GCC Code Coverage Report

Line	Branch	Exec	Source
1			/*
2			* QR Code generator library (C)
3			*
4			* Copyright (c) Project Nayuki. (MIT License)
5			* https://www.nayuki.io/page/qr-code-generator-library
6			*
7			* Permission is hereby granted, free of charge, to any person obtaining a copy of
8			* this software and associated documentation files (the "Software"), to deal in
9			* the Software without restriction, including without limitation the rights to
10			* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11			* the Software, and to permit persons to whom the Software is furnished to do so,
12			* subject to the following conditions:
13			* - The above copyright notice and this permission notice shall be included in
14			* all copies or substantial portions of the Software.
15			* - The Software is provided "as is", without warranty of any kind, express or
16			* implied, including but not limited to the warranties of merchantability,
17			* fitness for a particular purpose and noninfringement. In no event shall the
18			* authors or copyright holders be liable for any claim, damages or other
19			* liability, whether in an action of contract, tort or otherwise, arising from,
20			* out of or in connection with the Software or the use or other dealings in the
21			* Software.
22			*/
23
24			#include <assert.h>
25			#include <limits.h>
26			#include <stdlib.h>
27			#include <string.h>
28			#include "qrcodegen.h"
29
30			#ifndef QRCODEGEN_TEST
31			#define testable static // Keep functions private
32			#else
33			#define testable // Expose private functions
34			#endif
35
36
37			/*---- Forward declarations for private functions ----*/
38
39			// Regarding all public and private functions defined in this source file:
40			// - They require all pointer/array arguments to be not null unless the array length is zero.
41			// - They only read input scalar/array arguments, write to output pointer/array
42			// arguments, and return scalar values; they are "pure" functions.
43			// - They don't read mutable global variables or write to any global variables.
44			// - They don't perform I/O, read the clock, print to console, etc.
45			// - They allocate a small and constant amount of stack memory.
46			// - They don't allocate or free any memory on the heap.
47			// - They don't recurse or mutually recurse. All the code
48			// could be inlined into the top-level public functions.
49			// - They run in at most quadratic time with respect to input arguments.
50			// Most functions run in linear time, and some in constant time.
51			// There are no unbounded loops or non-obvious termination conditions.
52			// - They are completely thread-safe if the caller does not give the
53			// same writable buffer to concurrent calls to these functions.
54
55			testable void appendBitsToBuffer(unsigned int val, int numBits, uint8_t buffer[], int *bitLen);
56
57			testable void addEccAndInterleave(uint8_t data[], int version, enum qrcodegen_Ecc ecl, uint8_t result[]);
58			testable int getNumDataCodewords(int version, enum qrcodegen_Ecc ecl);
59			testable int getNumRawDataModules(int ver);
60
61			testable void calcReedSolomonGenerator(int degree, uint8_t result[]);
62			testable void calcReedSolomonRemainder(const uint8_t data[], int dataLen,
63			const uint8_t generator[], int degree, uint8_t result[]);
64			testable uint8_t finiteFieldMultiply(uint8_t x, uint8_t y);
65
66			testable void initializeFunctionModules(int version, uint8_t qrcode[]);
67			static void drawWhiteFunctionModules(uint8_t qrcode[], int version);
68			static void drawFormatBits(enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, uint8_t qrcode[]);
69			testable int getAlignmentPatternPositions(int version, uint8_t result[7]);
70			static void fillRectangle(int left, int top, int width, int height, uint8_t qrcode[]);
71
72			static void drawCodewords(const uint8_t data[], int dataLen, uint8_t qrcode[]);
73			static void applyMask(const uint8_t functionModules[], uint8_t qrcode[], enum qrcodegen_Mask mask);
74			static long getPenaltyScore(const uint8_t qrcode[]);
75			static void addRunToHistory(unsigned char run, unsigned char history[7]);
76			static bool hasFinderLikePattern(unsigned char runHistory[7]);
77
78			testable bool getModule(const uint8_t qrcode[], int x, int y);
79			testable void setModule(uint8_t qrcode[], int x, int y, bool isBlack);
80			testable void setModuleBounded(uint8_t qrcode[], int x, int y, bool isBlack);
81			static bool getBit(int x, int i);
82
83			testable int calcSegmentBitLength(enum qrcodegen_Mode mode, size_t numChars);
84			testable int getTotalBits(const struct qrcodegen_Segment segs[], size_t len, int version);
85			static int numCharCountBits(enum qrcodegen_Mode mode, int version);
86
87
88
89			/*---- Private tables of constants ----*/
90
91			// The set of all legal characters in alphanumeric mode, where each character
92			// value maps to the index in the string. For checking text and encoding segments.
93			static const char *ALPHANUMERIC_CHARSET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:";
94
95			// For generating error correction codes.
96			testable const int8_t ECC_CODEWORDS_PER_BLOCK[4][41] = {
97			// Version: (note that index 0 is for padding, and is set to an illegal value)
98			//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
99			{-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
100			{-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
101			{-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
102			{-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
103			};
104
105			#define qrcodegen_REED_SOLOMON_DEGREE_MAX 30 // Based on the table above
106
107			// For generating error correction codes.
108			testable const int8_t NUM_ERROR_CORRECTION_BLOCKS[4][41] = {
109			// Version: (note that index 0 is for padding, and is set to an illegal value)
110			//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
111			{-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
112			{-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
113			{-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
114			{-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
115			};
116
117			// For automatic mask pattern selection.
118			static const int PENALTY_N1 = 3;
119			static const int PENALTY_N2 = 3;
120			static const int PENALTY_N3 = 40;
121			static const int PENALTY_N4 = 10;
122
123
124
125			/*---- High-level QR Code encoding functions ----*/
126
127			// Public function - see documentation comment in header file.
128		✗	bool qrcodegen_encodeText(const char *text, uint8_t tempBuffer[], uint8_t qrcode[],
129			enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl) {
130
131		✗	size_t textLen = strlen(text);
132		✗	if (textLen == 0)
133		✗	return qrcodegen_encodeSegmentsAdvanced(NULL, 0, ecl, minVersion, maxVersion, mask, boostEcl, tempBuffer, qrcode);
134		✗	size_t bufLen = qrcodegen_BUFFER_LEN_FOR_VERSION(maxVersion);
135
136			struct qrcodegen_Segment seg;
137		✗	if (qrcodegen_isNumeric(text)) {
138		✗	if (qrcodegen_calcSegmentBufferSize(qrcodegen_Mode_NUMERIC, textLen) > bufLen)
139		✗	goto fail;
140		✗	seg = qrcodegen_makeNumeric(text, tempBuffer);
141		✗	} else if (qrcodegen_isAlphanumeric(text)) {
142		✗	if (qrcodegen_calcSegmentBufferSize(qrcodegen_Mode_ALPHANUMERIC, textLen) > bufLen)
143		✗	goto fail;
144		✗	seg = qrcodegen_makeAlphanumeric(text, tempBuffer);
145			} else {
146		✗	if (textLen > bufLen)
147		✗	goto fail;
148		✗	for (size_t i = 0; i < textLen; i++)
149		✗	tempBuffer[i] = (uint8_t)text[i];
150		✗	seg.mode = qrcodegen_Mode_BYTE;
151		✗	seg.bitLength = calcSegmentBitLength(seg.mode, textLen);
152		✗	if (seg.bitLength == -1)
153		✗	goto fail;
154		✗	seg.numChars = (int)textLen;
155		✗	seg.data = tempBuffer;
156			}
157		✗	return qrcodegen_encodeSegmentsAdvanced(&seg, 1, ecl, minVersion, maxVersion, mask, boostEcl, tempBuffer, qrcode);
158
159		✗	fail:
160		✗	qrcode[0] = 0; // Set size to invalid value for safety
161		✗	return false;
162			}
163
164
165			// Public function - see documentation comment in header file.
166		✗	bool qrcodegen_encodeBinary(uint8_t dataAndTemp[], size_t dataLen, uint8_t qrcode[],
167			enum qrcodegen_Ecc ecl, int minVersion, int maxVersion, enum qrcodegen_Mask mask, bool boostEcl) {
168
169			struct qrcodegen_Segment seg;
170		✗	seg.mode = qrcodegen_Mode_BYTE;
171		✗	seg.bitLength = calcSegmentBitLength(seg.mode, dataLen);
172		✗	if (seg.bitLength == -1) {
173		✗	qrcode[0] = 0; // Set size to invalid value for safety
174		✗	return false;
175			}
176		✗	seg.numChars = (int)dataLen;
177		✗	seg.data = dataAndTemp;
178		✗	return qrcodegen_encodeSegmentsAdvanced(&seg, 1, ecl, minVersion, maxVersion, mask, boostEcl, dataAndTemp, qrcode);
179			}
180
181
182			// Appends the given number of low-order bits of the given value to the given byte-based
183			// bit buffer, increasing the bit length. Requires 0 <= numBits <= 16 and val < 2^numBits.
184		✗	testable void appendBitsToBuffer(unsigned int val, int numBits, uint8_t buffer[], int *bitLen) {
185		✗	assert(0 <= numBits && numBits <= 16 && (unsigned long)val >> numBits == 0);
186		✗	for (int i = numBits - 1; i >= 0; i--, (*bitLen)++)
187		✗	buffer[*bitLen >> 3] |= ((val >> i) & 1) << (7 - (*bitLen & 7));
188		✗	}
189
190
191
192			/*---- Low-level QR Code encoding functions ----*/
193
194			// Public function - see documentation comment in header file.
195		✗	bool qrcodegen_encodeSegments(const struct qrcodegen_Segment segs[], size_t len,
196			enum qrcodegen_Ecc ecl, uint8_t tempBuffer[], uint8_t qrcode[]) {
197		✗	return qrcodegen_encodeSegmentsAdvanced(segs, len, ecl,
198			qrcodegen_VERSION_MIN, qrcodegen_VERSION_MAX, -1, true, tempBuffer, qrcode);
199			}
200
201
202			// Public function - see documentation comment in header file.
203		✗	bool qrcodegen_encodeSegmentsAdvanced(const struct qrcodegen_Segment segs[], size_t len, enum qrcodegen_Ecc ecl,
204			int minVersion, int maxVersion, int mask, bool boostEcl, uint8_t tempBuffer[], uint8_t qrcode[]) {
205		✗	assert(segs != NULL || len == 0);
206		✗	assert(qrcodegen_VERSION_MIN <= minVersion && minVersion <= maxVersion && maxVersion <= qrcodegen_VERSION_MAX);
207		✗	assert(0 <= (int)ecl && (int)ecl <= 3 && -1 <= (int)mask && (int)mask <= 7);
208
209			// Find the minimal version number to use
210			int version, dataUsedBits;
211		✗	for (version = minVersion; ; version++) {
212		✗	int dataCapacityBits = getNumDataCodewords(version, ecl) * 8; // Number of data bits available
213		✗	dataUsedBits = getTotalBits(segs, len, version);
214		✗	if (dataUsedBits != -1 && dataUsedBits <= dataCapacityBits)
215		✗	break; // This version number is found to be suitable
216		✗	if (version >= maxVersion) { // All versions in the range could not fit the given data
217		✗	qrcode[0] = 0; // Set size to invalid value for safety
218		✗	return false;
219			}
220			}
221		✗	assert(dataUsedBits != -1);
222
223			// Increase the error correction level while the data still fits in the current version number
224		✗	for (int i = (int)qrcodegen_Ecc_MEDIUM; i <= (int)qrcodegen_Ecc_HIGH; i++) { // From low to high
225		✗	if (boostEcl && dataUsedBits <= getNumDataCodewords(version, (enum qrcodegen_Ecc)i) * 8)
226		✗	ecl = (enum qrcodegen_Ecc)i;
227			}
228
229			// Concatenate all segments to create the data bit string
230		✗	memset(qrcode, 0, qrcodegen_BUFFER_LEN_FOR_VERSION(version) * sizeof(qrcode[0]));
231		✗	int bitLen = 0;
232		✗	for (size_t i = 0; i < len; i++) {
233		✗	const struct qrcodegen_Segment *seg = &segs[i];
234		✗	appendBitsToBuffer((int)seg->mode, 4, qrcode, &bitLen);
235		✗	appendBitsToBuffer(seg->numChars, numCharCountBits(seg->mode, version), qrcode, &bitLen);
236		✗	for (int j = 0; j < seg->bitLength; j++)
237		✗	appendBitsToBuffer((seg->data[j >> 3] >> (7 - (j & 7))) & 1, 1, qrcode, &bitLen);
238			}
239		✗	assert(bitLen == dataUsedBits);
240
241			// Add terminator and pad up to a byte if applicable
242		✗	int dataCapacityBits = getNumDataCodewords(version, ecl) * 8;
243		✗	assert(bitLen <= dataCapacityBits);
244		✗	int terminatorBits = dataCapacityBits - bitLen;
245		✗	if (terminatorBits > 4)
246		✗	terminatorBits = 4;
247		✗	appendBitsToBuffer(0, terminatorBits, qrcode, &bitLen);
248		✗	appendBitsToBuffer(0, (8 - bitLen % 8) % 8, qrcode, &bitLen);
249		✗	assert(bitLen % 8 == 0);
250
251			// Pad with alternating bytes until data capacity is reached
252		✗	for (uint8_t padByte = 0xEC; bitLen < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
253		✗	appendBitsToBuffer(padByte, 8, qrcode, &bitLen);
254
255			// Draw function and data codeword modules
256		✗	addEccAndInterleave(qrcode, version, ecl, tempBuffer);
257		✗	initializeFunctionModules(version, qrcode);
258		✗	drawCodewords(tempBuffer, getNumRawDataModules(version) / 8, qrcode);
259		✗	drawWhiteFunctionModules(qrcode, version);
260		✗	initializeFunctionModules(version, tempBuffer);
261
262			// Handle masking
263		✗	if (mask == qrcodegen_Mask_AUTO) { // Automatically choose best mask
264		✗	long minPenalty = LONG_MAX;
265		✗	for (int i = 0; i < 8; i++) {
266		✗	enum qrcodegen_Mask msk = (enum qrcodegen_Mask)i;
267		✗	drawFormatBits(ecl, msk, qrcode);
268		✗	applyMask(tempBuffer, qrcode, msk);
269		✗	long penalty = getPenaltyScore(qrcode);
270		✗	if (penalty < minPenalty) {
271		✗	mask = msk;
272		✗	minPenalty = penalty;
273			}
274		✗	applyMask(tempBuffer, qrcode, msk); // Undoes the mask due to XOR
275			}
276			}
277		✗	assert(0 <= (int)mask && (int)mask <= 7);
278		✗	drawFormatBits(ecl, mask, qrcode);
279		✗	applyMask(tempBuffer, qrcode, mask);
280		✗	return true;
281			}
282
283
284
285			/*---- Error correction code generation functions ----*/
286
287			// Appends error correction bytes to each block of the given data array, then interleaves
288			// bytes from the blocks and stores them in the result array. data[0 : dataLen] contains
289			// the input data. data[dataLen : rawCodewords] is used as a temporary work area and will
290			// be clobbered by this function. The final answer is stored in result[0 : rawCodewords].
291		✗	testable void addEccAndInterleave(uint8_t data[], int version, enum qrcodegen_Ecc ecl, uint8_t result[]) {
292			// Calculate parameter numbers
293		✗	assert(0 <= (int)ecl && (int)ecl < 4 && qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
294		✗	int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[(int)ecl][version];
295		✗	int blockEccLen = ECC_CODEWORDS_PER_BLOCK [(int)ecl][version];
296		✗	int rawCodewords = getNumRawDataModules(version) / 8;
297		✗	int dataLen = getNumDataCodewords(version, ecl);
298		✗	int numShortBlocks = numBlocks - rawCodewords % numBlocks;
299		✗	int shortBlockDataLen = rawCodewords / numBlocks - blockEccLen;
300
301			// Split data into blocks, calculate ECC, and interleave
302			// (not concatenate) the bytes into a single sequence
303			uint8_t generator[qrcodegen_REED_SOLOMON_DEGREE_MAX];
304		✗	calcReedSolomonGenerator(blockEccLen, generator);
305		✗	const uint8_t *dat = data;
306		✗	for (int i = 0; i < numBlocks; i++) {
307		✗	int datLen = shortBlockDataLen + (i < numShortBlocks ? 0 : 1);
308		✗	uint8_t *ecc = &data[dataLen]; // Temporary storage
309		✗	calcReedSolomonRemainder(dat, datLen, generator, blockEccLen, ecc);
310		✗	for (int j = 0, k = i; j < datLen; j++, k += numBlocks) { // Copy data
311		✗	if (j == shortBlockDataLen)
312		✗	k -= numShortBlocks;
313		✗	result[k] = dat[j];
314			}
315		✗	for (int j = 0, k = dataLen + i; j < blockEccLen; j++, k += numBlocks) // Copy ECC
316		✗	result[k] = ecc[j];
317		✗	dat += datLen;
318			}
319		✗	}
320
321
322			// Returns the number of 8-bit codewords that can be used for storing data (not ECC),
323			// for the given version number and error correction level. The result is in the range [9, 2956].
324		✗	testable int getNumDataCodewords(int version, enum qrcodegen_Ecc ecl) {
325		✗	int v = version, e = (int)ecl;
326		✗	assert(0 <= e && e < 4);
327		✗	return getNumRawDataModules(v) / 8
328		✗	- ECC_CODEWORDS_PER_BLOCK [e][v]
329		✗	* NUM_ERROR_CORRECTION_BLOCKS[e][v];
330			}
331
332
333			// Returns the number of data bits that can be stored in a QR Code of the given version number, after
334			// all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8.
335			// The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.
336		✗	testable int getNumRawDataModules(int ver) {
337		✗	assert(qrcodegen_VERSION_MIN <= ver && ver <= qrcodegen_VERSION_MAX);
338		✗	int result = (16 * ver + 128) * ver + 64;
339		✗	if (ver >= 2) {
340		✗	int numAlign = ver / 7 + 2;
341		✗	result -= (25 * numAlign - 10) * numAlign - 55;
342		✗	if (ver >= 7)
343		✗	result -= 36;
344			}
345		✗	return result;
346			}
347
348
349
350			/*---- Reed-Solomon ECC generator functions ----*/
351
352			// Calculates the Reed-Solomon generator polynomial of the given degree, storing in result[0 : degree].
353		✗	testable void calcReedSolomonGenerator(int degree, uint8_t result[]) {
354			// Start with the monomial x^0
355		✗	assert(1 <= degree && degree <= qrcodegen_REED_SOLOMON_DEGREE_MAX);
356		✗	memset(result, 0, degree * sizeof(result[0]));
357		✗	result[degree - 1] = 1;
358
359			// Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
360			// drop the highest term, and store the rest of the coefficients in order of descending powers.
361			// Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
362		✗	uint8_t root = 1;
363		✗	for (int i = 0; i < degree; i++) {
364			// Multiply the current product by (x - r^i)
365		✗	for (int j = 0; j < degree; j++) {
366		✗	result[j] = finiteFieldMultiply(result[j], root);
367		✗	if (j + 1 < degree)
368		✗	result[j] ^= result[j + 1];
369			}
370		✗	root = finiteFieldMultiply(root, 0x02);
371			}
372		✗	}
373
374
375			// Calculates the remainder of the polynomial data[0 : dataLen] when divided by the generator[0 : degree], where all
376			// polynomials are in big endian and the generator has an implicit leading 1 term, storing the result in result[0 : degree].
377		✗	testable void calcReedSolomonRemainder(const uint8_t data[], int dataLen,
378			const uint8_t generator[], int degree, uint8_t result[]) {
379
380			// Perform polynomial division
381		✗	assert(1 <= degree && degree <= qrcodegen_REED_SOLOMON_DEGREE_MAX);
382		✗	memset(result, 0, degree * sizeof(result[0]));
383		✗	for (int i = 0; i < dataLen; i++) {
384		✗	uint8_t factor = data[i] ^ result[0];
385		✗	memmove(&result[0], &result[1], (degree - 1) * sizeof(result[0]));
386		✗	result[degree - 1] = 0;
387		✗	for (int j = 0; j < degree; j++)
388		✗	result[j] ^= finiteFieldMultiply(generator[j], factor);
389			}
390		✗	}
391
392			#undef qrcodegen_REED_SOLOMON_DEGREE_MAX
393
394
395			// Returns the product of the two given field elements modulo GF(2^8/0x11D).
396			// All inputs are valid. This could be implemented as a 256*256 lookup table.
397		✗	testable uint8_t finiteFieldMultiply(uint8_t x, uint8_t y) {
398			// Russian peasant multiplication
399		✗	uint8_t z = 0;
400		✗	for (int i = 7; i >= 0; i--) {
401		✗	z = (z << 1) ^ ((z >> 7) * 0x11D);
402		✗	z ^= ((y >> i) & 1) * x;
403			}
404		✗	return z;
405			}
406
407
408
409			/*---- Drawing function modules ----*/
410
411			// Clears the given QR Code grid with white modules for the given
412			// version's size, then marks every function module as black.
413		✗	testable void initializeFunctionModules(int version, uint8_t qrcode[]) {
414			// Initialize QR Code
415		✗	int qrsize = version * 4 + 17;
416		✗	memset(qrcode, 0, ((qrsize * qrsize + 7) / 8 + 1) * sizeof(qrcode[0]));
417		✗	qrcode[0] = (uint8_t)qrsize;
418
419			// Fill horizontal and vertical timing patterns
420		✗	fillRectangle(6, 0, 1, qrsize, qrcode);
421		✗	fillRectangle(0, 6, qrsize, 1, qrcode);
422
423			// Fill 3 finder patterns (all corners except bottom right) and format bits
424		✗	fillRectangle(0, 0, 9, 9, qrcode);
425		✗	fillRectangle(qrsize - 8, 0, 8, 9, qrcode);
426		✗	fillRectangle(0, qrsize - 8, 9, 8, qrcode);
427
428			// Fill numerous alignment patterns
429			uint8_t alignPatPos[7];
430		✗	int numAlign = getAlignmentPatternPositions(version, alignPatPos);
431		✗	for (int i = 0; i < numAlign; i++) {
432		✗	for (int j = 0; j < numAlign; j++) {
433			// Don't draw on the three finder corners
434		✗	if (!((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0)))
435		✗	fillRectangle(alignPatPos[i] - 2, alignPatPos[j] - 2, 5, 5, qrcode);
436			}
437			}
438
439			// Fill version blocks
440		✗	if (version >= 7) {
441		✗	fillRectangle(qrsize - 11, 0, 3, 6, qrcode);
442		✗	fillRectangle(0, qrsize - 11, 6, 3, qrcode);
443			}
444		✗	}
445
446
447			// Draws white function modules and possibly some black modules onto the given QR Code, without changing
448			// non-function modules. This does not draw the format bits. This requires all function modules to be previously
449			// marked black (namely by initializeFunctionModules()), because this may skip redrawing black function modules.
450		✗	static void drawWhiteFunctionModules(uint8_t qrcode[], int version) {
451			// Draw horizontal and vertical timing patterns
452		✗	int qrsize = qrcodegen_getSize(qrcode);
453		✗	for (int i = 7; i < qrsize - 7; i += 2) {
454		✗	setModule(qrcode, 6, i, false);
455		✗	setModule(qrcode, i, 6, false);
456			}
457
458			// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
459		✗	for (int dy = -4; dy <= 4; dy++) {
460		✗	for (int dx = -4; dx <= 4; dx++) {
461		✗	int dist = abs(dx);
462		✗	if (abs(dy) > dist)
463		✗	dist = abs(dy);
464		✗	if (dist == 2 || dist == 4) {
465		✗	setModuleBounded(qrcode, 3 + dx, 3 + dy, false);
466		✗	setModuleBounded(qrcode, qrsize - 4 + dx, 3 + dy, false);
467		✗	setModuleBounded(qrcode, 3 + dx, qrsize - 4 + dy, false);
468			}
469			}
470			}
471
472			// Draw numerous alignment patterns
473			uint8_t alignPatPos[7];
474		✗	int numAlign = getAlignmentPatternPositions(version, alignPatPos);
475		✗	for (int i = 0; i < numAlign; i++) {
476		✗	for (int j = 0; j < numAlign; j++) {
477		✗	if ((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))
478		✗	continue; // Don't draw on the three finder corners
479		✗	for (int dy = -1; dy <= 1; dy++) {
480		✗	for (int dx = -1; dx <= 1; dx++)
481		✗	setModule(qrcode, alignPatPos[i] + dx, alignPatPos[j] + dy, dx == 0 && dy == 0);
482			}
483			}
484			}
485
486			// Draw version blocks
487		✗	if (version >= 7) {
488			// Calculate error correction code and pack bits
489		✗	int rem = version; // version is uint6, in the range [7, 40]
490		✗	for (int i = 0; i < 12; i++)
491		✗	rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
492		✗	long bits = (long)version << 12 | rem; // uint18
493		✗	assert(bits >> 18 == 0);
494
495			// Draw two copies
496		✗	for (int i = 0; i < 6; i++) {
497		✗	for (int j = 0; j < 3; j++) {
498		✗	int k = qrsize - 11 + j;
499		✗	setModule(qrcode, k, i, (bits & 1) != 0);
500		✗	setModule(qrcode, i, k, (bits & 1) != 0);
501		✗	bits >>= 1;
502			}
503			}
504			}
505		✗	}
506
507
508			// Draws two copies of the format bits (with its own error correction code) based
509			// on the given mask and error correction level. This always draws all modules of
510			// the format bits, unlike drawWhiteFunctionModules() which might skip black modules.
511		✗	static void drawFormatBits(enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, uint8_t qrcode[]) {
512			// Calculate error correction code and pack bits
513		✗	assert(0 <= (int)mask && (int)mask <= 7);
514			static const int table[] = {1, 0, 3, 2};
515		✗	int data = table[(int)ecl] << 3 | (int)mask; // errCorrLvl is uint2, mask is uint3
516		✗	int rem = data;
517		✗	for (int i = 0; i < 10; i++)
518		✗	rem = (rem << 1) ^ ((rem >> 9) * 0x537);
519		✗	int bits = (data << 10 | rem) ^ 0x5412; // uint15
520		✗	assert(bits >> 15 == 0);
521
522			// Draw first copy
523		✗	for (int i = 0; i <= 5; i++)
524		✗	setModule(qrcode, 8, i, getBit(bits, i));
525		✗	setModule(qrcode, 8, 7, getBit(bits, 6));
526		✗	setModule(qrcode, 8, 8, getBit(bits, 7));
527		✗	setModule(qrcode, 7, 8, getBit(bits, 8));
528		✗	for (int i = 9; i < 15; i++)
529		✗	setModule(qrcode, 14 - i, 8, getBit(bits, i));
530
531			// Draw second copy
532		✗	int qrsize = qrcodegen_getSize(qrcode);
533		✗	for (int i = 0; i < 8; i++)
534		✗	setModule(qrcode, qrsize - 1 - i, 8, getBit(bits, i));
535		✗	for (int i = 8; i < 15; i++)
536		✗	setModule(qrcode, 8, qrsize - 15 + i, getBit(bits, i));
537		✗	setModule(qrcode, 8, qrsize - 8, true); // Always black
538		✗	}
539
540
541			// Calculates and stores an ascending list of positions of alignment patterns
542			// for this version number, returning the length of the list (in the range [0,7]).
543			// Each position is in the range [0,177), and are used on both the x and y axes.
544			// This could be implemented as lookup table of 40 variable-length lists of unsigned bytes.
545		✗	testable int getAlignmentPatternPositions(int version, uint8_t result[7]) {
546		✗	if (version == 1)
547		✗	return 0;
548		✗	int numAlign = version / 7 + 2;
549		✗	int step = (version == 32) ? 26 :
550		✗	(version*4 + numAlign*2 + 1) / (numAlign*2 - 2) * 2;
551		✗	for (int i = numAlign - 1, pos = version * 4 + 10; i >= 1; i--, pos -= step)
552		✗	result[i] = pos;
553		✗	result[0] = 6;
554		✗	return numAlign;
555			}
556
557
558			// Sets every pixel in the range [left : left + width] * [top : top + height] to black.
559		✗	static void fillRectangle(int left, int top, int width, int height, uint8_t qrcode[]) {
560		✗	for (int dy = 0; dy < height; dy++) {
561		✗	for (int dx = 0; dx < width; dx++)
562		✗	setModule(qrcode, left + dx, top + dy, true);
563			}
564		✗	}
565
566
567
568			/*---- Drawing data modules and masking ----*/
569
570			// Draws the raw codewords (including data and ECC) onto the given QR Code. This requires the initial state of
571			// the QR Code to be black at function modules and white at codeword modules (including unused remainder bits).
572		✗	static void drawCodewords(const uint8_t data[], int dataLen, uint8_t qrcode[]) {
573		✗	int qrsize = qrcodegen_getSize(qrcode);
574		✗	int i = 0; // Bit index into the data
575			// Do the funny zigzag scan
576		✗	for (int right = qrsize - 1; right >= 1; right -= 2) { // Index of right column in each column pair
577		✗	if (right == 6)
578		✗	right = 5;
579		✗	for (int vert = 0; vert < qrsize; vert++) { // Vertical counter
580		✗	for (int j = 0; j < 2; j++) {
581		✗	int x = right - j; // Actual x coordinate
582		✗	bool upward = ((right + 1) & 2) == 0;
583		✗	int y = upward ? qrsize - 1 - vert : vert; // Actual y coordinate
584		✗	if (!getModule(qrcode, x, y) && i < dataLen * 8) {
585		✗	bool black = getBit(data[i >> 3], 7 - (i & 7));
586		✗	setModule(qrcode, x, y, black);
587		✗	i++;
588			}
589			// If this QR Code has any remainder bits (0 to 7), they were assigned as
590			// 0/false/white by the constructor and are left unchanged by this method
591			}
592			}
593			}
594		✗	assert(i == dataLen * 8);
595		✗	}
596
597
598			// XORs the codeword modules in this QR Code with the given mask pattern.
599			// The function modules must be marked and the codeword bits must be drawn
600			// before masking. Due to the arithmetic of XOR, calling applyMask() with
601			// the same mask value a second time will undo the mask. A final well-formed
602			// QR Code needs exactly one (not zero, two, etc.) mask applied.
603		✗	static void applyMask(const uint8_t functionModules[], uint8_t qrcode[], enum qrcodegen_Mask mask) {
604		✗	assert(0 <= (int)mask && (int)mask <= 7); // Disallows qrcodegen_Mask_AUTO
605		✗	int qrsize = qrcodegen_getSize(qrcode);
606		✗	for (int y = 0; y < qrsize; y++) {
607		✗	for (int x = 0; x < qrsize; x++) {
608		✗	if (getModule(functionModules, x, y))
609		✗	continue;
610			bool invert;
611		✗	switch ((int)mask) {
612		✗	case 0: invert = (x + y) % 2 == 0; break;
613		✗	case 1: invert = y % 2 == 0; break;
614		✗	case 2: invert = x % 3 == 0; break;
615		✗	case 3: invert = (x + y) % 3 == 0; break;
616		✗	case 4: invert = (x / 3 + y / 2) % 2 == 0; break;
617		✗	case 5: invert = x * y % 2 + x * y % 3 == 0; break;
618		✗	case 6: invert = (x * y % 2 + x * y % 3) % 2 == 0; break;
619		✗	case 7: invert = ((x + y) % 2 + x * y % 3) % 2 == 0; break;
620		✗	default: assert(false); return;
621			}
622		✗	bool val = getModule(qrcode, x, y);
623		✗	setModule(qrcode, x, y, val ^ invert);
624			}
625			}
626			}
627
628
629			// Calculates and returns the penalty score based on state of the given QR Code's current modules.
630			// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
631		✗	static long getPenaltyScore(const uint8_t qrcode[]) {
632		✗	int qrsize = qrcodegen_getSize(qrcode);
633		✗	long result = 0;
634
635			// Adjacent modules in row having same color, and finder-like patterns
636		✗	for (int y = 0; y < qrsize; y++) {
637		✗	unsigned char runHistory[7] = {0};
638		✗	bool color = false;
639		✗	unsigned char runX = 0;
640		✗	for (int x = 0; x < qrsize; x++) {
641		✗	if (getModule(qrcode, x, y) == color) {
642		✗	runX++;
643		✗	if (runX == 5)
644		✗	result += PENALTY_N1;
645		✗	else if (runX > 5)
646		✗	result++;
647			} else {
648		✗	addRunToHistory(runX, runHistory);
649		✗	if (!color && hasFinderLikePattern(runHistory))
650		✗	result += PENALTY_N3;
651		✗	color = getModule(qrcode, x, y);
652		✗	runX = 1;
653			}
654			}
655		✗	addRunToHistory(runX, runHistory);
656		✗	if (color)
657		✗	addRunToHistory(0, runHistory); // Dummy run of white
658		✗	if (hasFinderLikePattern(runHistory))
659		✗	result += PENALTY_N3;
660			}
661			// Adjacent modules in column having same color, and finder-like patterns
662		✗	for (int x = 0; x < qrsize; x++) {
663		✗	unsigned char runHistory[7] = {0};
664		✗	bool color = false;
665		✗	unsigned char runY = 0;
666		✗	for (int y = 0; y < qrsize; y++) {
667		✗	if (getModule(qrcode, x, y) == color) {
668		✗	runY++;
669		✗	if (runY == 5)
670		✗	result += PENALTY_N1;
671		✗	else if (runY > 5)
672		✗	result++;
673			} else {
674		✗	addRunToHistory(runY, runHistory);
675		✗	if (!color && hasFinderLikePattern(runHistory))
676		✗	result += PENALTY_N3;
677		✗	color = getModule(qrcode, x, y);
678		✗	runY = 1;
679			}
680			}
681		✗	addRunToHistory(runY, runHistory);
682		✗	if (color)
683		✗	addRunToHistory(0, runHistory); // Dummy run of white
684		✗	if (hasFinderLikePattern(runHistory))
685		✗	result += PENALTY_N3;
686			}
687
688			// 2*2 blocks of modules having same color
689		✗	for (int y = 0; y < qrsize - 1; y++) {
690		✗	for (int x = 0; x < qrsize - 1; x++) {
691		✗	bool color = getModule(qrcode, x, y);
692		✗	if ( color == getModule(qrcode, x + 1, y) &&
693		✗	color == getModule(qrcode, x, y + 1) &&
694		✗	color == getModule(qrcode, x + 1, y + 1))
695		✗	result += PENALTY_N2;
696			}
697			}
698
699			// Balance of black and white modules
700		✗	int black = 0;
701		✗	for (int y = 0; y < qrsize; y++) {
702		✗	for (int x = 0; x < qrsize; x++) {
703		✗	if (getModule(qrcode, x, y))
704		✗	black++;
705			}
706			}
707		✗	int total = qrsize * qrsize; // Note that size is odd, so black/total != 1/2
708			// Compute the smallest integer k >= 0 such that (45-5k)% <= black/total <= (55+5k)%
709		✗	int k = (int)((labs(black * 20L - total * 10L) + total - 1) / total) - 1;
710		✗	result += k * PENALTY_N4;
711		✗	return result;
712			}
713
714
715			// Inserts the given value to the front of the given array, which shifts over the
716			// existing values and deletes the last value. A helper function for getPenaltyScore().
717		✗	static void addRunToHistory(unsigned char run, unsigned char history[7]) {
718		✗	memmove(&history[1], &history[0], 6 * sizeof(history[0]));
719		✗	history[0] = run;
720		✗	}
721
722
723			// Tests whether the given run history has the pattern of ratio 1:1:3:1:1 in the middle, and
724			// surrounded by at least 4 on either or both ends. A helper function for getPenaltyScore().
725			// Must only be called immediately after a run of white modules has ended.
726		✗	static bool hasFinderLikePattern(unsigned char runHistory[7]) {
727		✗	unsigned char n = runHistory[1];
728			// The maximum QR Code size is 177, hence the run length n <= 177.
729			// Arithmetic is promoted to int, so n*4 will not overflow.
730		✗	return n > 0 && runHistory[2] == n && runHistory[4] == n && runHistory[5] == n
731		✗	&& runHistory[3] == n * 3 && (runHistory[0] >= n * 4 || runHistory[6] >= n * 4);
732			}
733
734
735
736			/*---- Basic QR Code information ----*/
737
738			// Public function - see documentation comment in header file.
739		✗	int qrcodegen_getSize(const uint8_t qrcode[]) {
740		✗	assert(qrcode != NULL);
741		✗	int result = qrcode[0];
742		✗	assert((qrcodegen_VERSION_MIN * 4 + 17) <= result
743			&& result <= (qrcodegen_VERSION_MAX * 4 + 17));
744		✗	return result;
745			}
746
747
748			// Public function - see documentation comment in header file.
749		✗	bool qrcodegen_getModule(const uint8_t qrcode[], int x, int y) {
750		✗	assert(qrcode != NULL);
751		✗	int qrsize = qrcode[0];
752		✗	return (0 <= x && x < qrsize && 0 <= y && y < qrsize) && getModule(qrcode, x, y);
753			}
754
755
756			// Gets the module at the given coordinates, which must be in bounds.
757		✗	testable bool getModule(const uint8_t qrcode[], int x, int y) {
758		✗	int qrsize = qrcode[0];
759		✗	assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
760		✗	int index = y * qrsize + x;
761		✗	return getBit(qrcode[(index >> 3) + 1], index & 7);
762			}
763
764
765			// Sets the module at the given coordinates, which must be in bounds.
766		✗	testable void setModule(uint8_t qrcode[], int x, int y, bool isBlack) {
767		✗	int qrsize = qrcode[0];
768		✗	assert(21 <= qrsize && qrsize <= 177 && 0 <= x && x < qrsize && 0 <= y && y < qrsize);
769		✗	int index = y * qrsize + x;
770		✗	int bitIndex = index & 7;
771		✗	int byteIndex = (index >> 3) + 1;
772		✗	if (isBlack)
773		✗	qrcode[byteIndex] |= 1 << bitIndex;
774			else
775		✗	qrcode[byteIndex] &= (1 << bitIndex) ^ 0xFF;
776		✗	}
777
778
779			// Sets the module at the given coordinates, doing nothing if out of bounds.
780		✗	testable void setModuleBounded(uint8_t qrcode[], int x, int y, bool isBlack) {
781		✗	int qrsize = qrcode[0];
782		✗	if (0 <= x && x < qrsize && 0 <= y && y < qrsize)
783		✗	setModule(qrcode, x, y, isBlack);
784		✗	}
785
786
787			// Returns true iff the i'th bit of x is set to 1. Requires x >= 0 and 0 <= i <= 14.
788		✗	static bool getBit(int x, int i) {
789		✗	return ((x >> i) & 1) != 0;
790			}
791
792
793
794			/*---- Segment handling ----*/
795
796			// Public function - see documentation comment in header file.
797		✗	bool qrcodegen_isAlphanumeric(const char *text) {
798		✗	assert(text != NULL);
799		✗	for (; *text != '\0'; text++) {
800		✗	if (strchr(ALPHANUMERIC_CHARSET, *text) == NULL)
801		✗	return false;
802			}
803		✗	return true;
804			}
805
806
807			// Public function - see documentation comment in header file.
808		✗	bool qrcodegen_isNumeric(const char *text) {
809		✗	assert(text != NULL);
810		✗	for (; *text != '\0'; text++) {
811		✗	if (*text < '0' || *text > '9')
812		✗	return false;
813			}
814		✗	return true;
815			}
816
817
818			// Public function - see documentation comment in header file.
819		✗	size_t qrcodegen_calcSegmentBufferSize(enum qrcodegen_Mode mode, size_t numChars) {
820		✗	int temp = calcSegmentBitLength(mode, numChars);
821		✗	if (temp == -1)
822		✗	return SIZE_MAX;
823		✗	assert(0 <= temp && temp <= INT16_MAX);
824		✗	return ((size_t)temp + 7) / 8;
825			}
826
827
828			// Returns the number of data bits needed to represent a segment
829			// containing the given number of characters using the given mode. Notes:
830			// - Returns -1 on failure, i.e. numChars > INT16_MAX or
831			// the number of needed bits exceeds INT16_MAX (i.e. 32767).
832			// - Otherwise, all valid results are in the range [0, INT16_MAX].
833			// - For byte mode, numChars measures the number of bytes, not Unicode code points.
834			// - For ECI mode, numChars must be 0, and the worst-case number of bits is returned.
835			// An actual ECI segment can have shorter data. For non-ECI modes, the result is exact.
836		✗	testable int calcSegmentBitLength(enum qrcodegen_Mode mode, size_t numChars) {
837			// All calculations are designed to avoid overflow on all platforms
838		✗	if (numChars > (unsigned int)INT16_MAX)
839		✗	return -1;
840		✗	long result = (long)numChars;
841		✗	if (mode == qrcodegen_Mode_NUMERIC)
842		✗	result = (result * 10 + 2) / 3; // ceil(10/3 * n)
843		✗	else if (mode == qrcodegen_Mode_ALPHANUMERIC)
844		✗	result = (result * 11 + 1) / 2; // ceil(11/2 * n)
845		✗	else if (mode == qrcodegen_Mode_BYTE)
846		✗	result *= 8;
847		✗	else if (mode == qrcodegen_Mode_KANJI)
848		✗	result *= 13;
849		✗	else if (mode == qrcodegen_Mode_ECI && numChars == 0)
850		✗	result = 3 * 8;
851			else { // Invalid argument
852		✗	assert(false);
853			return -1;
854			}
855		✗	assert(result >= 0);
856		✗	if (result > (unsigned int)INT16_MAX)
857		✗	return -1;
858		✗	return (int)result;
859			}
860
861
862			// Public function - see documentation comment in header file.
863		✗	struct qrcodegen_Segment qrcodegen_makeBytes(const uint8_t data[], size_t len, uint8_t buf[]) {
864		✗	assert(data != NULL || len == 0);
865			struct qrcodegen_Segment result;
866		✗	result.mode = qrcodegen_Mode_BYTE;
867		✗	result.bitLength = calcSegmentBitLength(result.mode, len);
868		✗	assert(result.bitLength != -1);
869		✗	result.numChars = (int)len;
870		✗	if (len > 0)
871		✗	memcpy(buf, data, len * sizeof(buf[0]));
872		✗	result.data = buf;
873		✗	return result;
874			}
875
876
877			// Public function - see documentation comment in header file.
878		✗	struct qrcodegen_Segment qrcodegen_makeNumeric(const char *digits, uint8_t buf[]) {
879		✗	assert(digits != NULL);
880			struct qrcodegen_Segment result;
881		✗	size_t len = strlen(digits);
882		✗	result.mode = qrcodegen_Mode_NUMERIC;
883		✗	int bitLen = calcSegmentBitLength(result.mode, len);
884		✗	assert(bitLen != -1);
885		✗	result.numChars = (int)len;
886		✗	if (bitLen > 0)
887		✗	memset(buf, 0, ((size_t)bitLen + 7) / 8 * sizeof(buf[0]));
888		✗	result.bitLength = 0;
889
890		✗	unsigned int accumData = 0;
891		✗	int accumCount = 0;
892		✗	for (; *digits != '\0'; digits++) {
893		✗	char c = *digits;
894		✗	assert('0' <= c && c <= '9');
895		✗	accumData = accumData * 10 + (unsigned int)(c - '0');
896		✗	accumCount++;
897		✗	if (accumCount == 3) {
898		✗	appendBitsToBuffer(accumData, 10, buf, &result.bitLength);
899		✗	accumData = 0;
900		✗	accumCount = 0;
901			}
902			}
903		✗	if (accumCount > 0) // 1 or 2 digits remaining
904		✗	appendBitsToBuffer(accumData, accumCount * 3 + 1, buf, &result.bitLength);
905		✗	assert(result.bitLength == bitLen);
906		✗	result.data = buf;
907		✗	return result;
908			}
909
910
911			// Public function - see documentation comment in header file.
912		✗	struct qrcodegen_Segment qrcodegen_makeAlphanumeric(const char *text, uint8_t buf[]) {
913		✗	assert(text != NULL);
914			struct qrcodegen_Segment result;
915		✗	size_t len = strlen(text);
916		✗	result.mode = qrcodegen_Mode_ALPHANUMERIC;
917		✗	int bitLen = calcSegmentBitLength(result.mode, len);
918		✗	assert(bitLen != -1);
919		✗	result.numChars = (int)len;
920		✗	if (bitLen > 0)
921		✗	memset(buf, 0, ((size_t)bitLen + 7) / 8 * sizeof(buf[0]));
922		✗	result.bitLength = 0;
923
924		✗	unsigned int accumData = 0;
925		✗	int accumCount = 0;
926		✗	for (; *text != '\0'; text++) {
927		✗	const char *temp = strchr(ALPHANUMERIC_CHARSET, *text);
928		✗	assert(temp != NULL);
929		✗	accumData = accumData * 45 + (unsigned int)(temp - ALPHANUMERIC_CHARSET);
930		✗	accumCount++;
931		✗	if (accumCount == 2) {
932		✗	appendBitsToBuffer(accumData, 11, buf, &result.bitLength);
933		✗	accumData = 0;
934		✗	accumCount = 0;
935			}
936			}
937		✗	if (accumCount > 0) // 1 character remaining
938		✗	appendBitsToBuffer(accumData, 6, buf, &result.bitLength);
939		✗	assert(result.bitLength == bitLen);
940		✗	result.data = buf;
941		✗	return result;
942			}
943
944
945			// Public function - see documentation comment in header file.
946		✗	struct qrcodegen_Segment qrcodegen_makeEci(long assignVal, uint8_t buf[]) {
947			struct qrcodegen_Segment result;
948		✗	result.mode = qrcodegen_Mode_ECI;
949		✗	result.numChars = 0;
950		✗	result.bitLength = 0;
951		✗	if (assignVal < 0)
952		✗	assert(false);
953		✗	else if (assignVal < (1 << 7)) {
954		✗	memset(buf, 0, 1 * sizeof(buf[0]));
955		✗	appendBitsToBuffer(assignVal, 8, buf, &result.bitLength);
956		✗	} else if (assignVal < (1 << 14)) {
957		✗	memset(buf, 0, 2 * sizeof(buf[0]));
958		✗	appendBitsToBuffer(2, 2, buf, &result.bitLength);
959		✗	appendBitsToBuffer(assignVal, 14, buf, &result.bitLength);
960		✗	} else if (assignVal < 1000000L) {
961		✗	memset(buf, 0, 3 * sizeof(buf[0]));
962		✗	appendBitsToBuffer(6, 3, buf, &result.bitLength);
963		✗	appendBitsToBuffer(assignVal >> 10, 11, buf, &result.bitLength);
964		✗	appendBitsToBuffer(assignVal & 0x3FF, 10, buf, &result.bitLength);
965			} else
966		✗	assert(false);
967		✗	result.data = buf;
968		✗	return result;
969			}
970
971
972			// Calculates the number of bits needed to encode the given segments at the given version.
973			// Returns a non-negative number if successful. Otherwise returns -1 if a segment has too
974			// many characters to fit its length field, or the total bits exceeds INT16_MAX.
975		✗	testable int getTotalBits(const struct qrcodegen_Segment segs[], size_t len, int version) {
976		✗	assert(segs != NULL || len == 0);
977		✗	long result = 0;
978		✗	for (size_t i = 0; i < len; i++) {
979		✗	int numChars = segs[i].numChars;
980		✗	int bitLength = segs[i].bitLength;
981		✗	assert(0 <= numChars && numChars <= INT16_MAX);
982		✗	assert(0 <= bitLength && bitLength <= INT16_MAX);
983		✗	int ccbits = numCharCountBits(segs[i].mode, version);
984		✗	assert(0 <= ccbits && ccbits <= 16);
985		✗	if (numChars >= (1L << ccbits))
986		✗	return -1; // The segment's length doesn't fit the field's bit width
987		✗	result += 4L + ccbits + bitLength;
988		✗	if (result > INT16_MAX)
989		✗	return -1; // The sum might overflow an int type
990			}
991		✗	assert(0 <= result && result <= INT16_MAX);
992		✗	return (int)result;
993			}
994
995
996			// Returns the bit width of the character count field for a segment in the given mode
997			// in a QR Code at the given version number. The result is in the range [0, 16].
998		✗	static int numCharCountBits(enum qrcodegen_Mode mode, int version) {
999		✗	assert(qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
1000		✗	int i = (version + 7) / 17;
1001		✗	switch (mode) {
1002		✗	case qrcodegen_Mode_NUMERIC : { static const int temp[] = {10, 12, 14}; return temp[i]; }
1003		✗	case qrcodegen_Mode_ALPHANUMERIC: { static const int temp[] = { 9, 11, 13}; return temp[i]; }
1004		✗	case qrcodegen_Mode_BYTE : { static const int temp[] = { 8, 16, 16}; return temp[i]; }
1005		✗	case qrcodegen_Mode_KANJI : { static const int temp[] = { 8, 10, 12}; return temp[i]; }
1006		✗	case qrcodegen_Mode_ECI : return 0;
1007		✗	default: assert(false); return -1; // Dummy value
1008			}
1009			}
1010