QR-Code-generator/c/qrcodegen.h

119 lines
4.5 KiB
C

/*
* 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 <stdint.h>
/*---- Enumeration types and constants ----*/
/*
* Represents the error correction level used in a QR Code symbol.
*/
enum qrcodegen_Ecc {
qrcodegen_Ecc_LOW,
qrcodegen_Ecc_MEDIUM,
qrcodegen_Ecc_QUARTILE,
qrcodegen_Ecc_HIGH,
};
/*
* Represents the mask pattern used in a QR Code symbol.
*/
enum qrcodegen_Mask {
qrcodegen_Mask_AUTO = -1,
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,
};
/*---- Macro constants and functions ----*/
// The minimum and maximum defined QR Code version numbers.
#define qrcodegen_VERSION_MIN 1
#define qrcodegen_VERSION_MAX 40
// 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.
#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 3917, which is just under 4 kilobytes.
#define qrcodegen_BUFFER_LEN_MAX qrcodegen_BUFFER_LEN_FOR_VERSION(qrcodegen_VERSION_MAX)
/*---- Top-level QR Code functions ----*/
/*
* Encodes the given text data to a QR Code symbol, returning the actual version number used.
* If the data is too long to fit in any version in the given range at the given ECC level,
* then 0 is returned. Both dataAndTemp and qrcode each must have length at least
* qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion). The text must be encoded in UTF-8.
* The resulting QR Code may use numeric, alphanumeric, or byte mode to encode the text.
*/
int 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 symbol, returning the actual version number used.
* If the data is too long to fit in any version in the given range at the given ECC level,
* then 0 is returned. dataAndTemp[0 : dataLen] represents the input data, and the function
* may overwrite the array's contents as a temporary work area. Both dataAndTemp and qrcode
* must have length at least qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion).
*/
int 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);
/*---- Low-level QR Code functions ----*/
/*
* Returns the side length of any QR Code of the given version number.
* The version must be in the range [1, 40]. The result is in the range [21, 177].
* Note that every 'uint8_t qrcode[]' buffer must have a length of at least
* ceil(size^2 / 8 + 1), which also equals qrcodegen_BUFFER_LEN_FOR_VERSION(version).
*/
int qrcodegen_getSize(int version);
/*
* Returns the color of the module (pixel) at the given coordinates, which is either
* true for white or false 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 version, int x, int y);