/** * qr frame data generator * from https://github.com/neocotic/qr.js */ // Private constants // ----------------- // Alignment pattern. var ALIGNMENT_DELTA = [ 0, 11, 15, 19, 23, 27, 31, 16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 24, 26, 28, 28, 22, 24, 24, 26, 26, 28, 28, 24, 24, 26, 26, 26, 28, 28, 24, 26, 26, 26, 28, 28 ] // There are four elements per version. The first two indicate the number of blocks, then the // data width, and finally the ECC width. var ECC_BLOCKS = [ 1, 0, 19, 7, 1, 0, 16, 10, 1, 0, 13, 13, 1, 0, 9, 17, 1, 0, 34, 10, 1, 0, 28, 16, 1, 0, 22, 22, 1, 0, 16, 28, 1, 0, 55, 15, 1, 0, 44, 26, 2, 0, 17, 18, 2, 0, 13, 22, 1, 0, 80, 20, 2, 0, 32, 18, 2, 0, 24, 26, 4, 0, 9, 16, 1, 0, 108, 26, 2, 0, 43, 24, 2, 2, 15, 18, 2, 2, 11, 22, 2, 0, 68, 18, 4, 0, 27, 16, 4, 0, 19, 24, 4, 0, 15, 28, 2, 0, 78, 20, 4, 0, 31, 18, 2, 4, 14, 18, 4, 1, 13, 26, 2, 0, 97, 24, 2, 2, 38, 22, 4, 2, 18, 22, 4, 2, 14, 26, 2, 0, 116, 30, 3, 2, 36, 22, 4, 4, 16, 20, 4, 4, 12, 24, 2, 2, 68, 18, 4, 1, 43, 26, 6, 2, 19, 24, 6, 2, 15, 28, 4, 0, 81, 20, 1, 4, 50, 30, 4, 4, 22, 28, 3, 8, 12, 24, 2, 2, 92, 24, 6, 2, 36, 22, 4, 6, 20, 26, 7, 4, 14, 28, 4, 0, 107, 26, 8, 1, 37, 22, 8, 4, 20, 24, 12, 4, 11, 22, 3, 1, 115, 30, 4, 5, 40, 24, 11, 5, 16, 20, 11, 5, 12, 24, 5, 1, 87, 22, 5, 5, 41, 24, 5, 7, 24, 30, 11, 7, 12, 24, 5, 1, 98, 24, 7, 3, 45, 28, 15, 2, 19, 24, 3, 13, 15, 30, 1, 5, 107, 28, 10, 1, 46, 28, 1, 15, 22, 28, 2, 17, 14, 28, 5, 1, 120, 30, 9, 4, 43, 26, 17, 1, 22, 28, 2, 19, 14, 28, 3, 4, 113, 28, 3, 11, 44, 26, 17, 4, 21, 26, 9, 16, 13, 26, 3, 5, 107, 28, 3, 13, 41, 26, 15, 5, 24, 30, 15, 10, 15, 28, 4, 4, 116, 28, 17, 0, 42, 26, 17, 6, 22, 28, 19, 6, 16, 30, 2, 7, 111, 28, 17, 0, 46, 28, 7, 16, 24, 30, 34, 0, 13, 24, 4, 5, 121, 30, 4, 14, 47, 28, 11, 14, 24, 30, 16, 14, 15, 30, 6, 4, 117, 30, 6, 14, 45, 28, 11, 16, 24, 30, 30, 2, 16, 30, 8, 4, 106, 26, 8, 13, 47, 28, 7, 22, 24, 30, 22, 13, 15, 30, 10, 2, 114, 28, 19, 4, 46, 28, 28, 6, 22, 28, 33, 4, 16, 30, 8, 4, 122, 30, 22, 3, 45, 28, 8, 26, 23, 30, 12, 28, 15, 30, 3, 10, 117, 30, 3, 23, 45, 28, 4, 31, 24, 30, 11, 31, 15, 30, 7, 7, 116, 30, 21, 7, 45, 28, 1, 37, 23, 30, 19, 26, 15, 30, 5, 10, 115, 30, 19, 10, 47, 28, 15, 25, 24, 30, 23, 25, 15, 30, 13, 3, 115, 30, 2, 29, 46, 28, 42, 1, 24, 30, 23, 28, 15, 30, 17, 0, 115, 30, 10, 23, 46, 28, 10, 35, 24, 30, 19, 35, 15, 30, 17, 1, 115, 30, 14, 21, 46, 28, 29, 19, 24, 30, 11, 46, 15, 30, 13, 6, 115, 30, 14, 23, 46, 28, 44, 7, 24, 30, 59, 1, 16, 30, 12, 7, 121, 30, 12, 26, 47, 28, 39, 14, 24, 30, 22, 41, 15, 30, 6, 14, 121, 30, 6, 34, 47, 28, 46, 10, 24, 30, 2, 64, 15, 30, 17, 4, 122, 30, 29, 14, 46, 28, 49, 10, 24, 30, 24, 46, 15, 30, 4, 18, 122, 30, 13, 32, 46, 28, 48, 14, 24, 30, 42, 32, 15, 30, 20, 4, 117, 30, 40, 7, 47, 28, 43, 22, 24, 30, 10, 67, 15, 30, 19, 6, 118, 30, 18, 31, 47, 28, 34, 34, 24, 30, 20, 61, 15, 30 ] // Map of human-readable ECC levels. var ECC_LEVELS = { L: 1 , M: 2 , Q: 3 , H: 4 } // Final format bits with mask (level << 3 | mask). var FINAL_FORMAT = [ 0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976, /* L */ 0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0, /* M */ 0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed, /* Q */ 0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b /* H */ ] // Galois field exponent table. var GALOIS_EXPONENT = [ 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26, 0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0, 0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23, 0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1, 0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0, 0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2, 0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce, 0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc, 0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54, 0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73, 0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff, 0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41, 0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6, 0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09, 0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16, 0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x00 ] // Galois field log table. var GALOIS_LOG = [ 0xff, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b, 0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71, 0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45, 0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6, 0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88, 0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40, 0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d, 0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57, 0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18, 0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e, 0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61, 0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2, 0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6, 0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a, 0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7, 0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf ] // *Badness* coefficients. var N1 = 3 var N2 = 3 var N3 = 40 var N4 = 10 // Version pattern. var VERSION_BLOCK = [ 0xc94, 0x5bc, 0xa99, 0x4d3, 0xbf6, 0x762, 0x847, 0x60d, 0x928, 0xb78, 0x45d, 0xa17, 0x532, 0x9a6, 0x683, 0x8c9, 0x7ec, 0xec4, 0x1e1, 0xfab, 0x08e, 0xc1a, 0x33f, 0xd75, 0x250, 0x9d5, 0x6f0, 0x8ba, 0x79f, 0xb0b, 0x42e, 0xa64, 0x541, 0xc69 ] // Generate the encoded QR image for the string provided. export function generateFrame(_str, ecc) { var i, j, k, m, t, v, x, y, version , eccLevel = ECC_LEVELS[ecc || 'L'] || 1 , str = _str || '' , width // Run lengths for badness. var badBuffer = [] // Data block. var dataBlock // ECC data blocks and tables. var eccBlock, neccBlock1, neccBlock2 // ECC buffer. var eccBuffer = [] // Image buffer. var frameBuffer = [] // Fixed part of the image. var frameMask = [] // Generator polynomial. var polynomial = [] // Data input buffer. var stringBuffer = [] // functions // Set bit to indicate cell in frame is immutable (symmetric around diagonal). function setMask(_x, _y) { var bit , x = _x , y = _y if (x > y) { bit = x x = y y = bit } bit = y bit *= y bit += y bit >>= 1 bit += x frameMask[bit] = 1 } // Enter alignment pattern. Foreground colour to frame, background to mask. Frame will be merged // with mask later. function addAlignment(_x, _y) { var i , x = _x , y = _y frameBuffer[x + width * y] = 1 for (i = -2; i < 2; i++) { frameBuffer[(x + i) + width * (y - 2)] = 1 frameBuffer[(x - 2) + width * (y + i + 1)] = 1 frameBuffer[(x + 2) + width * (y + i)] = 1 frameBuffer[(x + i + 1) + width * (y + 2)] = 1 } for (i = 0; i < 2; i++) { setMask(x - 1, y + i) setMask(x + 1, y - i) setMask(x - i, y - 1) setMask(x + i, y + 1) } } // Exponentiation mod N. function modN(_x) { var x = _x while (x >= 255) { x -= 255 x = (x >> 8) + (x & 255) } return x } // Calculate and append `ecc` data to the `data` block. If block is in the string buffer the // indices to buffers are used. function appendData(_data, _dataLength, _ecc, _eccLength) { var bit, i, j , data = _data , dataLength = _dataLength , ecc = _ecc , eccLength = _eccLength for (i = 0; i < eccLength; i++) { stringBuffer[ecc + i] = 0 } for (i = 0; i < dataLength; i++) { bit = GALOIS_LOG[stringBuffer[data + i] ^ stringBuffer[ecc]] if (bit !== 255) { for (j = 1; j < eccLength; j++) { stringBuffer[ecc + j - 1] = stringBuffer[ecc + j] ^ GALOIS_EXPONENT[modN(bit + polynomial[eccLength - j])] } } else { for (j = ecc; j < ecc + eccLength; j++) { stringBuffer[j] = stringBuffer[j + 1] } } stringBuffer[ecc + eccLength - 1] = bit === 255 ? 0 : GALOIS_EXPONENT[modN(bit + polynomial[0])] } } // Check mask since symmetricals use half. function isMasked(_x, _y) { var bit , x = _x , y = _y if (x > y) { bit = x x = y y = bit } bit = y bit += y * y bit >>= 1 bit += x return frameMask[bit] === 1 } // Apply the selected mask out of the 8 options. function applyMask(_mask) { var x, y, r3x, r3y , mask = _mask if (mask === 0) for (y = 0; y < width; y++) { for (x = 0; x < width; x++) { if (!((x + y) & 1) && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 1) for (y = 0; y < width; y++) { for (x = 0; x < width; x++) { if (!(y & 1) && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 2) for (y = 0; y < width; y++) { for (r3x = 0, x = 0; x < width; x++, r3x++) { if (r3x === 3) r3x = 0 if (!r3x && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 3) for (r3y = 0, y = 0; y < width; y++, r3y++) { if (r3y === 3) r3y = 0 for (r3x = r3y, x = 0; x < width; x++, r3x++) { if (r3x === 3) r3x = 0 if (!r3x && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 4) for (y = 0; y < width; y++) { for (r3x = 0, r3y = ((y >> 1) & 1), x = 0; x < width; x++, r3x++) { if (r3x === 3) { r3x = 0 r3y = !r3y } if (!r3y && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 5) for (r3y = 0, y = 0; y < width; y++, r3y++) { if (r3y === 3) r3y = 0 for (r3x = 0, x = 0; x < width; x++, r3x++) { if (r3x === 3) r3x = 0 if (!((x & y & 1) + !(!r3x | !r3y)) && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 6) for (r3y = 0, y = 0; y < width; y++, r3y++) { if (r3y === 3) r3y = 0 for (r3x = 0, x = 0; x < width; x++, r3x++) { if (r3x === 3) r3x = 0 if (!(((x & y & 1) + (r3x && (r3x === r3y))) & 1) && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } if (mask === 7) for (r3y = 0, y = 0; y < width; y++, r3y++) { if (r3y === 3) r3y = 0 for (r3x = 0, x = 0; x < width; x++, r3x++) { if (r3x === 3) r3x = 0 if (!(((r3x && (r3x === r3y)) + ((x + y) & 1)) & 1) && !isMasked(x, y)) { frameBuffer[x + y * width] ^= 1 } } } } // Using the table for the length of each run, calculate the amount of bad image. Long runs or // those that look like finders are called twice once for X and Y. function getBadRuns(_length) { var badRuns = 0 var i var length = _length for (i = 0; i <= length; i++) { if (badBuffer[i] >= 5) { badRuns += N1 + badBuffer[i] - 5 } } // FBFFFBF as in finder. for (i = 3; i < length - 1; i += 2) { if (badBuffer[i - 2] === badBuffer[i + 2] && badBuffer[i + 2] === badBuffer[i - 1] && badBuffer[i - 1] === badBuffer[i + 1] && badBuffer[i - 1] * 3 === badBuffer[i] && // Background around the foreground pattern? Not part of the specs. (badBuffer[i - 3] === 0 || i + 3 > length || badBuffer[i - 3] * 3 >= badBuffer[i] * 4 || badBuffer[i + 3] * 3 >= badBuffer[i] * 4)) { badRuns += N3 } } return badRuns } // Calculate how bad the masked image is (e.g. blocks, imbalance, runs, or finders). function checkBadness() { var b, b1, bad, big, bw, count, h, x, y bad = bw = count = 0 // Blocks of same colour. for (y = 0; y < width - 1; y++) { for (x = 0; x < width - 1; x++) { // All foreground colour. if ((frameBuffer[x + width * y] && frameBuffer[(x + 1) + width * y] && frameBuffer[x + width * (y + 1)] && frameBuffer[(x + 1) + width * (y + 1)]) || // All background colour. !(frameBuffer[x + width * y] || frameBuffer[(x + 1) + width * y] || frameBuffer[x + width * (y + 1)] || frameBuffer[(x + 1) + width * (y + 1)])) { bad += N2 } } } // X runs. for (y = 0; y < width; y++) { badBuffer[0] = 0 for (h = b = x = 0; x < width; x++) { if ((b1 = frameBuffer[x + width * y]) === b) { badBuffer[h]++ } else { badBuffer[++h] = 1 } b = b1 bw += b ? 1 : -1 } bad += getBadRuns(h) } if (bw < 0) bw = -bw big = bw big += big << 2 big <<= 1 while (big > width * width) { big -= width * width count++ } bad += count * N4 // Y runs. for (x = 0; x < width; x++) { badBuffer[0] = 0 for (h = b = y = 0; y < width; y++) { if ((b1 = frameBuffer[x + width * y]) === b) { badBuffer[h]++ } else { badBuffer[++h] = 1 } b = b1 } bad += getBadRuns(h) } return bad } function toUtf8(str) { var out, i, len, c; out = ""; len = str.length; for (i = 0; i < len; i++) { c = str.charCodeAt(i); if ((c >= 0x0001) && (c <= 0x007F)) { out += str.charAt(i); } else if (c > 0x07FF) { out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F)); out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F)); out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F)); } else { out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F)); out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F)); } } return out; } //end functions // Find the smallest version that fits the string. str = toUtf8(str) t = str.length version = 0 do { version++ k = (eccLevel - 1) * 4 + (version - 1) * 16 neccBlock1 = ECC_BLOCKS[k++] neccBlock2 = ECC_BLOCKS[k++] dataBlock = ECC_BLOCKS[k++] eccBlock = ECC_BLOCKS[k] k = dataBlock * (neccBlock1 + neccBlock2) + neccBlock2 - 3 + (version <= 9) if (t <= k) break } while (version < 40) // FIXME: Ensure that it fits insted of being truncated. width = 17 + 4 * version // Allocate, clear and setup data structures. v = dataBlock + (dataBlock + eccBlock) * (neccBlock1 + neccBlock2) + neccBlock2 for (t = 0; t < v; t++) { eccBuffer[t] = 0 } stringBuffer = str.slice(0) for (t = 0; t < width * width; t++) { frameBuffer[t] = 0 } for (t = 0; t < (width * (width + 1) + 1) / 2; t++) { frameMask[t] = 0 } // Insert finders: Foreground colour to frame and background to mask. for (t = 0; t < 3; t++) { k = y = 0 if (t === 1) k = (width - 7) if (t === 2) y = (width - 7) frameBuffer[(y + 3) + width * (k + 3)] = 1 for (x = 0; x < 6; x++) { frameBuffer[(y + x) + width * k] = 1 frameBuffer[y + width * (k + x + 1)] = 1 frameBuffer[(y + 6) + width * (k + x)] = 1 frameBuffer[(y + x + 1) + width * (k + 6)] = 1 } for (x = 1; x < 5; x++) { setMask(y + x, k + 1) setMask(y + 1, k + x + 1) setMask(y + 5, k + x) setMask(y + x + 1, k + 5) } for (x = 2; x < 4; x++) { frameBuffer[(y + x) + width * (k + 2)] = 1 frameBuffer[(y + 2) + width * (k + x + 1)] = 1 frameBuffer[(y + 4) + width * (k + x)] = 1 frameBuffer[(y + x + 1) + width * (k + 4)] = 1 } } // Alignment blocks. if (version > 1) { t = ALIGNMENT_DELTA[version] y = width - 7 for (; ;) { x = width - 7 while (x > t - 3) { addAlignment(x, y) if (x < t) break x -= t } if (y <= t + 9) break y -= t addAlignment(6, y) addAlignment(y, 6) } } // Single foreground cell. frameBuffer[8 + width * (width - 8)] = 1 // Timing gap (mask only). for (y = 0; y < 7; y++) { setMask(7, y, width) setMask(width - 8, y) setMask(7, y + width - 7) } for (x = 0; x < 8; x++) { setMask(x, 7) setMask(x + width - 8, 7) setMask(x, width - 8) } // Reserve mask, format area. for (x = 0; x < 9; x++) { setMask(x, 8) } for (x = 0; x < 8; x++) { setMask(x + width - 8, 8) setMask(8, x) } for (y = 0; y < 7; y++) { setMask(8, y + width - 7) } // Timing row/column. for (x = 0; x < width - 14; x++) { if (x & 1) { setMask(8 + x, 6) setMask(6, 8 + x) } else { frameBuffer[(8 + x) + width * 6] = 1 frameBuffer[6 + width * (8 + x)] = 1 } } // Version block. if (version > 6) { t = VERSION_BLOCK[version - 7] k = 17 for (x = 0; x < 6; x++) { for (y = 0; y < 3; y++, k--) { if (1 & (k > 11 ? version >> (k - 12) : t >> k)) { frameBuffer[(5 - x) + width * (2 - y + width - 11)] = 1 frameBuffer[(2 - y + width - 11) + width * (5 - x)] = 1 } else { setMask(5 - x, 2 - y + width - 11) setMask(2 - y + width - 11, 5 - x) } } } } // Sync mask bits. Only set above for background cells, so now add the foreground. for (y = 0; y < width; y++) { for (x = 0; x <= y; x++) { if (frameBuffer[x + width * y]) { setMask(x, y) } } } // Convert string to bit stream. 8-bit data to QR-coded 8-bit data (numeric, alphanum, or kanji // not supported). v = stringBuffer.length // String to array. for (i = 0; i < v; i++) { eccBuffer[i] = stringBuffer.charCodeAt(i) } stringBuffer = eccBuffer.slice(0) // Calculate max string length. x = dataBlock * (neccBlock1 + neccBlock2) + neccBlock2 if (v >= x - 2) { v = x - 2 if (version > 9) v-- } // Shift and re-pack to insert length prefix. i = v if (version > 9) { stringBuffer[i + 2] = 0 stringBuffer[i + 3] = 0 while (i--) { t = stringBuffer[i] stringBuffer[i + 3] |= 255 & (t << 4) stringBuffer[i + 2] = t >> 4 } stringBuffer[2] |= 255 & (v << 4) stringBuffer[1] = v >> 4 stringBuffer[0] = 0x40 | (v >> 12) } else { stringBuffer[i + 1] = 0 stringBuffer[i + 2] = 0 while (i--) { t = stringBuffer[i] stringBuffer[i + 2] |= 255 & (t << 4) stringBuffer[i + 1] = t >> 4 } stringBuffer[1] |= 255 & (v << 4) stringBuffer[0] = 0x40 | (v >> 4) } // Fill to end with pad pattern. i = v + 3 - (version < 10) while (i < x) { stringBuffer[i++] = 0xec stringBuffer[i++] = 0x11 } // Calculate generator polynomial. polynomial[0] = 1 for (i = 0; i < eccBlock; i++) { polynomial[i + 1] = 1 for (j = i; j > 0; j--) { polynomial[j] = polynomial[j] ? polynomial[j - 1] ^ GALOIS_EXPONENT[modN(GALOIS_LOG[polynomial[j]] + i)] : polynomial[j - 1] } polynomial[0] = GALOIS_EXPONENT[modN(GALOIS_LOG[polynomial[0]] + i)] } // Use logs for generator polynomial to save calculation step. for (i = 0; i <= eccBlock; i++) { polynomial[i] = GALOIS_LOG[polynomial[i]] } // Append ECC to data buffer. k = x y = 0 for (i = 0; i < neccBlock1; i++) { appendData(y, dataBlock, k, eccBlock) y += dataBlock k += eccBlock } for (i = 0; i < neccBlock2; i++) { appendData(y, dataBlock + 1, k, eccBlock) y += dataBlock + 1 k += eccBlock } // Interleave blocks. y = 0 for (i = 0; i < dataBlock; i++) { for (j = 0; j < neccBlock1; j++) { eccBuffer[y++] = stringBuffer[i + j * dataBlock] } for (j = 0; j < neccBlock2; j++) { eccBuffer[y++] = stringBuffer[(neccBlock1 * dataBlock) + i + (j * (dataBlock + 1))] } } for (j = 0; j < neccBlock2; j++) { eccBuffer[y++] = stringBuffer[(neccBlock1 * dataBlock) + i + (j * (dataBlock + 1))] } for (i = 0; i < eccBlock; i++) { for (j = 0; j < neccBlock1 + neccBlock2; j++) { eccBuffer[y++] = stringBuffer[x + i + j * eccBlock] } } stringBuffer = eccBuffer // Pack bits into frame avoiding masked area. x = y = width - 1 k = v = 1 // inteleaved data and ECC codes. m = (dataBlock + eccBlock) * (neccBlock1 + neccBlock2) + neccBlock2 for (i = 0; i < m; i++) { t = stringBuffer[i] for (j = 0; j < 8; j++, t <<= 1) { if (0x80 & t) { frameBuffer[x + width * y] = 1 } // Find next fill position. do { if (v) { x-- } else { x++ if (k) { if (y !== 0) { y-- } else { x -= 2 k = !k if (x === 6) { x-- y = 9 } } } else { if (y !== width - 1) { y++ } else { x -= 2 k = !k if (x === 6) { x-- y -= 8 } } } } v = !v } while (isMasked(x, y)) } } // Save pre-mask copy of frame. stringBuffer = frameBuffer.slice(0) t = 0 y = 30000 // Using `for` instead of `while` since in original Arduino code if an early mask was *good // enough* it wouldn't try for a better one since they get more complex and take longer. for (k = 0; k < 8; k++) { // Returns foreground-background imbalance. applyMask(k) x = checkBadness() // Is current mask better than previous best? if (x < y) { y = x t = k } // Don't increment `i` to a void redoing mask. if (t === 7) break // Reset for next pass. frameBuffer = stringBuffer.slice(0) } // Redo best mask as none were *good enough* (i.e. last wasn't `t`). if (t !== k) { applyMask(t) } // Add in final mask/ECC level bytes. y = FINAL_FORMAT[t + ((eccLevel - 1) << 3)] // Low byte. for (k = 0; k < 8; k++, y >>= 1) { if (y & 1) { frameBuffer[(width - 1 - k) + width * 8] = 1 if (k < 6) { frameBuffer[8 + width * k] = 1 } else { frameBuffer[8 + width * (k + 1)] = 1 } } } // High byte. for (k = 0; k < 7; k++, y >>= 1) { if (y & 1) { frameBuffer[8 + width * (width - 7 + k)] = 1 if (k) { frameBuffer[(6 - k) + width * 8] = 1 } else { frameBuffer[7 + width * 8] = 1 } } } // Finally, return the image data. return { frameBuffer: frameBuffer , width: width } }