/++
This is a port of the C code from https://www.nayuki.io/page/qr-code-generator-library
History:
Originally written in C by Project Nayuki.
Ported to D by me on July 26, 2021
+/
/*
* 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.
*/
module arsd.qrcode;
///
unittest {
import arsd.qrcode;
void main() {
import arsd.simpledisplay;
QrCode code = QrCode("http://arsdnet.net/");
enum drawsize = 4;
// you have to have some border around it
auto window = new SimpleWindow(code.size * drawsize + 80, code.size * drawsize + 80);
{
auto painter = window.draw;
painter.clear(Color.white);
foreach(y; 0 .. code.size)
foreach(x; 0 .. code.size) {
if(code[x, y]) {
painter.outlineColor = Color.black;
painter.fillColor = Color.black;
} else {
painter.outlineColor = Color.white;
painter.fillColor = Color.white;
}
painter.drawRectangle(Point(x * drawsize + 40, y * drawsize + 40), Size(drawsize, drawsize));
}
}
window.eventLoop(0);
}
main; // exclude from docs
}
import core.stdc.stddef;
import core.stdc.stdint;
import core.stdc.string;
import core.stdc.config;
import core.stdc.stdlib;
import core.stdc.math;
/*
* 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.
*/
alias qrcodegen_Ecc = int;
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.
*/
alias qrcodegen_Mask = int;
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.
*/
alias qrcodegen_Mode = int;
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.
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 ----*/
enum qrcodegen_VERSION_MIN = 1; // The minimum version number supported in the QR Code Model 2 standard
enum 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.
auto qrcodegen_BUFFER_LEN_FOR_VERSION(int n) { return ((((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.
auto qrcodegen_BUFFER_LEN_MAX() { return 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,
qrcodegen_Ecc ecl, int minVersion, int maxVersion, 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,
qrcodegen_Ecc ecl, int minVersion, int maxVersion, qrcodegen_Mask mask, bool boostEcl);
/*---- Functions to extract raw data from QR Codes ----*/
/*
* 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.
*/
/*---- Forward declarations for private functions ----*/
// Regarding all public and private functions defined in this source file:
// - They require all pointer/array arguments to be not null unless the array length is zero.
// - They only read input scalar/array arguments, write to output pointer/array
// arguments, and return scalar values; they are "pure" functions.
// - They don't read mutable global variables or write to any global variables.
// - They don't perform I/O, read the clock, print to console, etc.
// - They allocate a small and constant amount of stack memory.
// - They don't allocate or free any memory on the heap.
// - They don't recurse or mutually recurse. All the code
// could be inlined into the top-level public functions.
// - They run in at most quadratic time with respect to input arguments.
// Most functions run in linear time, and some in constant time.
// There are no unbounded loops or non-obvious termination conditions.
// - They are completely thread-safe if the caller does not give the
// same writable buffer to concurrent calls to these functions.
/*---- Private tables of constants ----*/
// The set of all legal characters in alphanumeric mode, where each character
// value maps to the index in the string. For checking text and encoding segments.
static const char *ALPHANUMERIC_CHARSET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:";
// For generating error correction codes.
private const int8_t[41][4] ECC_CODEWORDS_PER_BLOCK = [
// Version: (note that index 0 is for padding, and is set to an illegal value)
//0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
[-1, 7, 10, 15, 20, 26, 18, 20, 24, 30, 18, 20, 24, 26, 30, 22, 24, 28, 30, 28, 28, 28, 28, 30, 30, 26, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // Low
[-1, 10, 16, 26, 18, 24, 16, 18, 22, 22, 26, 30, 22, 22, 24, 24, 28, 28, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28], // Medium
[-1, 13, 22, 18, 26, 18, 24, 18, 22, 20, 24, 28, 26, 24, 20, 30, 24, 28, 28, 26, 30, 28, 30, 30, 30, 30, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // Quartile
[-1, 17, 28, 22, 16, 22, 28, 26, 26, 24, 28, 24, 28, 22, 24, 24, 30, 28, 28, 26, 28, 30, 24, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30], // High
];
enum qrcodegen_REED_SOLOMON_DEGREE_MAX = 30; // Based on the table above
// For generating error correction codes.
private const int8_t[41][4] NUM_ERROR_CORRECTION_BLOCKS = [
// Version: (note that index 0 is for padding, and is set to an illegal value)
//0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
[-1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25], // Low
[-1, 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 9, 9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49], // Medium
[-1, 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68], // Quartile
[-1, 1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81], // High
];
// For automatic mask pattern selection.
static const int PENALTY_N1 = 3;
static const int PENALTY_N2 = 3;
static const int PENALTY_N3 = 40;
static const int PENALTY_N4 = 10;
/*---- High-level QR Code encoding functions ----*/
// Public function - see documentation comment in header file.
bool qrcodegen_encodeText(const char *text, uint8_t* tempBuffer, uint8_t* qrcode,
qrcodegen_Ecc ecl, int minVersion, int maxVersion, qrcodegen_Mask mask, bool boostEcl) {
size_t textLen = strlen(text);
if (textLen == 0)
return qrcodegen_encodeSegmentsAdvanced(null, 0, ecl, minVersion, maxVersion, mask, boostEcl, tempBuffer, qrcode);
size_t bufLen = qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion);
qrcodegen_Segment seg;
if (qrcodegen_isNumeric(text)) {
if (qrcodegen_calcSegmentBufferSize(qrcodegen_Mode_NUMERIC, textLen) > bufLen)
goto fail;
seg = qrcodegen_makeNumeric(text, tempBuffer);
} else if (qrcodegen_isAlphanumeric(text)) {
if (qrcodegen_calcSegmentBufferSize(qrcodegen_Mode_ALPHANUMERIC, textLen) > bufLen)
goto fail;
seg = qrcodegen_makeAlphanumeric(text, tempBuffer);
} else {
if (textLen > bufLen)
goto fail;
for (size_t i = 0; i < textLen; i++)
tempBuffer[i] = cast(uint8_t)text[i];
seg.mode = qrcodegen_Mode_BYTE;
seg.bitLength = calcSegmentBitLength(seg.mode, textLen);
if (seg.bitLength == -1)
goto fail;
seg.numChars = cast(int)textLen;
seg.data = tempBuffer;
}
return qrcodegen_encodeSegmentsAdvanced(&seg, 1, ecl, minVersion, maxVersion, mask, boostEcl, tempBuffer, qrcode);
fail:
qrcode[0] = 0; // Set size to invalid value for safety
return false;
}
// Public function - see documentation comment in header file.
bool qrcodegen_encodeBinary(uint8_t* dataAndTemp, size_t dataLen, uint8_t* qrcode,
qrcodegen_Ecc ecl, int minVersion, int maxVersion, qrcodegen_Mask mask, bool boostEcl) {
qrcodegen_Segment seg;
seg.mode = qrcodegen_Mode_BYTE;
seg.bitLength = calcSegmentBitLength(seg.mode, dataLen);
if (seg.bitLength == -1) {
qrcode[0] = 0; // Set size to invalid value for safety
return false;
}
seg.numChars = cast(int)dataLen;
seg.data = dataAndTemp;
return qrcodegen_encodeSegmentsAdvanced(&seg, 1, ecl, minVersion, maxVersion, mask, boostEcl, dataAndTemp, qrcode);
}
// Appends the given number of low-order bits of the given value to the given byte-based
// bit buffer, increasing the bit length. Requires 0 <= numBits <= 16 and val < 2^numBits.
private void appendBitsToBuffer(uint val, int numBits, uint8_t* buffer, int *bitLen) {
assert(0 <= numBits && numBits <= 16 && cast(c_ulong)val >> numBits == 0);
for (int i = numBits - 1; i >= 0; i--, (*bitLen)++)
buffer[*bitLen >> 3] |= ((val >> i) & 1) << (7 - (*bitLen & 7));
}
/*---- Low-level QR Code encoding functions ----*/
// Public function - see documentation comment in header file.
/*
* 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 qrcodegen_Segment* segs, size_t len,
qrcodegen_Ecc ecl, uint8_t* tempBuffer, uint8_t* qrcode) {
return qrcodegen_encodeSegmentsAdvanced(segs, len, ecl,
qrcodegen_VERSION_MIN, qrcodegen_VERSION_MAX, qrcodegen_Mask_AUTO, true, tempBuffer, qrcode);
}
// Public function - see documentation comment in header file.
/*
* 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 is either between qrcodegen_Mask_0 to 7 to force that mask, or
* qrcodegen_Mask_AUTO 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 qrcodegen_Segment* segs, size_t len, qrcodegen_Ecc ecl,
int minVersion, int maxVersion, qrcodegen_Mask mask, bool boostEcl, uint8_t* tempBuffer, uint8_t* qrcode) {
assert(segs != null || len == 0);
assert(qrcodegen_VERSION_MIN <= minVersion && minVersion <= maxVersion && maxVersion <= qrcodegen_VERSION_MAX);
assert(0 <= cast(int)ecl && cast(int)ecl <= 3 && -1 <= cast(int)mask && cast(int)mask <= 7);
// Find the minimal version_ number to use
int version_, dataUsedBits;
for (version_ = minVersion; ; version_++) {
int dataCapacityBits = getNumDataCodewords(version_, ecl) * 8; // Number of data bits available
dataUsedBits = getTotalBits(segs, len, version_);
if (dataUsedBits != -1 && dataUsedBits <= dataCapacityBits)
break; // This version_ number is found to be suitable
if (version_ >= maxVersion) { // All version_s in the range could not fit the given data
qrcode[0] = 0; // Set size to invalid value for safety
return false;
}
}
assert(dataUsedBits != -1);
// Increase the error correction level while the data still fits in the current version_ number
for (int i = cast(int)qrcodegen_Ecc_MEDIUM; i <= cast(int)qrcodegen_Ecc_HIGH; i++) { // From low to high
if (boostEcl && dataUsedBits <= getNumDataCodewords(version_, cast(qrcodegen_Ecc)i) * 8)
ecl = cast(qrcodegen_Ecc)i;
}
// Concatenate all segments to create the data bit string
memset(qrcode, 0, cast(size_t)qrcodegen_BUFFER_LEN_FOR_VERSION(version_) * (qrcode[0]).sizeof);
int bitLen = 0;
for (size_t i = 0; i < len; i++) {
const qrcodegen_Segment *seg = &segs[i];
appendBitsToBuffer(cast(uint)seg.mode, 4, qrcode, &bitLen);
appendBitsToBuffer(cast(uint)seg.numChars, numCharCountBits(seg.mode, version_), qrcode, &bitLen);
for (int j = 0; j < seg.bitLength; j++) {
int bit = (seg.data[j >> 3] >> (7 - (j & 7))) & 1;
appendBitsToBuffer(cast(uint)bit, 1, qrcode, &bitLen);
}
}
assert(bitLen == dataUsedBits);
// Add terminator and pad up to a byte if applicable
int dataCapacityBits = getNumDataCodewords(version_, ecl) * 8;
assert(bitLen <= dataCapacityBits);
int terminatorBits = dataCapacityBits - bitLen;
if (terminatorBits > 4)
terminatorBits = 4;
appendBitsToBuffer(0, terminatorBits, qrcode, &bitLen);
appendBitsToBuffer(0, (8 - bitLen % 8) % 8, qrcode, &bitLen);
assert(bitLen % 8 == 0);
// Pad with alternating bytes until data capacity is reached
for (uint8_t padByte = 0xEC; bitLen < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
appendBitsToBuffer(padByte, 8, qrcode, &bitLen);
// Draw function and data codeword modules
addEccAndInterleave(qrcode, version_, ecl, tempBuffer);
initializeFunctionModules(version_, qrcode);
drawCodewords(tempBuffer, getNumRawDataModules(version_) / 8, qrcode);
drawWhiteFunctionModules(qrcode, version_);
initializeFunctionModules(version_, tempBuffer);
// Handle masking
if (mask == qrcodegen_Mask_AUTO) { // Automatically choose best mask
long minPenalty = long.max;
for (int i = 0; i < 8; i++) {
qrcodegen_Mask msk = cast(qrcodegen_Mask)i;
applyMask(tempBuffer, qrcode, msk);
drawFormatBits(ecl, msk, qrcode);
long penalty = getPenaltyScore(qrcode);
if (penalty < minPenalty) {
mask = msk;
minPenalty = penalty;
}
applyMask(tempBuffer, qrcode, msk); // Undoes the mask due to XOR
}
}
assert(0 <= cast(int)mask && cast(int)mask <= 7);
applyMask(tempBuffer, qrcode, mask);
drawFormatBits(ecl, mask, qrcode);
return true;
}
/*---- Error correction code generation functions ----*/
// Appends error correction bytes to each block of the given data array, then interleaves
// bytes from the blocks and stores them in the result array. data[0 : dataLen] contains
// the input data. data[dataLen : rawCodewords] is used as a temporary work area and will
// be clobbered by this function. The final answer is stored in result[0 : rawCodewords].
private void addEccAndInterleave(uint8_t* data, int version_, qrcodegen_Ecc ecl, uint8_t* result) {
// Calculate parameter numbers
assert(0 <= cast(int)ecl && cast(int)ecl < 4 && qrcodegen_VERSION_MIN <= version_ && version_ <= qrcodegen_VERSION_MAX);
int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[cast(int)ecl][version_];
int blockEccLen = ECC_CODEWORDS_PER_BLOCK [cast(int)ecl][version_];
int rawCodewords = getNumRawDataModules(version_) / 8;
int dataLen = getNumDataCodewords(version_, ecl);
int numShortBlocks = numBlocks - rawCodewords % numBlocks;
int shortBlockDataLen = rawCodewords / numBlocks - blockEccLen;
// Split data into blocks, calculate ECC, and interleave
// (not concatenate) the bytes into a single sequence
uint8_t[qrcodegen_REED_SOLOMON_DEGREE_MAX] rsdiv;
reedSolomonComputeDivisor(blockEccLen, rsdiv.ptr);
const(uint8_t)* dat = data;
for (int i = 0; i < numBlocks; i++) {
int datLen = shortBlockDataLen + (i < numShortBlocks ? 0 : 1);
uint8_t *ecc = &data[dataLen]; // Temporary storage
reedSolomonComputeRemainder(dat, datLen, rsdiv.ptr, blockEccLen, ecc);
for (int j = 0, k = i; j < datLen; j++, k += numBlocks) { // Copy data
if (j == shortBlockDataLen)
k -= numShortBlocks;
result[k] = dat[j];
}
for (int j = 0, k = dataLen + i; j < blockEccLen; j++, k += numBlocks) // Copy ECC
result[k] = ecc[j];
dat += datLen;
}
}
// Returns the number of 8-bit codewords that can be used for storing data (not ECC),
// for the given version_ number and error correction level. The result is in the range [9, 2956].
private int getNumDataCodewords(int version_, qrcodegen_Ecc ecl) {
int v = version_, e = cast(int)ecl;
assert(0 <= e && e < 4);
return getNumRawDataModules(v) / 8
- ECC_CODEWORDS_PER_BLOCK [e][v]
* NUM_ERROR_CORRECTION_BLOCKS[e][v];
}
// 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 int getNumRawDataModules(int ver) {
assert(qrcodegen_VERSION_MIN <= ver && ver <= qrcodegen_VERSION_MAX);
int result = (16 * ver + 128) * ver + 64;
if (ver >= 2) {
int numAlign = ver / 7 + 2;
result -= (25 * numAlign - 10) * numAlign - 55;
if (ver >= 7)
result -= 36;
}
assert(208 <= result && result <= 29648);
return result;
}
/*---- Reed-Solomon ECC generator functions ----*/
// Computes a Reed-Solomon ECC generator polynomial for the given degree, storing in result[0 : degree].
// This could be implemented as a lookup table over all possible parameter values, instead of as an algorithm.
private void reedSolomonComputeDivisor(int degree, uint8_t* result) {
assert(1 <= degree && degree <= qrcodegen_REED_SOLOMON_DEGREE_MAX);
// Polynomial coefficients are stored from highest to lowest power, excluding the leading term which is always 1.
// For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array {255, 8, 93}.
memset(result, 0, cast(size_t)degree * (result[0]).sizeof);
result[degree - 1] = 1; // Start off with the monomial x^0
// Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
// drop the highest monomial term which is always 1x^degree.
// Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
uint8_t root = 1;
for (int i = 0; i < degree; i++) {
// Multiply the current product by (x - r^i)
for (int j = 0; j < degree; j++) {
result[j] = reedSolomonMultiply(result[j], root);
if (j + 1 < degree)
result[j] ^= result[j + 1];
}
root = reedSolomonMultiply(root, 0x02);
}
}
// Computes the Reed-Solomon error correction codeword for the given data and divisor polynomials.
// The remainder when data[0 : dataLen] is divided by divisor[0 : degree] is stored in result[0 : degree].
// All polynomials are in big endian, and the generator has an implicit leading 1 term.
private void reedSolomonComputeRemainder(const uint8_t* data, int dataLen,
const uint8_t* generator, int degree, uint8_t* result) {
assert(1 <= degree && degree <= qrcodegen_REED_SOLOMON_DEGREE_MAX);
memset(result, 0, cast(size_t)degree * (result[0]).sizeof);
for (int i = 0; i < dataLen; i++) { // Polynomial division
uint8_t factor = data[i] ^ result[0];
memmove(&result[0], &result[1], cast(size_t)(degree - 1) * (result[0]).sizeof);
result[degree - 1] = 0;
for (int j = 0; j < degree; j++)
result[j] ^= reedSolomonMultiply(generator[j], factor);
}
}
// 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 uint8_t reedSolomonMultiply(uint8_t x, uint8_t y) {
// Russian peasant multiplication
uint8_t z = 0;
for (int i = 7; i >= 0; i--) {
z = cast(uint8_t)((z << 1) ^ ((z >> 7) * 0x11D));
z ^= ((y >> i) & 1) * x;
}
return z;
}
/*---- Drawing function modules ----*/
// Clears the given QR Code grid with white modules for the given
// version_'s size, then marks every function module as black.
private void initializeFunctionModules(int version_, uint8_t* qrcode) {
// Initialize QR Code
int qrsize = version_ * 4 + 17;
memset(qrcode, 0, cast(size_t)((qrsize * qrsize + 7) / 8 + 1) * (qrcode[0]).sizeof);
qrcode[0] = cast(uint8_t)qrsize;
// Fill horizontal and vertical timing patterns
fillRectangle(6, 0, 1, qrsize, qrcode);
fillRectangle(0, 6, qrsize, 1, qrcode);
// Fill 3 finder patterns (all corners except bottom right) and format bits
fillRectangle(0, 0, 9, 9, qrcode);
fillRectangle(qrsize - 8, 0, 8, 9, qrcode);
fillRectangle(0, qrsize - 8, 9, 8, qrcode);
// Fill numerous alignment patterns
uint8_t[7] alignPatPos;
int numAlign = getAlignmentPatternPositions(version_, alignPatPos);
for (int i = 0; i < numAlign; i++) {
for (int j = 0; j < numAlign; j++) {
// Don't draw on the three finder corners
if (!((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0)))
fillRectangle(alignPatPos[i] - 2, alignPatPos[j] - 2, 5, 5, qrcode);
}
}
// Fill version_ blocks
if (version_ >= 7) {
fillRectangle(qrsize - 11, 0, 3, 6, qrcode);
fillRectangle(0, qrsize - 11, 6, 3, qrcode);
}
}
// Draws white function modules and possibly some black modules onto the given QR Code, without changing
// non-function modules. This does not draw the format bits. This requires all function modules to be previously
// marked black (namely by initializeFunctionModules()), because this may skip redrawing black function modules.
static void drawWhiteFunctionModules(uint8_t* qrcode, int version_) {
// Draw horizontal and vertical timing patterns
int qrsize = qrcodegen_getSize(qrcode);
for (int i = 7; i < qrsize - 7; i += 2) {
setModule(qrcode, 6, i, false);
setModule(qrcode, i, 6, false);
}
// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
for (int dy = -4; dy <= 4; dy++) {
for (int dx = -4; dx <= 4; dx++) {
int dist = abs(dx);
if (abs(dy) > dist)
dist = abs(dy);
if (dist == 2 || dist == 4) {
setModuleBounded(qrcode, 3 + dx, 3 + dy, false);
setModuleBounded(qrcode, qrsize - 4 + dx, 3 + dy, false);
setModuleBounded(qrcode, 3 + dx, qrsize - 4 + dy, false);
}
}
}
// Draw numerous alignment patterns
uint8_t[7] alignPatPos;
int numAlign = getAlignmentPatternPositions(version_, alignPatPos);
for (int i = 0; i < numAlign; i++) {
for (int j = 0; j < numAlign; j++) {
if ((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))
continue; // Don't draw on the three finder corners
for (int dy = -1; dy <= 1; dy++) {
for (int dx = -1; dx <= 1; dx++)
setModule(qrcode, alignPatPos[i] + dx, alignPatPos[j] + dy, dx == 0 && dy == 0);
}
}
}
// Draw version_ blocks
if (version_ >= 7) {
// Calculate error correction code and pack bits
int rem = version_; // version_ is uint6, in the range [7, 40]
for (int i = 0; i < 12; i++)
rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
c_long bits = cast(c_long)version_ << 12 | rem; // uint18
assert(bits >> 18 == 0);
// Draw two copies
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 3; j++) {
int k = qrsize - 11 + j;
setModule(qrcode, k, i, (bits & 1) != 0);
setModule(qrcode, i, k, (bits & 1) != 0);
bits >>= 1;
}
}
}
}
// Draws two copies of the format bits (with its own error correction code) based
// on the given mask and error correction level. This always draws all modules of
// the format bits, unlike drawWhiteFunctionModules() which might skip black modules.
static void drawFormatBits(qrcodegen_Ecc ecl, qrcodegen_Mask mask, uint8_t* qrcode) {
// Calculate error correction code and pack bits
assert(0 <= cast(int)mask && cast(int)mask <= 7);
static const int[] table = [1, 0, 3, 2];
int data = table[cast(int)ecl] << 3 | cast(int)mask; // errCorrLvl is uint2, mask is uint3
int rem = data;
for (int i = 0; i < 10; i++)
rem = (rem << 1) ^ ((rem >> 9) * 0x537);
int bits = (data << 10 | rem) ^ 0x5412; // uint15
assert(bits >> 15 == 0);
// Draw first copy
for (int i = 0; i <= 5; i++)
setModule(qrcode, 8, i, getBit(bits, i));
setModule(qrcode, 8, 7, getBit(bits, 6));
setModule(qrcode, 8, 8, getBit(bits, 7));
setModule(qrcode, 7, 8, getBit(bits, 8));
for (int i = 9; i < 15; i++)
setModule(qrcode, 14 - i, 8, getBit(bits, i));
// Draw second copy
int qrsize = qrcodegen_getSize(qrcode);
for (int i = 0; i < 8; i++)
setModule(qrcode, qrsize - 1 - i, 8, getBit(bits, i));
for (int i = 8; i < 15; i++)
setModule(qrcode, 8, qrsize - 15 + i, getBit(bits, i));
setModule(qrcode, 8, qrsize - 8, true); // Always black
}
// Calculates and stores an ascending list of positions of alignment patterns
// for this version_ number, returning the length of the list (in the range [0,7]).
// 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 int getAlignmentPatternPositions(int version_, ref uint8_t[7] result) {
if (version_ == 1)
return 0;
int numAlign = version_ / 7 + 2;
int step = (version_ == 32) ? 26 :
(version_*4 + numAlign*2 + 1) / (numAlign*2 - 2) * 2;
for (int i = numAlign - 1, pos = version_ * 4 + 10; i >= 1; i--, pos -= step)
result[i] = cast(uint8_t)pos;
result[0] = 6;
return numAlign;
}
// Sets every pixel in the range [left : left + width] * [top : top + height] to black.
static void fillRectangle(int left, int top, int width, int height, uint8_t* qrcode) {
for (int dy = 0; dy < height; dy++) {
for (int dx = 0; dx < width; dx++)
setModule(qrcode, left + dx, top + dy, true);
}
}
/*---- Drawing data modules and masking ----*/
// Draws the raw codewords (including data and ECC) onto the given QR Code. This requires the initial state of
// the QR Code to be black at function modules and white at codeword modules (including unused remainder bits).
static void drawCodewords(const uint8_t* data, int dataLen, uint8_t* qrcode) {
int qrsize = qrcodegen_getSize(qrcode);
int i = 0; // Bit index into the data
// Do the funny zigzag scan
for (int right = qrsize - 1; right >= 1; right -= 2) { // Index of right column in each column pair
if (right == 6)
right = 5;
for (int vert = 0; vert < qrsize; vert++) { // Vertical counter
for (int j = 0; j < 2; j++) {
int x = right - j; // Actual x coordinate
bool upward = ((right + 1) & 2) == 0;
int y = upward ? qrsize - 1 - vert : vert; // Actual y coordinate
if (!getModule(qrcode, x, y) && i < dataLen * 8) {
bool black = getBit(data[i >> 3], 7 - (i & 7));
setModule(qrcode, x, y, black);
i++;
}
// If this QR Code has any remainder bits (0 to 7), they were assigned as
// 0/false/white by the constructor and are left unchanged by this method
}
}
}
assert(i == dataLen * 8);
}
// 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.
static void applyMask(const uint8_t* functionModules, uint8_t* qrcode, qrcodegen_Mask mask) {
assert(0 <= cast(int)mask && cast(int)mask <= 7); // Disallows qrcodegen_Mask_AUTO
int qrsize = qrcodegen_getSize(qrcode);
for (int y = 0; y < qrsize; y++) {
for (int x = 0; x < qrsize; x++) {
if (getModule(functionModules, x, y))
continue;
bool invert;
switch (cast(int)mask) {
case 0: invert = (x + y) % 2 == 0; break;
case 1: invert = y % 2 == 0; break;
case 2: invert = x % 3 == 0; break;
case 3: invert = (x + y) % 3 == 0; break;
case 4: invert = (x / 3 + y / 2) % 2 == 0; break;
case 5: invert = x * y % 2 + x * y % 3 == 0; break;
case 6: invert = (x * y % 2 + x * y % 3) % 2 == 0; break;
case 7: invert = ((x + y) % 2 + x * y % 3) % 2 == 0; break;
default: assert(false);
}
bool val = getModule(qrcode, x, y);
setModule(qrcode, x, y, val ^ invert);
}
}
}
// Calculates and returns the penalty score based on state of the given QR Code's current modules.
// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
static long getPenaltyScore(const uint8_t* qrcode) {
int qrsize = qrcodegen_getSize(qrcode);
long result = 0;
// Adjacent modules in row having same color, and finder-like patterns
for (int y = 0; y < qrsize; y++) {
bool runColor = false;
int runX = 0;
int[7] runHistory = 0;
for (int x = 0; x < qrsize; x++) {
if (getModule(qrcode, x, y) == runColor) {
runX++;
if (runX == 5)
result += PENALTY_N1;
else if (runX > 5)
result++;
} else {
finderPenaltyAddHistory(runX, runHistory, qrsize);
if (!runColor)
result += finderPenaltyCountPatterns(runHistory, qrsize) * PENALTY_N3;
runColor = getModule(qrcode, x, y);
runX = 1;
}
}
result += finderPenaltyTerminateAndCount(runColor, runX, runHistory, qrsize) * PENALTY_N3;
}
// Adjacent modules in column having same color, and finder-like patterns
for (int x = 0; x < qrsize; x++) {
bool runColor = false;
int runY = 0;
int[7] runHistory = 0;
for (int y = 0; y < qrsize; y++) {
if (getModule(qrcode, x, y) == runColor) {
runY++;
if (runY == 5)
result += PENALTY_N1;
else if (runY > 5)
result++;
} else {
finderPenaltyAddHistory(runY, runHistory, qrsize);
if (!runColor)
result += finderPenaltyCountPatterns(runHistory, qrsize) * PENALTY_N3;
runColor = getModule(qrcode, x, y);
runY = 1;
}
}
result += finderPenaltyTerminateAndCount(runColor, runY, runHistory, qrsize) * PENALTY_N3;
}
// 2*2 blocks of modules having same color
for (int y = 0; y < qrsize - 1; y++) {
for (int x = 0; x < qrsize - 1; x++) {
bool color = getModule(qrcode, x, y);
if ( color == getModule(qrcode, x + 1, y) &&
color == getModule(qrcode, x, y + 1) &&
color == getModule(qrcode, x + 1, y + 1))
result += PENALTY_N2;
}
}
// Balance of black and white modules
int black = 0;
for (int y = 0; y < qrsize; y++) {
for (int x = 0; x < qrsize; x++) {
if (getModule(qrcode, x, y))
black++;
}
}
int total = qrsize * qrsize; // Note that size is odd, so black/total != 1/2
// Compute the smallest integer k >= 0 such that (45-5k)% <= black/total <= (55+5k)%
int k = cast(int)((labs(black * 20 - total * 10) + total - 1) / total) - 1;
result += k * PENALTY_N4;
return result;
}
// Can only be called immediately after a white run is added, and
// returns either 0, 1, or 2. A helper function for getPenaltyScore().
static int finderPenaltyCountPatterns(const int[7] runHistory, int qrsize) {
int n = runHistory[1];
assert(n <= qrsize * 3);
bool core = n > 0 && runHistory[2] == n && runHistory[3] == n * 3 && runHistory[4] == n && runHistory[5] == n;
// The maximum QR Code size is 177, hence the black run length n <= 177.
// Arithmetic is promoted to int, so n*4 will not overflow.
return (core && runHistory[0] >= n * 4 && runHistory[6] >= n ? 1 : 0)
+ (core && runHistory[6] >= n * 4 && runHistory[0] >= n ? 1 : 0);
}
// Must be called at the end of a line (row or column) of modules. A helper function for getPenaltyScore().
static int finderPenaltyTerminateAndCount(bool currentRunColor, int currentRunLength, ref int[7] runHistory, int qrsize) {
if (currentRunColor) { // Terminate black run
finderPenaltyAddHistory(currentRunLength, runHistory, qrsize);
currentRunLength = 0;
}
currentRunLength += qrsize; // Add white border to final run
finderPenaltyAddHistory(currentRunLength, runHistory, qrsize);
return finderPenaltyCountPatterns(runHistory, qrsize);
}
// Pushes the given value to the front and drops the last value. A helper function for getPenaltyScore().
static void finderPenaltyAddHistory(int currentRunLength, ref int[7] runHistory, int qrsize) {
if (runHistory[0] == 0)
currentRunLength += qrsize; // Add white border to initial run
memmove(&runHistory[1], &runHistory[0], 6 * (runHistory[0]).sizeof);
runHistory[0] = currentRunLength;
}
/*---- Basic QR Code information ----*/
// Public function - see documentation comment in header file.
/*
* 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) {
assert(qrcode != null);
int result = qrcode[0];
assert((qrcodegen_VERSION_MIN * 4 + 17) <= result
&& result <= (qrcodegen_VERSION_MAX * 4 + 17));
return result;
}
// Public function - see documentation comment in header file.
/*
* 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) {
assert(qrcode != null);
int qrsize = qrcode[0];
return (0 <= x && x < qrsize && 0 <= y && y < qrsize) && getModule(qrcode, x, y);
}
// Gets the module at the given coordinates, which must be in bounds.
private bool getModule(const uint8_t* qrcode, int x, int y) {
int qrsize = qrcode[0];
assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
int index = y * qrsize + x;
return getBit(qrcode[(index >> 3) + 1], index & 7);
}
// Sets the module at the given coordinates, which must be in bounds.
private void setModule(uint8_t* qrcode, int x, int y, bool isBlack) {
int qrsize = qrcode[0];
assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
int index = y * qrsize + x;
int bitIndex = index & 7;
int byteIndex = (index >> 3) + 1;
if (isBlack)
qrcode[byteIndex] |= 1 << bitIndex;
else
qrcode[byteIndex] &= (1 << bitIndex) ^ 0xFF;
}
// Sets the module at the given coordinates, doing nothing if out of bounds.
private void setModuleBounded(uint8_t* qrcode, int x, int y, bool isBlack) {
int qrsize = qrcode[0];
if (0 <= x && x < qrsize && 0 <= y && y < qrsize)
setModule(qrcode, x, y, isBlack);
}
// Returns true iff the i'th bit of x is set to 1. Requires x >= 0 and 0 <= i <= 14.
static bool getBit(int x, int i) {
return ((x >> i) & 1) != 0;
}
/*---- Segment handling ----*/
// Public function - see documentation comment in header file.
/*
* 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) {
assert(text != null);
for (; *text != '\0'; text++) {
if (strchr(ALPHANUMERIC_CHARSET, *text) == null)
return false;
}
return true;
}
// Public function - see documentation comment in header file.
/*
* 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) {
assert(text != null);
for (; *text != '\0'; text++) {
if (*text < '0' || *text > '9')
return false;
}
return true;
}
// Public function - see documentation comment in header file.
/*
* 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(qrcodegen_Mode mode, size_t numChars) {
int temp = calcSegmentBitLength(mode, numChars);
if (temp == -1)
return SIZE_MAX;
assert(0 <= temp && temp <= INT16_MAX);
return (cast(size_t)temp + 7) / 8;
}
// Returns the number of data bits needed to represent a segment
// containing the given number of characters using the given mode. Notes:
// - Returns -1 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, INT16_MAX].
// - 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 bits is returned.
// An actual ECI segment can have shorter data. For non-ECI modes, the result is exact.
private int calcSegmentBitLength(qrcodegen_Mode mode, size_t numChars) {
// All calculations are designed to avoid overflow on all platforms
if (numChars > cast(uint)INT16_MAX)
return -1;
c_long result = cast(c_long)numChars;
if (mode == qrcodegen_Mode_NUMERIC)
result = (result * 10 + 2) / 3; // ceil(10/3 * n)
else if (mode == qrcodegen_Mode_ALPHANUMERIC)
result = (result * 11 + 1) / 2; // ceil(11/2 * n)
else if (mode == qrcodegen_Mode_BYTE)
result *= 8;
else if (mode == qrcodegen_Mode_KANJI)
result *= 13;
else if (mode == qrcodegen_Mode_ECI && numChars == 0)
result = 3 * 8;
else { // Invalid argument
assert(false);
}
assert(result >= 0);
if (result > INT16_MAX)
return -1;
return cast(int)result;
}
// Public function - see documentation comment in header file.
/*
* 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.
*/
qrcodegen_Segment qrcodegen_makeBytes(const uint8_t* data, size_t len, uint8_t* buf) {
assert(data != null || len == 0);
qrcodegen_Segment result;
result.mode = qrcodegen_Mode_BYTE;
result.bitLength = calcSegmentBitLength(result.mode, len);
assert(result.bitLength != -1);
result.numChars = cast(int)len;
if (len > 0)
memcpy(buf, data, len * (buf[0]).sizeof);
result.data = buf;
return result;
}
// Public function - see documentation comment in header file.
/*
* Returns a segment representing the given string of decimal digits encoded in numeric mode.
*/
qrcodegen_Segment qrcodegen_makeNumeric(const(char)* digits, uint8_t* buf) {
assert(digits != null);
qrcodegen_Segment result;
size_t len = strlen(digits);
result.mode = qrcodegen_Mode_NUMERIC;
int bitLen = calcSegmentBitLength(result.mode, len);
assert(bitLen != -1);
result.numChars = cast(int)len;
if (bitLen > 0)
memset(buf, 0, (cast(size_t)bitLen + 7) / 8 * (buf[0]).sizeof);
result.bitLength = 0;
uint accumData = 0;
int accumCount = 0;
for (; *digits != '\0'; digits++) {
char c = *digits;
assert('0' <= c && c <= '9');
accumData = accumData * 10 + cast(uint)(c - '0');
accumCount++;
if (accumCount == 3) {
appendBitsToBuffer(accumData, 10, buf, &result.bitLength);
accumData = 0;
accumCount = 0;
}
}
if (accumCount > 0) // 1 or 2 digits remaining
appendBitsToBuffer(accumData, accumCount * 3 + 1, buf, &result.bitLength);
assert(result.bitLength == bitLen);
result.data = buf;
return result;
}
// Public function - see documentation comment in header file.
/*
* 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.
*/
qrcodegen_Segment qrcodegen_makeAlphanumeric(const(char)* text, uint8_t* buf) {
assert(text != null);
qrcodegen_Segment result;
size_t len = strlen(text);
result.mode = qrcodegen_Mode_ALPHANUMERIC;
int bitLen = calcSegmentBitLength(result.mode, len);
assert(bitLen != -1);
result.numChars = cast(int)len;
if (bitLen > 0)
memset(buf, 0, (cast(size_t)bitLen + 7) / 8 * (buf[0]).sizeof);
result.bitLength = 0;
uint accumData = 0;
int accumCount = 0;
for (; *text != '\0'; text++) {
const char *temp = strchr(ALPHANUMERIC_CHARSET, *text);
assert(temp != null);
accumData = accumData * 45 + cast(uint)(temp - ALPHANUMERIC_CHARSET);
accumCount++;
if (accumCount == 2) {
appendBitsToBuffer(accumData, 11, buf, &result.bitLength);
accumData = 0;
accumCount = 0;
}
}
if (accumCount > 0) // 1 character remaining
appendBitsToBuffer(accumData, 6, buf, &result.bitLength);
assert(result.bitLength == bitLen);
result.data = buf;
return result;
}
// Public function - see documentation comment in header file.
/*
* Returns a segment representing an Extended Channel Interpretation
* (ECI) designator with the given assignment value.
*/
qrcodegen_Segment qrcodegen_makeEci(c_long assignVal, uint8_t* buf) {
qrcodegen_Segment result;
result.mode = qrcodegen_Mode_ECI;
result.numChars = 0;
result.bitLength = 0;
if (assignVal < 0)
assert(false);
else if (assignVal < (1 << 7)) {
memset(buf, 0, 1 * (buf[0]).sizeof);
appendBitsToBuffer(cast(uint)assignVal, 8, buf, &result.bitLength);
} else if (assignVal < (1 << 14)) {
memset(buf, 0, 2 * (buf[0]).sizeof);
appendBitsToBuffer(2, 2, buf, &result.bitLength);
appendBitsToBuffer(cast(uint)assignVal, 14, buf, &result.bitLength);
} else if (assignVal < 1000000L) {
memset(buf, 0, 3 * (buf[0]).sizeof);
appendBitsToBuffer(6, 3, buf, &result.bitLength);
appendBitsToBuffer(cast(uint)(assignVal >> 10), 11, buf, &result.bitLength);
appendBitsToBuffer(cast(uint)(assignVal & 0x3FF), 10, buf, &result.bitLength);
} else
assert(false);
result.data = buf;
return result;
}
// 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 INT16_MAX.
private int getTotalBits(const qrcodegen_Segment* segs, size_t len, int version_) {
assert(segs != null || len == 0);
long result = 0;
for (size_t i = 0; i < len; i++) {
int numChars = segs[i].numChars;
int bitLength = segs[i].bitLength;
assert(0 <= numChars && numChars <= INT16_MAX);
assert(0 <= bitLength && bitLength <= INT16_MAX);
int ccbits = numCharCountBits(segs[i].mode, version_);
assert(0 <= ccbits && ccbits <= 16);
if (numChars >= (1L << ccbits))
return -1; // The segment's length doesn't fit the field's bit width
result += 4L + ccbits + bitLength;
if (result > INT16_MAX)
return -1; // The sum might overflow an int type
}
assert(0 <= result && result <= INT16_MAX);
return cast(int)result;
}
// Returns the bit width of the character count field for a segment in the given mode
// in a QR Code at the given version_ number. The result is in the range [0, 16].
static int numCharCountBits(qrcodegen_Mode mode, int version_) {
assert(qrcodegen_VERSION_MIN <= version_ && version_ <= qrcodegen_VERSION_MAX);
int i = (version_ + 7) / 17;
switch (mode) {
case qrcodegen_Mode_NUMERIC : { static immutable int[] temp1 = [10, 12, 14]; return temp1[i]; }
case qrcodegen_Mode_ALPHANUMERIC: { static immutable int[] temp2 = [ 9, 11, 13]; return temp2[i]; }
case qrcodegen_Mode_BYTE : { static immutable int[] temp3 = [ 8, 16, 16]; return temp3[i]; }
case qrcodegen_Mode_KANJI : { static immutable int[] temp4 = [ 8, 10, 12]; return temp4[i]; }
case qrcodegen_Mode_ECI : return 0;
default: assert(false); // Dummy value
}
}
/++
+/
struct QrCode {
ubyte[qrcodegen_BUFFER_LEN_MAX] qrcode;
this(string text) {
ubyte[qrcodegen_BUFFER_LEN_MAX] tempBuffer;
bool ok = qrcodegen_encodeText((text ~ "\0").ptr, tempBuffer.ptr, qrcode.ptr,
qrcodegen_Ecc_MEDIUM, qrcodegen_VERSION_MIN, qrcodegen_VERSION_MAX, qrcodegen_Mask_AUTO, true);
if(!ok)
throw new Exception("qr code generation failed");
}
/++
The size of the square of the code. It is size x size.
+/
int size() {
return qrcodegen_getSize(qrcode.ptr);
}
/++
Returns true if it is a dark square, false if it is a light one.
+/
bool opIndex(int x, int y) {
return qrcodegen_getModule(qrcode.ptr, x, y);
}
}