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Diffstat (limited to 'external/qrcodegen/QrCode.hpp')
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diff --git a/external/qrcodegen/QrCode.hpp b/external/qrcodegen/QrCode.hpp new file mode 100644 index 000000000..7341e4102 --- /dev/null +++ b/external/qrcodegen/QrCode.hpp @@ -0,0 +1,556 @@ +/* + * 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. + */ + +#pragma once + +#include <array> +#include <cstdint> +#include <stdexcept> +#include <string> +#include <vector> + + +namespace qrcodegen { + +/* + * A segment of character/binary/control data in a QR Code symbol. + * Instances of this class are immutable. + * The mid-level way to create a segment is to take the payload data + * and call a static factory function such as QrSegment::makeNumeric(). + * The low-level way to create a segment is to custom-make the bit buffer + * and call the QrSegment() constructor with appropriate values. + * This segment class imposes no length restrictions, but QR Codes have restrictions. + * Even in the most favorable conditions, a QR Code can only hold 7089 characters of data. + * Any segment longer than this is meaningless for the purpose of generating QR Codes. + */ +class QrSegment final { + + /*---- Public helper enumeration ----*/ + + /* + * Describes how a segment's data bits are interpreted. Immutable. + */ + public: class Mode final { + + /*-- Constants --*/ + + public: static const Mode NUMERIC; + public: static const Mode ALPHANUMERIC; + public: static const Mode BYTE; + public: static const Mode KANJI; + public: static const Mode ECI; + + + /*-- Fields --*/ + + // The mode indicator bits, which is a uint4 value (range 0 to 15). + private: int modeBits; + + // Number of character count bits for three different version ranges. + private: int numBitsCharCount[3]; + + + /*-- Constructor --*/ + + private: Mode(int mode, int cc0, int cc1, int cc2); + + + /*-- Methods --*/ + + /* + * (Package-private) Returns the mode indicator bits, which is an unsigned 4-bit value (range 0 to 15). + */ + public: int getModeBits() const; + + /* + * (Package-private) Returns the bit width of the character count field for a segment in + * this mode in a QR Code at the given version number. The result is in the range [0, 16]. + */ + public: int numCharCountBits(int ver) const; + + }; + + + + /*---- Static factory functions (mid level) ----*/ + + /* + * Returns a segment representing the given binary data encoded in + * byte mode. All input byte vectors are acceptable. Any text string + * can be converted to UTF-8 bytes and encoded as a byte mode segment. + */ + public: static QrSegment makeBytes(const std::vector<std::uint8_t> &data); + + + /* + * Returns a segment representing the given string of decimal digits encoded in numeric mode. + */ + public: static QrSegment makeNumeric(const char *digits); + + + /* + * Returns a segment representing the given text string encoded in alphanumeric mode. + * The characters allowed are: 0 to 9, A to Z (uppercase only), space, + * dollar, percent, asterisk, plus, hyphen, period, slash, colon. + */ + public: static QrSegment makeAlphanumeric(const char *text); + + + /* + * Returns a list of zero or more segments to represent the given text string. The result + * may use various segment modes and switch modes to optimize the length of the bit stream. + */ + public: static std::vector<QrSegment> makeSegments(const char *text); + + + /* + * Returns a segment representing an Extended Channel Interpretation + * (ECI) designator with the given assignment value. + */ + public: static QrSegment makeEci(long assignVal); + + + /*---- Public static helper functions ----*/ + + /* + * Tests whether the given string can be encoded as a segment in alphanumeric mode. + * A string is encodable iff each character is in the following set: 0 to 9, A to Z + * (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon. + */ + public: static bool isAlphanumeric(const char *text); + + + /* + * Tests whether the given string can be encoded as a segment in numeric mode. + * A string is encodable iff each character is in the range 0 to 9. + */ + public: static bool isNumeric(const char *text); + + + + /*---- Instance fields ----*/ + + /* The mode indicator of this segment. Accessed through getMode(). */ + private: Mode mode; + + /* The length of this segment's unencoded data. Measured in characters for + * numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode. + * Always zero or positive. Not the same as the data's bit length. + * Accessed through getNumChars(). */ + private: int numChars; + + /* The data bits of this segment. Accessed through getData(). */ + private: std::vector<bool> data; + + + /*---- Constructors (low level) ----*/ + + /* + * Creates a new QR Code segment with the given attributes and data. + * The character count (numCh) must agree with the mode and the bit buffer length, + * but the constraint isn't checked. The given bit buffer is copied and stored. + */ + public: QrSegment(Mode md, int numCh, const std::vector<bool> &dt); + + + /* + * Creates a new QR Code segment with the given parameters and data. + * The character count (numCh) must agree with the mode and the bit buffer length, + * but the constraint isn't checked. The given bit buffer is moved and stored. + */ + public: QrSegment(Mode md, int numCh, std::vector<bool> &&dt); + + + /*---- Methods ----*/ + + /* + * Returns the mode field of this segment. + */ + public: Mode getMode() const; + + + /* + * Returns the character count field of this segment. + */ + public: int getNumChars() const; + + + /* + * Returns the data bits of this segment. + */ + public: const std::vector<bool> &getData() const; + + + // (Package-private) Calculates the number of bits needed to encode the given segments at + // the given version. Returns a non-negative number if successful. Otherwise returns -1 if a + // segment has too many characters to fit its length field, or the total bits exceeds INT_MAX. + public: static int getTotalBits(const std::vector<QrSegment> &segs, int version); + + + /*---- Private constant ----*/ + + /* The set of all legal characters in alphanumeric mode, where + * each character value maps to the index in the string. */ + private: static const char *ALPHANUMERIC_CHARSET; + +}; + + + +/* + * A QR Code symbol, which is a type of two-dimension barcode. + * Invented by Denso Wave and described in the ISO/IEC 18004 standard. + * Instances of this class represent an immutable square grid of black and white cells. + * The class provides static factory functions to create a QR Code from text or binary data. + * The class covers the QR Code Model 2 specification, supporting all versions (sizes) + * from 1 to 40, all 4 error correction levels, and 4 character encoding modes. + * + * Ways to create a QR Code object: + * - High level: Take the payload data and call QrCode::encodeText() or QrCode::encodeBinary(). + * - Mid level: Custom-make the list of segments and call QrCode::encodeSegments(). + * - Low level: Custom-make the array of data codeword bytes (including + * segment headers and final padding, excluding error correction codewords), + * supply the appropriate version number, and call the QrCode() constructor. + * (Note that all ways require supplying the desired error correction level.) + */ +class QrCode final { + + /*---- Public helper enumeration ----*/ + + /* + * The error correction level in a QR Code symbol. + */ + public: enum class Ecc { + LOW = 0 , // The QR Code can tolerate about 7% erroneous codewords + MEDIUM , // The QR Code can tolerate about 15% erroneous codewords + QUARTILE, // The QR Code can tolerate about 25% erroneous codewords + HIGH , // The QR Code can tolerate about 30% erroneous codewords + }; + + + // Returns a value in the range 0 to 3 (unsigned 2-bit integer). + private: static int getFormatBits(Ecc ecl); + + + + /*---- Static factory functions (high level) ----*/ + + /* + * Returns a QR Code representing the given Unicode text string at the given error correction level. + * As a conservative upper bound, this function is guaranteed to succeed for strings that have 2953 or fewer + * UTF-8 code units (not Unicode code points) if the low error correction level is used. The smallest possible + * QR Code version is automatically chosen for the output. The ECC level of the result may be higher than + * the ecl argument if it can be done without increasing the version. + */ + public: static QrCode encodeText(const char *text, Ecc ecl); + + + /* + * Returns a QR Code representing the given binary data at the given error correction level. + * This function always encodes using the binary segment mode, not any text mode. The maximum number of + * bytes allowed is 2953. The smallest possible QR Code version is automatically chosen for the output. + * The ECC level of the result may be higher than the ecl argument if it can be done without increasing the version. + */ + public: static QrCode encodeBinary(const std::vector<std::uint8_t> &data, Ecc ecl); + + + /*---- Static factory functions (mid level) ----*/ + + /* + * Returns a QR Code representing the given segments with the given encoding parameters. + * The smallest possible QR Code version within the given range is automatically + * chosen for the output. Iff boostEcl is true, then the ECC level of the result + * may be higher than the ecl argument if it can be done without increasing the + * version. The mask number is either between 0 to 7 (inclusive) to force that + * mask, or -1 to automatically choose an appropriate mask (which may be slow). + * This function allows the user to create a custom sequence of segments that switches + * between modes (such as alphanumeric and byte) to encode text in less space. + * This is a mid-level API; the high-level API is encodeText() and encodeBinary(). + */ + public: static QrCode encodeSegments(const std::vector<QrSegment> &segs, Ecc ecl, + int minVersion=1, int maxVersion=40, int mask=-1, bool boostEcl=true); // All optional parameters + + + + /*---- Instance fields ----*/ + + // Immutable scalar parameters: + + /* The version number of this QR Code, which is between 1 and 40 (inclusive). + * This determines the size of this barcode. */ + private: int version; + + /* The width and height of this QR Code, measured in modules, between + * 21 and 177 (inclusive). This is equal to version * 4 + 17. */ + private: int size; + + /* The error correction level used in this QR Code. */ + private: Ecc errorCorrectionLevel; + + /* The index of the mask pattern used in this QR Code, which is between 0 and 7 (inclusive). + * Even if a QR Code is created with automatic masking requested (mask = -1), + * the resulting object still has a mask value between 0 and 7. */ + private: int mask; + + // Private grids of modules/pixels, with dimensions of size*size: + + // The modules of this QR Code (false = white, true = black). + // Immutable after constructor finishes. Accessed through getModule(). + private: std::vector<std::vector<bool> > modules; + + // Indicates function modules that are not subjected to masking. Discarded when constructor finishes. + private: std::vector<std::vector<bool> > isFunction; + + + + /*---- Constructor (low level) ----*/ + + /* + * Creates a new QR Code with the given version number, + * error correction level, data codeword bytes, and mask number. + * This is a low-level API that most users should not use directly. + * A mid-level API is the encodeSegments() function. + */ + public: QrCode(int ver, Ecc ecl, const std::vector<std::uint8_t> &dataCodewords, int msk); + + + + /*---- Public instance methods ----*/ + + /* + * Returns this QR Code's version, in the range [1, 40]. + */ + public: int getVersion() const; + + + /* + * Returns this QR Code's size, in the range [21, 177]. + */ + public: int getSize() const; + + + /* + * Returns this QR Code's error correction level. + */ + public: Ecc getErrorCorrectionLevel() const; + + + /* + * Returns this QR Code's mask, in the range [0, 7]. + */ + public: int getMask() const; + + + /* + * Returns the color of the module (pixel) at the given coordinates, which is false + * for white or true for black. The top left corner has the coordinates (x=0, y=0). + * If the given coordinates are out of bounds, then false (white) is returned. + */ + public: bool getModule(int x, int y) const; + + + /* + * Returns a string of SVG code for an image depicting this QR Code, with the given number + * of border modules. The string always uses Unix newlines (\n), regardless of the platform. + */ + public: std::string toSvgString(int border) const; + + + + /*---- Private helper methods for constructor: Drawing function modules ----*/ + + // Reads this object's version field, and draws and marks all function modules. + private: void drawFunctionPatterns(); + + + // 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. + private: void drawFormatBits(int msk); + + + // Draws two copies of the version bits (with its own error correction code), + // based on this object's version field, iff 7 <= version <= 40. + private: void drawVersion(); + + + // Draws a 9*9 finder pattern including the border separator, + // with the center module at (x, y). Modules can be out of bounds. + private: void drawFinderPattern(int x, int y); + + + // Draws a 5*5 alignment pattern, with the center module + // at (x, y). All modules must be in bounds. + private: void drawAlignmentPattern(int x, int y); + + + // Sets the color of a module and marks it as a function module. + // Only used by the constructor. Coordinates must be in bounds. + private: void setFunctionModule(int x, int y, bool isBlack); + + + // Returns the color of the module at the given coordinates, which must be in range. + private: bool module(int x, int y) const; + + + /*---- Private helper methods for constructor: Codewords and masking ----*/ + + // Returns a new byte string representing the given data with the appropriate error correction + // codewords appended to it, based on this object's version and error correction level. + private: std::vector<std::uint8_t> addEccAndInterleave(const std::vector<std::uint8_t> &data) const; + + + // Draws the given sequence of 8-bit codewords (data and error correction) onto the entire + // data area of this QR Code. Function modules need to be marked off before this is called. + private: void drawCodewords(const std::vector<std::uint8_t> &data); + + + // XORs the codeword modules in this QR Code with the given mask pattern. + // The function modules must be marked and the codeword bits must be drawn + // before masking. Due to the arithmetic of XOR, calling applyMask() with + // the same mask value a second time will undo the mask. A final well-formed + // QR Code needs exactly one (not zero, two, etc.) mask applied. + private: void applyMask(int msk); + + + // 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. + private: long getPenaltyScore() const; + + + + /*---- Private helper functions ----*/ + + // Returns an ascending list of positions of alignment patterns for this version number. + // Each position is in the range [0,177), and are used on both the x and y axes. + // This could be implemented as lookup table of 40 variable-length lists of unsigned bytes. + private: std::vector<int> getAlignmentPatternPositions() const; + + + // 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. + private: static int getNumRawDataModules(int ver); + + + // Returns the number of 8-bit data (i.e. not error correction) codewords contained in any + // QR Code of the given version number and error correction level, with remainder bits discarded. + // This stateless pure function could be implemented as a (40*4)-cell lookup table. + private: static int getNumDataCodewords(int ver, Ecc ecl); + + + // Returns a Reed-Solomon ECC generator polynomial for the given degree. This could be + // implemented as a lookup table over all possible parameter values, instead of as an algorithm. + private: static std::vector<std::uint8_t> reedSolomonComputeDivisor(int degree); + + + // Returns the Reed-Solomon error correction codeword for the given data and divisor polynomials. + private: static std::vector<std::uint8_t> reedSolomonComputeRemainder(const std::vector<std::uint8_t> &data, const std::vector<std::uint8_t> &divisor); + + + // 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. + private: static std::uint8_t reedSolomonMultiply(std::uint8_t x, std::uint8_t y); + + + // Can only be called immediately after a white run is added, and + // returns either 0, 1, or 2. A helper function for getPenaltyScore(). + private: int finderPenaltyCountPatterns(const std::array<int,7> &runHistory) const; + + + // Must be called at the end of a line (row or column) of modules. A helper function for getPenaltyScore(). + private: int finderPenaltyTerminateAndCount(bool currentRunColor, int currentRunLength, std::array<int,7> &runHistory) const; + + + // Pushes the given value to the front and drops the last value. A helper function for getPenaltyScore(). + private: void finderPenaltyAddHistory(int currentRunLength, std::array<int,7> &runHistory) const; + + + // Returns true iff the i'th bit of x is set to 1. + private: static bool getBit(long x, int i); + + + /*---- Constants and tables ----*/ + + // The minimum version number supported in the QR Code Model 2 standard. + public: static constexpr int MIN_VERSION = 1; + + // The maximum version number supported in the QR Code Model 2 standard. + public: static constexpr int MAX_VERSION = 40; + + + // For use in getPenaltyScore(), when evaluating which mask is best. + private: static const int PENALTY_N1; + private: static const int PENALTY_N2; + private: static const int PENALTY_N3; + private: static const int PENALTY_N4; + + + private: static const std::int8_t ECC_CODEWORDS_PER_BLOCK[4][41]; + private: static const std::int8_t NUM_ERROR_CORRECTION_BLOCKS[4][41]; + +}; + + + +/*---- Public exception class ----*/ + +/* + * Thrown when the supplied data does not fit any QR Code version. Ways to handle this exception include: + * - Decrease the error correction level if it was greater than Ecc::LOW. + * - If the encodeSegments() function was called with a maxVersion argument, then increase + * it if it was less than QrCode::MAX_VERSION. (This advice does not apply to the other + * factory functions because they search all versions up to QrCode::MAX_VERSION.) + * - Split the text data into better or optimal segments in order to reduce the number of bits required. + * - Change the text or binary data to be shorter. + * - Change the text to fit the character set of a particular segment mode (e.g. alphanumeric). + * - Propagate the error upward to the caller/user. + */ +class data_too_long : public std::length_error { + + public: explicit data_too_long(const std::string &msg); + +}; + + + +/* + * An appendable sequence of bits (0s and 1s). Mainly used by QrSegment. + */ +class BitBuffer final : public std::vector<bool> { + + /*---- Constructor ----*/ + + // Creates an empty bit buffer (length 0). + public: BitBuffer(); + + + + /*---- Method ----*/ + + // Appends the given number of low-order bits of the given value + // to this buffer. Requires 0 <= len <= 31 and val < 2^len. + public: void appendBits(std::uint32_t val, int len); + +}; + +} |