/** * The MIT License (MIT) * * This library is written and maintained by Richard Moore. * Major parts were derived from Project Nayuki's library. * * Copyright (c) 2017 Richard Moore (https://github.com/ricmoo/QRCode) * Copyright (c) 2017 Project Nayuki (https://www.nayuki.io/page/qr-code-generator-library) * * 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. */ /** * Special thanks to Nayuki (https://www.nayuki.io/) from which this library was * heavily inspired and compared against. * * See: https://github.com/nayuki/QR-Code-generator/tree/master/cpp */ #include "qrcode.h" #include #include #if LOCK_VERSION == 0 static const uint16_t NUM_ERROR_CORRECTION_CODEWORDS[4][40] = { // 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level { 10, 16, 26, 36, 48, 64, 72, 88, 110, 130, 150, 176, 198, 216, 240, 280, 308, 338, 364, 416, 442, 476, 504, 560, 588, 644, 700, 728, 784, 812, 868, 924, 980, 1036, 1064, 1120, 1204, 1260, 1316, 1372}, // Medium { 7, 10, 15, 20, 26, 36, 40, 48, 60, 72, 80, 96, 104, 120, 132, 144, 168, 180, 196, 224, 224, 252, 270, 300, 312, 336, 360, 390, 420, 450, 480, 510, 540, 570, 570, 600, 630, 660, 720, 750}, // Low { 17, 28, 44, 64, 88, 112, 130, 156, 192, 224, 264, 308, 352, 384, 432, 480, 532, 588, 650, 700, 750, 816, 900, 960, 1050, 1110, 1200, 1260, 1350, 1440, 1530, 1620, 1710, 1800, 1890, 1980, 2100, 2220, 2310, 2430}, // High { 13, 22, 36, 52, 72, 96, 108, 132, 160, 192, 224, 260, 288, 320, 360, 408, 448, 504, 546, 600, 644, 690, 750, 810, 870, 952, 1020, 1050, 1140, 1200, 1290, 1350, 1440, 1530, 1590, 1680, 1770, 1860, 1950, 2040}, // Quartile }; static const uint8_t NUM_ERROR_CORRECTION_BLOCKS[4][40] = { // Version: (note that index 0 is for padding, and is set to an illegal value) // 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level { 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 9, 9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49}, // Medium { 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25}, // Low { 1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81}, // High { 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68}, // Quartile }; static const uint16_t NUM_RAW_DATA_MODULES[40] = { // 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 208, 359, 567, 807, 1079, 1383, 1568, 1936, 2336, 2768, 3232, 3728, 4256, 4651, 5243, 5867, 6523, // 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 7211, 7931, 8683, 9252, 10068, 10916, 11796, 12708, 13652, 14628, 15371, 16411, 17483, 18587, // 32, 33, 34, 35, 36, 37, 38, 39, 40 19723, 20891, 22091, 23008, 24272, 25568, 26896, 28256, 29648 }; // @TODO: Put other LOCK_VERSIONS here #elif LOCK_VERSION == 3 static const int16_t NUM_ERROR_CORRECTION_CODEWORDS[4] = { 26, 15, 44, 36 }; static const int8_t NUM_ERROR_CORRECTION_BLOCKS[4] = { 1, 1, 2, 2 }; static const uint16_t NUM_RAW_DATA_MODULES = 567; #else #error Unsupported LOCK_VERSION (add it...) #endif static int max(int a, int b) { if (a > b) { return a; } return b; } /* static int abs(int value) { if (value < 0) { return -value; } return value; } */ static int8_t getAlphanumeric(char c) { if (c >= '0' && c <= '9') { return (c - '0'); } if (c >= 'A' && c <= 'Z') { return (c - 'A' + 10); } switch (c) { case ' ': return 36; case '$': return 37; case '%': return 38; case '*': return 39; case '+': return 40; case '-': return 41; case '.': return 42; case '/': return 43; case ':': return 44; } return -1; } static bool isAlphanumeric(const char *text, uint16_t length) { while (length != 0) { if (getAlphanumeric(text[--length]) == -1) { return false; } } return true; } static bool isNumeric(const char *text, uint16_t length) { while (length != 0) { char c = text[--length]; if (c < '0' || c > '9') { return false; } } return true; } // We store the following tightly packed (less 8) in modeInfo // <=9 <=26 <= 40 // NUMERIC ( 10, 12, 14); // ALPHANUMERIC ( 9, 11, 13); // BYTE ( 8, 16, 16); static char getModeBits(uint8_t version, uint8_t mode) { // Note: We use 15 instead of 16; since 15 doesn't exist and we cannot store 16 (8 + 8) in 3 bits // hex(int("".join(reversed([('00' + bin(x - 8)[2:])[-3:] for x in [10, 9, 8, 12, 11, 15, 14, 13, 15]])), 2)) unsigned int modeInfo = 0x7bbb80a; #if LOCK_VERSION == 0 || LOCK_VERSION > 9 if (version > 9) { modeInfo >>= 9; } #endif #if LOCK_VERSION == 0 || LOCK_VERSION > 26 if (version > 26) { modeInfo >>= 9; } #endif char result = 8 + ((modeInfo >> (3 * mode)) & 0x07); if (result == 15) { result = 16; } return result; } typedef struct BitBucket { uint32_t bitOffsetOrWidth; uint16_t capacityBytes; uint8_t *data; } BitBucket; /* void bb_dump(BitBucket *bitBuffer) { printf("Buffer: "); for (uint32_t i = 0; i < bitBuffer->capacityBytes; i++) { printf("%02x", bitBuffer->data[i]); if ((i % 4) == 3) { printf(" "); } } printf("\n"); } */ static uint16_t bb_getGridSizeBytes(uint8_t size) { return (((size * size) + 7) / 8); } static uint16_t bb_getBufferSizeBytes(uint32_t bits) { return ((bits + 7) / 8); } static void bb_initBuffer(BitBucket *bitBuffer, uint8_t *data, int32_t capacityBytes) { bitBuffer->bitOffsetOrWidth = 0; bitBuffer->capacityBytes = capacityBytes; bitBuffer->data = data; memset(data, 0, bitBuffer->capacityBytes); } static void bb_initGrid(BitBucket *bitGrid, uint8_t *data, uint8_t size) { bitGrid->bitOffsetOrWidth = size; bitGrid->capacityBytes = bb_getGridSizeBytes(size); bitGrid->data = data; memset(data, 0, bitGrid->capacityBytes); } static void bb_appendBits(BitBucket *bitBuffer, uint32_t val, uint8_t length) { uint32_t offset = bitBuffer->bitOffsetOrWidth; for (int8_t i = length - 1; i >= 0; i--, offset++) { bitBuffer->data[offset >> 3] |= ((val >> i) & 1) << (7 - (offset & 7)); } bitBuffer->bitOffsetOrWidth = offset; } /* void bb_setBits(BitBucket *bitBuffer, uint32_t val, int offset, uint8_t length) { for (int8_t i = length - 1; i >= 0; i--, offset++) { bitBuffer->data[offset >> 3] |= ((val >> i) & 1) << (7 - (offset & 7)); } } */ static void bb_setBit(BitBucket *bitGrid, uint8_t x, uint8_t y, bool on) { uint32_t offset = y * bitGrid->bitOffsetOrWidth + x; uint8_t mask = 1 << (7 - (offset & 0x07)); if (on) { bitGrid->data[offset >> 3] |= mask; } else { bitGrid->data[offset >> 3] &= ~mask; } } static void bb_invertBit(BitBucket *bitGrid, uint8_t x, uint8_t y, bool invert) { uint32_t offset = y * bitGrid->bitOffsetOrWidth + x; uint8_t mask = 1 << (7 - (offset & 0x07)); bool on = ((bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0); if (on ^ invert) { bitGrid->data[offset >> 3] |= mask; } else { bitGrid->data[offset >> 3] &= ~mask; } } static bool bb_getBit(BitBucket *bitGrid, uint8_t x, uint8_t y) { uint32_t offset = y * bitGrid->bitOffsetOrWidth + x; return (bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0; } // XORs the data modules in this QR Code with the given mask pattern. Due to XOR's mathematical // properties, calling applyMask(m) twice with the same value is equivalent to no change at all. // This means it is possible to apply a mask, undo it, and try another mask. Note that a final // well-formed QR Code symbol needs exactly one mask applied (not zero, not two, etc.). static void applyMask(BitBucket *modules, BitBucket *isFunction, uint8_t mask) { uint8_t size = modules->bitOffsetOrWidth; for (uint8_t y = 0; y < size; y++) { for (uint8_t x = 0; x < size; x++) { if (bb_getBit(isFunction, x, y)) { continue; } bool invert = 0; switch (mask) { case 0: invert = (x + y) % 2 == 0; break; case 1: invert = y % 2 == 0; break; case 2: invert = x % 3 == 0; break; case 3: invert = (x + y) % 3 == 0; break; case 4: invert = (x / 3 + y / 2) % 2 == 0; break; case 5: invert = x * y % 2 + x * y % 3 == 0; break; case 6: invert = (x * y % 2 + x * y % 3) % 2 == 0; break; case 7: invert = ((x + y) % 2 + x * y % 3) % 2 == 0; break; } bb_invertBit(modules, x, y, invert); } } } static void setFunctionModule(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y, bool on) { bb_setBit(modules, x, y, on); bb_setBit(isFunction, x, y, true); } // Draws a 9*9 finder pattern including the border separator, with the center module at (x, y). static void drawFinderPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) { uint8_t size = modules->bitOffsetOrWidth; for (int8_t i = -4; i <= 4; i++) { for (int8_t j = -4; j <= 4; j++) { uint8_t dist = max(abs(i), abs(j)); // Chebyshev/infinity norm int16_t xx = x + j, yy = y + i; if (0 <= xx && xx < size && 0 <= yy && yy < size) { setFunctionModule(modules, isFunction, xx, yy, dist != 2 && dist != 4); } } } } // Draws a 5*5 alignment pattern, with the center module at (x, y). static void drawAlignmentPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) { for (int8_t i = -2; i <= 2; i++) { for (int8_t j = -2; j <= 2; j++) { setFunctionModule(modules, isFunction, x + j, y + i, max(abs(i), abs(j)) != 1); } } } // Draws two copies of the format bits (with its own error correction code) // based on the given mask and this object's error correction level field. static void drawFormatBits(BitBucket *modules, BitBucket *isFunction, uint8_t ecc, uint8_t mask) { uint8_t size = modules->bitOffsetOrWidth; // Calculate error correction code and pack bits uint32_t data = ecc << 3 | mask; // errCorrLvl is uint2, mask is uint3 uint32_t rem = data; for (int i = 0; i < 10; i++) { rem = (rem << 1) ^ ((rem >> 9) * 0x537); } data = data << 10 | rem; data ^= 0x5412; // uint15 // Draw first copy for (uint8_t i = 0; i <= 5; i++) { setFunctionModule(modules, isFunction, 8, i, ((data >> i) & 1) != 0); } setFunctionModule(modules, isFunction, 8, 7, ((data >> 6) & 1) != 0); setFunctionModule(modules, isFunction, 8, 8, ((data >> 7) & 1) != 0); setFunctionModule(modules, isFunction, 7, 8, ((data >> 8) & 1) != 0); for (int8_t i = 9; i < 15; i++) { setFunctionModule(modules, isFunction, 14 - i, 8, ((data >> i) & 1) != 0); } // Draw second copy for (int8_t i = 0; i <= 7; i++) { setFunctionModule(modules, isFunction, size - 1 - i, 8, ((data >> i) & 1) != 0); } for (int8_t i = 8; i < 15; i++) { setFunctionModule(modules, isFunction, 8, size - 15 + i, ((data >> i) & 1) != 0); } setFunctionModule(modules, isFunction, 8, size - 8, true); } // Draws two copies of the version bits (with its own error correction code), // based on this object's version field (which only has an effect for 7 <= version <= 40). static void drawVersion(BitBucket *modules, BitBucket *isFunction, uint8_t version) { int8_t size = modules->bitOffsetOrWidth; #if LOCK_VERSION != 0 && LOCK_VERSION < 7 return; #else if (version < 7) { return; } // Calculate error correction code and pack bits uint32_t rem = version; // version is uint6, in the range [7, 40] for (uint8_t i = 0; i < 12; i++) { rem = (rem << 1) ^ ((rem >> 11) * 0x1F25); } uint32_t data = version << 12 | rem; // uint18 // Draw two copies for (uint8_t i = 0; i < 18; i++) { bool bit = ((data >> i) & 1) != 0; uint8_t a = size - 11 + i % 3, b = i / 3; setFunctionModule(modules, isFunction, a, b, bit); setFunctionModule(modules, isFunction, b, a, bit); } #endif } static void drawFunctionPatterns(BitBucket *modules, BitBucket *isFunction, uint8_t version, uint8_t ecc) { uint8_t size = modules->bitOffsetOrWidth; // Draw the horizontal and vertical timing patterns for (uint8_t i = 0; i < size; i++) { setFunctionModule(modules, isFunction, 6, i, i % 2 == 0); setFunctionModule(modules, isFunction, i, 6, i % 2 == 0); } // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules) drawFinderPattern(modules, isFunction, 3, 3); drawFinderPattern(modules, isFunction, size - 4, 3); drawFinderPattern(modules, isFunction, 3, size - 4); #if LOCK_VERSION == 0 || LOCK_VERSION > 1 if (version > 1) { // Draw the numerous alignment patterns uint8_t alignCount = version / 7 + 2; uint8_t step; if (version != 32) { step = (version * 4 + alignCount * 2 + 1) / (2 * alignCount - 2) * 2; // ceil((size - 13) / (2*numAlign - 2)) * 2 } else { // C-C-C-Combo breaker! step = 26; } uint8_t alignPositionIndex = alignCount - 1; uint8_t alignPosition[alignCount]; alignPosition[0] = 6; uint8_t size = version * 4 + 17; for (uint8_t i = 0, pos = size - 7; i < alignCount - 1; i++, pos -= step) { alignPosition[alignPositionIndex--] = pos; } for (uint8_t i = 0; i < alignCount; i++) { for (uint8_t j = 0; j < alignCount; j++) { if ((i == 0 && j == 0) || (i == 0 && j == alignCount - 1) || (i == alignCount - 1 && j == 0)) { continue; // Skip the three finder corners } else { drawAlignmentPattern(modules, isFunction, alignPosition[i], alignPosition[j]); } } } } #endif // Draw configuration data drawFormatBits(modules, isFunction, ecc, 0); // Dummy mask value; overwritten later in the constructor drawVersion(modules, isFunction, version); } // Draws the given sequence of 8-bit codewords (data and error correction) onto the entire // data area of this QR Code symbol. Function modules need to be marked off before this is called. static void drawCodewords(BitBucket *modules, BitBucket *isFunction, BitBucket *codewords) { uint32_t bitLength = codewords->bitOffsetOrWidth; uint8_t *data = codewords->data; uint8_t size = modules->bitOffsetOrWidth; // Bit index into the data uint32_t i = 0; // Do the funny zigzag scan for (int16_t right = size - 1; right >= 1; right -= 2) { // Index of right column in each column pair if (right == 6) { right = 5; } for (uint8_t vert = 0; vert < size; vert++) { // Vertical counter for (int j = 0; j < 2; j++) { uint8_t x = right - j; // Actual x coordinate bool upwards = ((right & 2) == 0) ^ (x < 6); uint8_t y = upwards ? size - 1 - vert : vert; // Actual y coordinate if (!bb_getBit(isFunction, x, y) && i < bitLength) { bb_setBit(modules, x, y, ((data[i >> 3] >> (7 - (i & 7))) & 1) != 0); i++; } // If there are any remainder bits (0 to 7), they are already // set to 0/false/white when the grid of modules was initialized } } } } #define PENALTY_N1 3 #define PENALTY_N2 3 #define PENALTY_N3 40 #define PENALTY_N4 10 // Calculates and returns the penalty score based on state of this QR Code's current modules. // This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score. // @TODO: This can be optimized by working with the bytes instead of bits. static uint32_t getPenaltyScore(BitBucket *modules) { uint32_t result = 0; uint8_t size = modules->bitOffsetOrWidth; // Adjacent modules in row having same color for (uint8_t y = 0; y < size; y++) { bool colorX = bb_getBit(modules, 0, y); for (uint8_t x = 1, runX = 1; x < size; x++) { bool cx = bb_getBit(modules, x, y); if (cx != colorX) { colorX = cx; runX = 1; } else { runX++; if (runX == 5) { result += PENALTY_N1; } else if (runX > 5) { result++; } } } } // Adjacent modules in column having same color for (uint8_t x = 0; x < size; x++) { bool colorY = bb_getBit(modules, x, 0); for (uint8_t y = 1, runY = 1; y < size; y++) { bool cy = bb_getBit(modules, x, y); if (cy != colorY) { colorY = cy; runY = 1; } else { runY++; if (runY == 5) { result += PENALTY_N1; } else if (runY > 5) { result++; } } } } uint16_t black = 0; for (uint8_t y = 0; y < size; y++) { uint16_t bitsRow = 0, bitsCol = 0; for (uint8_t x = 0; x < size; x++) { bool color = bb_getBit(modules, x, y); // 2*2 blocks of modules having same color if (x > 0 && y > 0) { bool colorUL = bb_getBit(modules, x - 1, y - 1); bool colorUR = bb_getBit(modules, x, y - 1); bool colorL = bb_getBit(modules, x - 1, y); if (color == colorUL && color == colorUR && color == colorL) { result += PENALTY_N2; } } // Finder-like pattern in rows and columns bitsRow = ((bitsRow << 1) & 0x7FF) | color; bitsCol = ((bitsCol << 1) & 0x7FF) | bb_getBit(modules, y, x); // Needs 11 bits accumulated if (x >= 10) { if (bitsRow == 0x05D || bitsRow == 0x5D0) { result += PENALTY_N3; } if (bitsCol == 0x05D || bitsCol == 0x5D0) { result += PENALTY_N3; } } // Balance of black and white modules if (color) { black++; } } } // Find smallest k such that (45-5k)% <= dark/total <= (55+5k)% uint16_t total = size * size; for (uint16_t k = 0; black * 20 < (9 - k) * total || black * 20 > (11 + k) * total; k++) { result += PENALTY_N4; } return result; } static uint8_t rs_multiply(uint8_t x, uint8_t y) { // Russian peasant multiplication // See: https://en.wikipedia.org/wiki/Ancient_Egyptian_multiplication uint16_t z = 0; for (int8_t i = 7; i >= 0; i--) { z = (z << 1) ^ ((z >> 7) * 0x11D); z ^= ((y >> i) & 1) * x; } return z; } static void rs_init(uint8_t degree, uint8_t *coeff) { memset(coeff, 0, degree); coeff[degree - 1] = 1; // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}), // drop the highest term, and store the rest of the coefficients in order of descending powers. // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D). uint16_t root = 1; for (uint8_t i = 0; i < degree; i++) { // Multiply the current product by (x - r^i) for (uint8_t j = 0; j < degree; j++) { coeff[j] = rs_multiply(coeff[j], root); if (j + 1 < degree) { coeff[j] ^= coeff[j + 1]; } } root = (root << 1) ^ ((root >> 7) * 0x11D); // Multiply by 0x02 mod GF(2^8/0x11D) } } static void rs_getRemainder(uint8_t degree, uint8_t *coeff, uint8_t *data, uint8_t length, uint8_t *result, uint8_t stride) { // Compute the remainder by performing polynomial division //for (uint8_t i = 0; i < degree; i++) { result[] = 0; } //memset(result, 0, degree); for (uint8_t i = 0; i < length; i++) { uint8_t factor = data[i] ^ result[0]; for (uint8_t j = 1; j < degree; j++) { result[(j - 1) * stride] = result[j * stride]; } result[(degree - 1) * stride] = 0; for (uint8_t j = 0; j < degree; j++) { result[j * stride] ^= rs_multiply(coeff[j], factor); } } } static int8_t encodeDataCodewords(BitBucket *dataCodewords, const uint8_t *text, uint16_t length, uint8_t version) { int8_t mode = MODE_BYTE; if (isNumeric((char*)text, length)) { mode = MODE_NUMERIC; bb_appendBits(dataCodewords, 1 << MODE_NUMERIC, 4); bb_appendBits(dataCodewords, length, getModeBits(version, MODE_NUMERIC)); uint16_t accumData = 0; uint8_t accumCount = 0; for (uint16_t i = 0; i < length; i++) { accumData = accumData * 10 + ((char)(text[i]) - '0'); accumCount++; if (accumCount == 3) { bb_appendBits(dataCodewords, accumData, 10); accumData = 0; accumCount = 0; } } // 1 or 2 digits remaining if (accumCount > 0) { bb_appendBits(dataCodewords, accumData, accumCount * 3 + 1); } } else if (isAlphanumeric((char*)text, length)) { mode = MODE_ALPHANUMERIC; bb_appendBits(dataCodewords, 1 << MODE_ALPHANUMERIC, 4); bb_appendBits(dataCodewords, length, getModeBits(version, MODE_ALPHANUMERIC)); uint16_t accumData = 0; uint8_t accumCount = 0; for (uint16_t i = 0; i < length; i++) { accumData = accumData * 45 + getAlphanumeric((char)(text[i])); accumCount++; if (accumCount == 2) { bb_appendBits(dataCodewords, accumData, 11); accumData = 0; accumCount = 0; } } // 1 character remaining if (accumCount > 0) { bb_appendBits(dataCodewords, accumData, 6); } } else { bb_appendBits(dataCodewords, 1 << MODE_BYTE, 4); bb_appendBits(dataCodewords, length, getModeBits(version, MODE_BYTE)); for (uint16_t i = 0; i < length; i++) { bb_appendBits(dataCodewords, (char)(text[i]), 8); } } //bb_setBits(dataCodewords, length, 4, getModeBits(version, mode)); return mode; } static void performErrorCorrection(uint8_t version, uint8_t ecc, BitBucket *data) { // See: http://www.thonky.com/qr-code-tutorial/structure-final-message #if LOCK_VERSION == 0 uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc][version - 1]; uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc][version - 1]; uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1]; #else uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc]; uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc]; uint16_t moduleCount = NUM_RAW_DATA_MODULES; #endif uint8_t blockEccLen = totalEcc / numBlocks; uint8_t numShortBlocks = numBlocks - moduleCount / 8 % numBlocks; uint8_t shortBlockLen = moduleCount / 8 / numBlocks; uint8_t shortDataBlockLen = shortBlockLen - blockEccLen; uint8_t result[data->capacityBytes]; memset(result, 0, sizeof(result)); uint8_t coeff[blockEccLen]; rs_init(blockEccLen, coeff); uint16_t offset = 0; uint8_t *dataBytes = data->data; // Interleave all short blocks for (uint8_t i = 0; i < shortDataBlockLen; i++) { uint16_t index = i; uint8_t stride = shortDataBlockLen; for (uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) { result[offset++] = dataBytes[index]; #if LOCK_VERSION == 0 || LOCK_VERSION >= 5 if (blockNum == numShortBlocks) { stride++; } #endif index += stride; } } // Version less than 5 only have short blocks #if LOCK_VERSION == 0 || LOCK_VERSION >= 5 { // Interleave long blocks uint16_t index = shortDataBlockLen * (numShortBlocks + 1); uint8_t stride = shortDataBlockLen; for (uint8_t blockNum = 0; blockNum < numBlocks - numShortBlocks; blockNum++) { result[offset++] = dataBytes[index]; if (blockNum == 0) { stride++; } index += stride; } } #endif // Add all ecc blocks, interleaved uint8_t blockSize = shortDataBlockLen; for (uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) { #if LOCK_VERSION == 0 || LOCK_VERSION >= 5 if (blockNum == numShortBlocks) { blockSize++; } #endif rs_getRemainder(blockEccLen, coeff, dataBytes, blockSize, &result[offset + blockNum], numBlocks); dataBytes += blockSize; } memcpy(data->data, result, data->capacityBytes); data->bitOffsetOrWidth = moduleCount; } // We store the Format bits tightly packed into a single byte (each of the 4 modes is 2 bits) // The format bits can be determined by ECC_FORMAT_BITS >> (2 * ecc) static const uint8_t ECC_FORMAT_BITS = (0x02 << 6) | (0x03 << 4) | (0x00 << 2) | (0x01 << 0); uint16_t qrcode_getBufferSize(uint8_t version) { return bb_getGridSizeBytes(4 * version + 17); } // @TODO: Return error if data is too big. int8_t qrcode_initBytes(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, uint8_t *data, uint16_t length) { uint8_t size = version * 4 + 17; qrcode->version = version; qrcode->size = size; qrcode->ecc = ecc; qrcode->modules = modules; uint8_t eccFormatBits = (ECC_FORMAT_BITS >> (2 * ecc)) & 0x03; #if LOCK_VERSION == 0 uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1]; uint16_t dataCapacity = moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits][version - 1]; #else version = LOCK_VERSION; uint16_t moduleCount = NUM_RAW_DATA_MODULES; uint16_t dataCapacity = moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits]; #endif struct BitBucket codewords; uint8_t codewordBytes[bb_getBufferSizeBytes(moduleCount)]; bb_initBuffer(&codewords, codewordBytes, (int32_t)sizeof(codewordBytes)); // Place the data code words into the buffer int8_t mode = encodeDataCodewords(&codewords, data, length, version); if (mode < 0) { return -1; } qrcode->mode = mode; // Add terminator and pad up to a byte if applicable uint32_t padding = (dataCapacity * 8) - codewords.bitOffsetOrWidth; if (padding > 4) { padding = 4; } bb_appendBits(&codewords, 0, padding); bb_appendBits(&codewords, 0, (8 - codewords.bitOffsetOrWidth % 8) % 8); // Pad with alternate bytes until data capacity is reached for (uint8_t padByte = 0xEC; codewords.bitOffsetOrWidth < (dataCapacity * 8); padByte ^= 0xEC ^ 0x11) { bb_appendBits(&codewords, padByte, 8); } BitBucket modulesGrid; bb_initGrid(&modulesGrid, modules, size); BitBucket isFunctionGrid; uint8_t isFunctionGridBytes[bb_getGridSizeBytes(size)]; bb_initGrid(&isFunctionGrid, isFunctionGridBytes, size); // Draw function patterns, draw all codewords, do masking drawFunctionPatterns(&modulesGrid, &isFunctionGrid, version, eccFormatBits); performErrorCorrection(version, eccFormatBits, &codewords); drawCodewords(&modulesGrid, &isFunctionGrid, &codewords); // Find the best (lowest penalty) mask uint8_t mask = 0; int32_t minPenalty = INT32_MAX; for (uint8_t i = 0; i < 8; i++) { drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, i); applyMask(&modulesGrid, &isFunctionGrid, i); int penalty = getPenaltyScore(&modulesGrid); if (penalty < minPenalty) { mask = i; minPenalty = penalty; } applyMask(&modulesGrid, &isFunctionGrid, i); // Undoes the mask due to XOR } qrcode->mask = mask; // Overwrite old format bits drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, mask); // Apply the final choice of mask applyMask(&modulesGrid, &isFunctionGrid, mask); return 0; } int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data) { return qrcode_initBytes(qrcode, modules, version, ecc, (uint8_t*)data, strlen(data)); } bool qrcode_getModule(QRCode *qrcode, uint8_t x, uint8_t y) { if (x >= qrcode->size || y >= qrcode->size) { return false; } uint32_t offset = y * qrcode->size + x; return (qrcode->modules[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0; } /* uint8_t qrcode_getHexLength(QRCode *qrcode) { return ((qrcode->size * qrcode->size) + 7) / 4; } void qrcode_getHex(QRCode *qrcode, char *result) { } */