12, 24,
    2, 2, 92, 24, 6, 2, 36, 22, 4, 6, 20, 26, 7, 4, 14, 28,
    4, 0, 107, 26, 8, 1, 37, 22, 8, 4, 20, 24, 12, 4, 11, 22,
    3, 1, 115, 30, 4, 5, 40, 24, 11, 5, 16, 20, 11, 5, 12, 24,
    5, 1, 87, 22, 5, 5, 41, 24, 5, 7, 24, 30, 11, 7, 12, 24,
    5, 1, 98, 24, 7, 3, 45, 28, 15, 2, 19, 24, 3, 13, 15, 30,
    1, 5, 107, 28, 10, 1, 46, 28, 1, 15, 22, 28, 2, 17, 14, 28,
    5, 1, 120, 30, 9, 4, 43, 26, 17, 1, 22, 28, 2, 19, 14, 28,
    3, 4, 113, 28, 3, 11, 44, 26, 17, 4, 21, 26, 9, 16, 13, 26,
    3, 5, 107, 28, 3, 13, 41, 26, 15, 5, 24, 30, 15, 10, 15, 28,
    4, 4, 116, 28, 17, 0, 42, 26, 17, 6, 22, 28, 19, 6, 16, 30,
    2, 7, 111, 28, 17, 0, 46, 28, 7, 16, 24, 30, 34, 0, 13, 24,
    4, 5, 121, 30, 4, 14, 47, 28, 11, 14, 24, 30, 16, 14, 15, 30,
    6, 4, 117, 30, 6, 14, 45, 28, 11, 16, 24, 30, 30, 2, 16, 30,
    8, 4, 106, 26, 8, 13, 47, 28, 7, 22, 24, 30, 22, 13, 15, 30,
    10, 2, 114, 28, 19, 4, 46, 28, 28, 6, 22, 28, 33, 4, 16, 30,
    8, 4, 122, 30, 22, 3, 45, 28, 8, 26, 23, 30, 12, 28, 15, 30,
    3, 10, 117, 30, 3, 23, 45, 28, 4, 31, 24, 30, 11, 31, 15, 30,
    7, 7, 116, 30, 21, 7, 45, 28, 1, 37, 23, 30, 19, 26, 15, 30,
    5, 10, 115, 30, 19, 10, 47, 28, 15, 25, 24, 30, 23, 25, 15, 30,
    13, 3, 115, 30, 2, 29, 46, 28, 42, 1, 24, 30, 23, 28, 15, 30,
    17, 0, 115, 30, 10, 23, 46, 28, 10, 35, 24, 30, 19, 35, 15, 30,
    17, 1, 115, 30, 14, 21, 46, 28, 29, 19, 24, 30, 11, 46, 15, 30,
    13, 6, 115, 30, 14, 23, 46, 28, 44, 7, 24, 30, 59, 1, 16, 30,
    12, 7, 121, 30, 12, 26, 47, 28, 39, 14, 24, 30, 22, 41, 15, 30,
    6, 14, 121, 30, 6, 34, 47, 28, 46, 10, 24, 30, 2, 64, 15, 30,
    17, 4, 122, 30, 29, 14, 46, 28, 49, 10, 24, 30, 24, 46, 15, 30,
    4, 18, 122, 30, 13, 32, 46, 28, 48, 14, 24, 30, 42, 32, 15, 30,
    20, 4, 117, 30, 40, 7, 47, 28, 43, 22, 24, 30, 10, 67, 15, 30,
    19, 6, 118, 30, 18, 31, 47, 28, 34, 34, 24, 30, 20, 61, 15, 30
  ]

  // Galois field log table
  var glog = [
    0xff, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
    0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
    0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,
    0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,
    0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,
    0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,
    0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d,
    0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,
    0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,
    0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,
    0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,
    0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,
    0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,
    0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,
    0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,
    0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf
  ]

  // Galios field exponent table
  var gexp = [
    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,
    0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,
    0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,
    0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,
    0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,
    0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,
    0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,
    0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,
    0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,
    0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,
    0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,
    0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,
    0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,
    0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,
    0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,
    0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x00
  ]

  // Working buffers:
  // data input and ecc append, image working buffer, fixed part of image, run lengths for badness
  var strinbuf = []
  var eccbuf = []
  var qrframe = []
  var framask = []
  var rlens = []
  // Control values - width is based on version, last 4 are from table.
  var version, width, neccblk1, neccblk2, datablkw, eccblkwid
  var ecclevel = 2
  // set bit to indicate cell in qrframe is immutable.  symmetric around diagonal
  function setmask (x, y) {
    var bt
    if (x > y) {
      bt = x
      x = y
      y = bt
    }
    // y*y = 1+3+5...
    bt = y
    bt *= y
    bt += y
    bt >>= 1
    bt += x
    framask[bt] = 1
  }

  // enter alignment pattern - black to qrframe, white to mask (later black frame merged to mask)
  function putalign (x, y) {
    var j

    qrframe[x + width * y] = 1
    for (j = -2; j < 2; j++) {
      qrframe[(x + j) + width * (y - 2)] = 1
      qrframe[(x - 2) + width * (y + j + 1)] = 1
      qrframe[(x + 2) + width * (y + j)] = 1
      qrframe[(x + j + 1) + width * (y + 2)] = 1
    }
    for (j = 0; j < 2; j++) {
      setmask(x - 1, y + j)
      setmask(x + 1, y - j)
      setmask(x - j, y - 1)
      setmask(x + j, y + 1)
    }
  }

  //= =======================================================================
  // Reed Solomon error correction
  // exponentiation mod N
  function modnn (x) {
    while (x >= 255) {
      x -= 255
      x = (x >> 8) + (x & 255)
    }
    return x
  }

  var genpoly = []

  // Calculate and append ECC data to data block.  Block is in strinbuf, indexes to buffers given.
  function appendrs (data, dlen, ecbuf, eclen) {
    var i, j, fb

    for (i = 0; i < eclen; i++) { strinbuf[ecbuf + i] = 0 }
    for (i = 0; i < dlen; i++) {
      fb = glog[strinbuf[data + i] ^ strinbuf[ecbuf]]
      if (fb !== 255) {
        for (j = 1; j < eclen; j++) { strinbuf[ecbuf + j - 1] = strinbuf[ecbuf + j] ^ gexp[modnn(fb + genpoly[eclen - j])] }
      } else {
        for (j = ecbuf; j < ecbuf + eclen; j++) { strinbuf[j] = strinbuf[j + 1] }
      }
      strinbuf[ecbuf + eclen - 1] = fb === 255 ? 0 : gexp[modnn(fb + genpoly[0])]
    }
  }

  //= =======================================================================
  // Frame data insert following the path rules

  // check mask - since symmetrical use half.
  function ismasked (x, y) {
    var bt
    if (x > y) {
      bt = x
      x = y
      y = bt
    }
    bt = y
    bt += y * y
    bt >>= 1
    bt += x
    return framask[bt]
  }

  //= =======================================================================
  //  Apply the selected mask out of the 8.
  function applymask (m) {
    var x, y, r3x, r3y

    switch (m) {
      case 0:
        for (y = 0; y < width; y++) {
          for (x = 0; x < width; x++) {
            if (!((x + y) & 1) && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 1:
        for (y = 0; y < width; y++) {
          for (x = 0; x < width; x++) {
            if (!(y & 1) && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 2:
        for (y = 0; y < width; y++) {
          for (r3x = 0, x = 0; x < width; x++, r3x++) {
            if (r3x === 3) { r3x = 0 }
            if (!r3x && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 3:
        for (r3y = 0, y = 0; y < width; y++, r3y++) {
          if (r3y === 3) { r3y = 0 }
          for (r3x = r3y, x = 0; x < width; x++, r3x++) {
            if (r3x === 3) { r3x = 0 }
            if (!r3x && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 4:
        for (y = 0; y < width; y++) {
          for (r3x = 0, r3y = ((y >> 1) & 1), x = 0; x < width; x++, r3x++) {
            if (r3x === 3) {
              r3x = 0
              r3y = !r3y
            }
            if (!r3y && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 5:
        for (r3y = 0, y = 0; y < width; y++, r3y++) {
          if (r3y === 3) { r3y = 0 }
          for (r3x = 0, x = 0; x < width; x++, r3x++) {
            if (r3x === 3) { r3x = 0 }
            if (!((x & y & 1) + !(!r3x | !r3y)) && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 6:
        for (r3y = 0, y = 0; y < width; y++, r3y++) {
          if (r3y === 3) { r3y = 0 }
          for (r3x = 0, x = 0; x < width; x++, r3x++) {
            if (r3x === 3) { r3x = 0 }
            if (!(((x & y & 1) + (r3x && (r3x === r3y))) & 1) && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
      case 7:
        for (r3y = 0, y = 0; y < width; y++, r3y++) {
          if (r3y === 3) { r3y = 0 }
          for (r3x = 0, x = 0; x < width; x++, r3x++) {
            if (r3x === 3) { r3x = 0 }
            if (!(((r3x && (r3x === r3y)) + ((x + y) & 1)) & 1) && !ismasked(x, y)) { qrframe[x + y * width] ^= 1 }
          }
        }
        break
    }
  }

  // Badness coefficients.
  var N1 = 3
  var N2 = 3
  var N3 = 40
  var N4 = 10

  // Using the table of the length of each run, calculate the amount of bad image
  // - long runs or those that look like finders; called twice, once each for X and Y
  function badruns (length) {
    var i
    var runsbad = 0
    for (i = 0; i <= length; i++) {
      if (rlens[i] >= 5) { runsbad += N1 + rlens[i] - 5 }
    }
    // BwBBBwB as in finder
    for (i = 3; i < length - 1; i += 2) {
      if (rlens[i - 2] === rlens[i + 2] &&
              rlens[i + 2] === rlens[i - 1] &&
              rlens[i - 1] === rlens[i + 1] &&
              rlens[i - 1] * 3 === rlens[i] &&
              // white around the black pattern? Not part of spec
              (rlens[i - 3] === 0 || // beginning
                  i + 3 > length || // end
                  rlens[i - 3] * 3 >= rlens[i] * 4 || rlens[i + 3] * 3 >= rlens[i] * 4)
      ) { runsbad += N3 }
    }
    return runsbad
  }

  // Calculate how bad the masked image is - blocks, imbalance, runs, or finders.
  function badcheck () {
    var x, y, h, b, b1
    var thisbad = 0
    var bw = 0

    // blocks of same color.
    for (y = 0; y < width - 1; y++) {
      for (x = 0; x < width - 1; x++) {
        if ((qrframe[x + width * y] && qrframe[(x + 1) + width * y] &&
                   qrframe[x + width * (y + 1)] && qrframe[(x + 1) + width * (y + 1)]) || // all black
                  !(qrframe[x + width * y] || qrframe[(x + 1) + width * y] ||
                       qrframe[x + width * (y + 1)] || qrframe[(x + 1) + width * (y + 1)])) {
          thisbad += N2
        }
      }
    }

    // X runs
    for (y = 0; y < width; y++) {
      rlens[0] = 0
      for (h = b = x = 0; x < width; x++) {
        if ((b1 = qrframe[x + width * y]) === b) { rlens[h]++ } else { rlens[++h] = 1 }
        b = b1
        bw += b ? 1 : -1
      }
      thisbad += badruns(h)
    }

    // black/white imbalance
    if (bw < 0) { bw = -bw }

    var big = bw
    var count = 0
    big += big << 2
    big <<= 1
    while (big > width * width) {
      big -= width * width
      count++
    }
    thisbad += count * N4

    // Y runs
    for (x = 0; x < width; x++) {
      rlens[0] = 0
      for (h = b = y = 0; y < width; y++) {
        if ((b1 = qrframe[x + width * y]) === b) { rlens[h]++ } else { rlens[++h] = 1 }
        b = b1
      }
      thisbad += badruns(h)
    }
    return thisbad
  }

  function genframe (instring) {
    var x, y, k, t, v, i, j, m

    // find the smallest version that fits the string
    t = instring.length
    version = 0
    do {
      version++
      k = (ecclevel - 1) * 4 + (version - 1) * 16
      neccblk1 = eccblocks[k++]
      neccblk2 = eccblocks[k++]
      datablkw = eccblocks[k++]
      eccblkwid = eccblocks[k]
      k = datablkw * (neccblk1 + neccblk2) + neccblk2 - 3 + (version <= 9)
      if (t <= k) { break }
    } while (version < 40)

    // FIXME - insure that it fits insted of being truncated
    width = 17 + 4 * version

    // allocate, clear and setup data structures
    v = datablkw + (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2
    for (t = 0; t < v; t++) { eccbuf[t] = 0 }
    strinbuf = instring.slice(0)

    for (t = 0; t < width * width; t++) { qrframe[t] = 0 }

    for (t = 0; t < (width * (width + 1) + 1) / 2; t++) { framask[t] = 0 }

    // insert finders - black to frame, white to mask
    for (t = 0; t < 3; t++) {
      k = 0
      y = 0
      if (t === 1) { k = (width - 7) }
      if (t === 2) { y = (width - 7) }
      qrframe[(y + 3) + width * (k + 3)] = 1
      for (x = 0; x < 6; x++) {
        qrframe[(y + x) + width * k] = 1
        qrframe[y + width * (k + x + 1)] = 1
        qrframe[(y + 6) + width * (k + x)] = 1
        qrframe[(y + x + 1) + width * (k + 6)] = 1
      }
      for (x = 1; x < 5; x++) {
        setmask(y + x, k + 1)
        setmask(y + 1, k + x + 1)
        setmask(y + 5, k + x)
        setmask(y + x + 1, k + 5)
      }
      for (x = 2; x < 4; x++) {
        qrframe[(y + x) + width * (k + 2)] = 1
        qrframe[(y + 2) + width * (k + x + 1)] = 1
        qrframe[(y + 4) + width * (k + x)] = 1
        qrframe[(y + x + 1) + width * (k + 4)] = 1
      }
    }

    // alignment blocks
    if (version > 1) {
      t = adelta[version]
      y = width - 7
      for (;;) {
        x = width - 7
        while (x > t - 3) {
          putalign(x, y)
          if (x < t) { break }
          x -= t
        }
        if (y <= t + 9) { break }
        y -= t
        putalign(6, y)
        putalign(y, 6)
      }
    }

    // single black
    qrframe[8 + width * (width - 8)] = 1

    // timing gap - mask only
    for (y = 0; y < 7; y++) {
      setmask(7, y)
      setmask(width - 8, y)
      setmask(7, y + width - 7)
    }
    for (x = 0; x < 8; x++) {
      setmask(x, 7)
      setmask(x + width - 8, 7)
      setmask(x, width - 8)
    }

    // reserve mask-format area
    for (x = 0; x < 9; x++) { setmask(x, 8) }
    for (x = 0; x < 8; x++) {
      setmask(x + width - 8, 8)
      setmask(8, x)
    }
    for (y = 0; y < 7; y++) { setmask(8, y + width - 7) }

    // timing row/col
    for (x = 0; x < width - 14; x++) {
      if (x & 1) {
        setmask(8 + x, 6)
        setmask(6, 8 + x)
      } else {
        qrframe[(8 + x) + width * 6] = 1
        qrframe[6 + width * (8 + x)] = 1
      }
    }

    // version block
    if (version > 6) {
      t = vpat[version - 7]
      k = 17
      for (x = 0; x < 6; x++) {
        for (y = 0; y < 3; y++, k--) {
          if (1 & (k > 11 ? version >> (k - 12) : t >> k)) {
            qrframe[(5 - x) + width * (2 - y + width - 11)] = 1
            qrframe[(2 - y + width - 11) + width * (5 - x)] = 1
          } else {
            setmask(5 - x, 2 - y + width - 11)
            setmask(2 - y + width - 11, 5 - x)
          }
        }
      }
    }

    // sync mask bits - only set above for white spaces, so add in black bits
    for (y = 0; y < width; y++) {
      for (x = 0; x <= y; x++) {
        if (qrframe[x + width * y]) { setmask(x, y) }
      }
    }

    // convert string to bitstream
    // 8 bit data to QR-coded 8 bit data (numeric or alphanum, or kanji not supported)
    v = strinbuf.length

    // string to array
    for (i = 0; i < v; i++) { eccbuf[i] = strinbuf.charCodeAt(i) }
    strinbuf = eccbuf.slice(0)

    // calculate max string length
    x = datablkw * (neccblk1 + neccblk2) + neccblk2
    if (v >= x - 2) {
      v = x - 2
      if (version > 9) { v-- }
    }

    // shift and repack to insert length prefix
    i = v
    if (version > 9) {
      strinbuf[i + 2] = 0
      strinbuf[i + 3] = 0
      while (i--) {
        t = strinbuf[i]
        strinbuf[i + 3] |= 255 & (t << 4)
        strinbuf[i + 2] = t >> 4
      }
      strinbuf[2] |= 255 & (v << 4)
      strinbuf[1] = v >> 4
      strinbuf[0] = 0x40 | (v >> 12)
    } else {
      strinbuf[i + 1] = 0
      strinbuf[i + 2] = 0
      while (i--) {
        t = strinbuf[i]
        strinbuf[i + 2] |= 255 & (t << 4)
        strinbuf[i + 1] = t >> 4
      }
      strinbuf[1] |= 255 & (v << 4)
      strinbuf[0] = 0x40 | (v >> 4)
    }
    // fill to end with pad pattern
    i = v + 3 - (version < 10)
    while (i < x) {
      strinbuf[i++] = 0xec
      // buffer has room    if (i === x)      break;
      strinbuf[i++] = 0x11
    }

    // calculate and append ECC

    // calculate generator polynomial
    genpoly[0] = 1
    for (i = 0; i < eccblkwid; i++) {
      genpoly[i + 1] = 1
      for (j = i; j > 0; j--) {
        genpoly[j] = genpoly[j]
          ? genpoly[j - 1] ^ gexp[modnn(glog[genpoly[j]] + i)] : genpoly[j - 1]
      }
      genpoly[0] = gexp[modnn(glog[genpoly[0]] + i)]
    }
    for (i = 0; i <= eccblkwid; i++) { genpoly[i] = glog[genpoly[i]] } // use logs for genpoly[] to save calc step

    // append ecc to data buffer
    k = x
    y = 0
    for (i = 0; i < neccblk1; i++) {
      appendrs(y, datablkw, k, eccblkwid)
      y += datablkw
      k += eccblkwid
    }
    for (i = 0; i < neccblk2; i++) {
      appendrs(y, datablkw + 1, k, eccblkwid)
      y += datablkw + 1
      k += eccblkwid
    }
    // interleave blocks
    y = 0
    for (i = 0; i < datablkw; i++) {
      for (j = 0; j < neccblk1; j++) { eccbuf[y++] = strinbuf[i + j * datablkw] }
      for (j = 0; j < neccblk2; j++) { eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))] }
    }
    for (j = 0; j < neccblk2; j++) { eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))] }
    for (i = 0; i < eccblkwid; i++) {
      for (j = 0; j < neccblk1 + neccblk2; j++) { eccbuf[y++] = strinbuf[x + i + j * eccblkwid] }
    }
    strinbuf = eccbuf

    // pack bits into frame avoiding masked area.
    x = y = width - 1
    k = v = 1 // up, minus
    /* inteleaved data and ecc codes */
    m = (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2
    for (i = 0; i < m; i++) {
      t = strinbuf[i]
      for (j = 0; j < 8; j++, t <<= 1) {
        if (0x80 & t) { qrframe[x + width * y] = 1 }
        do { // find next fill position
          if (v) { x-- } else {
            x++
            if (k) {
              if (y !== 0) { y-- } else {
                x -= 2
                k = !k
                if (x === 6) {
                  x--
                  y = 9
                }
              }
            } else {
              if (y !== width - 1) { y++ } else {
                x -= 2
                k = !k
                if (x === 6) {
                  x--
                  y -= 8
                }
              }
            }
          }
          v = !v
        } while (ismasked(x, y))
      }
    }

    // save pre-mask copy of frame
    strinbuf = qrframe.slice(0)
    t = 0 // best
    y = 30000 // demerit
    // for instead of while since in original arduino code
    // if an early mask was "good enough" it wouldn't try for a better one
    // since they get more complex and take longer.
    for (k = 0; k < 8; k++) {
      applymask(k) // returns black-white imbalance
      x = badcheck()
      if (x < y) { // current mask better than previous best?
        y = x
        t = k
      }
      if (t === 7) { break } // don't increment i to a void redoing mask
      qrframe = strinbuf.slice(0) // reset for next pass
    }
    if (t !== k) { applymask(t) }

    // add in final mask/ecclevel bytes
    y = fmtword[t + ((ecclevel - 1) << 3)]
    // low byte
    for (k = 0; k < 8; k++, y >>= 1) {
      if (y & 1) {
        qrframe[(width - 1 - k) + width * 8] = 1
        if (k < 6) { qrframe[8 + width * k] = 1 } else { qrframe[8 + width * (k + 1)] = 1 }
      }
    }
    // high byte
    for (k = 0; k < 7; k++, y >>= 1) {
      if (y & 1) {
        qrframe[8 + width * (width - 7 + k)] = 1
        if (k) { qrframe[(6 - k) + width * 8] = 1 } else { qrframe[7 + width * 8] = 1 }
      }
    }

    // return image
    return qrframe
  }

  var _canvas = null
  var _size = null

  var api = {

    get ecclevel () {
      return ecclevel
    },

    set ecclevel (val) {
      ecclevel = val
    },

    get size () {
      return _size
    },

    set size (val) {
      _size = val
    },

    get canvas () {
      return _canvas
    },

    set canvas (el) {
      _canvas = el
    },

    getFrame: function (string) {
      return genframe(string)
    },

    draw: function (string, canvas, size, ecc) {
      ecclevel = ecc || ecclevel
      canvas = canvas || _canvas

      if (!canvas) {
        console.warn('No canvas provided to draw QR code in!')
        return
      }

      size = size || _size || Math.min(canvas.width, canvas.height)

      var frame = genframe(string)
      var ctx = canvas.ctx
      var px = Math.round(size / (width + 8))

      var roundedSize = px * (width + 8)
      var offset = Math.floor((size - roundedSize) / 2)

      size = roundedSize

      ctx.clearRect(0, 0, canvas.width, canvas.height)
      ctx.setFillStyle('#000000')

      for (var i = 0; i < width; i++) {
        for (var j = 0; j < width; j++) {
          if (frame[j * width + i]) {
            ctx.fillRect(px * (4 + i) + offset, px * (4 + j) + offset, px, px)
          }
        }
      }
      ctx.draw()
    }
  }

  module.exports = {
    api: api
  }
})()

使用同條形碼一樣，引入時可放一起

var qrcode = require('./qrcode')

function convertlength (length) {
  return Math.round(wx.getSystemInfoSync().windowWidth * length / 750)
}

function qrc (id, code, width, height) {
  qrcode.api.draw(code, {
    ctx: wx.createCanvasContext(id),
    width: convertlength(width),
    height: convertlength(height)
  })
}

module.exports = {
  qrcode: qrc
}

 

 

 

 

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