Did some code improvements, added comments for incomprehensible lines

Demo/main.cpp

@@ -1,15 +1,19 @@
 #include <iostream>
 #include <locale>
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
-#include <Windows.h>
+#if defined(WIN32) || defined(_WIN32) || defined(__WIN32)
+#define IS_WINDOWS
+#endif
+
+#ifdef IS_WINDOWS
+#include <IS_WINDOWSows.h>
 #endif
 
 #include "../QRCodeLibrary/QRCode.hpp"
 
 using namespace std;
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
+#ifdef IS_WINDOWS
 std::string cp1251_to_utf8(const char* str)
 {
 	std::string res;
@@ -49,18 +53,19 @@ string str_of(unsigned k, const string& input) {
 #endif
 
 int main() {
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
+#ifdef IS_WINDOWS
 	SetConsoleCP(1251);
 #endif
 
-	string input, buff;
+	string input;
+	string buff;
 
 	while (getline(cin, buff)) {
 		input += buff + '\n';
 	}
 	input.pop_back();
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
+#ifdef IS_WINDOWS
 	input = cp1251_to_utf8(input.c_str());
 #endif
 
@@ -70,7 +75,7 @@ int main() {
 
 #define SQUARE_WIDTH 2
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
+#ifdef IS_WINDOWS
 	const string long_sep = string((res.size() + 8) * SQUARE_WIDTH, 219),
 		short_sep = string(4 * SQUARE_WIDTH, 219),
 		black = string(SQUARE_WIDTH, ' '),
@@ -106,7 +111,7 @@ int main() {
 	for (int i = 0; i < 4; i++)
 		cout << long_sep << endl;
 
-#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
+#ifdef IS_WINDOWS
 	system("pause");
 #endif
-}
+}

QRCodeLibrary/BitArray.cpp

@@ -8,15 +8,15 @@ bool BitArray::get(unsigned index) const
 {
 	if (index >= size) throw std::out_of_range("No such element in array");
 
-    return (v[index / 8] >> (8 - 1 - index % 8)) & 1;
+    return (v[index / 8] >> (8 - index % 8 - 1)) & 1;
 }
 
 BitArray::operator std::string() const 
 {
 	std::stringstream res;
 
 	for (unsigned i = 0; i < size; i++)
-		res << static_cast<int>((*this).get(i));
+		res << static_cast<int>(get(i));
 
 	return res.str();
 }
@@ -25,32 +25,31 @@ void BitArray::set(unsigned index, bool val)
 {
 	if (index >= size) throw std::out_of_range("No such element in array");
 
-	if (val)
-		v[index / 8] |= 1 << (8 - 1 - index % 8);
+	if (val == 1)
+		v[index / 8] |= 1 << (8 - index % 8 - 1);
 	else
-		v[index / 8] &= ~(1 << (8 - 1 - index % 8));
+		v[index / 8] &= ~(1 << (8 - index % 8 - 1));
 }
 
 unsigned BitArray::set(unsigned index, int32_t val, unsigned size)
 {
 	if (index >= this->size) throw std::out_of_range("No such element in array");
 
-	unsigned shift = index % 8, written = 0;
+	unsigned shift = index % 8;
+	unsigned written = 0;
 
 	if (size > this->size - index) throw std::out_of_range("Number of bits to write from this index is more than BitArray capability");
 
-	index /= 8;
+	for (int i = index / 8; written < size; i++) {
+		int input_shift = size - (8 - shift) - written; // right shift for written data
+		int right_rem = input_shift < 0 ? -input_shift : 0; // how many bits should I take from right side of original byte
 
-	while (written < size) {
-		int input_shift = size - (8 - shift) - written;
-		int right_rem = input_shift < 0 ? -input_shift : 0;
-
-		v[index] = ((v[index] >> (8 - shift)) << (8 - shift)) |
-			(unsigned char)(((1 << (8 - shift)) - 1) & ((input_shift >= 0) ? (val >> input_shift) : (val << -input_shift))) |
-			(v[index] & ((1 << right_rem) - 1));
+		v[i] = (v[i] & (-1 << (8 - shift))) |
+			(((1 << (8 - shift)) - 1) &
+			  ((input_shift >= 0) ? (val >> input_shift) : (val << -input_shift))) |
+			(v[i] & ((1 << right_rem) - 1));
 
 		written += 8 - shift;
-		index++;
 		shift = 0;
 	}
 

QRCodeLibrary/BitArray.hpp

@@ -8,7 +8,7 @@
 
 using namespace std;
 
-constexpr unsigned ceil_div(unsigned a, unsigned b) {
+constexpr static unsigned ceil_div(unsigned a, unsigned b) {
 	if (b == 0) throw runtime_error("Dividion by zero not possible");
 	return a / b + (a % b > 0);
 }
@@ -17,15 +17,16 @@ class BitArray
 {
 public:
 	BitArray(unsigned size_ = 0) : size{ size_ }, v(ceil_div(size_, 8), 0) {};
-	BitArray(const vector<unsigned char>& input) : size(to_U(input.size()) * 8), v{ input } {};
+	BitArray(const byte_list& input) : size(to_U(input.size()) * 8), v{ input } {};
 
 	operator std::string() const;
 
-	unsigned size;
-	vector<unsigned char> v;
+	unsigned size; // array size in bits
+	byte_list v;
 
 	bool get(unsigned index) const;
 	void set(unsigned index, bool val);
+	// sets least size bits of val starting from index
 	unsigned set(unsigned index, int32_t val, unsigned size);
 
 	void resize(unsigned new_size);

QRCodeLibrary/DataBlocks.cpp

@@ -4,20 +4,19 @@
 #include "Tables.hpp"
 #include "utils.hpp"
 
-vector<unsigned char>& DataBlocks::compose_joined_data_and_EC_blocks()
+DataBlocks::DataBlocks(const byte_list& e_data_, CorrectionLevel corr_lvl_, char version_) : e_data{ e_data_ }, corr_lvl{ corr_lvl_ }, version{ version_ } 
 {
 	vector<pair<unsigned, unsigned>>data_block_sizes;
 
 	divide_to_blocks(data_block_sizes, to_U(e_data.size()), Tables::data_blocks_number.at(corr_lvl).at(version));
 
 	unsigned EC_bytes_number = Tables::correction_bytes_num.at(corr_lvl).at(version);
-	vector<vector<unsigned char>> EC_blocks(data_block_sizes.size(), vector<unsigned char>());
+	vector<byte_list> EC_blocks(data_block_sizes.size(), byte_list());
+
 	for (unsigned i = 0; i < data_block_sizes.size(); i++)
 		compose_EC_bytes(EC_blocks[i], e_data.cbegin() + data_block_sizes[i].second, EC_bytes_number, data_block_sizes[i].first);
 
 	join_data_and_EC_blocks(data, e_data, data_block_sizes, EC_blocks, EC_bytes_number);
-
-	return data;
 }
 
 void DataBlocks::divide_to_blocks(vector<pair<unsigned, unsigned>>& db_sizes, unsigned data_size, unsigned db_number)
@@ -33,14 +32,16 @@ void DataBlocks::divide_to_blocks(vector<pair<unsigned, unsigned>>& db_sizes, un
 	}
 }
 
-void DataBlocks::compose_EC_bytes(vector<unsigned char>& res, const vector<unsigned char>::const_iterator& src, unsigned corr_bytes_num, unsigned db_size)
+void DataBlocks::compose_EC_bytes(byte_list& res, const byte_list::const_iterator& src, unsigned corr_bytes_num, unsigned db_size)
 {
 	res.reserve(max(db_size, corr_bytes_num));
 	res.insert(res.end(), src, src + db_size);
 	res.resize(res.capacity(), 0);
 
+	auto gen_poly = Tables::reed_solomon_generative_polynomial.at(corr_bytes_num);
+
 	for (unsigned j = 0; j < db_size; j++) {
-		unsigned char A = res[0];
+		unsigned char A = res[0]; 
 		res.erase(res.begin());
 		res.push_back(0);
 
@@ -50,7 +51,7 @@ void DataBlocks::compose_EC_bytes(vector<unsigned char>& res, const vector<unsig
 		unsigned char B = Tables::reverse_galois_field.at(A);
 
 		for (unsigned k = 0; k < corr_bytes_num; k++) {
-			unsigned char C = (Tables::reed_solomon_generative_polynomial.at(corr_bytes_num).at(k) + B) % 255;
+			unsigned char C = (gen_poly.at(k) + B) % 255;
 			res[k] ^= Tables::galois_field[C];
 		}
 	}
@@ -60,20 +61,16 @@ unsigned get_db_byte_index(unsigned block_index, unsigned byte_index, const vect
 	return db_sizes[block_index].second + byte_index;
 }
 
-void DataBlocks::join_data_and_EC_blocks(vector<unsigned char>& res, const vector<unsigned char>& e_data, const vector<pair<unsigned, unsigned>>& db_sizes, const vector<vector<unsigned char>>& ec_codes, unsigned ec_bytes_number)
+void DataBlocks::join_data_and_EC_blocks(byte_list& res, const byte_list& e_data, const vector<pair<unsigned, unsigned>>& db_sizes, const vector<byte_list>& ec_codes, unsigned ec_bytes_number)
 {
-	if (ec_codes.size())
-		res.reserve(e_data.size() + ec_codes.at(0).size() * ec_codes.size());
-	else
-		res.reserve(e_data.size());
+	res.reserve(e_data.size() + ec_codes.at(0).size() * ec_codes.size());
 
 	for (unsigned i = 0; i < db_sizes[db_sizes.size() - 1].first; i++)
 		for (unsigned j = 0; j < db_sizes.size(); j++)
 			if (i < db_sizes[j].first)
 				res.push_back(e_data[get_db_byte_index(j, i, db_sizes)]);
 
-	if (ec_codes.size())
-		for (unsigned i = 0; i < ec_bytes_number; i++)
-			for (unsigned j = 0; j < ec_codes.size(); j++)
-				res.push_back(ec_codes[j][i]);
+	for (unsigned i = 0; i < ec_bytes_number; i++)
+		for (unsigned j = 0; j < ec_codes.size(); j++)
+			res.push_back(ec_codes[j][i]);
 }

QRCodeLibrary/DataBlocks.hpp

@@ -10,19 +10,19 @@ using namespace std;
 class DataBlocks
 {
 public:
-	DataBlocks(const vector<unsigned char>& e_data_, CorrectionLevel corr_lvl_, char version_) : e_data{ e_data_ }, corr_lvl{ corr_lvl_ }, version{ version_ } {};
+	DataBlocks(const byte_list& e_data_, CorrectionLevel corr_lvl_, char version_);
 
-	vector<unsigned char>& compose_joined_data_and_EC_blocks();
+	byte_list& get_joined_data_and_EC_blocks() { return data; };
 
 	static void divide_to_blocks(vector<pair<unsigned, unsigned>>& db_sizes, unsigned data_size, unsigned db_number);
-	static void compose_EC_bytes(vector<unsigned char>& res, const vector<unsigned char>::const_iterator& src, unsigned corr_bytes_num, unsigned db_size);
-	static void join_data_and_EC_blocks(vector<unsigned char>&res, const vector<unsigned char>& e_data, const vector<pair<unsigned, unsigned>>& db_sizes, const vector<vector<unsigned char>>& ec_codes, unsigned ec_bytes_number);
+	static void compose_EC_bytes(byte_list& res, const byte_list::const_iterator& src, unsigned corr_bytes_num, unsigned db_size);
+	static void join_data_and_EC_blocks(byte_list&res, const byte_list& e_data, const vector<pair<unsigned, unsigned>>& db_sizes, const vector<byte_list>& ec_codes, unsigned ec_bytes_number);
 
 private:
-	const vector<unsigned char>& e_data;
+	const byte_list& e_data;
 	CorrectionLevel corr_lvl;
 	char version;
 
-	vector<unsigned char> data;
+	byte_list data;
 };
 

QRCodeLibrary/Encoder.cpp

@@ -6,7 +6,7 @@
 
 #include <stdexcept>
 
-BitArray& Encoder::encode()
+Encoder::Encoder(const byte_list& input_, CorrectionLevel corr_lvl_, QRCodeMethod method_, char version_): input{ input_ }, corr_lvl{ corr_lvl_ }, method{ method_ }, version{ version_ }
 {
 	unsigned encoded_bit_num = calculate_encoded_input_size(to_U(input.size()), method);
 	unsigned metadata_bit_num = calculate_metadata_size(method, ((version < 0) ? 0 : version));
@@ -27,8 +27,6 @@ BitArray& Encoder::encode()
 	encode_input(metadata_bit_num);
 
 	pad_data(e, metadata_bit_num + encoded_bit_num);
-
-	return e;
 }
 
 char Encoder::determite_version(unsigned size, CorrectionLevel corr_lvl)
@@ -65,17 +63,20 @@ void Encoder::write_metadata(unsigned input_size, unsigned input_bits_amount_siz
 
 void Encoder::encode_numeric(const string& input, BitArray& out, unsigned offset)
 {
+	int bin;
 	for (unsigned i = 0; i < input.size() / 3; i++) {
-		int bin = stoi(input.substr(i * 3, 3));
+		bin = stoi(input.substr(i * 3, 3));
 		out.set(offset + i * 10, bin, 10);
 	}
 
 	if (input.size() % 3 == 2) {
-		int bin = stoi(input.substr(input.size() - 2, 2));
+		bin = stoi(input.substr(input.size() - 2, 2));
 		out.set(offset + to_U(input.size()) / 3 * 10, bin, 7);
 	}
-	else if (input.size() % 3 == 1)
-		out.set(offset + to_U(input.size()) / 3 * 10, input[input.size() - 1] - '0', 4);
+	else if (input.size() % 3 == 1) {
+		bin = input[input.size() - 1] - '0';
+		out.set(offset + to_U(input.size()) / 3 * 10, bin, 4);
+	}
 }
 
 void Encoder::encode_alphabetic(const string& input, BitArray& out, unsigned offset)
@@ -118,7 +119,7 @@ void Encoder::pad_data(BitArray& arr, unsigned bits_written)
 		arr.v[i] = ((i - encoded_bytes) % 2 == 0) ? 0b11101100 : 0b00010001;
 }
 
-BitArray Encoder::get_data() const
+BitArray& Encoder::get_data()
 {
 	if (e.size == 0) throw std::runtime_error("Data is not calculated yet");
 

QRCodeLibrary/Encoder.hpp

@@ -13,9 +13,7 @@ using namespace std;
 class Encoder
 {
 public:
-	Encoder(const byte_list& input_, CorrectionLevel corr_lvl_ = CorrectionLevel::M, QRCodeMethod method_ = QRCodeMethod::Dynamic, char version_ = -1) : input{ input_ }, corr_lvl{ corr_lvl_ }, method{ method_ }, version{ version_ } {};
-
-	BitArray& encode();
+	Encoder(const byte_list& input_, CorrectionLevel corr_lvl_ = CorrectionLevel::M, QRCodeMethod method_ = QRCodeMethod::Dynamic, char version_ = -1);
 
 	static char determite_version(unsigned size, CorrectionLevel corr_lvl);
 
@@ -45,7 +43,7 @@ class Encoder
 	static void pad_data(BitArray& arr, unsigned bits_written);
 
 	constexpr char get_version() const { return version; };
-	BitArray get_data() const;
+	BitArray& get_data();
 
 private:
 	static constexpr unsigned char encode_char(char ch);

QRCodeLibrary/QRCode.cpp

@@ -14,19 +14,15 @@ QRCode::QRCode(const byte_list& input_, CorrectionLevel corr_lvl_, QRCodeMethod
 		else
 			method = QRCodeMethod::Byte;
 	}
-
 	Encoder encoder(input, corr_lvl, method, version);
-	const BitArray& encoded_data = encoder.encode();
+	const BitArray& encoded_data = encoder.get_data();
 	version = encoder.get_version();
 
 	DataBlocks data_blocks(encoded_data.v, corr_lvl, version);
-	const BitArray final_message(data_blocks.compose_joined_data_and_EC_blocks());
+	const BitArray final_message(data_blocks.get_joined_data_and_EC_blocks());
 
 	matrix.set_version(version);
-
 	matrix.draw_patterns();
-
 	matrix.place_metadata(corr_lvl, mask_n);
-
 	matrix.place_data(final_message, mask_n);
 }