143 lines
5.9 KiB
C
143 lines
5.9 KiB
C
/*
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* QR Code generator library (C)
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*
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* Copyright (c) Project Nayuki. (MIT License)
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* https://www.nayuki.io/page/qr-code-generator-library
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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* - The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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* - The Software is provided "as is", without warranty of any kind, express or
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* implied, including but not limited to the warranties of merchantability,
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* fitness for a particular purpose and noninfringement. In no event shall the
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* authors or copyright holders be liable for any claim, damages or other
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* liability, whether in an action of contract, tort or otherwise, arising from,
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* out of or in connection with the Software or the use or other dealings in the
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* Software.
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*/
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#pragma once
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdint.h>
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/*---- Enumeration types and values ----*/
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/*
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* Represents the error correction level used in a QR Code symbol.
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*/
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enum qrcodegen_Ecc {
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qrcodegen_Ecc_LOW = 0,
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qrcodegen_Ecc_MEDIUM,
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qrcodegen_Ecc_QUARTILE,
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qrcodegen_Ecc_HIGH,
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};
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/*
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* Represents the mask pattern used in a QR Code symbol.
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*/
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enum qrcodegen_Mask {
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qrcodegen_Mask_AUTO = -1,
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qrcodegen_Mask_0 = 0,
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qrcodegen_Mask_1,
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qrcodegen_Mask_2,
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qrcodegen_Mask_3,
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qrcodegen_Mask_4,
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qrcodegen_Mask_5,
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qrcodegen_Mask_6,
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qrcodegen_Mask_7,
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};
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/*---- Macro constants and functions ----*/
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// The minimum and maximum defined QR Code version numbers for Model 2.
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#define qrcodegen_VERSION_MIN 1
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#define qrcodegen_VERSION_MAX 40
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// Calculates the number of bytes needed to store any QR Code up to and including the given version number,
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// as a compile-time constant. For example, 'uint8_t buffer[qrcodegen_BUFFER_LEN_FOR_VERSION(25)];'
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// can store any single QR Code from version 1 to 25, inclusive.
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#define qrcodegen_BUFFER_LEN_FOR_VERSION(n) ((((n) * 4 + 17) * ((n) * 4 + 17) + 7) / 8 + 1)
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// The worst-case number of bytes needed to store one QR Code, up to and including
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// version 40. This value equals 3918, which is just under 4 kilobytes.
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#define qrcodegen_BUFFER_LEN_MAX qrcodegen_BUFFER_LEN_FOR_VERSION(qrcodegen_VERSION_MAX)
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/*---- Functions to generate QR Codes ----*/
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/*
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* Encodes the given text string to a QR Code symbol, returning true if encoding succeeded.
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* If the data is too long to fit in any version in the given range
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* at the given ECC level, then false is returned.
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* - The input text must be encoded in UTF-8 and contain no NULs.
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* - The variables ecl and mask must correspond to enum constant values.
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* - Requires 1 <= minVersion <= maxVersion <= 40.
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* - The arrays tempBuffer and qrcode must each have a length
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* of at least qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion).
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* - After the function returns, tempBuffer contains no useful data.
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* - If successful, the resulting QR Code may use numeric,
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* alphanumeric, or byte mode to encode the text.
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* - In the most optimistic case, a QR Code at version 40 with low ECC
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* can hold any UTF-8 string up to 2953 bytes, or any alphanumeric string
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* up to 4296 characters, or any digit string up to 7089 characters.
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* These numbers represent the hard upper limit of the QR Code standard.
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* - Please consult the QR Code specification for information on
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* data capacities per version, ECC level, and text encoding mode.
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*/
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bool qrcodegen_encodeText(const char *text, uint8_t tempBuffer[], uint8_t qrcode[],
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enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl);
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/*
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* Encodes the given binary data to a QR Code symbol, returning true if encoding succeeded.
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* If the data is too long to fit in any version in the given range
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* at the given ECC level, then false is returned.
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* - The input array range dataAndTemp[0 : dataLen] should normally be
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* valid UTF-8 text, but is not required by the QR Code standard.
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* - The variables ecl and mask must correspond to enum constant values.
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* - Requires 1 <= minVersion <= maxVersion <= 40.
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* - The arrays dataAndTemp and qrcode must each have a length
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* of at least qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion).
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* - After the function returns, the contents of dataAndTemp may have changed,
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* and does not represent useful data anymore.
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* - If successful, the resulting QR Code will use byte mode to encode the data.
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* - In the most optimistic case, a QR Code at version 40 with low ECC can hold any byte
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* sequence up to length 2953. This is the hard upper limit of the QR Code standard.
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* - Please consult the QR Code specification for information on
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* data capacities per version, ECC level, and text encoding mode.
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*/
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bool qrcodegen_encodeBinary(uint8_t dataAndTemp[], size_t dataLen, uint8_t qrcode[],
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enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl);
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/*---- Functions to extract raw data from QR Codes ----*/
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/*
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* Returns the side length of the given QR Code, assuming that encoding succeeded.
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* The result is in the range [21, 177]. Note that the length of the array buffer
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* is related to the side length - every 'uint8_t qrcode[]' must have length at least
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* qrcodegen_BUFFER_LEN_FOR_VERSION(version), which equals ceil(size^2 / 8 + 1).
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*/
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int qrcodegen_getSize(const uint8_t qrcode[]);
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/*
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* Returns the color of the module (pixel) at the given coordinates, which is either
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* false for white or true for black. The top left corner has the coordinates (x=0, y=0).
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* If the given coordinates are out of bounds, then false (white) is returned.
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*/
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bool qrcodegen_getModule(const uint8_t qrcode[], int x, int y);
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