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PersonalVotingMachine/extended-setup/components/qrcode/qrcode.c
valeh 26b0ba5954 first commit
2020-12-22 14:30:09 +02:00

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/**
* The MIT License (MIT)
*
* Copyright (c) 2017 Richard Moore
*
* 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 <stdlib.h>
#include <string.h>
//#pragma mark - Error Correction Lookup tables
#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;
}
*/
//#pragma mark - Mode testing and conversion
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;
}
//#pragma mark - Counting
// 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;
}
//#pragma mark - BitBucket
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;
}
//#pragma mark - Drawing Patterns
// 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
}
}
}
}
//#pragma mark - Penalty Calculation
#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;
}
//#pragma mark - Reed-Solomon Generator
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);
}
}
}
//#pragma mark - QrCode
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);
//#pragma mark - Public QRCode functions
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) {
}
*/
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