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author | Krzysiek Madejski <krzysztof.madejski@epf.org.pl> | 2019-02-21 20:28:13 +0100 |
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committer | Wim <wim@42.be> | 2019-02-21 20:28:13 +0100 |
commit | 55e79063d6edbbf4560fd14edc45ce9558afaf7a (patch) | |
tree | 9ee9470119066556210a9226ae05b2c73ebda5e6 /vendor/github.com/skip2 | |
parent | 46f4bbb3b5e93ff489c0125c66b1c29fcb001e22 (diff) | |
download | matterbridge-msglm-55e79063d6edbbf4560fd14edc45ce9558afaf7a.tar.gz matterbridge-msglm-55e79063d6edbbf4560fd14edc45ce9558afaf7a.tar.bz2 matterbridge-msglm-55e79063d6edbbf4560fd14edc45ce9558afaf7a.zip |
Add initial WhatsApp support (#711)
Diffstat (limited to 'vendor/github.com/skip2')
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/.gitignore | 4 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/.travis.yml | 8 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/LICENSE | 19 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/README.md | 80 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/bitset/bitset.go | 273 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/encoder.go | 455 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/qrcode.go | 589 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/reedsolomon/gf2_8.go | 387 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/reedsolomon/gf_poly.go | 216 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/reedsolomon/reed_solomon.go | 73 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/regular_symbol.go | 309 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/symbol.go | 309 | ||||
-rw-r--r-- | vendor/github.com/skip2/go-qrcode/version.go | 3050 |
13 files changed, 5772 insertions, 0 deletions
diff --git a/vendor/github.com/skip2/go-qrcode/.gitignore b/vendor/github.com/skip2/go-qrcode/.gitignore new file mode 100644 index 00000000..bc1be2bb --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/.gitignore @@ -0,0 +1,4 @@ +*.sw* +*.png +*.directory +qrcode/qrcode diff --git a/vendor/github.com/skip2/go-qrcode/.travis.yml b/vendor/github.com/skip2/go-qrcode/.travis.yml new file mode 100644 index 00000000..7ced8fb1 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/.travis.yml @@ -0,0 +1,8 @@ +language: go + +go: + - 1.7 + +script: + - go test -v ./... + diff --git a/vendor/github.com/skip2/go-qrcode/LICENSE b/vendor/github.com/skip2/go-qrcode/LICENSE new file mode 100644 index 00000000..342c5e5a --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/LICENSE @@ -0,0 +1,19 @@ +Copyright (c) 2014 Tom Harwood + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. diff --git a/vendor/github.com/skip2/go-qrcode/README.md b/vendor/github.com/skip2/go-qrcode/README.md new file mode 100644 index 00000000..8281ed3e --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/README.md @@ -0,0 +1,80 @@ +# go-qrcode # + +<img src='https://skip.org/img/nyancat-youtube-qr.png' align='right'> + +Package qrcode implements a QR Code encoder. [![Build Status](https://travis-ci.org/skip2/go-qrcode.svg?branch=master)](https://travis-ci.org/skip2/go-qrcode) + +A QR Code is a matrix (two-dimensional) barcode. Arbitrary content may be encoded, with URLs being a popular choice :) + +Each QR Code contains error recovery information to aid reading damaged or obscured codes. There are four levels of error recovery: Low, medium, high and highest. QR Codes with a higher recovery level are more robust to damage, at the cost of being physically larger. + +## Install + + go get -u github.com/skip2/go-qrcode/... + +A command-line tool `qrcode` will be built into `$GOPATH/bin/`. + +## Usage + + import qrcode "github.com/skip2/go-qrcode" + +- **Create a PNG image:** + + var png []byte + png, err := qrcode.Encode("https://example.org", qrcode.Medium, 256) + +- **Create a PNG image and write to a file:** + + err := qrcode.WriteFile("https://example.org", qrcode.Medium, 256, "qr.png") + +- **Create a PNG image with custom colors and write to file:** + + err := qrcode.WriteColorFile("https://example.org", qrcode.Medium, 256, color.Black, color.White, "qr.png") + +All examples use the qrcode.Medium error Recovery Level and create a fixed +256x256px size QR Code. The last function creates a white on black instead of black +on white QR Code. + +The maximum capacity of a QR Code varies according to the content encoded and +the error recovery level. The maximum capacity is 2,953 bytes, 4,296 +alphanumeric characters, 7,089 numeric digits, or a combination of these. + +## Documentation + +[![godoc](https://godoc.org/github.com/skip2/go-qrcode?status.png)](https://godoc.org/github.com/skip2/go-qrcode) + +## Demoapp + +[http://go-qrcode.appspot.com](http://go-qrcode.appspot.com) + +## CLI + +A command-line tool `qrcode` will be built into `$GOPATH/bin/`. + +``` +qrcode -- QR Code encoder in Go +https://github.com/skip2/go-qrcode + +Flags: + -o string + out PNG file prefix, empty for stdout + -s int + image size (pixel) (default 256) + +Usage: + 1. Arguments except for flags are joined by " " and used to generate QR code. + Default output is STDOUT, pipe to imagemagick command "display" to display + on any X server. + + qrcode hello word | display + + 2. Save to file if "display" not available: + + qrcode "homepage: https://github.com/skip2/go-qrcode" > out.png +``` + +## Links + +- [http://en.wikipedia.org/wiki/QR_code](http://en.wikipedia.org/wiki/QR_code) +- [ISO/IEC 18004:2006](http://www.iso.org/iso/catalogue_detail.htm?csnumber=43655) - Main QR Code specification (approx CHF 198,00)<br> +- [https://github.com/qpliu/qrencode-go/](https://github.com/qpliu/qrencode-go/) - alternative Go QR encoding library based on [ZXing](https://github.com/zxing/zxing) diff --git a/vendor/github.com/skip2/go-qrcode/bitset/bitset.go b/vendor/github.com/skip2/go-qrcode/bitset/bitset.go new file mode 100644 index 00000000..fba3bf4d --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/bitset/bitset.go @@ -0,0 +1,273 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +// Package bitset implements an append only bit array. +// +// To create a Bitset and append some bits: +// // Bitset Contents +// b := bitset.New() // {} +// b.AppendBools(true, true, false) // {1, 1, 0} +// b.AppendBools(true) // {1, 1, 0, 1} +// b.AppendValue(0x02, 4) // {1, 1, 0, 1, 0, 0, 1, 0} +// +// To read values: +// +// len := b.Len() // 8 +// v := b.At(0) // 1 +// v = b.At(1) // 1 +// v = b.At(2) // 0 +// v = b.At(8) // 0 +package bitset + +import ( + "bytes" + "fmt" + "log" +) + +const ( + b0 = false + b1 = true +) + +// Bitset stores an array of bits. +type Bitset struct { + // The number of bits stored. + numBits int + + // Storage for individual bits. + bits []byte +} + +// New returns an initialised Bitset with optional initial bits v. +func New(v ...bool) *Bitset { + b := &Bitset{numBits: 0, bits: make([]byte, 0)} + b.AppendBools(v...) + + return b +} + +// Clone returns a copy. +func Clone(from *Bitset) *Bitset { + return &Bitset{numBits: from.numBits, bits: from.bits[:]} +} + +// Substr returns a substring, consisting of the bits from indexes start to end. +func (b *Bitset) Substr(start int, end int) *Bitset { + if start > end || end > b.numBits { + log.Panicf("Out of range start=%d end=%d numBits=%d", start, end, b.numBits) + } + + result := New() + result.ensureCapacity(end - start) + + for i := start; i < end; i++ { + if b.At(i) { + result.bits[result.numBits/8] |= 0x80 >> uint(result.numBits%8) + } + result.numBits++ + } + + return result +} + +// NewFromBase2String constructs and returns a Bitset from a string. The string +// consists of '1', '0' or ' ' characters, e.g. "1010 0101". The '1' and '0' +// characters represent true/false bits respectively, and ' ' characters are +// ignored. +// +// The function panics if the input string contains other characters. +func NewFromBase2String(b2string string) *Bitset { + b := &Bitset{numBits: 0, bits: make([]byte, 0)} + + for _, c := range b2string { + switch c { + case '1': + b.AppendBools(true) + case '0': + b.AppendBools(false) + case ' ': + default: + log.Panicf("Invalid char %c in NewFromBase2String", c) + } + } + + return b +} + +// AppendBytes appends a list of whole bytes. +func (b *Bitset) AppendBytes(data []byte) { + for _, d := range data { + b.AppendByte(d, 8) + } +} + +// AppendByte appends the numBits least significant bits from value. +func (b *Bitset) AppendByte(value byte, numBits int) { + b.ensureCapacity(numBits) + + if numBits > 8 { + log.Panicf("numBits %d out of range 0-8", numBits) + } + + for i := numBits - 1; i >= 0; i-- { + if value&(1<<uint(i)) != 0 { + b.bits[b.numBits/8] |= 0x80 >> uint(b.numBits%8) + } + + b.numBits++ + } +} + +// AppendUint32 appends the numBits least significant bits from value. +func (b *Bitset) AppendUint32(value uint32, numBits int) { + b.ensureCapacity(numBits) + + if numBits > 32 { + log.Panicf("numBits %d out of range 0-32", numBits) + } + + for i := numBits - 1; i >= 0; i-- { + if value&(1<<uint(i)) != 0 { + b.bits[b.numBits/8] |= 0x80 >> uint(b.numBits%8) + } + + b.numBits++ + } +} + +// ensureCapacity ensures the Bitset can store an additional |numBits|. +// +// The underlying array is expanded if necessary. To prevent frequent +// reallocation, expanding the underlying array at least doubles its capacity. +func (b *Bitset) ensureCapacity(numBits int) { + numBits += b.numBits + + newNumBytes := numBits / 8 + if numBits%8 != 0 { + newNumBytes++ + } + + if len(b.bits) >= newNumBytes { + return + } + + b.bits = append(b.bits, make([]byte, newNumBytes+2*len(b.bits))...) +} + +// Append bits copied from |other|. +// +// The new length is b.Len() + other.Len(). +func (b *Bitset) Append(other *Bitset) { + b.ensureCapacity(other.numBits) + + for i := 0; i < other.numBits; i++ { + if other.At(i) { + b.bits[b.numBits/8] |= 0x80 >> uint(b.numBits%8) + } + b.numBits++ + } +} + +// AppendBools appends bits to the Bitset. +func (b *Bitset) AppendBools(bits ...bool) { + b.ensureCapacity(len(bits)) + + for _, v := range bits { + if v { + b.bits[b.numBits/8] |= 0x80 >> uint(b.numBits%8) + } + b.numBits++ + } +} + +// AppendNumBools appends num bits of value value. +func (b *Bitset) AppendNumBools(num int, value bool) { + for i := 0; i < num; i++ { + b.AppendBools(value) + } +} + +// String returns a human readable representation of the Bitset's contents. +func (b *Bitset) String() string { + var bitString string + for i := 0; i < b.numBits; i++ { + if (i % 8) == 0 { + bitString += " " + } + + if (b.bits[i/8] & (0x80 >> byte(i%8))) != 0 { + bitString += "1" + } else { + bitString += "0" + } + } + + return fmt.Sprintf("numBits=%d, bits=%s", b.numBits, bitString) +} + +// Len returns the length of the Bitset in bits. +func (b *Bitset) Len() int { + return b.numBits +} + +// Bits returns the contents of the Bitset. +func (b *Bitset) Bits() []bool { + result := make([]bool, b.numBits) + + var i int + for i = 0; i < b.numBits; i++ { + result[i] = (b.bits[i/8] & (0x80 >> byte(i%8))) != 0 + } + + return result +} + +// At returns the value of the bit at |index|. +func (b *Bitset) At(index int) bool { + if index >= b.numBits { + log.Panicf("Index %d out of range", index) + } + + return (b.bits[index/8] & (0x80 >> byte(index%8))) != 0 +} + +// Equals returns true if the Bitset equals other. +func (b *Bitset) Equals(other *Bitset) bool { + if b.numBits != other.numBits { + return false + } + + if !bytes.Equal(b.bits[0:b.numBits/8], other.bits[0:b.numBits/8]) { + return false + } + + for i := 8 * (b.numBits / 8); i < b.numBits; i++ { + a := (b.bits[i/8] & (0x80 >> byte(i%8))) + b := (other.bits[i/8] & (0x80 >> byte(i%8))) + + if a != b { + return false + } + } + + return true +} + +// ByteAt returns a byte consisting of upto 8 bits starting at index. +func (b *Bitset) ByteAt(index int) byte { + if index < 0 || index >= b.numBits { + log.Panicf("Index %d out of range", index) + } + + var result byte + + for i := index; i < index+8 && i < b.numBits; i++ { + result <<= 1 + if b.At(i) { + result |= 1 + } + } + + return result +} diff --git a/vendor/github.com/skip2/go-qrcode/encoder.go b/vendor/github.com/skip2/go-qrcode/encoder.go new file mode 100644 index 00000000..713378c0 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/encoder.go @@ -0,0 +1,455 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package qrcode + +import ( + "errors" + "log" + + bitset "github.com/skip2/go-qrcode/bitset" +) + +// Data encoding. +// +// The main data portion of a QR Code consists of one or more segments of data. +// A segment consists of: +// +// - The segment Data Mode: numeric, alphanumeric, or byte. +// - The length of segment in bits. +// - Encoded data. +// +// For example, the string "123ZZ#!#!" may be represented as: +// +// [numeric, 3, "123"] [alphanumeric, 2, "ZZ"] [byte, 4, "#!#!"] +// +// Multiple data modes exist to minimise the size of encoded data. For example, +// 8-bit bytes require 8 bits to encode each, but base 10 numeric data can be +// encoded at a higher density of 3 numbers (e.g. 123) per 10 bits. +// +// Some data can be represented in multiple modes. Numeric data can be +// represented in all three modes, whereas alphanumeric data (e.g. 'A') can be +// represented in alphanumeric and byte mode. +// +// Starting a new segment (to use a different Data Mode) has a cost, the bits to +// state the new segment Data Mode and length. To minimise each QR Code's symbol +// size, an optimisation routine coalesces segment types where possible, to +// reduce the encoded data length. +// +// There are several other data modes available (e.g. Kanji mode) which are not +// implemented here. + +// A segment encoding mode. +type dataMode uint8 + +const ( + // Each dataMode is a subset of the subsequent dataMode: + // dataModeNone < dataModeNumeric < dataModeAlphanumeric < dataModeByte + // + // This ordering is important for determining which data modes a character can + // be encoded with. E.g. 'E' can be encoded in both dataModeAlphanumeric and + // dataModeByte. + dataModeNone dataMode = 1 << iota + dataModeNumeric + dataModeAlphanumeric + dataModeByte +) + +// dataModeString returns d as a short printable string. +func dataModeString(d dataMode) string { + switch d { + case dataModeNone: + return "none" + case dataModeNumeric: + return "numeric" + case dataModeAlphanumeric: + return "alphanumeric" + case dataModeByte: + return "byte" + } + + return "unknown" +} + +type dataEncoderType uint8 + +const ( + dataEncoderType1To9 dataEncoderType = iota + dataEncoderType10To26 + dataEncoderType27To40 +) + +// segment is a single segment of data. +type segment struct { + // Data Mode (e.g. numeric). + dataMode dataMode + + // segment data (e.g. "abc"). + data []byte +} + +// A dataEncoder encodes data for a particular QR Code version. +type dataEncoder struct { + // Minimum & maximum versions supported. + minVersion int + maxVersion int + + // Mode indicator bit sequences. + numericModeIndicator *bitset.Bitset + alphanumericModeIndicator *bitset.Bitset + byteModeIndicator *bitset.Bitset + + // Character count lengths. + numNumericCharCountBits int + numAlphanumericCharCountBits int + numByteCharCountBits int + + // The raw input data. + data []byte + + // The data classified into unoptimised segments. + actual []segment + + // The data classified into optimised segments. + optimised []segment +} + +// newDataEncoder constructs a dataEncoder. +func newDataEncoder(t dataEncoderType) *dataEncoder { + d := &dataEncoder{} + + switch t { + case dataEncoderType1To9: + d = &dataEncoder{ + minVersion: 1, + maxVersion: 9, + numericModeIndicator: bitset.New(b0, b0, b0, b1), + alphanumericModeIndicator: bitset.New(b0, b0, b1, b0), + byteModeIndicator: bitset.New(b0, b1, b0, b0), + numNumericCharCountBits: 10, + numAlphanumericCharCountBits: 9, + numByteCharCountBits: 8, + } + case dataEncoderType10To26: + d = &dataEncoder{ + minVersion: 10, + maxVersion: 26, + numericModeIndicator: bitset.New(b0, b0, b0, b1), + alphanumericModeIndicator: bitset.New(b0, b0, b1, b0), + byteModeIndicator: bitset.New(b0, b1, b0, b0), + numNumericCharCountBits: 12, + numAlphanumericCharCountBits: 11, + numByteCharCountBits: 16, + } + case dataEncoderType27To40: + d = &dataEncoder{ + minVersion: 27, + maxVersion: 40, + numericModeIndicator: bitset.New(b0, b0, b0, b1), + alphanumericModeIndicator: bitset.New(b0, b0, b1, b0), + byteModeIndicator: bitset.New(b0, b1, b0, b0), + numNumericCharCountBits: 14, + numAlphanumericCharCountBits: 13, + numByteCharCountBits: 16, + } + default: + log.Panic("Unknown dataEncoderType") + } + + return d +} + +// encode data as one or more segments and return the encoded data. +// +// The returned data does not include the terminator bit sequence. +func (d *dataEncoder) encode(data []byte) (*bitset.Bitset, error) { + d.data = data + d.actual = nil + d.optimised = nil + + if len(data) == 0 { + return nil, errors.New("no data to encode") + } + + // Classify data into unoptimised segments. + d.classifyDataModes() + + // Optimise segments. + err := d.optimiseDataModes() + if err != nil { + return nil, err + } + + // Encode data. + encoded := bitset.New() + for _, s := range d.optimised { + d.encodeDataRaw(s.data, s.dataMode, encoded) + } + + return encoded, nil +} + +// classifyDataModes classifies the raw data into unoptimised segments. +// e.g. "123ZZ#!#!" => +// [numeric, 3, "123"] [alphanumeric, 2, "ZZ"] [byte, 4, "#!#!"]. +func (d *dataEncoder) classifyDataModes() { + var start int + mode := dataModeNone + + for i, v := range d.data { + newMode := dataModeNone + switch { + case v >= 0x30 && v <= 0x39: + newMode = dataModeNumeric + case v == 0x20 || v == 0x24 || v == 0x25 || v == 0x2a || v == 0x2b || v == + 0x2d || v == 0x2e || v == 0x2f || v == 0x3a || (v >= 0x41 && v <= 0x5a): + newMode = dataModeAlphanumeric + default: + newMode = dataModeByte + } + + if newMode != mode { + if i > 0 { + d.actual = append(d.actual, segment{dataMode: mode, data: d.data[start:i]}) + + start = i + } + + mode = newMode + } + } + + d.actual = append(d.actual, segment{dataMode: mode, data: d.data[start:len(d.data)]}) +} + +// optimiseDataModes optimises the list of segments to reduce the overall output +// encoded data length. +// +// The algorithm coalesces adjacent segments. segments are only coalesced when +// the Data Modes are compatible, and when the coalesced segment has a shorter +// encoded length than separate segments. +// +// Multiple segments may be coalesced. For example a string of alternating +// alphanumeric/numeric segments ANANANANA can be optimised to just A. +func (d *dataEncoder) optimiseDataModes() error { + for i := 0; i < len(d.actual); { + mode := d.actual[i].dataMode + numChars := len(d.actual[i].data) + + j := i + 1 + for j < len(d.actual) { + nextNumChars := len(d.actual[j].data) + nextMode := d.actual[j].dataMode + + if nextMode > mode { + break + } + + coalescedLength, err := d.encodedLength(mode, numChars+nextNumChars) + + if err != nil { + return err + } + + seperateLength1, err := d.encodedLength(mode, numChars) + + if err != nil { + return err + } + + seperateLength2, err := d.encodedLength(nextMode, nextNumChars) + + if err != nil { + return err + } + + if coalescedLength < seperateLength1+seperateLength2 { + j++ + numChars += nextNumChars + } else { + break + } + } + + optimised := segment{dataMode: mode, + data: make([]byte, 0, numChars)} + + for k := i; k < j; k++ { + optimised.data = append(optimised.data, d.actual[k].data...) + } + + d.optimised = append(d.optimised, optimised) + + i = j + } + + return nil +} + +// encodeDataRaw encodes data in dataMode. The encoded data is appended to +// encoded. +func (d *dataEncoder) encodeDataRaw(data []byte, dataMode dataMode, encoded *bitset.Bitset) { + modeIndicator := d.modeIndicator(dataMode) + charCountBits := d.charCountBits(dataMode) + + // Append mode indicator. + encoded.Append(modeIndicator) + + // Append character count. + encoded.AppendUint32(uint32(len(data)), charCountBits) + + // Append data. + switch dataMode { + case dataModeNumeric: + for i := 0; i < len(data); i += 3 { + charsRemaining := len(data) - i + + var value uint32 + bitsUsed := 1 + + for j := 0; j < charsRemaining && j < 3; j++ { + value *= 10 + value += uint32(data[i+j] - 0x30) + bitsUsed += 3 + } + encoded.AppendUint32(value, bitsUsed) + } + case dataModeAlphanumeric: + for i := 0; i < len(data); i += 2 { + charsRemaining := len(data) - i + + var value uint32 + for j := 0; j < charsRemaining && j < 2; j++ { + value *= 45 + value += encodeAlphanumericCharacter(data[i+j]) + } + + bitsUsed := 6 + if charsRemaining > 1 { + bitsUsed = 11 + } + + encoded.AppendUint32(value, bitsUsed) + } + case dataModeByte: + for _, b := range data { + encoded.AppendByte(b, 8) + } + } +} + +// modeIndicator returns the segment header bits for a segment of type dataMode. +func (d *dataEncoder) modeIndicator(dataMode dataMode) *bitset.Bitset { + switch dataMode { + case dataModeNumeric: + return d.numericModeIndicator + case dataModeAlphanumeric: + return d.alphanumericModeIndicator + case dataModeByte: + return d.byteModeIndicator + default: + log.Panic("Unknown data mode") + } + + return nil +} + +// charCountBits returns the number of bits used to encode the length of a data +// segment of type dataMode. +func (d *dataEncoder) charCountBits(dataMode dataMode) int { + switch dataMode { + case dataModeNumeric: + return d.numNumericCharCountBits + case dataModeAlphanumeric: + return d.numAlphanumericCharCountBits + case dataModeByte: + return d.numByteCharCountBits + default: + log.Panic("Unknown data mode") + } + + return 0 +} + +// encodedLength returns the number of bits required to encode n symbols in +// dataMode. +// +// The number of bits required is affected by: +// - QR code type - Mode Indicator length. +// - Data mode - number of bits used to represent data length. +// - Data mode - how the data is encoded. +// - Number of symbols encoded. +// +// An error is returned if the mode is not supported, or the length requested is +// too long to be represented. +func (d *dataEncoder) encodedLength(dataMode dataMode, n int) (int, error) { + modeIndicator := d.modeIndicator(dataMode) + charCountBits := d.charCountBits(dataMode) + + if modeIndicator == nil { + return 0, errors.New("mode not supported") + } + + maxLength := (1 << uint8(charCountBits)) - 1 + + if n > maxLength { + return 0, errors.New("length too long to be represented") + } + + length := modeIndicator.Len() + charCountBits + + switch dataMode { + case dataModeNumeric: + length += 10 * (n / 3) + + if n%3 != 0 { + length += 1 + 3*(n%3) + } + case dataModeAlphanumeric: + length += 11 * (n / 2) + length += 6 * (n % 2) + case dataModeByte: + length += 8 * n + } + + return length, nil +} + +// encodeAlphanumericChar returns the QR Code encoded value of v. +// +// v must be a QR Code defined alphanumeric character: 0-9, A-Z, SP, $%*+-./ or +// :. The characters are mapped to values in the range 0-44 respectively. +func encodeAlphanumericCharacter(v byte) uint32 { + c := uint32(v) + + switch { + case c >= '0' && c <= '9': + // 0-9 encoded as 0-9. + return c - '0' + case c >= 'A' && c <= 'Z': + // A-Z encoded as 10-35. + return c - 'A' + 10 + case c == ' ': + return 36 + case c == '$': + return 37 + case c == '%': + return 38 + case c == '*': + return 39 + case c == '+': + return 40 + case c == '-': + return 41 + case c == '.': + return 42 + case c == '/': + return 43 + case c == ':': + return 44 + default: + log.Panicf("encodeAlphanumericCharacter() with non alphanumeric char %v.", v) + } + + return 0 +} diff --git a/vendor/github.com/skip2/go-qrcode/qrcode.go b/vendor/github.com/skip2/go-qrcode/qrcode.go new file mode 100644 index 00000000..9428d863 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/qrcode.go @@ -0,0 +1,589 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +/* +Package qrcode implements a QR Code encoder. + +A QR Code is a matrix (two-dimensional) barcode. Arbitrary content may be +encoded. + +A QR Code contains error recovery information to aid reading damaged or +obscured codes. There are four levels of error recovery: qrcode.{Low, Medium, +High, Highest}. QR Codes with a higher recovery level are more robust to damage, +at the cost of being physically larger. + +Three functions cover most use cases: + +- Create a PNG image: + + var png []byte + png, err := qrcode.Encode("https://example.org", qrcode.Medium, 256) + +- Create a PNG image and write to a file: + + err := qrcode.WriteFile("https://example.org", qrcode.Medium, 256, "qr.png") + +- Create a PNG image with custom colors and write to file: + + err := qrcode.WriteColorFile("https://example.org", qrcode.Medium, 256, color.Black, color.White, "qr.png") + +All examples use the qrcode.Medium error Recovery Level and create a fixed +256x256px size QR Code. The last function creates a white on black instead of black +on white QR Code. + +To generate a variable sized image instead, specify a negative size (in place of +the 256 above), such as -4 or -5. Larger negative numbers create larger images: +A size of -5 sets each module (QR Code "pixel") to be 5px wide/high. + +- Create a PNG image (variable size, with minimum white padding) and write to a file: + + err := qrcode.WriteFile("https://example.org", qrcode.Medium, -5, "qr.png") + +The maximum capacity of a QR Code varies according to the content encoded and +the error recovery level. The maximum capacity is 2,953 bytes, 4,296 +alphanumeric characters, 7,089 numeric digits, or a combination of these. + +This package implements a subset of QR Code 2005, as defined in ISO/IEC +18004:2006. +*/ +package qrcode + +import ( + "bytes" + "errors" + "image" + "image/color" + "image/png" + "io" + "io/ioutil" + "log" + "os" + + bitset "github.com/skip2/go-qrcode/bitset" + reedsolomon "github.com/skip2/go-qrcode/reedsolomon" +) + +// Encode a QR Code and return a raw PNG image. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently returned. Negative values for size cause a +// variable sized image to be returned: See the documentation for Image(). +// +// To serve over HTTP, remember to send a Content-Type: image/png header. +func Encode(content string, level RecoveryLevel, size int) ([]byte, error) { + var q *QRCode + + q, err := New(content, level) + + if err != nil { + return nil, err + } + + return q.PNG(size) +} + +// WriteFile encodes, then writes a QR Code to the given filename in PNG format. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently written. Negative values for size cause a variable +// sized image to be written: See the documentation for Image(). +func WriteFile(content string, level RecoveryLevel, size int, filename string) error { + var q *QRCode + + q, err := New(content, level) + + if err != nil { + return err + } + + return q.WriteFile(size, filename) +} + +// WriteColorFile encodes, then writes a QR Code to the given filename in PNG format. +// With WriteColorFile you can also specify the colors you want to use. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently written. Negative values for size cause a variable +// sized image to be written: See the documentation for Image(). +func WriteColorFile(content string, level RecoveryLevel, size int, background, + foreground color.Color, filename string) error { + + var q *QRCode + + q, err := New(content, level) + + q.BackgroundColor = background + q.ForegroundColor = foreground + + if err != nil { + return err + } + + return q.WriteFile(size, filename) +} + +// A QRCode represents a valid encoded QRCode. +type QRCode struct { + // Original content encoded. + Content string + + // QR Code type. + Level RecoveryLevel + VersionNumber int + + // User settable drawing options. + ForegroundColor color.Color + BackgroundColor color.Color + + encoder *dataEncoder + version qrCodeVersion + + data *bitset.Bitset + symbol *symbol + mask int +} + +// New constructs a QRCode. +// +// var q *qrcode.QRCode +// q, err := qrcode.New("my content", qrcode.Medium) +// +// An error occurs if the content is too long. +func New(content string, level RecoveryLevel) (*QRCode, error) { + encoders := []dataEncoderType{dataEncoderType1To9, dataEncoderType10To26, + dataEncoderType27To40} + + var encoder *dataEncoder + var encoded *bitset.Bitset + var chosenVersion *qrCodeVersion + var err error + + for _, t := range encoders { + encoder = newDataEncoder(t) + encoded, err = encoder.encode([]byte(content)) + + if err != nil { + continue + } + + chosenVersion = chooseQRCodeVersion(level, encoder, encoded.Len()) + + if chosenVersion != nil { + break + } + } + + if err != nil { + return nil, err + } else if chosenVersion == nil { + return nil, errors.New("content too long to encode") + } + + q := &QRCode{ + Content: content, + + Level: level, + VersionNumber: chosenVersion.version, + + ForegroundColor: color.Black, + BackgroundColor: color.White, + + encoder: encoder, + data: encoded, + version: *chosenVersion, + } + + q.encode(chosenVersion.numTerminatorBitsRequired(encoded.Len())) + + return q, nil +} + +func newWithForcedVersion(content string, version int, level RecoveryLevel) (*QRCode, error) { + var encoder *dataEncoder + + switch { + case version >= 1 && version <= 9: + encoder = newDataEncoder(dataEncoderType1To9) + case version >= 10 && version <= 26: + encoder = newDataEncoder(dataEncoderType10To26) + case version >= 27 && version <= 40: + encoder = newDataEncoder(dataEncoderType27To40) + default: + log.Fatalf("Invalid version %d (expected 1-40 inclusive)", version) + } + + var encoded *bitset.Bitset + encoded, err := encoder.encode([]byte(content)) + + if err != nil { + return nil, err + } + + chosenVersion := getQRCodeVersion(level, version) + + if chosenVersion == nil { + return nil, errors.New("cannot find QR Code version") + } + + q := &QRCode{ + Content: content, + + Level: level, + VersionNumber: chosenVersion.version, + + ForegroundColor: color.Black, + BackgroundColor: color.White, + + encoder: encoder, + data: encoded, + version: *chosenVersion, + } + + q.encode(chosenVersion.numTerminatorBitsRequired(encoded.Len())) + + return q, nil +} + +// Bitmap returns the QR Code as a 2D array of 1-bit pixels. +// +// bitmap[y][x] is true if the pixel at (x, y) is set. +// +// The bitmap includes the required "quiet zone" around the QR Code to aid +// decoding. +func (q *QRCode) Bitmap() [][]bool { + return q.symbol.bitmap() +} + +// Image returns the QR Code as an image.Image. +// +// A positive size sets a fixed image width and height (e.g. 256 yields an +// 256x256px image). +// +// Depending on the amount of data encoded, fixed size images can have different +// amounts of padding (white space around the QR Code). As an alternative, a +// variable sized image can be generated instead: +// +// A negative size causes a variable sized image to be returned. The image +// returned is the minimum size required for the QR Code. Choose a larger +// negative number to increase the scale of the image. e.g. a size of -5 causes +// each module (QR Code "pixel") to be 5px in size. +func (q *QRCode) Image(size int) image.Image { + // Minimum pixels (both width and height) required. + realSize := q.symbol.size + + // Variable size support. + if size < 0 { + size = size * -1 * realSize + } + + // Actual pixels available to draw the symbol. Automatically increase the + // image size if it's not large enough. + if size < realSize { + size = realSize + } + + // Size of each module drawn. + pixelsPerModule := size / realSize + + // Center the symbol within the image. + offset := (size - realSize*pixelsPerModule) / 2 + + rect := image.Rectangle{Min: image.Point{0, 0}, Max: image.Point{size, size}} + + // Saves a few bytes to have them in this order + p := color.Palette([]color.Color{q.BackgroundColor, q.ForegroundColor}) + img := image.NewPaletted(rect, p) + fgClr := uint8(img.Palette.Index(q.ForegroundColor)) + + bitmap := q.symbol.bitmap() + for y, row := range bitmap { + for x, v := range row { + if v { + startX := x*pixelsPerModule + offset + startY := y*pixelsPerModule + offset + for i := startX; i < startX+pixelsPerModule; i++ { + for j := startY; j < startY+pixelsPerModule; j++ { + pos := img.PixOffset(i, j) + img.Pix[pos] = fgClr + } + } + } + } + } + + return img +} + +// PNG returns the QR Code as a PNG image. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently returned. Negative values for size cause a +// variable sized image to be returned: See the documentation for Image(). +func (q *QRCode) PNG(size int) ([]byte, error) { + img := q.Image(size) + + encoder := png.Encoder{CompressionLevel: png.BestCompression} + + var b bytes.Buffer + err := encoder.Encode(&b, img) + + if err != nil { + return nil, err + } + + return b.Bytes(), nil +} + +// Write writes the QR Code as a PNG image to io.Writer. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently written. Negative values for size cause a +// variable sized image to be written: See the documentation for Image(). +func (q *QRCode) Write(size int, out io.Writer) error { + var png []byte + + png, err := q.PNG(size) + + if err != nil { + return err + } + _, err = out.Write(png) + return err +} + +// WriteFile writes the QR Code as a PNG image to the specified file. +// +// size is both the image width and height in pixels. If size is too small then +// a larger image is silently written. Negative values for size cause a +// variable sized image to be written: See the documentation for Image(). +func (q *QRCode) WriteFile(size int, filename string) error { + var png []byte + + png, err := q.PNG(size) + + if err != nil { + return err + } + + return ioutil.WriteFile(filename, png, os.FileMode(0644)) +} + +// encode completes the steps required to encode the QR Code. These include +// adding the terminator bits and padding, splitting the data into blocks and +// applying the error correction, and selecting the best data mask. +func (q *QRCode) encode(numTerminatorBits int) { + q.addTerminatorBits(numTerminatorBits) + q.addPadding() + + encoded := q.encodeBlocks() + + const numMasks int = 8 + penalty := 0 + + for mask := 0; mask < numMasks; mask++ { + var s *symbol + var err error + + s, err = buildRegularSymbol(q.version, mask, encoded) + + if err != nil { + log.Panic(err.Error()) + } + + numEmptyModules := s.numEmptyModules() + if numEmptyModules != 0 { + log.Panicf("bug: numEmptyModules is %d (expected 0) (version=%d)", + numEmptyModules, q.VersionNumber) + } + + p := s.penaltyScore() + + //log.Printf("mask=%d p=%3d p1=%3d p2=%3d p3=%3d p4=%d\n", mask, p, s.penalty1(), s.penalty2(), s.penalty3(), s.penalty4()) + + if q.symbol == nil || p < penalty { + q.symbol = s + q.mask = mask + penalty = p + } + } +} + +// addTerminatorBits adds final terminator bits to the encoded data. +// +// The number of terminator bits required is determined when the QR Code version +// is chosen (which itself depends on the length of the data encoded). The +// terminator bits are thus added after the QR Code version +// is chosen, rather than at the data encoding stage. +func (q *QRCode) addTerminatorBits(numTerminatorBits int) { + q.data.AppendNumBools(numTerminatorBits, false) +} + +// encodeBlocks takes the completed (terminated & padded) encoded data, splits +// the data into blocks (as specified by the QR Code version), applies error +// correction to each block, then interleaves the blocks together. +// +// The QR Code's final data sequence is returned. +func (q *QRCode) encodeBlocks() *bitset.Bitset { + // Split into blocks. + type dataBlock struct { + data *bitset.Bitset + ecStartOffset int + } + + block := make([]dataBlock, q.version.numBlocks()) + + start := 0 + end := 0 + blockID := 0 + + for _, b := range q.version.block { + for j := 0; j < b.numBlocks; j++ { + start = end + end = start + b.numDataCodewords*8 + + // Apply error correction to each block. + numErrorCodewords := b.numCodewords - b.numDataCodewords + block[blockID].data = reedsolomon.Encode(q.data.Substr(start, end), numErrorCodewords) + block[blockID].ecStartOffset = end - start + + blockID++ + } + } + + // Interleave the blocks. + + result := bitset.New() + + // Combine data blocks. + working := true + for i := 0; working; i += 8 { + working = false + + for j, b := range block { + if i >= block[j].ecStartOffset { + continue + } + + result.Append(b.data.Substr(i, i+8)) + + working = true + } + } + + // Combine error correction blocks. + working = true + for i := 0; working; i += 8 { + working = false + + for j, b := range block { + offset := i + block[j].ecStartOffset + if offset >= block[j].data.Len() { + continue + } + + result.Append(b.data.Substr(offset, offset+8)) + + working = true + } + } + + // Append remainder bits. + result.AppendNumBools(q.version.numRemainderBits, false) + + return result +} + +// max returns the maximum of a and b. +func max(a int, b int) int { + if a > b { + return a + } + + return b +} + +// addPadding pads the encoded data upto the full length required. +func (q *QRCode) addPadding() { + numDataBits := q.version.numDataBits() + + if q.data.Len() == numDataBits { + return + } + + // Pad to the nearest codeword boundary. + q.data.AppendNumBools(q.version.numBitsToPadToCodeword(q.data.Len()), false) + + // Pad codewords 0b11101100 and 0b00010001. + padding := [2]*bitset.Bitset{ + bitset.New(true, true, true, false, true, true, false, false), + bitset.New(false, false, false, true, false, false, false, true), + } + + // Insert pad codewords alternately. + i := 0 + for numDataBits-q.data.Len() >= 8 { + q.data.Append(padding[i]) + + i = 1 - i // Alternate between 0 and 1. + } + + if q.data.Len() != numDataBits { + log.Panicf("BUG: got len %d, expected %d", q.data.Len(), numDataBits) + } +} + +// ToString produces a multi-line string that forms a QR-code image. +func (q *QRCode) ToString(inverseColor bool) string { + bits := q.Bitmap() + var buf bytes.Buffer + for y := range bits { + for x := range bits[y] { + if bits[y][x] != inverseColor { + buf.WriteString(" ") + } else { + buf.WriteString("██") + } + } + buf.WriteString("\n") + } + return buf.String() +} + +// ToSmallString produces a multi-line string that forms a QR-code image, a +// factor two smaller in x and y then ToString. +func (q *QRCode) ToSmallString(inverseColor bool) string { + bits := q.Bitmap() + var buf bytes.Buffer + // if there is an odd number of rows, the last one needs special treatment + for y := 0; y < len(bits)-1; y += 2 { + for x := range bits[y] { + if bits[y][x] == bits[y+1][x] { + if bits[y][x] != inverseColor { + buf.WriteString(" ") + } else { + buf.WriteString("â–ˆ") + } + } else { + if bits[y][x] != inverseColor { + buf.WriteString("â–„") + } else { + buf.WriteString("â–€") + } + } + } + buf.WriteString("\n") + } + // special treatment for the last row if odd + if len(bits)%2 == 1 { + y := len(bits) - 1 + for x := range bits[y] { + if bits[y][x] != inverseColor { + buf.WriteString(" ") + } else { + buf.WriteString("â–€") + } + } + buf.WriteString("\n") + } + return buf.String() +} diff --git a/vendor/github.com/skip2/go-qrcode/reedsolomon/gf2_8.go b/vendor/github.com/skip2/go-qrcode/reedsolomon/gf2_8.go new file mode 100644 index 00000000..6a7003f7 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/reedsolomon/gf2_8.go @@ -0,0 +1,387 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package reedsolomon + +// Addition, subtraction, multiplication, and division in GF(2^8). +// Operations are performed modulo x^8 + x^4 + x^3 + x^2 + 1. + +// http://en.wikipedia.org/wiki/Finite_field_arithmetic + +import "log" + +const ( + gfZero = gfElement(0) + gfOne = gfElement(1) +) + +var ( + gfExpTable = [256]gfElement{ + /* 0 - 9 */ 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, + /* 10 - 19 */ 116, 232, 205, 135, 19, 38, 76, 152, 45, 90, + /* 20 - 29 */ 180, 117, 234, 201, 143, 3, 6, 12, 24, 48, + /* 30 - 39 */ 96, 192, 157, 39, 78, 156, 37, 74, 148, 53, + /* 40 - 49 */ 106, 212, 181, 119, 238, 193, 159, 35, 70, 140, + /* 50 - 59 */ 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, + /* 60 - 69 */ 185, 111, 222, 161, 95, 190, 97, 194, 153, 47, + /* 70 - 79 */ 94, 188, 101, 202, 137, 15, 30, 60, 120, 240, + /* 80 - 89 */ 253, 231, 211, 187, 107, 214, 177, 127, 254, 225, + /* 90 - 99 */ 223, 163, 91, 182, 113, 226, 217, 175, 67, 134, + /* 100 - 109 */ 17, 34, 68, 136, 13, 26, 52, 104, 208, 189, + /* 110 - 119 */ 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, + /* 120 - 129 */ 59, 118, 236, 197, 151, 51, 102, 204, 133, 23, + /* 130 - 139 */ 46, 92, 184, 109, 218, 169, 79, 158, 33, 66, + /* 140 - 149 */ 132, 21, 42, 84, 168, 77, 154, 41, 82, 164, + /* 150 - 159 */ 85, 170, 73, 146, 57, 114, 228, 213, 183, 115, + /* 160 - 169 */ 230, 209, 191, 99, 198, 145, 63, 126, 252, 229, + /* 170 - 179 */ 215, 179, 123, 246, 241, 255, 227, 219, 171, 75, + /* 180 - 189 */ 150, 49, 98, 196, 149, 55, 110, 220, 165, 87, + /* 190 - 199 */ 174, 65, 130, 25, 50, 100, 200, 141, 7, 14, + /* 200 - 209 */ 28, 56, 112, 224, 221, 167, 83, 166, 81, 162, + /* 210 - 219 */ 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, + /* 220 - 229 */ 172, 69, 138, 9, 18, 36, 72, 144, 61, 122, + /* 230 - 239 */ 244, 245, 247, 243, 251, 235, 203, 139, 11, 22, + /* 240 - 249 */ 44, 88, 176, 125, 250, 233, 207, 131, 27, 54, + /* 250 - 255 */ 108, 216, 173, 71, 142, 1} + + gfLogTable = [256]int{ + /* 0 - 9 */ -1, 0, 1, 25, 2, 50, 26, 198, 3, 223, + /* 10 - 19 */ 51, 238, 27, 104, 199, 75, 4, 100, 224, 14, + /* 20 - 29 */ 52, 141, 239, 129, 28, 193, 105, 248, 200, 8, + /* 30 - 39 */ 76, 113, 5, 138, 101, 47, 225, 36, 15, 33, + /* 40 - 49 */ 53, 147, 142, 218, 240, 18, 130, 69, 29, 181, + /* 50 - 59 */ 194, 125, 106, 39, 249, 185, 201, 154, 9, 120, + /* 60 - 69 */ 77, 228, 114, 166, 6, 191, 139, 98, 102, 221, + /* 70 - 79 */ 48, 253, 226, 152, 37, 179, 16, 145, 34, 136, + /* 80 - 89 */ 54, 208, 148, 206, 143, 150, 219, 189, 241, 210, + /* 90 - 99 */ 19, 92, 131, 56, 70, 64, 30, 66, 182, 163, + /* 100 - 109 */ 195, 72, 126, 110, 107, 58, 40, 84, 250, 133, + /* 110 - 119 */ 186, 61, 202, 94, 155, 159, 10, 21, 121, 43, + /* 120 - 129 */ 78, 212, 229, 172, 115, 243, 167, 87, 7, 112, + /* 130 - 139 */ 192, 247, 140, 128, 99, 13, 103, 74, 222, 237, + /* 140 - 149 */ 49, 197, 254, 24, 227, 165, 153, 119, 38, 184, + /* 150 - 159 */ 180, 124, 17, 68, 146, 217, 35, 32, 137, 46, + /* 160 - 169 */ 55, 63, 209, 91, 149, 188, 207, 205, 144, 135, + /* 170 - 179 */ 151, 178, 220, 252, 190, 97, 242, 86, 211, 171, + /* 180 - 189 */ 20, 42, 93, 158, 132, 60, 57, 83, 71, 109, + /* 190 - 199 */ 65, 162, 31, 45, 67, 216, 183, 123, 164, 118, + /* 200 - 209 */ 196, 23, 73, 236, 127, 12, 111, 246, 108, 161, + /* 210 - 219 */ 59, 82, 41, 157, 85, 170, 251, 96, 134, 177, + /* 220 - 229 */ 187, 204, 62, 90, 203, 89, 95, 176, 156, 169, + /* 230 - 239 */ 160, 81, 11, 245, 22, 235, 122, 117, 44, 215, + /* 240 - 249 */ 79, 174, 213, 233, 230, 231, 173, 232, 116, 214, + /* 250 - 255 */ 244, 234, 168, 80, 88, 175} +) + +// gfElement is an element in GF(2^8). +type gfElement uint8 + +// newGFElement creates and returns a new gfElement. +func newGFElement(data byte) gfElement { + return gfElement(data) +} + +// gfAdd returns a + b. +func gfAdd(a, b gfElement) gfElement { + return a ^ b +} + +// gfSub returns a - b. +// +// Note addition is equivalent to subtraction in GF(2). +func gfSub(a, b gfElement) gfElement { + return a ^ b +} + +// gfMultiply returns a * b. +func gfMultiply(a, b gfElement) gfElement { + if a == gfZero || b == gfZero { + return gfZero + } + + return gfExpTable[(gfLogTable[a]+gfLogTable[b])%255] +} + +// gfDivide returns a / b. +// +// Divide by zero results in a panic. +func gfDivide(a, b gfElement) gfElement { + if a == gfZero { + return gfZero + } else if b == gfZero { + log.Panicln("Divide by zero") + } + + return gfMultiply(a, gfInverse(b)) +} + +// gfInverse returns the multiplicative inverse of a, a^-1. +// +// a * a^-1 = 1 +func gfInverse(a gfElement) gfElement { + if a == gfZero { + log.Panicln("No multiplicative inverse of 0") + } + + return gfExpTable[255-gfLogTable[a]] +} + +// a^i | bits | polynomial | decimal +// -------------------------------------------------------------------------- +// 0 | 000000000 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 0 +// a^0 | 000000001 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 1 +// a^1 | 000000010 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 2 +// a^2 | 000000100 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 4 +// a^3 | 000001000 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 8 +// a^4 | 000010000 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 16 +// a^5 | 000100000 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 32 +// a^6 | 001000000 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 64 +// a^7 | 010000000 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 128 +// a^8 | 000011101 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 29 +// a^9 | 000111010 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 58 +// a^10 | 001110100 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 116 +// a^11 | 011101000 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 232 +// a^12 | 011001101 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 205 +// a^13 | 010000111 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 135 +// a^14 | 000010011 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 19 +// a^15 | 000100110 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 38 +// a^16 | 001001100 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 76 +// a^17 | 010011000 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 152 +// a^18 | 000101101 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 45 +// a^19 | 001011010 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 90 +// a^20 | 010110100 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 180 +// a^21 | 001110101 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 117 +// a^22 | 011101010 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 234 +// a^23 | 011001001 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 201 +// a^24 | 010001111 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 143 +// a^25 | 000000011 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 3 +// a^26 | 000000110 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 6 +// a^27 | 000001100 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 12 +// a^28 | 000011000 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 24 +// a^29 | 000110000 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 48 +// a^30 | 001100000 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 96 +// a^31 | 011000000 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 192 +// a^32 | 010011101 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 157 +// a^33 | 000100111 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 39 +// a^34 | 001001110 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 78 +// a^35 | 010011100 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 156 +// a^36 | 000100101 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 37 +// a^37 | 001001010 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 74 +// a^38 | 010010100 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 148 +// a^39 | 000110101 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 53 +// a^40 | 001101010 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 106 +// a^41 | 011010100 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 212 +// a^42 | 010110101 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 181 +// a^43 | 001110111 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 119 +// a^44 | 011101110 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 238 +// a^45 | 011000001 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 193 +// a^46 | 010011111 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 159 +// a^47 | 000100011 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 35 +// a^48 | 001000110 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 70 +// a^49 | 010001100 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 140 +// a^50 | 000000101 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 5 +// a^51 | 000001010 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 10 +// a^52 | 000010100 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 20 +// a^53 | 000101000 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 40 +// a^54 | 001010000 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 80 +// a^55 | 010100000 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 160 +// a^56 | 001011101 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 93 +// a^57 | 010111010 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 186 +// a^58 | 001101001 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 105 +// a^59 | 011010010 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 210 +// a^60 | 010111001 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 185 +// a^61 | 001101111 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 111 +// a^62 | 011011110 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 222 +// a^63 | 010100001 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 161 +// a^64 | 001011111 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 95 +// a^65 | 010111110 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 190 +// a^66 | 001100001 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 97 +// a^67 | 011000010 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 194 +// a^68 | 010011001 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 153 +// a^69 | 000101111 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 47 +// a^70 | 001011110 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 94 +// a^71 | 010111100 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 188 +// a^72 | 001100101 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 101 +// a^73 | 011001010 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 202 +// a^74 | 010001001 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 137 +// a^75 | 000001111 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 15 +// a^76 | 000011110 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 30 +// a^77 | 000111100 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 60 +// a^78 | 001111000 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 120 +// a^79 | 011110000 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 240 +// a^80 | 011111101 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 253 +// a^81 | 011100111 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 231 +// a^82 | 011010011 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 211 +// a^83 | 010111011 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 187 +// a^84 | 001101011 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 107 +// a^85 | 011010110 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 214 +// a^86 | 010110001 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 177 +// a^87 | 001111111 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 127 +// a^88 | 011111110 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 254 +// a^89 | 011100001 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 225 +// a^90 | 011011111 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 223 +// a^91 | 010100011 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 163 +// a^92 | 001011011 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 91 +// a^93 | 010110110 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 182 +// a^94 | 001110001 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 113 +// a^95 | 011100010 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 226 +// a^96 | 011011001 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 217 +// a^97 | 010101111 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 175 +// a^98 | 001000011 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 67 +// a^99 | 010000110 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 134 +// a^100 | 000010001 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 17 +// a^101 | 000100010 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 34 +// a^102 | 001000100 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 68 +// a^103 | 010001000 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 136 +// a^104 | 000001101 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 13 +// a^105 | 000011010 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 26 +// a^106 | 000110100 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 52 +// a^107 | 001101000 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 104 +// a^108 | 011010000 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 208 +// a^109 | 010111101 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 189 +// a^110 | 001100111 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 103 +// a^111 | 011001110 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 206 +// a^112 | 010000001 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 129 +// a^113 | 000011111 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 31 +// a^114 | 000111110 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 62 +// a^115 | 001111100 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 124 +// a^116 | 011111000 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 248 +// a^117 | 011101101 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 237 +// a^118 | 011000111 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 199 +// a^119 | 010010011 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 147 +// a^120 | 000111011 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 59 +// a^121 | 001110110 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 118 +// a^122 | 011101100 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 236 +// a^123 | 011000101 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 197 +// a^124 | 010010111 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 151 +// a^125 | 000110011 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 51 +// a^126 | 001100110 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 102 +// a^127 | 011001100 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 204 +// a^128 | 010000101 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 133 +// a^129 | 000010111 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 23 +// a^130 | 000101110 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 46 +// a^131 | 001011100 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 92 +// a^132 | 010111000 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 184 +// a^133 | 001101101 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 109 +// a^134 | 011011010 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 218 +// a^135 | 010101001 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 169 +// a^136 | 001001111 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 79 +// a^137 | 010011110 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 158 +// a^138 | 000100001 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 33 +// a^139 | 001000010 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 66 +// a^140 | 010000100 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 132 +// a^141 | 000010101 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 21 +// a^142 | 000101010 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 42 +// a^143 | 001010100 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 84 +// a^144 | 010101000 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 168 +// a^145 | 001001101 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 77 +// a^146 | 010011010 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 154 +// a^147 | 000101001 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 41 +// a^148 | 001010010 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 82 +// a^149 | 010100100 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 164 +// a^150 | 001010101 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 85 +// a^151 | 010101010 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 170 +// a^152 | 001001001 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 73 +// a^153 | 010010010 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 146 +// a^154 | 000111001 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 57 +// a^155 | 001110010 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 114 +// a^156 | 011100100 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 228 +// a^157 | 011010101 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 213 +// a^158 | 010110111 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 183 +// a^159 | 001110011 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 115 +// a^160 | 011100110 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 230 +// a^161 | 011010001 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 209 +// a^162 | 010111111 | 0x^8 1x^7 0x^6 1x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 191 +// a^163 | 001100011 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 99 +// a^164 | 011000110 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 198 +// a^165 | 010010001 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 145 +// a^166 | 000111111 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 63 +// a^167 | 001111110 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 1x^2 1x^1 0x^0 | 126 +// a^168 | 011111100 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 252 +// a^169 | 011100101 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 229 +// a^170 | 011010111 | 0x^8 1x^7 1x^6 0x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 215 +// a^171 | 010110011 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 179 +// a^172 | 001111011 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 123 +// a^173 | 011110110 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 246 +// a^174 | 011110001 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 241 +// a^175 | 011111111 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 1x^2 1x^1 1x^0 | 255 +// a^176 | 011100011 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 227 +// a^177 | 011011011 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 219 +// a^178 | 010101011 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 171 +// a^179 | 001001011 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 75 +// a^180 | 010010110 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 150 +// a^181 | 000110001 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 49 +// a^182 | 001100010 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 98 +// a^183 | 011000100 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 196 +// a^184 | 010010101 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 149 +// a^185 | 000110111 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 55 +// a^186 | 001101110 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 110 +// a^187 | 011011100 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 220 +// a^188 | 010100101 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 165 +// a^189 | 001010111 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 87 +// a^190 | 010101110 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 174 +// a^191 | 001000001 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 65 +// a^192 | 010000010 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 130 +// a^193 | 000011001 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 25 +// a^194 | 000110010 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 50 +// a^195 | 001100100 | 0x^8 0x^7 1x^6 1x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 100 +// a^196 | 011001000 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 200 +// a^197 | 010001101 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 141 +// a^198 | 000000111 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 7 +// a^199 | 000001110 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 14 +// a^200 | 000011100 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 1x^2 0x^1 0x^0 | 28 +// a^201 | 000111000 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 56 +// a^202 | 001110000 | 0x^8 0x^7 1x^6 1x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 112 +// a^203 | 011100000 | 0x^8 1x^7 1x^6 1x^5 0x^4 0x^3 0x^2 0x^1 0x^0 | 224 +// a^204 | 011011101 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 221 +// a^205 | 010100111 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 167 +// a^206 | 001010011 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 83 +// a^207 | 010100110 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 1x^2 1x^1 0x^0 | 166 +// a^208 | 001010001 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 0x^2 0x^1 1x^0 | 81 +// a^209 | 010100010 | 0x^8 1x^7 0x^6 1x^5 0x^4 0x^3 0x^2 1x^1 0x^0 | 162 +// a^210 | 001011001 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 89 +// a^211 | 010110010 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 178 +// a^212 | 001111001 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 121 +// a^213 | 011110010 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 242 +// a^214 | 011111001 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 0x^2 0x^1 1x^0 | 249 +// a^215 | 011101111 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 239 +// a^216 | 011000011 | 0x^8 1x^7 1x^6 0x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 195 +// a^217 | 010011011 | 0x^8 1x^7 0x^6 0x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 155 +// a^218 | 000101011 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 43 +// a^219 | 001010110 | 0x^8 0x^7 1x^6 0x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 86 +// a^220 | 010101100 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 172 +// a^221 | 001000101 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 1x^2 0x^1 1x^0 | 69 +// a^222 | 010001010 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 0x^2 1x^1 0x^0 | 138 +// a^223 | 000001001 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 9 +// a^224 | 000010010 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 0x^2 1x^1 0x^0 | 18 +// a^225 | 000100100 | 0x^8 0x^7 0x^6 1x^5 0x^4 0x^3 1x^2 0x^1 0x^0 | 36 +// a^226 | 001001000 | 0x^8 0x^7 1x^6 0x^5 0x^4 1x^3 0x^2 0x^1 0x^0 | 72 +// a^227 | 010010000 | 0x^8 1x^7 0x^6 0x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 144 +// a^228 | 000111101 | 0x^8 0x^7 0x^6 1x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 61 +// a^229 | 001111010 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 122 +// a^230 | 011110100 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 1x^2 0x^1 0x^0 | 244 +// a^231 | 011110101 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 1x^2 0x^1 1x^0 | 245 +// a^232 | 011110111 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 1x^2 1x^1 1x^0 | 247 +// a^233 | 011110011 | 0x^8 1x^7 1x^6 1x^5 1x^4 0x^3 0x^2 1x^1 1x^0 | 243 +// a^234 | 011111011 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 251 +// a^235 | 011101011 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 235 +// a^236 | 011001011 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 203 +// a^237 | 010001011 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 139 +// a^238 | 000001011 | 0x^8 0x^7 0x^6 0x^5 0x^4 1x^3 0x^2 1x^1 1x^0 | 11 +// a^239 | 000010110 | 0x^8 0x^7 0x^6 0x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 22 +// a^240 | 000101100 | 0x^8 0x^7 0x^6 1x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 44 +// a^241 | 001011000 | 0x^8 0x^7 1x^6 0x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 88 +// a^242 | 010110000 | 0x^8 1x^7 0x^6 1x^5 1x^4 0x^3 0x^2 0x^1 0x^0 | 176 +// a^243 | 001111101 | 0x^8 0x^7 1x^6 1x^5 1x^4 1x^3 1x^2 0x^1 1x^0 | 125 +// a^244 | 011111010 | 0x^8 1x^7 1x^6 1x^5 1x^4 1x^3 0x^2 1x^1 0x^0 | 250 +// a^245 | 011101001 | 0x^8 1x^7 1x^6 1x^5 0x^4 1x^3 0x^2 0x^1 1x^0 | 233 +// a^246 | 011001111 | 0x^8 1x^7 1x^6 0x^5 0x^4 1x^3 1x^2 1x^1 1x^0 | 207 +// a^247 | 010000011 | 0x^8 1x^7 0x^6 0x^5 0x^4 0x^3 0x^2 1x^1 1x^0 | 131 +// a^248 | 000011011 | 0x^8 0x^7 0x^6 0x^5 1x^4 1x^3 0x^2 1x^1 1x^0 | 27 +// a^249 | 000110110 | 0x^8 0x^7 0x^6 1x^5 1x^4 0x^3 1x^2 1x^1 0x^0 | 54 +// a^250 | 001101100 | 0x^8 0x^7 1x^6 1x^5 0x^4 1x^3 1x^2 0x^1 0x^0 | 108 +// a^251 | 011011000 | 0x^8 1x^7 1x^6 0x^5 1x^4 1x^3 0x^2 0x^1 0x^0 | 216 +// a^252 | 010101101 | 0x^8 1x^7 0x^6 1x^5 0x^4 1x^3 1x^2 0x^1 1x^0 | 173 +// a^253 | 001000111 | 0x^8 0x^7 1x^6 0x^5 0x^4 0x^3 1x^2 1x^1 1x^0 | 71 +// a^254 | 010001110 | 0x^8 1x^7 0x^6 0x^5 0x^4 1x^3 1x^2 1x^1 0x^0 | 142 +// a^255 | 000000001 | 0x^8 0x^7 0x^6 0x^5 0x^4 0x^3 0x^2 0x^1 1x^0 | 1 diff --git a/vendor/github.com/skip2/go-qrcode/reedsolomon/gf_poly.go b/vendor/github.com/skip2/go-qrcode/reedsolomon/gf_poly.go new file mode 100644 index 00000000..962f5454 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/reedsolomon/gf_poly.go @@ -0,0 +1,216 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package reedsolomon + +import ( + "fmt" + "log" + + bitset "github.com/skip2/go-qrcode/bitset" +) + +// gfPoly is a polynomial over GF(2^8). +type gfPoly struct { + // The ith value is the coefficient of the ith degree of x. + // term[0]*(x^0) + term[1]*(x^1) + term[2]*(x^2) ... + term []gfElement +} + +// newGFPolyFromData returns |data| as a polynomial over GF(2^8). +// +// Each data byte becomes the coefficient of an x term. +// +// For an n byte input the polynomial is: +// data[n-1]*(x^n-1) + data[n-2]*(x^n-2) ... + data[0]*(x^0). +func newGFPolyFromData(data *bitset.Bitset) gfPoly { + numTotalBytes := data.Len() / 8 + if data.Len()%8 != 0 { + numTotalBytes++ + } + + result := gfPoly{term: make([]gfElement, numTotalBytes)} + + i := numTotalBytes - 1 + for j := 0; j < data.Len(); j += 8 { + result.term[i] = gfElement(data.ByteAt(j)) + i-- + } + + return result +} + +// newGFPolyMonomial returns term*(x^degree). +func newGFPolyMonomial(term gfElement, degree int) gfPoly { + if term == gfZero { + return gfPoly{} + } + + result := gfPoly{term: make([]gfElement, degree+1)} + result.term[degree] = term + + return result +} + +func (e gfPoly) data(numTerms int) []byte { + result := make([]byte, numTerms) + + i := numTerms - len(e.term) + for j := len(e.term) - 1; j >= 0; j-- { + result[i] = byte(e.term[j]) + i++ + } + + return result +} + +// numTerms returns the number of +func (e gfPoly) numTerms() int { + return len(e.term) +} + +// gfPolyMultiply returns a * b. +func gfPolyMultiply(a, b gfPoly) gfPoly { + numATerms := a.numTerms() + numBTerms := b.numTerms() + + result := gfPoly{term: make([]gfElement, numATerms+numBTerms)} + + for i := 0; i < numATerms; i++ { + for j := 0; j < numBTerms; j++ { + if a.term[i] != 0 && b.term[j] != 0 { + monomial := gfPoly{term: make([]gfElement, i+j+1)} + monomial.term[i+j] = gfMultiply(a.term[i], b.term[j]) + + result = gfPolyAdd(result, monomial) + } + } + } + + return result.normalised() +} + +// gfPolyRemainder return the remainder of numerator / denominator. +func gfPolyRemainder(numerator, denominator gfPoly) gfPoly { + if denominator.equals(gfPoly{}) { + log.Panicln("Remainder by zero") + } + + remainder := numerator + + for remainder.numTerms() >= denominator.numTerms() { + degree := remainder.numTerms() - denominator.numTerms() + coefficient := gfDivide(remainder.term[remainder.numTerms()-1], + denominator.term[denominator.numTerms()-1]) + + divisor := gfPolyMultiply(denominator, + newGFPolyMonomial(coefficient, degree)) + + remainder = gfPolyAdd(remainder, divisor) + } + + return remainder.normalised() +} + +// gfPolyAdd returns a + b. +func gfPolyAdd(a, b gfPoly) gfPoly { + numATerms := a.numTerms() + numBTerms := b.numTerms() + + numTerms := numATerms + if numBTerms > numTerms { + numTerms = numBTerms + } + + result := gfPoly{term: make([]gfElement, numTerms)} + + for i := 0; i < numTerms; i++ { + switch { + case numATerms > i && numBTerms > i: + result.term[i] = gfAdd(a.term[i], b.term[i]) + case numATerms > i: + result.term[i] = a.term[i] + default: + result.term[i] = b.term[i] + } + } + + return result.normalised() +} + +func (e gfPoly) normalised() gfPoly { + numTerms := e.numTerms() + maxNonzeroTerm := numTerms - 1 + + for i := numTerms - 1; i >= 0; i-- { + if e.term[i] != 0 { + break + } + + maxNonzeroTerm = i - 1 + } + + if maxNonzeroTerm < 0 { + return gfPoly{} + } else if maxNonzeroTerm < numTerms-1 { + e.term = e.term[0 : maxNonzeroTerm+1] + } + + return e +} + +func (e gfPoly) string(useIndexForm bool) string { + var str string + numTerms := e.numTerms() + + for i := numTerms - 1; i >= 0; i-- { + if e.term[i] > 0 { + if len(str) > 0 { + str += " + " + } + + if !useIndexForm { + str += fmt.Sprintf("%dx^%d", e.term[i], i) + } else { + str += fmt.Sprintf("a^%dx^%d", gfLogTable[e.term[i]], i) + } + } + } + + if len(str) == 0 { + str = "0" + } + + return str +} + +// equals returns true if e == other. +func (e gfPoly) equals(other gfPoly) bool { + var minecPoly *gfPoly + var maxecPoly *gfPoly + + if e.numTerms() > other.numTerms() { + minecPoly = &other + maxecPoly = &e + } else { + minecPoly = &e + maxecPoly = &other + } + + numMinTerms := minecPoly.numTerms() + numMaxTerms := maxecPoly.numTerms() + + for i := 0; i < numMinTerms; i++ { + if e.term[i] != other.term[i] { + return false + } + } + + for i := numMinTerms; i < numMaxTerms; i++ { + if maxecPoly.term[i] != 0 { + return false + } + } + + return true +} diff --git a/vendor/github.com/skip2/go-qrcode/reedsolomon/reed_solomon.go b/vendor/github.com/skip2/go-qrcode/reedsolomon/reed_solomon.go new file mode 100644 index 00000000..561697b4 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/reedsolomon/reed_solomon.go @@ -0,0 +1,73 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +// Package reedsolomon provides error correction encoding for QR Code 2005. +// +// QR Code 2005 uses a Reed-Solomon error correcting code to detect and correct +// errors encountered during decoding. +// +// The generated RS codes are systematic, and consist of the input data with +// error correction bytes appended. +package reedsolomon + +import ( + "log" + + bitset "github.com/skip2/go-qrcode/bitset" +) + +// Encode data for QR Code 2005 using the appropriate Reed-Solomon code. +// +// numECBytes is the number of error correction bytes to append, and is +// determined by the target QR Code's version and error correction level. +// +// ISO/IEC 18004 table 9 specifies the numECBytes required. e.g. a 1-L code has +// numECBytes=7. +func Encode(data *bitset.Bitset, numECBytes int) *bitset.Bitset { + // Create a polynomial representing |data|. + // + // The bytes are interpreted as the sequence of coefficients of a polynomial. + // The last byte's value becomes the x^0 coefficient, the second to last + // becomes the x^1 coefficient and so on. + ecpoly := newGFPolyFromData(data) + ecpoly = gfPolyMultiply(ecpoly, newGFPolyMonomial(gfOne, numECBytes)) + + // Pick the generator polynomial. + generator := rsGeneratorPoly(numECBytes) + + // Generate the error correction bytes. + remainder := gfPolyRemainder(ecpoly, generator) + + // Combine the data & error correcting bytes. + // The mathematically correct answer is: + // + // result := gfPolyAdd(ecpoly, remainder). + // + // The encoding used by QR Code 2005 is slightly different this result: To + // preserve the original |data| bit sequence exactly, the data and remainder + // are combined manually below. This ensures any most significant zero bits + // are preserved (and not optimised away). + result := bitset.Clone(data) + result.AppendBytes(remainder.data(numECBytes)) + + return result +} + +// rsGeneratorPoly returns the Reed-Solomon generator polynomial with |degree|. +// +// The generator polynomial is calculated as: +// (x + a^0)(x + a^1)...(x + a^degree-1) +func rsGeneratorPoly(degree int) gfPoly { + if degree < 2 { + log.Panic("degree < 2") + } + + generator := gfPoly{term: []gfElement{1}} + + for i := 0; i < degree; i++ { + nextPoly := gfPoly{term: []gfElement{gfExpTable[i], 1}} + generator = gfPolyMultiply(generator, nextPoly) + } + + return generator +} diff --git a/vendor/github.com/skip2/go-qrcode/regular_symbol.go b/vendor/github.com/skip2/go-qrcode/regular_symbol.go new file mode 100644 index 00000000..134be18e --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/regular_symbol.go @@ -0,0 +1,309 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package qrcode + +import ( + bitset "github.com/skip2/go-qrcode/bitset" +) + +type regularSymbol struct { + version qrCodeVersion + mask int + + data *bitset.Bitset + + symbol *symbol + size int +} + +// Abbreviated true/false. +const ( + b0 = false + b1 = true +) + +var ( + alignmentPatternCenter = [][]int{ + {}, // Version 0 doesn't exist. + {}, // Version 1 doesn't use alignment patterns. + {6, 18}, + {6, 22}, + {6, 26}, + {6, 30}, + {6, 34}, + {6, 22, 38}, + {6, 24, 42}, + {6, 26, 46}, + {6, 28, 50}, + {6, 30, 54}, + {6, 32, 58}, + {6, 34, 62}, + {6, 26, 46, 66}, + {6, 26, 48, 70}, + {6, 26, 50, 74}, + {6, 30, 54, 78}, + {6, 30, 56, 82}, + {6, 30, 58, 86}, + {6, 34, 62, 90}, + {6, 28, 50, 72, 94}, + {6, 26, 50, 74, 98}, + {6, 30, 54, 78, 102}, + {6, 28, 54, 80, 106}, + {6, 32, 58, 84, 110}, + {6, 30, 58, 86, 114}, + {6, 34, 62, 90, 118}, + {6, 26, 50, 74, 98, 122}, + {6, 30, 54, 78, 102, 126}, + {6, 26, 52, 78, 104, 130}, + {6, 30, 56, 82, 108, 134}, + {6, 34, 60, 86, 112, 138}, + {6, 30, 58, 86, 114, 142}, + {6, 34, 62, 90, 118, 146}, + {6, 30, 54, 78, 102, 126, 150}, + {6, 24, 50, 76, 102, 128, 154}, + {6, 28, 54, 80, 106, 132, 158}, + {6, 32, 58, 84, 110, 136, 162}, + {6, 26, 54, 82, 110, 138, 166}, + {6, 30, 58, 86, 114, 142, 170}, + } + + finderPattern = [][]bool{ + {b1, b1, b1, b1, b1, b1, b1}, + {b1, b0, b0, b0, b0, b0, b1}, + {b1, b0, b1, b1, b1, b0, b1}, + {b1, b0, b1, b1, b1, b0, b1}, + {b1, b0, b1, b1, b1, b0, b1}, + {b1, b0, b0, b0, b0, b0, b1}, + {b1, b1, b1, b1, b1, b1, b1}, + } + + finderPatternSize = 7 + + finderPatternHorizontalBorder = [][]bool{ + {b0, b0, b0, b0, b0, b0, b0, b0}, + } + + finderPatternVerticalBorder = [][]bool{ + {b0}, + {b0}, + {b0}, + {b0}, + {b0}, + {b0}, + {b0}, + {b0}, + } + + alignmentPattern = [][]bool{ + {b1, b1, b1, b1, b1}, + {b1, b0, b0, b0, b1}, + {b1, b0, b1, b0, b1}, + {b1, b0, b0, b0, b1}, + {b1, b1, b1, b1, b1}, + } +) + +func buildRegularSymbol(version qrCodeVersion, mask int, + data *bitset.Bitset) (*symbol, error) { + m := ®ularSymbol{ + version: version, + mask: mask, + data: data, + + symbol: newSymbol(version.symbolSize(), version.quietZoneSize()), + size: version.symbolSize(), + } + + m.addFinderPatterns() + m.addAlignmentPatterns() + m.addTimingPatterns() + m.addFormatInfo() + m.addVersionInfo() + + ok, err := m.addData() + if !ok { + return nil, err + } + + return m.symbol, nil +} + +func (m *regularSymbol) addFinderPatterns() { + fpSize := finderPatternSize + fp := finderPattern + fpHBorder := finderPatternHorizontalBorder + fpVBorder := finderPatternVerticalBorder + + // Top left Finder Pattern. + m.symbol.set2dPattern(0, 0, fp) + m.symbol.set2dPattern(0, fpSize, fpHBorder) + m.symbol.set2dPattern(fpSize, 0, fpVBorder) + + // Top right Finder Pattern. + m.symbol.set2dPattern(m.size-fpSize, 0, fp) + m.symbol.set2dPattern(m.size-fpSize-1, fpSize, fpHBorder) + m.symbol.set2dPattern(m.size-fpSize-1, 0, fpVBorder) + + // Bottom left Finder Pattern. + m.symbol.set2dPattern(0, m.size-fpSize, fp) + m.symbol.set2dPattern(0, m.size-fpSize-1, fpHBorder) + m.symbol.set2dPattern(fpSize, m.size-fpSize-1, fpVBorder) +} + +func (m *regularSymbol) addAlignmentPatterns() { + for _, x := range alignmentPatternCenter[m.version.version] { + for _, y := range alignmentPatternCenter[m.version.version] { + if !m.symbol.empty(x, y) { + continue + } + + m.symbol.set2dPattern(x-2, y-2, alignmentPattern) + } + } +} + +func (m *regularSymbol) addTimingPatterns() { + value := true + + for i := finderPatternSize + 1; i < m.size-finderPatternSize; i++ { + m.symbol.set(i, finderPatternSize-1, value) + m.symbol.set(finderPatternSize-1, i, value) + + value = !value + } +} + +func (m *regularSymbol) addFormatInfo() { + fpSize := finderPatternSize + l := formatInfoLengthBits - 1 + + f := m.version.formatInfo(m.mask) + + // Bits 0-7, under the top right finder pattern. + for i := 0; i <= 7; i++ { + m.symbol.set(m.size-i-1, fpSize+1, f.At(l-i)) + } + + // Bits 0-5, right of the top left finder pattern. + for i := 0; i <= 5; i++ { + m.symbol.set(fpSize+1, i, f.At(l-i)) + } + + // Bits 6-8 on the corner of the top left finder pattern. + m.symbol.set(fpSize+1, fpSize, f.At(l-6)) + m.symbol.set(fpSize+1, fpSize+1, f.At(l-7)) + m.symbol.set(fpSize, fpSize+1, f.At(l-8)) + + // Bits 9-14 on the underside of the top left finder pattern. + for i := 9; i <= 14; i++ { + m.symbol.set(14-i, fpSize+1, f.At(l-i)) + } + + // Bits 8-14 on the right side of the bottom left finder pattern. + for i := 8; i <= 14; i++ { + m.symbol.set(fpSize+1, m.size-fpSize+i-8, f.At(l-i)) + } + + // Always dark symbol. + m.symbol.set(fpSize+1, m.size-fpSize-1, true) +} + +func (m *regularSymbol) addVersionInfo() { + fpSize := finderPatternSize + + v := m.version.versionInfo() + l := versionInfoLengthBits - 1 + + if v == nil { + return + } + + for i := 0; i < v.Len(); i++ { + // Above the bottom left finder pattern. + m.symbol.set(i/3, m.size-fpSize-4+i%3, v.At(l-i)) + + // Left of the top right finder pattern. + m.symbol.set(m.size-fpSize-4+i%3, i/3, v.At(l-i)) + } +} + +type direction uint8 + +const ( + up direction = iota + down +) + +func (m *regularSymbol) addData() (bool, error) { + xOffset := 1 + dir := up + + x := m.size - 2 + y := m.size - 1 + + for i := 0; i < m.data.Len(); i++ { + var mask bool + switch m.mask { + case 0: + mask = (y+x+xOffset)%2 == 0 + case 1: + mask = y%2 == 0 + case 2: + mask = (x+xOffset)%3 == 0 + case 3: + mask = (y+x+xOffset)%3 == 0 + case 4: + mask = (y/2+(x+xOffset)/3)%2 == 0 + case 5: + mask = (y*(x+xOffset))%2+(y*(x+xOffset))%3 == 0 + case 6: + mask = ((y*(x+xOffset))%2+((y*(x+xOffset))%3))%2 == 0 + case 7: + mask = ((y+x+xOffset)%2+((y*(x+xOffset))%3))%2 == 0 + } + + // != is equivalent to XOR. + m.symbol.set(x+xOffset, y, mask != m.data.At(i)) + + if i == m.data.Len()-1 { + break + } + + // Find next free bit in the symbol. + for { + if xOffset == 1 { + xOffset = 0 + } else { + xOffset = 1 + + if dir == up { + if y > 0 { + y-- + } else { + dir = down + x -= 2 + } + } else { + if y < m.size-1 { + y++ + } else { + dir = up + x -= 2 + } + } + } + + // Skip over the vertical timing pattern entirely. + if x == 5 { + x-- + } + + if m.symbol.empty(x+xOffset, y) { + break + } + } + } + + return true, nil +} diff --git a/vendor/github.com/skip2/go-qrcode/symbol.go b/vendor/github.com/skip2/go-qrcode/symbol.go new file mode 100644 index 00000000..0cb1327c --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/symbol.go @@ -0,0 +1,309 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package qrcode + +// symbol is a 2D array of bits representing a QR Code symbol. +// +// A symbol consists of size*size modules, with each module normally drawn as a +// black or white square. The symbol also has a border of quietZoneSize modules. +// +// A (fictional) size=2, quietZoneSize=1 QR Code looks like: +// +// +----+ +// | | +// | ab | +// | cd | +// | | +// +----+ +// +// For ease of implementation, the functions to set/get bits ignore the border, +// so (0,0)=a, (0,1)=b, (1,0)=c, and (1,1)=d. The entire symbol (including the +// border) is returned by bitmap(). +// +type symbol struct { + // Value of module at [y][x]. True is set. + module [][]bool + + // True if the module at [y][x] is used (to either true or false). + // Used to identify unused modules. + isUsed [][]bool + + // Combined width/height of the symbol and quiet zones. + // + // size = symbolSize + 2*quietZoneSize. + size int + + // Width/height of the symbol only. + symbolSize int + + // Width/height of a single quiet zone. + quietZoneSize int +} + +// newSymbol constructs a symbol of size size*size, with a border of +// quietZoneSize. +func newSymbol(size int, quietZoneSize int) *symbol { + var m symbol + + m.module = make([][]bool, size+2*quietZoneSize) + m.isUsed = make([][]bool, size+2*quietZoneSize) + + for i := range m.module { + m.module[i] = make([]bool, size+2*quietZoneSize) + m.isUsed[i] = make([]bool, size+2*quietZoneSize) + } + + m.size = size + 2*quietZoneSize + m.symbolSize = size + m.quietZoneSize = quietZoneSize + + return &m +} + +// get returns the module value at (x, y). +func (m *symbol) get(x int, y int) (v bool) { + v = m.module[y+m.quietZoneSize][x+m.quietZoneSize] + return +} + +// empty returns true if the module at (x, y) has not been set (to either true +// or false). +func (m *symbol) empty(x int, y int) bool { + return !m.isUsed[y+m.quietZoneSize][x+m.quietZoneSize] +} + +// numEmptyModules returns the number of empty modules. +// +// Initially numEmptyModules is symbolSize * symbolSize. After every module has +// been set (to either true or false), the number of empty modules is zero. +func (m *symbol) numEmptyModules() int { + var count int + for y := 0; y < m.symbolSize; y++ { + for x := 0; x < m.symbolSize; x++ { + if !m.isUsed[y+m.quietZoneSize][x+m.quietZoneSize] { + count++ + } + } + } + + return count +} + +// set sets the module at (x, y) to v. +func (m *symbol) set(x int, y int, v bool) { + m.module[y+m.quietZoneSize][x+m.quietZoneSize] = v + m.isUsed[y+m.quietZoneSize][x+m.quietZoneSize] = true +} + +// set2dPattern sets a 2D array of modules, starting at (x, y). +func (m *symbol) set2dPattern(x int, y int, v [][]bool) { + for j, row := range v { + for i, value := range row { + m.set(x+i, y+j, value) + } + } +} + +// bitmap returns the entire symbol, including the quiet zone. +func (m *symbol) bitmap() [][]bool { + module := make([][]bool, len(m.module)) + + for i := range m.module { + module[i] = m.module[i][:] + } + + return module +} + +// string returns a pictorial representation of the symbol, suitable for +// printing in a TTY. +func (m *symbol) string() string { + var result string + + for _, row := range m.module { + for _, value := range row { + switch value { + case true: + result += " " + case false: + // Unicode 'FULL BLOCK' (U+2588). + result += "██" + } + } + result += "\n" + } + + return result +} + +// Constants used to weight penalty calculations. Specified by ISO/IEC +// 18004:2006. +const ( + penaltyWeight1 = 3 + penaltyWeight2 = 3 + penaltyWeight3 = 40 + penaltyWeight4 = 10 +) + +// penaltyScore returns the penalty score of the symbol. The penalty score +// consists of the sum of the four individual penalty types. +func (m *symbol) penaltyScore() int { + return m.penalty1() + m.penalty2() + m.penalty3() + m.penalty4() +} + +// penalty1 returns the penalty score for "adjacent modules in row/column with +// same colour". +// +// The numbers of adjacent matching modules and scores are: +// 0-5: score = 0 +// 6+ : score = penaltyWeight1 + (numAdjacentModules - 5) +func (m *symbol) penalty1() int { + penalty := 0 + + for x := 0; x < m.symbolSize; x++ { + lastValue := m.get(x, 0) + count := 1 + + for y := 1; y < m.symbolSize; y++ { + v := m.get(x, y) + + if v != lastValue { + count = 1 + lastValue = v + } else { + count++ + if count == 6 { + penalty += penaltyWeight1 + 1 + } else if count > 6 { + penalty++ + } + } + } + } + + for y := 0; y < m.symbolSize; y++ { + lastValue := m.get(0, y) + count := 1 + + for x := 1; x < m.symbolSize; x++ { + v := m.get(x, y) + + if v != lastValue { + count = 1 + lastValue = v + } else { + count++ + if count == 6 { + penalty += penaltyWeight1 + 1 + } else if count > 6 { + penalty++ + } + } + } + } + + return penalty +} + +// penalty2 returns the penalty score for "block of modules in the same colour". +// +// m*n: score = penaltyWeight2 * (m-1) * (n-1). +func (m *symbol) penalty2() int { + penalty := 0 + + for y := 1; y < m.symbolSize; y++ { + for x := 1; x < m.symbolSize; x++ { + topLeft := m.get(x-1, y-1) + above := m.get(x, y-1) + left := m.get(x-1, y) + current := m.get(x, y) + + if current == left && current == above && current == topLeft { + penalty++ + } + } + } + + return penalty * penaltyWeight2 +} + +// penalty3 returns the penalty score for "1:1:3:1:1 ratio +// (dark:light:dark:light:dark) pattern in row/column, preceded or followed by +// light area 4 modules wide". +// +// Existence of the pattern scores penaltyWeight3. +func (m *symbol) penalty3() int { + penalty := 0 + + for y := 0; y < m.symbolSize; y++ { + var bitBuffer int16 = 0x00 + + for x := 0; x < m.symbolSize; x++ { + bitBuffer <<= 1 + if v := m.get(x, y); v { + bitBuffer |= 1 + } + + switch bitBuffer & 0x7ff { + // 0b000 0101 1101 or 0b10111010000 + // 0x05d or 0x5d0 + case 0x05d, 0x5d0: + penalty += penaltyWeight3 + bitBuffer = 0xFF + default: + if x == m.symbolSize-1 && (bitBuffer&0x7f) == 0x5d { + penalty += penaltyWeight3 + bitBuffer = 0xFF + } + } + } + } + + for x := 0; x < m.symbolSize; x++ { + var bitBuffer int16 = 0x00 + + for y := 0; y < m.symbolSize; y++ { + bitBuffer <<= 1 + if v := m.get(x, y); v { + bitBuffer |= 1 + } + + switch bitBuffer & 0x7ff { + // 0b000 0101 1101 or 0b10111010000 + // 0x05d or 0x5d0 + case 0x05d, 0x5d0: + penalty += penaltyWeight3 + bitBuffer = 0xFF + default: + if y == m.symbolSize-1 && (bitBuffer&0x7f) == 0x5d { + penalty += penaltyWeight3 + bitBuffer = 0xFF + } + } + } + } + + return penalty +} + +// penalty4 returns the penalty score... +func (m *symbol) penalty4() int { + numModules := m.symbolSize * m.symbolSize + numDarkModules := 0 + + for x := 0; x < m.symbolSize; x++ { + for y := 0; y < m.symbolSize; y++ { + if v := m.get(x, y); v { + numDarkModules++ + } + } + } + + numDarkModuleDeviation := numModules/2 - numDarkModules + if numDarkModuleDeviation < 0 { + numDarkModuleDeviation *= -1 + } + + return penaltyWeight4 * (numDarkModuleDeviation / (numModules / 20)) +} diff --git a/vendor/github.com/skip2/go-qrcode/version.go b/vendor/github.com/skip2/go-qrcode/version.go new file mode 100644 index 00000000..738cf3d3 --- /dev/null +++ b/vendor/github.com/skip2/go-qrcode/version.go @@ -0,0 +1,3050 @@ +// go-qrcode +// Copyright 2014 Tom Harwood + +package qrcode + +import ( + "log" + + bitset "github.com/skip2/go-qrcode/bitset" +) + +// Error detection/recovery capacity. +// +// There are several levels of error detection/recovery capacity. Higher levels +// of error recovery are able to correct more errors, with the trade-off of +// increased symbol size. +type RecoveryLevel int + +const ( + // Level L: 7% error recovery. + Low RecoveryLevel = iota + + // Level M: 15% error recovery. Good default choice. + Medium + + // Level Q: 25% error recovery. + High + + // Level H: 30% error recovery. + Highest +) + +// qrCodeVersion describes the data length and encoding order of a single QR +// Code version. There are 40 versions numbers x 4 recovery levels == 160 +// possible qrCodeVersion structures. +type qrCodeVersion struct { + // Version number (1-40 inclusive). + version int + + // Error recovery level. + level RecoveryLevel + + dataEncoderType dataEncoderType + + // Encoded data can be split into multiple blocks. Each block contains data + // and error recovery bytes. + // + // Larger QR Codes contain more blocks. + block []block + + // Number of bits required to pad the combined data & error correction bit + // stream up to the symbol's full capacity. + numRemainderBits int +} + +type block struct { + numBlocks int + + // Total codewords (numCodewords == numErrorCodewords+numDataCodewords). + numCodewords int + + // Number of data codewords. + numDataCodewords int +} + +var ( + versions = []qrCodeVersion{ + { + 1, + Low, + dataEncoderType1To9, + []block{ + { + 1, + 26, + 19, + }, + }, + 0, + }, + { + 1, + Medium, + dataEncoderType1To9, + []block{ + { + 1, + 26, + 16, + }, + }, + 0, + }, + { + 1, + High, + dataEncoderType1To9, + []block{ + { + 1, + 26, + 13, + }, + }, + 0, + }, + { + 1, + Highest, + dataEncoderType1To9, + []block{ + { + 1, + 26, + 9, + }, + }, + 0, + }, + { + 2, + Low, + dataEncoderType1To9, + []block{ + { + 1, + 44, + 34, + }, + }, + 7, + }, + { + 2, + Medium, + dataEncoderType1To9, + []block{ + { + 1, + 44, + 28, + }, + }, + 7, + }, + { + 2, + High, + dataEncoderType1To9, + []block{ + { + 1, + 44, + 22, + }, + }, + 7, + }, + { + 2, + Highest, + dataEncoderType1To9, + []block{ + { + 1, + 44, + 16, + }, + }, + 7, + }, + { + 3, + Low, + dataEncoderType1To9, + []block{ + { + 1, + 70, + 55, + }, + }, + 7, + }, + { + 3, + Medium, + dataEncoderType1To9, + []block{ + { + 1, + 70, + 44, + }, + }, + 7, + }, + { + 3, + High, + dataEncoderType1To9, + []block{ + { + 2, + 35, + 17, + }, + }, + 7, + }, + { + 3, + Highest, + dataEncoderType1To9, + []block{ + { + 2, + 35, + 13, + }, + }, + 7, + }, + { + 4, + Low, + dataEncoderType1To9, + []block{ + { + 1, + 100, + 80, + }, + }, + 7, + }, + { + 4, + Medium, + dataEncoderType1To9, + []block{ + { + 2, + 50, + 32, + }, + }, + 7, + }, + { + 4, + High, + dataEncoderType1To9, + []block{ + { + 2, + 50, + 24, + }, + }, + 7, + }, + { + 4, + Highest, + dataEncoderType1To9, + []block{ + { + 4, + 25, + 9, + }, + }, + 7, + }, + { + 5, + Low, + dataEncoderType1To9, + []block{ + { + 1, + 134, + 108, + }, + }, + 7, + }, + { + 5, + Medium, + dataEncoderType1To9, + []block{ + { + 2, + 67, + 43, + }, + }, + 7, + }, + { + 5, + High, + dataEncoderType1To9, + []block{ + { + 2, + 33, + 15, + }, + { + 2, + 34, + 16, + }, + }, + 7, + }, + { + 5, + Highest, + dataEncoderType1To9, + []block{ + { + 2, + 33, + 11, + }, + { + 2, + 34, + 12, + }, + }, + 7, + }, + { + 6, + Low, + dataEncoderType1To9, + []block{ + { + 2, + 86, + 68, + }, + }, + 7, + }, + { + 6, + Medium, + dataEncoderType1To9, + []block{ + { + 4, + 43, + 27, + }, + }, + 7, + }, + { + 6, + High, + dataEncoderType1To9, + []block{ + { + 4, + 43, + 19, + }, + }, + 7, + }, + { + 6, + Highest, + dataEncoderType1To9, + []block{ + { + 4, + 43, + 15, + }, + }, + 7, + }, + { + 7, + Low, + dataEncoderType1To9, + []block{ + { + 2, + 98, + 78, + }, + }, + 0, + }, + { + 7, + Medium, + dataEncoderType1To9, + []block{ + { + 4, + 49, + 31, + }, + }, + 0, + }, + { + 7, + High, + dataEncoderType1To9, + []block{ + { + 2, + 32, + 14, + }, + { + 4, + 33, + 15, + }, + }, + 0, + }, + { + 7, + Highest, + dataEncoderType1To9, + []block{ + { + 4, + 39, + 13, + }, + { + 1, + 40, + 14, + }, + }, + 0, + }, + { + 8, + Low, + dataEncoderType1To9, + []block{ + { + 2, + 121, + 97, + }, + }, + 0, + }, + { + 8, + Medium, + dataEncoderType1To9, + []block{ + { + 2, + 60, + 38, + }, + { + 2, + 61, + 39, + }, + }, + 0, + }, + { + 8, + High, + dataEncoderType1To9, + []block{ + { + 4, + 40, + 18, + }, + { + 2, + 41, + 19, + }, + }, + 0, + }, + { + 8, + Highest, + dataEncoderType1To9, + []block{ + { + 4, + 40, + 14, + }, + { + 2, + 41, + 15, + }, + }, + 0, + }, + { + 9, + Low, + dataEncoderType1To9, + []block{ + { + 2, + 146, + 116, + }, + }, + 0, + }, + { + 9, + Medium, + dataEncoderType1To9, + []block{ + { + 3, + 58, + 36, + }, + { + 2, + 59, + 37, + }, + }, + 0, + }, + { + 9, + High, + dataEncoderType1To9, + []block{ + { + 4, + 36, + 16, + }, + { + 4, + 37, + 17, + }, + }, + 0, + }, + { + 9, + Highest, + dataEncoderType1To9, + []block{ + { + 4, + 36, + 12, + }, + { + 4, + 37, + 13, + }, + }, + 0, + }, + { + 10, + Low, + dataEncoderType10To26, + []block{ + { + 2, + 86, + 68, + }, + { + 2, + 87, + 69, + }, + }, + 0, + }, + { + 10, + Medium, + dataEncoderType10To26, + []block{ + { + 4, + 69, + 43, + }, + { + 1, + 70, + 44, + }, + }, + 0, + }, + { + 10, + High, + dataEncoderType10To26, + []block{ + { + 6, + 43, + 19, + }, + { + 2, + 44, + 20, + }, + }, + 0, + }, + { + 10, + Highest, + dataEncoderType10To26, + []block{ + { + 6, + 43, + 15, + }, + { + 2, + 44, + 16, + }, + }, + 0, + }, + { + 11, + Low, + dataEncoderType10To26, + []block{ + { + 4, + 101, + 81, + }, + }, + 0, + }, + { + 11, + Medium, + dataEncoderType10To26, + []block{ + { + 1, + 80, + 50, + }, + { + 4, + 81, + 51, + }, + }, + 0, + }, + { + 11, + High, + dataEncoderType10To26, + []block{ + { + 4, + 50, + 22, + }, + { + 4, + 51, + 23, + }, + }, + 0, + }, + { + 11, + Highest, + dataEncoderType10To26, + []block{ + { + 3, + 36, + 12, + }, + { + 8, + 37, + 13, + }, + }, + 0, + }, + { + 12, + Low, + dataEncoderType10To26, + []block{ + { + 2, + 116, + 92, + }, + { + 2, + 117, + 93, + }, + }, + 0, + }, + { + 12, + Medium, + dataEncoderType10To26, + []block{ + { + 6, + 58, + 36, + }, + { + 2, + 59, + 37, + }, + }, + 0, + }, + { + 12, + High, + dataEncoderType10To26, + []block{ + { + 4, + 46, + 20, + }, + { + 6, + 47, + 21, + }, + }, + 0, + }, + { + 12, + Highest, + dataEncoderType10To26, + []block{ + { + 7, + 42, + 14, + }, + { + 4, + 43, + 15, + }, + }, + 0, + }, + { + 13, + Low, + dataEncoderType10To26, + []block{ + { + 4, + 133, + 107, + }, + }, + 0, + }, + { + 13, + Medium, + dataEncoderType10To26, + []block{ + { + 8, + 59, + 37, + }, + { + 1, + 60, + 38, + }, + }, + 0, + }, + { + 13, + High, + dataEncoderType10To26, + []block{ + { + 8, + 44, + 20, + }, + { + 4, + 45, + 21, + }, + }, + 0, + }, + { + 13, + Highest, + dataEncoderType10To26, + []block{ + { + 12, + 33, + 11, + }, + { + 4, + 34, + 12, + }, + }, + 0, + }, + { + 14, + Low, + dataEncoderType10To26, + []block{ + { + 3, + 145, + 115, + }, + { + 1, + 146, + 116, + }, + }, + 3, + }, + { + 14, + Medium, + dataEncoderType10To26, + []block{ + { + 4, + 64, + 40, + }, + { + 5, + 65, + 41, + }, + }, + 3, + }, + { + 14, + High, + dataEncoderType10To26, + []block{ + { + 11, + 36, + 16, + }, + { + 5, + 37, + 17, + }, + }, + 3, + }, + { + 14, + Highest, + dataEncoderType10To26, + []block{ + { + 11, + 36, + 12, + }, + { + 5, + 37, + 13, + }, + }, + 3, + }, + { + 15, + Low, + dataEncoderType10To26, + []block{ + { + 5, + 109, + 87, + }, + { + 1, + 110, + 88, + }, + }, + 3, + }, + { + 15, + Medium, + dataEncoderType10To26, + []block{ + { + 5, + 65, + 41, + }, + { + 5, + 66, + 42, + }, + }, + 3, + }, + { + 15, + High, + dataEncoderType10To26, + []block{ + { + 5, + 54, + 24, + }, + { + 7, + 55, + 25, + }, + }, + 3, + }, + { + 15, + Highest, + dataEncoderType10To26, + []block{ + { + 11, + 36, + 12, + }, + { + 7, + 37, + 13, + }, + }, + 3, + }, + { + 16, + Low, + dataEncoderType10To26, + []block{ + { + 5, + 122, + 98, + }, + { + 1, + 123, + 99, + }, + }, + 3, + }, + { + 16, + Medium, + dataEncoderType10To26, + []block{ + { + 7, + 73, + 45, + }, + { + 3, + 74, + 46, + }, + }, + 3, + }, + { + 16, + High, + dataEncoderType10To26, + []block{ + { + 15, + 43, + 19, + }, + { + 2, + 44, + 20, + }, + }, + 3, + }, + { + 16, + Highest, + dataEncoderType10To26, + []block{ + { + 3, + 45, + 15, + }, + { + 13, + 46, + 16, + }, + }, + 3, + }, + { + 17, + Low, + dataEncoderType10To26, + []block{ + { + 1, + 135, + 107, + }, + { + 5, + 136, + 108, + }, + }, + 3, + }, + { + 17, + Medium, + dataEncoderType10To26, + []block{ + { + 10, + 74, + 46, + }, + { + 1, + 75, + 47, + }, + }, + 3, + }, + { + 17, + High, + dataEncoderType10To26, + []block{ + { + 1, + 50, + 22, + }, + { + 15, + 51, + 23, + }, + }, + 3, + }, + { + 17, + Highest, + dataEncoderType10To26, + []block{ + { + 2, + 42, + 14, + }, + { + 17, + 43, + 15, + }, + }, + 3, + }, + { + 18, + Low, + dataEncoderType10To26, + []block{ + { + 5, + 150, + 120, + }, + { + 1, + 151, + 121, + }, + }, + 3, + }, + { + 18, + Medium, + dataEncoderType10To26, + []block{ + { + 9, + 69, + 43, + }, + { + 4, + 70, + 44, + }, + }, + 3, + }, + { + 18, + High, + dataEncoderType10To26, + []block{ + { + 17, + 50, + 22, + }, + { + 1, + 51, + 23, + }, + }, + 3, + }, + { + 18, + Highest, + dataEncoderType10To26, + []block{ + { + 2, + 42, + 14, + }, + { + 19, + 43, + 15, + }, + }, + 3, + }, + { + 19, + Low, + dataEncoderType10To26, + []block{ + { + 3, + 141, + 113, + }, + { + 4, + 142, + 114, + }, + }, + 3, + }, + { + 19, + Medium, + dataEncoderType10To26, + []block{ + { + 3, + 70, + 44, + }, + { + 11, + 71, + 45, + }, + }, + 3, + }, + { + 19, + High, + dataEncoderType10To26, + []block{ + { + 17, + 47, + 21, + }, + { + 4, + 48, + 22, + }, + }, + 3, + }, + { + 19, + Highest, + dataEncoderType10To26, + []block{ + { + 9, + 39, + 13, + }, + { + 16, + 40, + 14, + }, + }, + 3, + }, + { + 20, + Low, + dataEncoderType10To26, + []block{ + { + 3, + 135, + 107, + }, + { + 5, + 136, + 108, + }, + }, + 3, + }, + { + 20, + Medium, + dataEncoderType10To26, + []block{ + { + 3, + 67, + 41, + }, + { + 13, + 68, + 42, + }, + }, + 3, + }, + { + 20, + High, + dataEncoderType10To26, + []block{ + { + 15, + 54, + 24, + }, + { + 5, + 55, + 25, + }, + }, + 3, + }, + { + 20, + Highest, + dataEncoderType10To26, + []block{ + { + 15, + 43, + 15, + }, + { + 10, + 44, + 16, + }, + }, + 3, + }, + { + 21, + Low, + dataEncoderType10To26, + []block{ + { + 4, + 144, + 116, + }, + { + 4, + 145, + 117, + }, + }, + 4, + }, + { + 21, + Medium, + dataEncoderType10To26, + []block{ + { + 17, + 68, + 42, + }, + }, + 4, + }, + { + 21, + High, + dataEncoderType10To26, + []block{ + { + 17, + 50, + 22, + }, + { + 6, + 51, + 23, + }, + }, + 4, + }, + { + 21, + Highest, + dataEncoderType10To26, + []block{ + { + 19, + 46, + 16, + }, + { + 6, + 47, + 17, + }, + }, + 4, + }, + { + 22, + Low, + dataEncoderType10To26, + []block{ + { + 2, + 139, + 111, + }, + { + 7, + 140, + 112, + }, + }, + 4, + }, + { + 22, + Medium, + dataEncoderType10To26, + []block{ + { + 17, + 74, + 46, + }, + }, + 4, + }, + { + 22, + High, + dataEncoderType10To26, + []block{ + { + 7, + 54, + 24, + }, + { + 16, + 55, + 25, + }, + }, + 4, + }, + { + 22, + Highest, + dataEncoderType10To26, + []block{ + { + 34, + 37, + 13, + }, + }, + 4, + }, + { + 23, + Low, + dataEncoderType10To26, + []block{ + { + 4, + 151, + 121, + }, + { + 5, + 152, + 122, + }, + }, + 4, + }, + { + 23, + Medium, + dataEncoderType10To26, + []block{ + { + 4, + 75, + 47, + }, + { + 14, + 76, + 48, + }, + }, + 4, + }, + { + 23, + High, + dataEncoderType10To26, + []block{ + { + 11, + 54, + 24, + }, + { + 14, + 55, + 25, + }, + }, + 4, + }, + { + 23, + Highest, + dataEncoderType10To26, + []block{ + { + 16, + 45, + 15, + }, + { + 14, + 46, + 16, + }, + }, + 4, + }, + { + 24, + Low, + dataEncoderType10To26, + []block{ + { + 6, + 147, + 117, + }, + { + 4, + 148, + 118, + }, + }, + 4, + }, + { + 24, + Medium, + dataEncoderType10To26, + []block{ + { + 6, + 73, + 45, + }, + { + 14, + 74, + 46, + }, + }, + 4, + }, + { + 24, + High, + dataEncoderType10To26, + []block{ + { + 11, + 54, + 24, + }, + { + 16, + 55, + 25, + }, + }, + 4, + }, + { + 24, + Highest, + dataEncoderType10To26, + []block{ + { + 30, + 46, + 16, + }, + { + 2, + 47, + 17, + }, + }, + 4, + }, + { + 25, + Low, + dataEncoderType10To26, + []block{ + { + 8, + 132, + 106, + }, + { + 4, + 133, + 107, + }, + }, + 4, + }, + { + 25, + Medium, + dataEncoderType10To26, + []block{ + { + 8, + 75, + 47, + }, + { + 13, + 76, + 48, + }, + }, + 4, + }, + { + 25, + High, + dataEncoderType10To26, + []block{ + { + 7, + 54, + 24, + }, + { + 22, + 55, + 25, + }, + }, + 4, + }, + { + 25, + Highest, + dataEncoderType10To26, + []block{ + { + 22, + 45, + 15, + }, + { + 13, + 46, + 16, + }, + }, + 4, + }, + { + 26, + Low, + dataEncoderType10To26, + []block{ + { + 10, + 142, + 114, + }, + { + 2, + 143, + 115, + }, + }, + 4, + }, + { + 26, + Medium, + dataEncoderType10To26, + []block{ + { + 19, + 74, + 46, + }, + { + 4, + 75, + 47, + }, + }, + 4, + }, + { + 26, + High, + dataEncoderType10To26, + []block{ + { + 28, + 50, + 22, + }, + { + 6, + 51, + 23, + }, + }, + 4, + }, + { + 26, + Highest, + dataEncoderType10To26, + []block{ + { + 33, + 46, + 16, + }, + { + 4, + 47, + 17, + }, + }, + 4, + }, + { + 27, + Low, + dataEncoderType27To40, + []block{ + { + 8, + 152, + 122, + }, + { + 4, + 153, + 123, + }, + }, + 4, + }, + { + 27, + Medium, + dataEncoderType27To40, + []block{ + { + 22, + 73, + 45, + }, + { + 3, + 74, + 46, + }, + }, + 4, + }, + { + 27, + High, + dataEncoderType27To40, + []block{ + { + 8, + 53, + 23, + }, + { + 26, + 54, + 24, + }, + }, + 4, + }, + { + 27, + Highest, + dataEncoderType27To40, + []block{ + { + 12, + 45, + 15, + }, + { + 28, + 46, + 16, + }, + }, + 4, + }, + { + 28, + Low, + dataEncoderType27To40, + []block{ + { + 3, + 147, + 117, + }, + { + 10, + 148, + 118, + }, + }, + 3, + }, + { + 28, + Medium, + dataEncoderType27To40, + []block{ + { + 3, + 73, + 45, + }, + { + 23, + 74, + 46, + }, + }, + 3, + }, + { + 28, + High, + dataEncoderType27To40, + []block{ + { + 4, + 54, + 24, + }, + { + 31, + 55, + 25, + }, + }, + 3, + }, + { + 28, + Highest, + dataEncoderType27To40, + []block{ + { + 11, + 45, + 15, + }, + { + 31, + 46, + 16, + }, + }, + 3, + }, + { + 29, + Low, + dataEncoderType27To40, + []block{ + { + 7, + 146, + 116, + }, + { + 7, + 147, + 117, + }, + }, + 3, + }, + { + 29, + Medium, + dataEncoderType27To40, + []block{ + { + 21, + 73, + 45, + }, + { + 7, + 74, + 46, + }, + }, + 3, + }, + { + 29, + High, + dataEncoderType27To40, + []block{ + { + 1, + 53, + 23, + }, + { + 37, + 54, + 24, + }, + }, + 3, + }, + { + 29, + Highest, + dataEncoderType27To40, + []block{ + { + 19, + 45, + 15, + }, + { + 26, + 46, + 16, + }, + }, + 3, + }, + { + 30, + Low, + dataEncoderType27To40, + []block{ + { + 5, + 145, + 115, + }, + { + 10, + 146, + 116, + }, + }, + 3, + }, + { + 30, + Medium, + dataEncoderType27To40, + []block{ + { + 19, + 75, + 47, + }, + { + 10, + 76, + 48, + }, + }, + 3, + }, + { + 30, + High, + dataEncoderType27To40, + []block{ + { + 15, + 54, + 24, + }, + { + 25, + 55, + 25, + }, + }, + 3, + }, + { + 30, + Highest, + dataEncoderType27To40, + []block{ + { + 23, + 45, + 15, + }, + { + 25, + 46, + 16, + }, + }, + 3, + }, + { + 31, + Low, + dataEncoderType27To40, + []block{ + { + 13, + 145, + 115, + }, + { + 3, + 146, + 116, + }, + }, + 3, + }, + { + 31, + Medium, + dataEncoderType27To40, + []block{ + { + 2, + 74, + 46, + }, + { + 29, + 75, + 47, + }, + }, + 3, + }, + { + 31, + High, + dataEncoderType27To40, + []block{ + { + 42, + 54, + 24, + }, + { + 1, + 55, + 25, + }, + }, + 3, + }, + { + 31, + Highest, + dataEncoderType27To40, + []block{ + { + 23, + 45, + 15, + }, + { + 28, + 46, + 16, + }, + }, + 3, + }, + { + 32, + Low, + dataEncoderType27To40, + []block{ + { + 17, + 145, + 115, + }, + }, + 3, + }, + { + 32, + Medium, + dataEncoderType27To40, + []block{ + { + 10, + 74, + 46, + }, + { + 23, + 75, + 47, + }, + }, + 3, + }, + { + 32, + High, + dataEncoderType27To40, + []block{ + { + 10, + 54, + 24, + }, + { + 35, + 55, + 25, + }, + }, + 3, + }, + { + 32, + Highest, + dataEncoderType27To40, + []block{ + { + 19, + 45, + 15, + }, + { + 35, + 46, + 16, + }, + }, + 3, + }, + { + 33, + Low, + dataEncoderType27To40, + []block{ + { + 17, + 145, + 115, + }, + { + 1, + 146, + 116, + }, + }, + 3, + }, + { + 33, + Medium, + dataEncoderType27To40, + []block{ + { + 14, + 74, + 46, + }, + { + 21, + 75, + 47, + }, + }, + 3, + }, + { + 33, + High, + dataEncoderType27To40, + []block{ + { + 29, + 54, + 24, + }, + { + 19, + 55, + 25, + }, + }, + 3, + }, + { + 33, + Highest, + dataEncoderType27To40, + []block{ + { + 11, + 45, + 15, + }, + { + 46, + 46, + 16, + }, + }, + 3, + }, + { + 34, + Low, + dataEncoderType27To40, + []block{ + { + 13, + 145, + 115, + }, + { + 6, + 146, + 116, + }, + }, + 3, + }, + { + 34, + Medium, + dataEncoderType27To40, + []block{ + { + 14, + 74, + 46, + }, + { + 23, + 75, + 47, + }, + }, + 3, + }, + { + 34, + High, + dataEncoderType27To40, + []block{ + { + 44, + 54, + 24, + }, + { + 7, + 55, + 25, + }, + }, + 3, + }, + { + 34, + Highest, + dataEncoderType27To40, + []block{ + { + 59, + 46, + 16, + }, + { + 1, + 47, + 17, + }, + }, + 3, + }, + { + 35, + Low, + dataEncoderType27To40, + []block{ + { + 12, + 151, + 121, + }, + { + 7, + 152, + 122, + }, + }, + 0, + }, + { + 35, + Medium, + dataEncoderType27To40, + []block{ + { + 12, + 75, + 47, + }, + { + 26, + 76, + 48, + }, + }, + 0, + }, + { + 35, + High, + dataEncoderType27To40, + []block{ + { + 39, + 54, + 24, + }, + { + 14, + 55, + 25, + }, + }, + 0, + }, + { + 35, + Highest, + dataEncoderType27To40, + []block{ + { + 22, + 45, + 15, + }, + { + 41, + 46, + 16, + }, + }, + 0, + }, + { + 36, + Low, + dataEncoderType27To40, + []block{ + { + 6, + 151, + 121, + }, + { + 14, + 152, + 122, + }, + }, + 0, + }, + { + 36, + Medium, + dataEncoderType27To40, + []block{ + { + 6, + 75, + 47, + }, + { + 34, + 76, + 48, + }, + }, + 0, + }, + { + 36, + High, + dataEncoderType27To40, + []block{ + { + 46, + 54, + 24, + }, + { + 10, + 55, + 25, + }, + }, + 0, + }, + { + 36, + Highest, + dataEncoderType27To40, + []block{ + { + 2, + 45, + 15, + }, + { + 64, + 46, + 16, + }, + }, + 0, + }, + { + 37, + Low, + dataEncoderType27To40, + []block{ + { + 17, + 152, + 122, + }, + { + 4, + 153, + 123, + }, + }, + 0, + }, + { + 37, + Medium, + dataEncoderType27To40, + []block{ + { + 29, + 74, + 46, + }, + { + 14, + 75, + 47, + }, + }, + 0, + }, + { + 37, + High, + dataEncoderType27To40, + []block{ + { + 49, + 54, + 24, + }, + { + 10, + 55, + 25, + }, + }, + 0, + }, + { + 37, + Highest, + dataEncoderType27To40, + []block{ + { + 24, + 45, + 15, + }, + { + 46, + 46, + 16, + }, + }, + 0, + }, + { + 38, + Low, + dataEncoderType27To40, + []block{ + { + 4, + 152, + 122, + }, + { + 18, + 153, + 123, + }, + }, + 0, + }, + { + 38, + Medium, + dataEncoderType27To40, + []block{ + { + 13, + 74, + 46, + }, + { + 32, + 75, + 47, + }, + }, + 0, + }, + { + 38, + High, + dataEncoderType27To40, + []block{ + { + 48, + 54, + 24, + }, + { + 14, + 55, + 25, + }, + }, + 0, + }, + { + 38, + Highest, + dataEncoderType27To40, + []block{ + { + 42, + 45, + 15, + }, + { + 32, + 46, + 16, + }, + }, + 0, + }, + { + 39, + Low, + dataEncoderType27To40, + []block{ + { + 20, + 147, + 117, + }, + { + 4, + 148, + 118, + }, + }, + 0, + }, + { + 39, + Medium, + dataEncoderType27To40, + []block{ + { + 40, + 75, + 47, + }, + { + 7, + 76, + 48, + }, + }, + 0, + }, + { + 39, + High, + dataEncoderType27To40, + []block{ + { + 43, + 54, + 24, + }, + { + 22, + 55, + 25, + }, + }, + 0, + }, + { + 39, + Highest, + dataEncoderType27To40, + []block{ + { + 10, + 45, + 15, + }, + { + 67, + 46, + 16, + }, + }, + 0, + }, + { + 40, + Low, + dataEncoderType27To40, + []block{ + { + 19, + 148, + 118, + }, + { + 6, + 149, + 119, + }, + }, + 0, + }, + { + 40, + Medium, + dataEncoderType27To40, + []block{ + { + 18, + 75, + 47, + }, + { + 31, + 76, + 48, + }, + }, + 0, + }, + { + 40, + High, + dataEncoderType27To40, + []block{ + { + 34, + 54, + 24, + }, + { + 34, + 55, + 25, + }, + }, + 0, + }, + { + 40, + Highest, + dataEncoderType27To40, + []block{ + { + 20, + 45, + 15, + }, + { + 61, + 46, + 16, + }, + }, + 0, + }, + } +) + +var ( + // Each QR Code contains a 15-bit Format Information value. The 15 bits + // consist of 5 data bits concatenated with 10 error correction bits. + // + // The 5 data bits consist of: + // - 2 bits for the error correction level (L=01, M=00, G=11, H=10). + // - 3 bits for the data mask pattern identifier. + // + // formatBitSequence is a mapping from the 5 data bits to the completed 15-bit + // Format Information value. + // + // For example, a QR Code using error correction level L, and data mask + // pattern identifier 001: + // + // 01 | 001 = 01001 = 0x9 + // formatBitSequence[0x9].qrCode = 0x72f3 = 111001011110011 + formatBitSequence = []struct { + regular uint32 + micro uint32 + }{ + {0x5412, 0x4445}, + {0x5125, 0x4172}, + {0x5e7c, 0x4e2b}, + {0x5b4b, 0x4b1c}, + {0x45f9, 0x55ae}, + {0x40ce, 0x5099}, + {0x4f97, 0x5fc0}, + {0x4aa0, 0x5af7}, + {0x77c4, 0x6793}, + {0x72f3, 0x62a4}, + {0x7daa, 0x6dfd}, + {0x789d, 0x68ca}, + {0x662f, 0x7678}, + {0x6318, 0x734f}, + {0x6c41, 0x7c16}, + {0x6976, 0x7921}, + {0x1689, 0x06de}, + {0x13be, 0x03e9}, + {0x1ce7, 0x0cb0}, + {0x19d0, 0x0987}, + {0x0762, 0x1735}, + {0x0255, 0x1202}, + {0x0d0c, 0x1d5b}, + {0x083b, 0x186c}, + {0x355f, 0x2508}, + {0x3068, 0x203f}, + {0x3f31, 0x2f66}, + {0x3a06, 0x2a51}, + {0x24b4, 0x34e3}, + {0x2183, 0x31d4}, + {0x2eda, 0x3e8d}, + {0x2bed, 0x3bba}, + } + + // QR Codes version 7 and higher contain an 18-bit Version Information value, + // consisting of a 6 data bits and 12 error correction bits. + // + // versionBitSequence is a mapping from QR Code version to the completed + // 18-bit Version Information value. + // + // For example, a QR code of version 7: + // versionBitSequence[0x7] = 0x07c94 = 000111110010010100 + versionBitSequence = []uint32{ + 0x00000, + 0x00000, + 0x00000, + 0x00000, + 0x00000, + 0x00000, + 0x00000, + 0x07c94, + 0x085bc, + 0x09a99, + 0x0a4d3, + 0x0bbf6, + 0x0c762, + 0x0d847, + 0x0e60d, + 0x0f928, + 0x10b78, + 0x1145d, + 0x12a17, + 0x13532, + 0x149a6, + 0x15683, + 0x168c9, + 0x177ec, + 0x18ec4, + 0x191e1, + 0x1afab, + 0x1b08e, + 0x1cc1a, + 0x1d33f, + 0x1ed75, + 0x1f250, + 0x209d5, + 0x216f0, + 0x228ba, + 0x2379f, + 0x24b0b, + 0x2542e, + 0x26a64, + 0x27541, + 0x28c69, + } +) + +const ( + formatInfoLengthBits = 15 + versionInfoLengthBits = 18 +) + +// formatInfo returns the 15-bit Format Information value for a QR +// code. +func (v qrCodeVersion) formatInfo(maskPattern int) *bitset.Bitset { + formatID := 0 + + switch v.level { + case Low: + formatID = 0x08 // 0b01000 + case Medium: + formatID = 0x00 // 0b00000 + case High: + formatID = 0x18 // 0b11000 + case Highest: + formatID = 0x10 // 0b10000 + default: + log.Panicf("Invalid level %d", v.level) + } + + if maskPattern < 0 || maskPattern > 7 { + log.Panicf("Invalid maskPattern %d", maskPattern) + } + + formatID |= maskPattern & 0x7 + + result := bitset.New() + + result.AppendUint32(formatBitSequence[formatID].regular, formatInfoLengthBits) + + return result +} + +// versionInfo returns the 18-bit Version Information value for a QR Code. +// +// Version Information is applicable only to QR Codes versions 7-40 inclusive. +// nil is returned if Version Information is not required. +func (v qrCodeVersion) versionInfo() *bitset.Bitset { + if v.version < 7 { + return nil + } + + result := bitset.New() + result.AppendUint32(versionBitSequence[v.version], 18) + + return result +} + +// numDataBits returns the data capacity in bits. +func (v qrCodeVersion) numDataBits() int { + numDataBits := 0 + for _, b := range v.block { + numDataBits += 8 * b.numBlocks * b.numDataCodewords // 8 bits in a byte + } + + return numDataBits +} + +// chooseQRCodeVersion chooses the most suitable QR Code version for a stated +// data length in bits, the error recovery level required, and the data encoder +// used. +// +// The chosen QR Code version is the smallest version able to fit numDataBits +// and the optional terminator bits required by the specified encoder. +// +// On success the chosen QR Code version is returned. +func chooseQRCodeVersion(level RecoveryLevel, encoder *dataEncoder, numDataBits int) *qrCodeVersion { + var chosenVersion *qrCodeVersion + + for _, v := range versions { + if v.level != level { + continue + } else if v.version < encoder.minVersion { + continue + } else if v.version > encoder.maxVersion { + break + } + + numFreeBits := v.numDataBits() - numDataBits + + if numFreeBits >= 0 { + chosenVersion = &v + break + } + } + + return chosenVersion +} + +func (v qrCodeVersion) numTerminatorBitsRequired(numDataBits int) int { + numFreeBits := v.numDataBits() - numDataBits + + var numTerminatorBits int + + switch { + case numFreeBits >= 4: + numTerminatorBits = 4 + default: + numTerminatorBits = numFreeBits + } + + return numTerminatorBits +} + +// numBlocks returns the number of blocks. +func (v qrCodeVersion) numBlocks() int { + numBlocks := 0 + + for _, b := range v.block { + numBlocks += b.numBlocks + } + + return numBlocks +} + +// numBitsToPadToCodeword returns the number of bits required to pad data of +// length numDataBits upto the nearest codeword size. +func (v qrCodeVersion) numBitsToPadToCodeword(numDataBits int) int { + if numDataBits == v.numDataBits() { + return 0 + } + + return (8 - numDataBits%8) % 8 +} + +// symbolSize returns the size of the QR Code symbol in number of modules (which +// is both the width and height, since QR codes are square). The QR Code has +// size symbolSize() x symbolSize() pixels. This does not include the quiet +// zone. +func (v qrCodeVersion) symbolSize() int { + return 21 + (v.version-1)*4 +} + +// quietZoneSize returns the number of pixels of border space on each side of +// the QR Code. The quiet space assists with decoding. +func (v qrCodeVersion) quietZoneSize() int { + return 4 +} + +// getQRCodeVersion returns the QR Code version by version number and recovery +// level. Returns nil if the requested combination is not defined. +func getQRCodeVersion(level RecoveryLevel, version int) *qrCodeVersion { + for _, v := range versions { + if v.level == level && v.version == version { + return &v + } + } + + return nil +} |