You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
846 lines
34 KiB
846 lines
34 KiB
/*
|
|
* QR Code generator library (C)
|
|
*
|
|
* Copyright (c) Project Nayuki. (MIT License)
|
|
* 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.
|
|
*/
|
|
|
|
#include <assert.h>
|
|
#include <limits.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "qrcodegen.h"
|
|
|
|
#ifdef QRCODEGEN_TEST
|
|
#define testable // Expose private functions
|
|
#else
|
|
#define testable static // Keep functions private
|
|
#endif
|
|
|
|
|
|
/*---- Forward declarations for private functions ----*/
|
|
|
|
// Regarding all public and private functions defined in this source file:
|
|
// - They require all pointer/array arguments to be not null.
|
|
// - They only read input scalar/array arguments, write to output pointer/array
|
|
// arguments, and return scalar values; they are "pure" functions.
|
|
// - They don't read mutable global variables or write to any global variables.
|
|
// - They don't perform I/O, read the clock, print to console, etc.
|
|
// - They allocate a small and constant amount of stack memory.
|
|
// - They don't allocate or free any memory on the heap.
|
|
// - They don't recurse or mutually recurse. All the code
|
|
// could be inlined into the top-level public functions.
|
|
// - They run in at most quadratic time with respect to input arguments.
|
|
// Most functions run in linear time, and some in constant time.
|
|
// There are no unbounded loops or non-obvious termination conditions.
|
|
// - They are completely thread-safe if the caller does not give the
|
|
// same writable buffer to concurrent calls to these functions.
|
|
|
|
testable int getTextProperties(const char *text, bool *isNumeric, bool *isAlphanumeric, int *textBits);
|
|
static int fitVersionToData(int minVersion, int maxVersion, enum qrcodegen_Ecc ecl,
|
|
int dataLen, int dataBitLen, int ver1To9LenBits, int ver10To26LenBits, int ver27To40LenBits);
|
|
static void encodeQrCodeTail(uint8_t dataAndQrcode[], int bitLen, uint8_t tempBuffer[],
|
|
int version, enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, bool boostEcl);
|
|
testable void appendBitsToBuffer(unsigned int val, int numBits, uint8_t buffer[], int *bitLen);
|
|
|
|
testable void appendErrorCorrection(uint8_t data[], int version, enum qrcodegen_Ecc ecl, uint8_t result[]);
|
|
testable int getNumDataCodewords(int version, enum qrcodegen_Ecc ecl);
|
|
testable int getNumRawDataModules(int version);
|
|
|
|
testable void calcReedSolomonGenerator(int degree, uint8_t result[]);
|
|
testable void calcReedSolomonRemainder(const uint8_t data[], int dataLen, const uint8_t generator[], int degree, uint8_t result[]);
|
|
testable uint8_t finiteFieldMultiply(uint8_t x, uint8_t y);
|
|
|
|
testable void initializeFunctionModules(int version, uint8_t qrcode[]);
|
|
static void drawWhiteFunctionModules(uint8_t qrcode[], int version);
|
|
static void drawFormatBits(enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, uint8_t qrcode[]);
|
|
testable int getAlignmentPatternPositions(int version, uint8_t result[7]);
|
|
static void fillRectangle(int left, int top, int width, int height, uint8_t qrcode[]);
|
|
|
|
static void drawCodewords(const uint8_t data[], int dataLen, uint8_t qrcode[]);
|
|
static void applyMask(const uint8_t functionModules[], uint8_t qrcode[], enum qrcodegen_Mask mask);
|
|
static long getPenaltyScore(const uint8_t qrcode[]);
|
|
|
|
testable bool getModule(const uint8_t qrcode[], int x, int y);
|
|
testable void setModule(uint8_t qrcode[], int x, int y, bool isBlack);
|
|
testable void setModuleBounded(uint8_t qrcode[], int x, int y, bool isBlack);
|
|
|
|
|
|
|
|
/*---- Private tables of constants ----*/
|
|
|
|
// For checking text and encoding segments.
|
|
static const char *ALPHANUMERIC_CHARSET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:";
|
|
|
|
// For generating error correction codes.
|
|
testable const int8_t ECC_CODEWORDS_PER_BLOCK[4][41] = {
|
|
// Version: (note that index 0 is for padding, and is set to an illegal value)
|
|
//0, 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, 7, 10, 15, 20, 26, 18, 20, 24, 30, 18, 20, 24, 26, 30, 22, 24, 28, 30, 28, 28, 28, 28, 30, 30, 26, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // Low
|
|
{-1, 10, 16, 26, 18, 24, 16, 18, 22, 22, 26, 30, 22, 22, 24, 24, 28, 28, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28}, // Medium
|
|
{-1, 13, 22, 18, 26, 18, 24, 18, 22, 20, 24, 28, 26, 24, 20, 30, 24, 28, 28, 26, 30, 28, 30, 30, 30, 30, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // Quartile
|
|
{-1, 17, 28, 22, 16, 22, 28, 26, 26, 24, 28, 24, 28, 22, 24, 24, 30, 28, 28, 26, 28, 30, 24, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // High
|
|
};
|
|
|
|
// For generating error correction codes.
|
|
testable const int8_t NUM_ERROR_CORRECTION_BLOCKS[4][41] = {
|
|
// Version: (note that index 0 is for padding, and is set to an illegal value)
|
|
//0, 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, 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, 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, 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
|
|
{-1, 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
|
|
};
|
|
|
|
// For automatic mask pattern selection.
|
|
static const int PENALTY_N1 = 3;
|
|
static const int PENALTY_N2 = 3;
|
|
static const int PENALTY_N3 = 40;
|
|
static const int PENALTY_N4 = 10;
|
|
|
|
|
|
|
|
/*---- High-level QR Code encoding functions ----*/
|
|
|
|
// Public function - see documentation comment in header file.
|
|
bool qrcodegen_encodeText(const char *text, uint8_t tempBuffer[], uint8_t qrcode[],
|
|
enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl) {
|
|
assert(text != NULL && tempBuffer != NULL && qrcode != NULL);
|
|
assert(qrcodegen_VERSION_MIN <= minVersion && minVersion <= maxVersion && maxVersion <= qrcodegen_VERSION_MAX);
|
|
assert(0 <= (int)ecl && (int)ecl <= 3 && -1 <= (int)mask && (int)mask <= 7);
|
|
|
|
// Get text properties
|
|
bool isNumeric, isAlphanumeric;
|
|
int textBits;
|
|
int textLen = getTextProperties(text, &isNumeric, &isAlphanumeric, &textBits);
|
|
if (textLen < 0)
|
|
goto fail;
|
|
|
|
if (!isAlphanumeric) { // Fully handle in binary mode
|
|
if (textLen > qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion))
|
|
goto fail;
|
|
for (int i = 0; i < textLen; i++)
|
|
tempBuffer[i] = (uint8_t)text[i];
|
|
return qrcodegen_encodeBinary(tempBuffer, (size_t)textLen, qrcode, ecl, minVersion, maxVersion, mask, boostEcl);
|
|
}
|
|
|
|
int version = fitVersionToData(minVersion, maxVersion, ecl, textLen, (int)textBits,
|
|
(isNumeric ? 10 : 9), (isNumeric ? 12 : 11), (isNumeric ? 14 : 13));
|
|
if (version == 0)
|
|
goto fail;
|
|
memset(qrcode, 0, qrcodegen_BUFFER_LEN_FOR_VERSION(version) * sizeof(qrcode[0]));
|
|
int bitLen = 0;
|
|
|
|
// Make segment header and append data
|
|
if (isNumeric && textLen > 0) {
|
|
appendBitsToBuffer(1, 4, qrcode, &bitLen);
|
|
int lengthBits = version <= 9 ? 10 : (version <= 26 ? 12 : 14);
|
|
appendBitsToBuffer((unsigned int)textLen, lengthBits, qrcode, &bitLen);
|
|
int accumData = 0;
|
|
int accumCount = 0;
|
|
for (const char *p = text; *p != '\0'; p++) {
|
|
accumData = accumData * 10 + (*p - '0');
|
|
accumCount++;
|
|
if (accumCount == 3) {
|
|
appendBitsToBuffer(accumData, 10, qrcode, &bitLen);
|
|
accumData = 0;
|
|
accumCount = 0;
|
|
}
|
|
}
|
|
if (accumCount > 0) // 1 or 2 digits remaining
|
|
appendBitsToBuffer(accumData, accumCount * 3 + 1, qrcode, &bitLen);
|
|
|
|
} else if (isAlphanumeric && textLen > 0) {
|
|
appendBitsToBuffer(2, 4, qrcode, &bitLen);
|
|
int lengthBits = version <= 9 ? 9 : (version <= 26 ? 11 : 13);
|
|
appendBitsToBuffer((unsigned int)textLen, lengthBits, qrcode, &bitLen);
|
|
int accumData = 0;
|
|
int accumCount = 0;
|
|
for (const char *p = text; *p != '\0'; p++) {
|
|
accumData = accumData * 45 + (strchr(ALPHANUMERIC_CHARSET, *p) - ALPHANUMERIC_CHARSET);
|
|
accumCount++;
|
|
if (accumCount == 2) {
|
|
appendBitsToBuffer(accumData, 11, qrcode, &bitLen);
|
|
accumData = 0;
|
|
accumCount = 0;
|
|
}
|
|
}
|
|
if (accumCount > 0) // 1 character remaining
|
|
appendBitsToBuffer(accumData, 6, qrcode, &bitLen);
|
|
}
|
|
|
|
// Make QR Code
|
|
encodeQrCodeTail(qrcode, bitLen, tempBuffer, version, ecl, mask, boostEcl);
|
|
return true;
|
|
|
|
fail:
|
|
qrcode[0] = 0; // An invalid size value for safety
|
|
return false;
|
|
}
|
|
|
|
|
|
// Public function - see documentation comment in header file.
|
|
bool qrcodegen_encodeBinary(uint8_t dataAndTemp[], size_t dataLen, uint8_t qrcode[],
|
|
enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl) {
|
|
assert(dataAndTemp != NULL && qrcode != NULL);
|
|
assert(qrcodegen_VERSION_MIN <= minVersion && minVersion <= maxVersion && maxVersion <= qrcodegen_VERSION_MAX);
|
|
assert(0 <= (int)ecl && (int)ecl <= 3 && -1 <= (int)mask && (int)mask <= 7);
|
|
|
|
// Check length and find version
|
|
if (dataLen > INT16_MAX / 8)
|
|
goto fail;
|
|
// Now dataLen * 8 <= 32767 <= INT_MAX
|
|
int version = fitVersionToData(minVersion, maxVersion, ecl, (int)dataLen, (int)dataLen * 8, 8, 16, 16);
|
|
if (version == 0)
|
|
goto fail;
|
|
|
|
// Make bit sequence and QR Code
|
|
memset(qrcode, 0, qrcodegen_BUFFER_LEN_FOR_VERSION(version) * sizeof(qrcode[0]));
|
|
int bitLen = 0;
|
|
appendBitsToBuffer(4, 4, qrcode, &bitLen);
|
|
appendBitsToBuffer((unsigned int)dataLen, (version <= 9 ? 8 : 16), qrcode, &bitLen);
|
|
for (size_t i = 0; i < dataLen; i++)
|
|
appendBitsToBuffer(dataAndTemp[i], 8, qrcode, &bitLen);
|
|
encodeQrCodeTail(qrcode, bitLen, dataAndTemp, version, ecl, mask, boostEcl);
|
|
return true;
|
|
|
|
fail:
|
|
qrcode[0] = 0; // An invalid size value for safety
|
|
return false;
|
|
}
|
|
|
|
|
|
// Scans the given string, returns the number of characters, and sets output variables.
|
|
// Returns a negative number if the length would exceed INT16_MAX or textBits would exceed INT_MAX.
|
|
// Note that INT16_MAX <= 32767 <= INT_MAX and INT16_MAX < 65535 <= SIZE_MAX.
|
|
// If the return value is negative, then the pointees of output arguments might not be set.
|
|
testable int getTextProperties(const char *text, bool *isNumeric, bool *isAlphanumeric, int *textBits) {
|
|
int textLen = 0;
|
|
*isNumeric = true;
|
|
*isAlphanumeric = true;
|
|
for (const char *p = text; *p != '\0'; p++, textLen++) { // Read every character
|
|
if (textLen >= INT16_MAX)
|
|
return -1;
|
|
char c = *p;
|
|
if (c < '0' || c > '9') {
|
|
*isNumeric = false;
|
|
*isAlphanumeric &= strchr(ALPHANUMERIC_CHARSET, c) != NULL;
|
|
}
|
|
}
|
|
|
|
long tempBits;
|
|
if (*isNumeric)
|
|
tempBits = textLen * 3L + (textLen + 2L) / 3;
|
|
else if (*isAlphanumeric)
|
|
tempBits = textLen * 5L + (textLen + 1L) / 2;
|
|
else // Binary mode
|
|
tempBits = textLen * 8L;
|
|
|
|
if (tempBits > INT_MAX)
|
|
return -1;
|
|
*textBits = (int)tempBits;
|
|
return textLen;
|
|
}
|
|
|
|
|
|
// Returns the minimum possible version in the given range to fit one
|
|
// segment with the given characteristics, or 0 if no version fits the data.
|
|
static int fitVersionToData(int minVersion, int maxVersion, enum qrcodegen_Ecc ecl,
|
|
int dataLen, int dataBitLen, int ver1To9LenBits, int ver10To26LenBits, int ver27To40LenBits) {
|
|
|
|
assert(qrcodegen_VERSION_MIN <= minVersion && minVersion <= maxVersion && maxVersion <= qrcodegen_VERSION_MAX);
|
|
assert(0 <= (int)ecl && (int)ecl <= 3);
|
|
assert(dataLen >= 0 && dataBitLen >= 0);
|
|
assert(1 <= ver1To9LenBits && ver1To9LenBits <= 16);
|
|
assert(1 <= ver10To26LenBits && ver10To26LenBits <= 16);
|
|
assert(1 <= ver27To40LenBits && ver27To40LenBits <= 16);
|
|
|
|
for (int version = minVersion; ; version++) {
|
|
int lengthBits;
|
|
if (version <= 9) lengthBits = ver1To9LenBits;
|
|
else if (version <= 26) lengthBits = ver10To26LenBits;
|
|
else lengthBits = ver27To40LenBits;
|
|
if (dataLen < (1L << lengthBits)) {
|
|
int dataCapacityBits = getNumDataCodewords(version, ecl) * 8; // Number of data bits available
|
|
int header = 4 + lengthBits;
|
|
if (dataBitLen <= INT_MAX - header && header + dataBitLen <= dataCapacityBits)
|
|
return version; // This version number is found to be suitable
|
|
}
|
|
if (version >= maxVersion) // All versions in the range could not fit the given data
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
|
|
// Given a data bit sequence in dataAndQrcode without terminator or padding or ECC, plus the given QR Code
|
|
// encoding parameters, this function handles ECC level boosting, bit stream termination and padding,
|
|
// ECC computation, and block interleaving. Then the function renders the QR Code symbol back to the array
|
|
// dataAndQrcode and handles automatic mask selection. The initial bit length must fit the given version and
|
|
// ECC level, and each of the two arrays must have length at least qrcodegen_BUFFER_LEN_FOR_VERSION(version).
|
|
static void encodeQrCodeTail(uint8_t dataAndQrcode[], int bitLen, uint8_t tempBuffer[],
|
|
int version, enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, bool boostEcl) {
|
|
|
|
if (boostEcl) {
|
|
if (bitLen <= getNumDataCodewords(version, qrcodegen_Ecc_MEDIUM ) * 8) ecl = qrcodegen_Ecc_MEDIUM ;
|
|
if (bitLen <= getNumDataCodewords(version, qrcodegen_Ecc_QUARTILE) * 8) ecl = qrcodegen_Ecc_QUARTILE;
|
|
if (bitLen <= getNumDataCodewords(version, qrcodegen_Ecc_HIGH ) * 8) ecl = qrcodegen_Ecc_HIGH ;
|
|
}
|
|
int dataCapacityBits = getNumDataCodewords(version, ecl) * 8;
|
|
|
|
// Add terminator, bit padding, byte padding
|
|
int terminatorBits = dataCapacityBits - bitLen;
|
|
if (terminatorBits > 4)
|
|
terminatorBits = 4;
|
|
appendBitsToBuffer(0, terminatorBits, dataAndQrcode, &bitLen);
|
|
appendBitsToBuffer(0, (8 - bitLen % 8) % 8, dataAndQrcode, &bitLen);
|
|
for (uint8_t padByte = 0xEC; bitLen < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
|
|
appendBitsToBuffer(padByte, 8, dataAndQrcode, &bitLen);
|
|
assert(bitLen % 8 == 0);
|
|
|
|
// Draw function and data codeword modules
|
|
appendErrorCorrection(dataAndQrcode, version, ecl, tempBuffer);
|
|
initializeFunctionModules(version, dataAndQrcode);
|
|
drawCodewords(tempBuffer, getNumRawDataModules(version) / 8, dataAndQrcode);
|
|
drawWhiteFunctionModules(dataAndQrcode, version);
|
|
initializeFunctionModules(version, tempBuffer);
|
|
|
|
// Handle masking
|
|
if (mask == qrcodegen_Mask_AUTO) { // Automatically choose best mask
|
|
long minPenalty = LONG_MAX;
|
|
for (int i = 0; i < 8; i++) {
|
|
drawFormatBits(ecl, (enum qrcodegen_Mask)i, dataAndQrcode);
|
|
applyMask(tempBuffer, dataAndQrcode, (enum qrcodegen_Mask)i);
|
|
long penalty = getPenaltyScore(dataAndQrcode);
|
|
if (penalty < minPenalty) {
|
|
mask = (enum qrcodegen_Mask)i;
|
|
minPenalty = penalty;
|
|
}
|
|
applyMask(tempBuffer, dataAndQrcode, (enum qrcodegen_Mask)i); // Undoes the mask due to XOR
|
|
}
|
|
}
|
|
assert(0 <= (int)mask && (int)mask <= 7);
|
|
drawFormatBits(ecl, mask, dataAndQrcode);
|
|
applyMask(tempBuffer, dataAndQrcode, mask);
|
|
}
|
|
|
|
|
|
// Appends the given sequence of bits to the given byte-based bit buffer, increasing the bit length.
|
|
testable void appendBitsToBuffer(unsigned int val, int numBits, uint8_t buffer[], int *bitLen) {
|
|
assert(0 <= numBits && numBits <= 16 && (long)val >> numBits == 0);
|
|
for (int i = numBits - 1; i >= 0; i--, (*bitLen)++)
|
|
buffer[*bitLen >> 3] |= ((val >> i) & 1) << (7 - (*bitLen & 7));
|
|
}
|
|
|
|
|
|
|
|
/*---- Error correction code generation functions ----*/
|
|
|
|
// Appends error correction bytes to each block of the given data array, then interleaves bytes
|
|
// from the blocks and stores them in the result array. data[0 : rawCodewords - totalEcc] contains
|
|
// the input data. data[rawCodewords - totalEcc : rawCodewords] is used as a temporary work area
|
|
// and will be clobbered by this function. The final answer is stored in result[0 : rawCodewords].
|
|
testable void appendErrorCorrection(uint8_t data[], int version, enum qrcodegen_Ecc ecl, uint8_t result[]) {
|
|
// Calculate parameter numbers
|
|
assert(0 <= (int)ecl && (int)ecl < 4 && qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
|
|
int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[(int)ecl][version];
|
|
int blockEccLen = ECC_CODEWORDS_PER_BLOCK[(int)ecl][version];
|
|
int rawCodewords = getNumRawDataModules(version) / 8;
|
|
int dataLen = rawCodewords - blockEccLen * numBlocks;
|
|
int numShortBlocks = numBlocks - rawCodewords % numBlocks;
|
|
int shortBlockDataLen = rawCodewords / numBlocks - blockEccLen;
|
|
|
|
// Split data into blocks and append ECC after all data
|
|
uint8_t generator[30];
|
|
calcReedSolomonGenerator(blockEccLen, generator);
|
|
for (int i = 0, j = dataLen, k = 0; i < numBlocks; i++) {
|
|
int blockLen = shortBlockDataLen;
|
|
if (i >= numShortBlocks)
|
|
blockLen++;
|
|
calcReedSolomonRemainder(&data[k], blockLen, generator, blockEccLen, &data[j]);
|
|
j += blockEccLen;
|
|
k += blockLen;
|
|
}
|
|
|
|
// Interleave (not concatenate) the bytes from every block into a single sequence
|
|
for (int i = 0, k = 0; i < numBlocks; i++) {
|
|
for (int j = 0, l = i; j < shortBlockDataLen; j++, k++, l += numBlocks)
|
|
result[l] = data[k];
|
|
if (i >= numShortBlocks)
|
|
k++;
|
|
}
|
|
for (int i = numShortBlocks, k = (numShortBlocks + 1) * shortBlockDataLen, l = numBlocks * shortBlockDataLen;
|
|
i < numBlocks; i++, k += shortBlockDataLen + 1, l++)
|
|
result[l] = data[k];
|
|
for (int i = 0, k = dataLen; i < numBlocks; i++) {
|
|
for (int j = 0, l = dataLen + i; j < blockEccLen; j++, k++, l += numBlocks)
|
|
result[l] = data[k];
|
|
}
|
|
}
|
|
|
|
|
|
// Returns the number of 8-bit codewords that can be used for storing data (not ECC),
|
|
// for the given version number and error correction level. The result is in the range [9, 2956].
|
|
testable int getNumDataCodewords(int version, enum qrcodegen_Ecc ecl) {
|
|
int v = version, e = (int)ecl;
|
|
assert(0 <= e && e < 4 && qrcodegen_VERSION_MIN <= v && v <= qrcodegen_VERSION_MAX);
|
|
return getNumRawDataModules(v) / 8 - ECC_CODEWORDS_PER_BLOCK[e][v] * NUM_ERROR_CORRECTION_BLOCKS[e][v];
|
|
}
|
|
|
|
|
|
// Returns the number of data bits that can be stored in a QR Code of the given version number, after
|
|
// all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8.
|
|
// The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.
|
|
testable int getNumRawDataModules(int version) {
|
|
assert(qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
|
|
int result = (16 * version + 128) * version + 64;
|
|
if (version >= 2) {
|
|
int numAlign = version / 7 + 2;
|
|
result -= (25 * numAlign - 10) * numAlign - 55;
|
|
if (version >= 7)
|
|
result -= 18 * 2; // Subtract version information
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
|
|
/*---- Reed-Solomon ECC generator functions ----*/
|
|
|
|
// Calculates the Reed-Solomon generator polynomial of the given degree, storing in result[0 : degree].
|
|
testable void calcReedSolomonGenerator(int degree, uint8_t result[]) {
|
|
// Start with the monomial x^0
|
|
assert(1 <= degree && degree <= 30);
|
|
memset(result, 0, degree * sizeof(result[0]));
|
|
result[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).
|
|
uint8_t root = 1;
|
|
for (int i = 0; i < degree; i++) {
|
|
// Multiply the current product by (x - r^i)
|
|
for (int j = 0; j < degree; j++) {
|
|
result[j] = finiteFieldMultiply(result[j], root);
|
|
if (j + 1 < degree)
|
|
result[j] ^= result[j + 1];
|
|
}
|
|
root = finiteFieldMultiply(root, 0x02);
|
|
}
|
|
}
|
|
|
|
|
|
// Calculates the remainder of the polynomial data[0 : dataLen] when divided by the generator[0 : degree], where all
|
|
// polynomials are in big endian and the generator has an implicit leading 1 term, storing the result in result[0 : degree].
|
|
testable void calcReedSolomonRemainder(const uint8_t data[], int dataLen, const uint8_t generator[], int degree, uint8_t result[]) {
|
|
// Perform polynomial division
|
|
assert(1 <= degree && degree <= 30);
|
|
memset(result, 0, degree * sizeof(result[0]));
|
|
for (int i = 0; i < dataLen; i++) {
|
|
uint8_t factor = data[i] ^ result[0];
|
|
memmove(&result[0], &result[1], (degree - 1) * sizeof(result[0]));
|
|
result[degree - 1] = 0;
|
|
for (int j = 0; j < degree; j++)
|
|
result[j] ^= finiteFieldMultiply(generator[j], factor);
|
|
}
|
|
}
|
|
|
|
|
|
// Returns the product of the two given field elements modulo GF(2^8/0x11D).
|
|
// All inputs are valid. This could be implemented as a 256*256 lookup table.
|
|
testable uint8_t finiteFieldMultiply(uint8_t x, uint8_t y) {
|
|
// Russian peasant multiplication
|
|
uint8_t z = 0;
|
|
for (int i = 7; i >= 0; i--) {
|
|
z = (z << 1) ^ ((z >> 7) * 0x11D);
|
|
z ^= ((y >> i) & 1) * x;
|
|
}
|
|
return z;
|
|
}
|
|
|
|
|
|
|
|
/*---- Drawing function modules ----*/
|
|
|
|
// Clears the given QR Code grid with white modules for the given
|
|
// version's size, then marks every function module as black.
|
|
testable void initializeFunctionModules(int version, uint8_t qrcode[]) {
|
|
// Initialize QR Code
|
|
int qrsize = version * 4 + 17;
|
|
memset(qrcode, 0, ((qrsize * qrsize + 7) / 8 + 1) * sizeof(qrcode[0]));
|
|
qrcode[0] = (uint8_t)qrsize;
|
|
|
|
// Fill horizontal and vertical timing patterns
|
|
fillRectangle(6, 0, 1, qrsize, qrcode);
|
|
fillRectangle(0, 6, qrsize, 1, qrcode);
|
|
|
|
// Fill 3 finder patterns (all corners except bottom right) and format bits
|
|
fillRectangle(0, 0, 9, 9, qrcode);
|
|
fillRectangle(qrsize - 8, 0, 8, 9, qrcode);
|
|
fillRectangle(0, qrsize - 8, 9, 8, qrcode);
|
|
|
|
// Fill numerous alignment patterns
|
|
uint8_t alignPatPos[7] = {0};
|
|
int numAlign = getAlignmentPatternPositions(version, alignPatPos);
|
|
for (int i = 0; i < numAlign; i++) {
|
|
for (int j = 0; j < numAlign; j++) {
|
|
if ((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))
|
|
continue; // Skip the three finder corners
|
|
else
|
|
fillRectangle(alignPatPos[i] - 2, alignPatPos[j] - 2, 5, 5, qrcode);
|
|
}
|
|
}
|
|
|
|
// Fill version blocks
|
|
if (version >= 7) {
|
|
fillRectangle(qrsize - 11, 0, 3, 6, qrcode);
|
|
fillRectangle(0, qrsize - 11, 6, 3, qrcode);
|
|
}
|
|
}
|
|
|
|
|
|
// Draws white function modules and possibly some black modules onto the given QR Code, without changing
|
|
// non-function modules. This does not draw the format bits. This requires all function modules to be previously
|
|
// marked black (namely by initializeFunctionModules()), because this may skip redrawing black function modules.
|
|
static void drawWhiteFunctionModules(uint8_t qrcode[], int version) {
|
|
// Draw horizontal and vertical timing patterns
|
|
int qrsize = qrcodegen_getSize(qrcode);
|
|
for (int i = 7; i < qrsize - 7; i += 2) {
|
|
setModule(qrcode, 6, i, false);
|
|
setModule(qrcode, i, 6, false);
|
|
}
|
|
|
|
// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
|
|
for (int i = -4; i <= 4; i++) {
|
|
for (int j = -4; j <= 4; j++) {
|
|
int dist = abs(i);
|
|
if (abs(j) > dist)
|
|
dist = abs(j);
|
|
if (dist == 2 || dist == 4) {
|
|
setModuleBounded(qrcode, 3 + j, 3 + i, false);
|
|
setModuleBounded(qrcode, qrsize - 4 + j, 3 + i, false);
|
|
setModuleBounded(qrcode, 3 + j, qrsize - 4 + i, false);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Draw numerous alignment patterns
|
|
uint8_t alignPatPos[7] = {0};
|
|
int numAlign = getAlignmentPatternPositions(version, alignPatPos);
|
|
for (int i = 0; i < numAlign; i++) {
|
|
for (int j = 0; j < numAlign; j++) {
|
|
if ((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))
|
|
continue; // Skip the three finder corners
|
|
else {
|
|
for (int k = -1; k <= 1; k++) {
|
|
for (int l = -1; l <= 1; l++)
|
|
setModule(qrcode, alignPatPos[i] + l, alignPatPos[j] + k, k == 0 && l == 0);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Draw version blocks
|
|
if (version >= 7) {
|
|
// Calculate error correction code and pack bits
|
|
int rem = version; // version is uint6, in the range [7, 40]
|
|
for (int i = 0; i < 12; i++)
|
|
rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
|
|
long data = (long)version << 12 | rem; // uint18
|
|
assert(data >> 18 == 0);
|
|
|
|
// Draw two copies
|
|
for (int i = 0; i < 6; i++) {
|
|
for (int j = 0; j < 3; j++) {
|
|
int k = qrsize - 11 + j;
|
|
setModule(qrcode, k, i, (data & 1) != 0);
|
|
setModule(qrcode, i, k, (data & 1) != 0);
|
|
data >>= 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Draws two copies of the format bits (with its own error correction code) based
|
|
// on the given mask and error correction level. This always draws all modules of
|
|
// the format bits, unlike drawWhiteFunctionModules() which might skip black modules.
|
|
static void drawFormatBits(enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, uint8_t qrcode[]) {
|
|
// Calculate error correction code and pack bits
|
|
assert(0 <= (int)mask && (int)mask <= 7);
|
|
int data;
|
|
switch (ecl) {
|
|
case qrcodegen_Ecc_LOW : data = 1; break;
|
|
case qrcodegen_Ecc_MEDIUM : data = 0; break;
|
|
case qrcodegen_Ecc_QUARTILE: data = 3; break;
|
|
case qrcodegen_Ecc_HIGH : data = 2; break;
|
|
default: assert(false);
|
|
}
|
|
data = data << 3 | (int)mask; // ecl-derived value is uint2, mask is uint3
|
|
int rem = data;
|
|
for (int i = 0; i < 10; i++)
|
|
rem = (rem << 1) ^ ((rem >> 9) * 0x537);
|
|
data = data << 10 | rem;
|
|
data ^= 0x5412; // uint15
|
|
assert(data >> 15 == 0);
|
|
|
|
// Draw first copy
|
|
for (int i = 0; i <= 5; i++)
|
|
setModule(qrcode, 8, i, ((data >> i) & 1) != 0);
|
|
setModule(qrcode, 8, 7, ((data >> 6) & 1) != 0);
|
|
setModule(qrcode, 8, 8, ((data >> 7) & 1) != 0);
|
|
setModule(qrcode, 7, 8, ((data >> 8) & 1) != 0);
|
|
for (int i = 9; i < 15; i++)
|
|
setModule(qrcode, 14 - i, 8, ((data >> i) & 1) != 0);
|
|
|
|
// Draw second copy
|
|
int qrsize = qrcodegen_getSize(qrcode);
|
|
for (int i = 0; i <= 7; i++)
|
|
setModule(qrcode, qrsize - 1 - i, 8, ((data >> i) & 1) != 0);
|
|
for (int i = 8; i < 15; i++)
|
|
setModule(qrcode, 8, qrsize - 15 + i, ((data >> i) & 1) != 0);
|
|
setModule(qrcode, 8, qrsize - 8, true);
|
|
}
|
|
|
|
|
|
// Calculates the positions of alignment patterns in ascending order for the given version number,
|
|
// storing them to the given array and returning an array length in the range [0, 7].
|
|
testable int getAlignmentPatternPositions(int version, uint8_t result[7]) {
|
|
if (version == 1)
|
|
return 0;
|
|
int qrsize = version * 4 + 17;
|
|
int numAlign = version / 7 + 2;
|
|
int step;
|
|
if (version != 32)
|
|
step = (version * 4 + numAlign * 2 + 1) / (2 * numAlign - 2) * 2; // ceil((qrsize - 13) / (2*numAlign - 2)) * 2
|
|
else // C-C-C-Combo breaker!
|
|
step = 26;
|
|
for (int i = numAlign - 1, pos = qrsize - 7; i >= 1; i--, pos -= step)
|
|
result[i] = pos;
|
|
result[0] = 6;
|
|
return numAlign;
|
|
}
|
|
|
|
|
|
// Sets every pixel in the range [left : left + width] * [top : top + height] to black.
|
|
static void fillRectangle(int left, int top, int width, int height, uint8_t qrcode[]) {
|
|
for (int dy = 0; dy < height; dy++) {
|
|
for (int dx = 0; dx < width; dx++)
|
|
setModule(qrcode, left + dx, top + dy, true);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*---- Drawing data modules and masking ----*/
|
|
|
|
// Draws the raw codewords (including data and ECC) onto the given QR Code. This requires the initial state of
|
|
// the QR Code to be black at function modules and white at codeword modules (including unused remainder bits).
|
|
static void drawCodewords(const uint8_t data[], int dataLen, uint8_t qrcode[]) {
|
|
int qrsize = qrcodegen_getSize(qrcode);
|
|
int i = 0; // Bit index into the data
|
|
// Do the funny zigzag scan
|
|
for (int right = qrsize - 1; right >= 1; right -= 2) { // Index of right column in each column pair
|
|
if (right == 6)
|
|
right = 5;
|
|
for (int vert = 0; vert < qrsize; vert++) { // Vertical counter
|
|
for (int j = 0; j < 2; j++) {
|
|
int x = right - j; // Actual x coordinate
|
|
bool upward = ((right + 1) & 2) == 0;
|
|
int y = upward ? qrsize - 1 - vert : vert; // Actual y coordinate
|
|
if (!getModule(qrcode, x, y) && i < dataLen * 8) {
|
|
bool black = ((data[i >> 3] >> (7 - (i & 7))) & 1) != 0;
|
|
setModule(qrcode, x, y, black);
|
|
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
|
|
}
|
|
}
|
|
}
|
|
assert(i == dataLen * 8);
|
|
}
|
|
|
|
|
|
// 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(const uint8_t functionModules[], uint8_t qrcode[], enum qrcodegen_Mask mask) {
|
|
assert(0 <= (int)mask && (int)mask <= 7); // Disallows qrcodegen_Mask_AUTO
|
|
int qrsize = qrcodegen_getSize(qrcode);
|
|
for (int y = 0; y < qrsize; y++) {
|
|
for (int x = 0; x < qrsize; x++) {
|
|
if (getModule(functionModules, x, y))
|
|
continue;
|
|
bool invert;
|
|
switch ((int)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;
|
|
default: assert(false);
|
|
}
|
|
bool val = getModule(qrcode, x, y);
|
|
setModule(qrcode, x, y, val ^ invert);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Calculates and returns the penalty score based on state of the given QR Code's current modules.
|
|
// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
|
|
static long getPenaltyScore(const uint8_t qrcode[]) {
|
|
int qrsize = qrcodegen_getSize(qrcode);
|
|
long result = 0;
|
|
|
|
// Adjacent modules in row having same color
|
|
for (int y = 0; y < qrsize; y++) {
|
|
bool colorX;
|
|
for (int x = 0, runX; x < qrsize; x++) {
|
|
if (x == 0 || getModule(qrcode, x, y) != colorX) {
|
|
colorX = getModule(qrcode, x, y);
|
|
runX = 1;
|
|
} else {
|
|
runX++;
|
|
if (runX == 5)
|
|
result += PENALTY_N1;
|
|
else if (runX > 5)
|
|
result++;
|
|
}
|
|
}
|
|
}
|
|
// Adjacent modules in column having same color
|
|
for (int x = 0; x < qrsize; x++) {
|
|
bool colorY;
|
|
for (int y = 0, runY; y < qrsize; y++) {
|
|
if (y == 0 || getModule(qrcode, x, y) != colorY) {
|
|
colorY = getModule(qrcode, x, y);
|
|
runY = 1;
|
|
} else {
|
|
runY++;
|
|
if (runY == 5)
|
|
result += PENALTY_N1;
|
|
else if (runY > 5)
|
|
result++;
|
|
}
|
|
}
|
|
}
|
|
|
|
// 2*2 blocks of modules having same color
|
|
for (int y = 0; y < qrsize - 1; y++) {
|
|
for (int x = 0; x < qrsize - 1; x++) {
|
|
bool color = getModule(qrcode, x, y);
|
|
if ( color == getModule(qrcode, x + 1, y) &&
|
|
color == getModule(qrcode, x, y + 1) &&
|
|
color == getModule(qrcode, x + 1, y + 1))
|
|
result += PENALTY_N2;
|
|
}
|
|
}
|
|
|
|
// Finder-like pattern in rows
|
|
for (int y = 0; y < qrsize; y++) {
|
|
for (int x = 0, bits = 0; x < qrsize; x++) {
|
|
bits = ((bits << 1) & 0x7FF) | (getModule(qrcode, x, y) ? 1 : 0);
|
|
if (x >= 10 && (bits == 0x05D || bits == 0x5D0)) // Needs 11 bits accumulated
|
|
result += PENALTY_N3;
|
|
}
|
|
}
|
|
// Finder-like pattern in columns
|
|
for (int x = 0; x < qrsize; x++) {
|
|
for (int y = 0, bits = 0; y < qrsize; y++) {
|
|
bits = ((bits << 1) & 0x7FF) | (getModule(qrcode, x, y) ? 1 : 0);
|
|
if (y >= 10 && (bits == 0x05D || bits == 0x5D0)) // Needs 11 bits accumulated
|
|
result += PENALTY_N3;
|
|
}
|
|
}
|
|
|
|
// Balance of black and white modules
|
|
int black = 0;
|
|
for (int y = 0; y < qrsize; y++) {
|
|
for (int x = 0; x < qrsize; x++) {
|
|
if (getModule(qrcode, x, y))
|
|
black++;
|
|
}
|
|
}
|
|
int total = qrsize * qrsize;
|
|
// Find smallest k such that (45-5k)% <= dark/total <= (55+5k)%
|
|
for (int k = 0; black*20L < (9L-k)*total || black*20L > (11L+k)*total; k++)
|
|
result += PENALTY_N4;
|
|
return result;
|
|
}
|
|
|
|
|
|
|
|
/*---- Basic QR Code information ----*/
|
|
|
|
// Public function - see documentation comment in header file.
|
|
int qrcodegen_getSize(const uint8_t qrcode[]) {
|
|
assert(qrcode != NULL);
|
|
int result = qrcode[0];
|
|
assert((qrcodegen_VERSION_MIN * 4 + 17) <= result
|
|
&& result <= (qrcodegen_VERSION_MAX * 4 + 17));
|
|
return result;
|
|
}
|
|
|
|
|
|
// Public function - see documentation comment in header file.
|
|
bool qrcodegen_getModule(const uint8_t qrcode[], int x, int y) {
|
|
assert(qrcode != NULL);
|
|
int qrsize = qrcode[0];
|
|
return (0 <= x && x < qrsize && 0 <= y && y < qrsize) && getModule(qrcode, x, y);
|
|
}
|
|
|
|
|
|
// Gets the module at the given coordinates, which must be in bounds.
|
|
testable bool getModule(const uint8_t qrcode[], int x, int y) {
|
|
int qrsize = qrcode[0];
|
|
assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
|
|
int index = y * qrsize + x;
|
|
int bitIndex = index & 7;
|
|
int byteIndex = (index >> 3) + 1;
|
|
return ((qrcode[byteIndex] >> bitIndex) & 1) != 0;
|
|
}
|
|
|
|
|
|
// Sets the module at the given coordinates, which must be in bounds.
|
|
testable void setModule(uint8_t qrcode[], int x, int y, bool isBlack) {
|
|
int qrsize = qrcode[0];
|
|
assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
|
|
int index = y * qrsize + x;
|
|
int bitIndex = index & 7;
|
|
int byteIndex = (index >> 3) + 1;
|
|
if (isBlack)
|
|
qrcode[byteIndex] |= 1 << bitIndex;
|
|
else
|
|
qrcode[byteIndex] &= (1 << bitIndex) ^ 0xFF;
|
|
}
|
|
|
|
|
|
// Sets the module at the given coordinates, doing nothing if out of bounds.
|
|
testable void setModuleBounded(uint8_t qrcode[], int x, int y, bool isBlack) {
|
|
int qrsize = qrcode[0];
|
|
if (0 <= x && x < qrsize && 0 <= y && y < qrsize)
|
|
setModule(qrcode, x, y, isBlack);
|
|
}
|