summaryrefslogtreecommitdiffstats
path: root/panels/network/qrcodegen.h
diff options
context:
space:
mode:
Diffstat (limited to 'panels/network/qrcodegen.h')
-rw-r--r--panels/network/qrcodegen.h311
1 files changed, 311 insertions, 0 deletions
diff --git a/panels/network/qrcodegen.h b/panels/network/qrcodegen.h
new file mode 100644
index 0000000..55e2bfe
--- /dev/null
+++ b/panels/network/qrcodegen.h
@@ -0,0 +1,311 @@
+/*
+ * 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);
+
+
+#ifdef __cplusplus
+}
+#endif