From 105887d46817da3586cfe69c463a0873f9a7d5bb Mon Sep 17 00:00:00 2001
From: dm1sh <me@dmitriy.icu>
Date: Sat, 11 Dec 2021 14:00:25 +0300
Subject: [PATCH] Added BitArray class

---
 QRCodeLibrary/BitArray.cpp                  | 37 +++++++++++++++++++
 QRCodeLibrary/BitArray.hpp                  | 23 ++++++++++++
 QRCodeLibrary/QRCodeLibrary.vcxproj         |  2 ++
 QRCodeLibrary/QRCodeLibrary.vcxproj.filters |  6 ++++
 tests/BitArray_test.cpp                     | 40 +++++++++++++++++++++
 tests/tests.vcxproj                         |  1 +
 6 files changed, 109 insertions(+)
 create mode 100644 QRCodeLibrary/BitArray.cpp
 create mode 100644 QRCodeLibrary/BitArray.hpp
 create mode 100644 tests/BitArray_test.cpp

diff --git a/QRCodeLibrary/BitArray.cpp b/QRCodeLibrary/BitArray.cpp
new file mode 100644
index 0000000..35f9bce
--- /dev/null
+++ b/QRCodeLibrary/BitArray.cpp
@@ -0,0 +1,37 @@
+#include "pch.h"
+#include "BitArray.hpp"
+
+bool BitArray::get(unsigned index)
+{
+    return (v[index / 8] >> (8 - 1 - index % 8)) & 1;
+}
+
+void BitArray::set(unsigned index, bool val)
+{
+	if (val)
+		v[index / 8] |= 1 << (8 - 1 - index % 8);
+	else
+		v[index / 8] &= ~(1 << (8 - 1 - index % 8));
+}
+
+unsigned BitArray::set(unsigned index, int32_t val, unsigned size)
+{
+	unsigned shift = index % 8, written = 0;
+	size = std::min(size, this->size - index);
+	index /= 8;
+
+	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));
+
+		written += 8 - shift;
+		index++;
+		shift = 0;
+	}
+
+	return written;
+}
diff --git a/QRCodeLibrary/BitArray.hpp b/QRCodeLibrary/BitArray.hpp
new file mode 100644
index 0000000..5a45ec1
--- /dev/null
+++ b/QRCodeLibrary/BitArray.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <vector>
+
+using namespace std;
+
+constexpr unsigned ceil_div(unsigned a, unsigned b) {
+	return a / b + (a % b > 0);
+}
+
+class BitArray
+{
+public:
+	BitArray(unsigned size_ = 0) : size{ size_ }, v(ceil_div(size_, 8)) {};
+	
+	unsigned size;
+	vector<unsigned char> v;
+
+	bool get(unsigned index);
+	void set(unsigned index, bool val);
+	unsigned set(unsigned index, int32_t val, unsigned size);
+};
+
diff --git a/QRCodeLibrary/QRCodeLibrary.vcxproj b/QRCodeLibrary/QRCodeLibrary.vcxproj
index 708b399..de4fc7f 100644
--- a/QRCodeLibrary/QRCodeLibrary.vcxproj
+++ b/QRCodeLibrary/QRCodeLibrary.vcxproj
@@ -151,6 +151,7 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClInclude Include="BitArray.hpp" />
     <ClInclude Include="Encode.hpp" />
     <ClInclude Include="framework.h" />
     <ClInclude Include="Method.hpp" />
@@ -159,6 +160,7 @@
     <ClInclude Include="Tables.hpp" />
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="BitArray.cpp" />
     <ClCompile Include="Encode.cpp" />
     <ClCompile Include="Method.cpp" />
     <ClCompile Include="pch.cpp">
diff --git a/QRCodeLibrary/QRCodeLibrary.vcxproj.filters b/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
index 7113336..61415b4 100644
--- a/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
+++ b/QRCodeLibrary/QRCodeLibrary.vcxproj.filters
@@ -33,6 +33,9 @@
     <ClInclude Include="Encode.hpp">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="BitArray.hpp">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="pch.cpp">
@@ -50,5 +53,8 @@
     <ClCompile Include="Encode.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="BitArray.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/tests/BitArray_test.cpp b/tests/BitArray_test.cpp
new file mode 100644
index 0000000..2ee35d3
--- /dev/null
+++ b/tests/BitArray_test.cpp
@@ -0,0 +1,40 @@
+#include "pch.h"
+
+#define protected public
+#define private public
+
+#include "../QRCodeLibrary/BitArray.hpp"
+
+class BitArrayTests: public ::testing::Test {
+public:
+	BitArrayTests() : ::testing::Test(), a1(15) {};
+
+	void SetUp() override {
+		a1.v[0] = static_cast<unsigned char>(0b10101010);
+		a1.v[1] = static_cast<unsigned char>(0b11111111);
+	}
+
+protected:
+	BitArray a1;
+};
+
+TEST_F(BitArrayTests, GetsBitByIndex) {
+	EXPECT_EQ(a1.get(10), 1);
+	EXPECT_EQ(a1.get(0), 1);
+	EXPECT_EQ(a1.get(1), 0);
+}
+
+TEST_F(BitArrayTests, SetsIndividualBit) {
+	a1.set(0, 0);
+	a1.set(1, 1);
+	EXPECT_EQ(a1.get(0), 0);
+	EXPECT_EQ(a1.get(1), 1);
+}
+
+TEST_F(BitArrayTests, SetsMultipleBits) {
+	a1.set(9, 0b00110, 5);
+	EXPECT_EQ(a1.v[1], 0b10011011);
+
+	a1.set(2, 0b111, 3);
+	EXPECT_EQ(a1.v[0], 0b10111010);
+}
diff --git a/tests/tests.vcxproj b/tests/tests.vcxproj
index ab443c2..4680b04 100644
--- a/tests/tests.vcxproj
+++ b/tests/tests.vcxproj
@@ -36,6 +36,7 @@
     <ClInclude Include="pch.h" />
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="BitArray_test.cpp" />
     <ClCompile Include="Encode_test.cpp" />
     <ClCompile Include="Method_test.cpp" />
     <ClCompile Include="QRCode_test.cpp" />