/*
  * 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 <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 
 /*
  * This library creates QR Code symbols, which is a type of two-dimension barcode.
  * Invented by Denso Wave and described in the ISO/IEC 18004 standard.
  * A QR Code structure is an immutable square grid of black and white cells.
  * The library provides functions to create a QR Code from text or binary data.
  * The library 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 qrcodegen_encodeText() or qrcodegen_encodeBinary().
  * - Low level: Custom-make the list of segments and call
  *   qrcodegen_encodeSegments() or qrcodegen_encodeSegmentsAdvanced().
  * (Note that all ways require supplying the desired error correction level and various byte buffers.)
  */
 
 
 /*---- Enum and struct types----*/
 
 /*
  * The error correction level in a QR Code symbol.
  */
 enum qrcodegen_Ecc {
 	// Must be declared in ascending order of error protection
 	// so that an internal qrcodegen function works properly
 	qrcodegen_Ecc_LOW = 0 ,  // The QR Code can tolerate about  7% erroneous codewords
 	qrcodegen_Ecc_MEDIUM  ,  // The QR Code can tolerate about 15% erroneous codewords
 	qrcodegen_Ecc_QUARTILE,  // The QR Code can tolerate about 25% erroneous codewords
 	qrcodegen_Ecc_HIGH    ,  // The QR Code can tolerate about 30% erroneous codewords
 };
 
 
 /*
  * The mask pattern used in a QR Code symbol.
  */
 enum qrcodegen_Mask {
 	// A special value to tell the QR Code encoder to
 	// automatically select an appropriate mask pattern
 	qrcodegen_Mask_AUTO = -1,
 	// The eight actual mask patterns
 	qrcodegen_Mask_0 = 0,
 	qrcodegen_Mask_1,
 	qrcodegen_Mask_2,
 	qrcodegen_Mask_3,
 	qrcodegen_Mask_4,
 	qrcodegen_Mask_5,
 	qrcodegen_Mask_6,
 	qrcodegen_Mask_7,
 };
 
 
 /*
  * Describes how a segment's data bits are interpreted.
  */
 enum qrcodegen_Mode {
 	qrcodegen_Mode_NUMERIC      = 0x1,
 	qrcodegen_Mode_ALPHANUMERIC = 0x2,
 	qrcodegen_Mode_BYTE         = 0x4,
 	qrcodegen_Mode_KANJI        = 0x8,
 	qrcodegen_Mode_ECI          = 0x7,
 };
 
 
 /*
  * A segment of character/binary/control data in a QR Code symbol.
  * The mid-level way to create a segment is to take the payload data
  * and call a factory function such as qrcodegen_makeNumeric().
  * The low-level way to create a segment is to custom-make the bit buffer
  * and initialize a qrcodegen_Segment struct with appropriate values.
  * 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.
  * Moreover, the maximum allowed bit length is 32767 because
  * the largest QR Code (version 40) has 31329 modules.
  */
 struct qrcodegen_Segment {
 	// The mode indicator of this segment.
 	enum qrcodegen_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.
 	int numChars;
 	
 	// The data bits of this segment, packed in bitwise big endian.
 	// Can be null if the bit length is zero.
 	uint8_t *data;
 	
 	// The number of valid data bits used in the buffer. Requires
 	// 0 <= bitLength <= 32767, and bitLength <= (capacity of data array) * 8.
 	// The character count (numChars) must agree with the mode and the bit buffer length.
 	int bitLength;
 };
 
 
 
 /*---- Macro constants and functions ----*/
 
 #define qrcodegen_VERSION_MIN   1  // The minimum version number supported in the QR Code Model 2 standard
 #define qrcodegen_VERSION_MAX  40  // The maximum version number supported in the QR Code Model 2 standard
 
 // Calculates the number of bytes needed to store any QR Code up to and including the given version number,
 // as a compile-time constant. For example, 'uint8_t buffer[qrcodegen_BUFFER_LEN_FOR_VERSION(25)];'
 // can store any single QR Code from version 1 to 25 (inclusive). The result fits in an int (or int16).
 // Requires qrcodegen_VERSION_MIN <= n <= qrcodegen_VERSION_MAX.
 #define qrcodegen_BUFFER_LEN_FOR_VERSION(n)  ((((n) * 4 + 17) * ((n) * 4 + 17) + 7) / 8 + 1)
 
 // The worst-case number of bytes needed to store one QR Code, up to and including
 // version 40. This value equals 3918, which is just under 4 kilobytes.
 // Use this more convenient value to avoid calculating tighter memory bounds for buffers.
 #define qrcodegen_BUFFER_LEN_MAX  qrcodegen_BUFFER_LEN_FOR_VERSION(qrcodegen_VERSION_MAX)
 
 
 
 /*---- Functions (high level) to generate QR Codes ----*/
 
 /*
  * Encodes the given text string to a QR Code, returning true if encoding succeeded.
  * If the data is too long to fit in any version in the given range
  * at the given ECC level, then false is returned.
  * - The input text must be encoded in UTF-8 and contain no NULs.
  * - The variables ecl and mask must correspond to enum constant values.
  * - Requires 1 <= minVersion <= maxVersion <= 40.
  * - The arrays tempBuffer and qrcode must each have a length
  *   of at least qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion).
  * - After the function returns, tempBuffer contains no useful data.
  * - If successful, the resulting QR Code may use numeric,
  *   alphanumeric, or byte mode to encode the text.
  * - In the most optimistic case, a QR Code at version 40 with low ECC
  *   can hold any UTF-8 string up to 2953 bytes, or any alphanumeric string
  *   up to 4296 characters, or any digit string up to 7089 characters.
  *   These numbers represent the hard upper limit of the QR Code standard.
  * - Please consult the QR Code specification for information on
  *   data capacities per version, ECC level, and text encoding mode.
  */
 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);
 
 
 /*
  * Encodes the given binary data to a QR Code, returning true if encoding succeeded.
  * If the data is too long to fit in any version in the given range
  * at the given ECC level, then false is returned.
  * - The input array range dataAndTemp[0 : dataLen] should normally be
  *   valid UTF-8 text, but is not required by the QR Code standard.
  * - The variables ecl and mask must correspond to enum constant values.
  * - Requires 1 <= minVersion <= maxVersion <= 40.
  * - The arrays dataAndTemp and qrcode must each have a length
  *   of at least qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion).
  * - After the function returns, the contents of dataAndTemp may have changed,
  *   and does not represent useful data anymore.
  * - If successful, the resulting QR Code will use byte mode to encode the data.
  * - In the most optimistic case, a QR Code at version 40 with low ECC can hold any byte
  *   sequence up to length 2953. This is the hard upper limit of the QR Code standard.
  * - Please consult the QR Code specification for information on
  *   data capacities per version, ECC level, and text encoding mode.
  */
 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);
 
 
 /*---- Functions (low level) to generate QR Codes ----*/
 
 /*
  * Renders a QR Code representing the given segments at the given error correction level.
  * The smallest possible QR Code version is automatically chosen for the output. Returns true if
  * QR Code creation succeeded, or false if the data is too long to fit in any version. The ECC level
  * of the result may be higher than the ecl argument if it can be done without increasing the version.
  * 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 low-level API; the high-level API is qrcodegen_encodeText() and qrcodegen_encodeBinary().
  * To save memory, the segments' data buffers can alias/overlap tempBuffer, and will
  * result in them being clobbered, but the QR Code output will still be correct.
  * But the qrcode array must not overlap tempBuffer or any segment's data buffer.
  */
 bool qrcodegen_encodeSegments(const struct qrcodegen_Segment segs[], size_t len,
 	enum qrcodegen_Ecc ecl, uint8_t tempBuffer[], uint8_t qrcode[]);
 
 
 /*
  * Renders a QR Code representing the given segments with the given encoding parameters.
  * Returns true if QR Code creation succeeded, or false if the data is too long to fit in the range of versions.
  * 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 low-level API; the high-level API is qrcodegen_encodeText() and qrcodegen_encodeBinary().
  * To save memory, the segments' data buffers can alias/overlap tempBuffer, and will
  * result in them being clobbered, but the QR Code output will still be correct.
  * But the qrcode array must not overlap tempBuffer or any segment's data buffer.
  */
 bool qrcodegen_encodeSegmentsAdvanced(const struct qrcodegen_Segment segs[], size_t len, enum qrcodegen_Ecc ecl,
 	int minVersion, int maxVersion, int mask, bool boostEcl, uint8_t tempBuffer[], uint8_t qrcode[]);
 
 
 /*
  * 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.
  */
 bool qrcodegen_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.
  */
 bool qrcodegen_isNumeric(const char *text);
 
 
 /*
  * Returns the number of bytes (uint8_t) needed for the data buffer of a segment
  * containing the given number of characters using the given mode. Notes:
  * - Returns SIZE_MAX on failure, i.e. numChars > INT16_MAX or
  *   the number of needed bits exceeds INT16_MAX (i.e. 32767).
  * - Otherwise, all valid results are in the range [0, ceil(INT16_MAX / 8)], i.e. at most 4096.
  * - It is okay for the user to allocate more bytes for the buffer than needed.
  * - For byte mode, numChars measures the number of bytes, not Unicode code points.
  * - For ECI mode, numChars must be 0, and the worst-case number of bytes is returned.
  *   An actual ECI segment can have shorter data. For non-ECI modes, the result is exact.
  */
 size_t qrcodegen_calcSegmentBufferSize(enum qrcodegen_Mode mode, size_t numChars);
 
 
 /*
  * Returns a segment representing the given binary data encoded in
  * byte mode. All input byte arrays are acceptable. Any text string
  * can be converted to UTF-8 bytes and encoded as a byte mode segment.
  */
 struct qrcodegen_Segment qrcodegen_makeBytes(const uint8_t data[], size_t len, uint8_t buf[]);
 
 
 /*
  * Returns a segment representing the given string of decimal digits encoded in numeric mode.
  */
 struct qrcodegen_Segment qrcodegen_makeNumeric(const char *digits, uint8_t buf[]);
 
 
 /*
  * 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.
  */
 struct qrcodegen_Segment qrcodegen_makeAlphanumeric(const char *text, uint8_t buf[]);
 
 
 /*
  * Returns a segment representing an Extended Channel Interpretation
  * (ECI) designator with the given assignment value.
  */
 struct qrcodegen_Segment qrcodegen_makeEci(long assignVal, uint8_t buf[]);
 
 
 /*---- Functions to extract raw data from QR Codes ----*/
 
 /*
  * Returns the side length of the given QR Code, assuming that encoding succeeded.
  * The result is in the range [21, 177]. Note that the length of the array buffer
  * is related to the side length - every 'uint8_t qrcode[]' must have length at least
  * qrcodegen_BUFFER_LEN_FOR_VERSION(version), which equals ceil(size^2 / 8 + 1).
  */
 int qrcodegen_getSize(const uint8_t qrcode[]);
 
 
 /*
  * 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.
  */
 bool qrcodegen_getModule(const uint8_t qrcode[], int x, int y);
 
 /*
  * Returns the qrcode size of the specified version. Returns -1 on failure
  */
 int qrcodegen_version2size(int version);
 /*
  * Returns the min version of the data that can be stored. Returns -1 on failure
  */
 int qrcodegen_getMinFitVersion(enum qrcodegen_Ecc ecl, size_t dataLen);
 
 #ifdef __cplusplus
 }
 #endif

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