Merge pull request #8 from KredeGC/dev

Add double trait

Author: KredeGC

README.md

@@ -254,10 +254,10 @@ uint32_t value = 27; // We can choose any value below 2^5. Otherwise we need mor
 writer.serialize_bits(value, 5);
 
 // Flush the writer's remaining state into the buffer
-uint32_t num_bytes = writer.flush();
+uint32_t num_bits = writer.flush();
 
 // Create a reader, referencing the buffer and bytes written
-bit_reader reader(buffer, num_bytes);
+bit_reader reader(buffer, num_bits);
 
 // Read the value back
 uint32_t out_value; // We don't have to initialize it yet
@@ -275,10 +275,10 @@ int32_t value = -45; // We can choose any value within the range below
 writer.serialize<int32_t>(value, -90, 40); // A lower and upper bound which the value will be quantized between
 
 // Flush the writer's remaining state into the buffer
-uint32_t num_bytes = writer.flush();
+uint32_t num_bits = writer.flush();
 
 // Create a reader by moving and invalidating the writer
-bit_reader reader(buffer, num_bytes);
+bit_reader reader(buffer, num_bits);
 
 // Read the value back
 int32_t out_value; // We don't have to initialize it yet
@@ -296,10 +296,10 @@ const char* value = "Hello world!";
 writer.serialize<const char*>(value, 32U); // The second argument is the maximum size we expect the string to be
 
 // Flush the writer's remaining state into the buffer
-uint32_t num_bytes = writer.flush();
+uint32_t num_bits = writer.flush();
 
 // Create a reader by moving and invalidating the writer
-bit_reader reader(buffer, num_bytes);
+bit_reader reader(buffer, num_bits);
 
 // Read the value back
 char out_value[32]; // Set the size to the max size
@@ -317,10 +317,10 @@ std::string value = "Hello world!";
 writer.serialize<std::string>(value, 32U); // The second argument is the maximum size we expect the string to be
 
 // Flush the writer's remaining state into the buffer
-uint32_t num_bytes = writer.flush();
+uint32_t num_bits = writer.flush();
 
 // Create a reader by moving and invalidating the writer
-bit_reader reader(buffer, num_bytes);
+bit_reader reader(buffer, num_bits);
 
 // Read the value back
 std::string out_value; // The string will be resized if the output doesn't fit
@@ -339,10 +339,10 @@ float value = 1.2345678f;
 writer.serialize<bounded_range>(range, value);
 
 // Flush the writer's remaining state into the buffer
-uint32_t num_bytes = writer.flush();
+uint32_t num_bits = writer.flush();
 
 // Create a reader by moving and invalidating the writer
-bit_reader reader(buffer, num_bytes);
+bit_reader reader(buffer, num_bits);
 
 // Read the value back
 float out_value;
@@ -354,7 +354,7 @@ These examples can also be seen in [`src/test/examples_test.cpp`](https://github
 # Extensibility
 The library is made with extensibility in mind.
 The `bit_writer` and `bit_reader` use a template trait specialization of the given type to deduce how to serialize and deserialize the object.
-The only requirements of the trait is that it has (or can deduce) 2 static functions which take a bit_writer& and a bit_reader& respectively as their first argument.
+The only requirements of the trait is that it has (or can deduce) 2 static functions which take a `bit_writer&` and a `bit_reader&` respectively as their first argument.
 The 2 functions must also return a bool indicating whether the serialization was a success or not, but can otherwise take any number of additional arguments.
 
 ## Adding new serializables types

include/bitstream/quantization/bounded_range.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <cstdint>
-
 /*
  *  Copyright (c) 2018 Stanislav Denisov
  *
@@ -24,6 +22,8 @@
  *  SOFTWARE.
  */
 
+#include <cstdint>
+
 namespace bitstream
 {
 	/**

include/bitstream/quantization/half_precision.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <cstdint>
-
 /*
  *  Copyright (c) 2018 Stanislav Denisov
  *
@@ -24,36 +22,25 @@
  *  SOFTWARE.
  */
 
+#include <cstdint>
+#include <cstring>
+
 namespace bitstream
 {
 	/**
 	 * @brief Class for quantizing single-precision floats into half-precision
 	*/
 	class half_precision
 	{
-	private:
-		union Values
-		{
-			float f;
-			int32_t i;
-		};
-
 	public:
 		inline static uint16_t quantize(float value)
 		{
-			Values values
-			{
-				value
-			};
+			int32_t tmp;
+			std::memcpy(&tmp, &value, sizeof(float));
 
-			return quantize(values.i);
-		}
-
-		inline static uint16_t quantize(int32_t value)
-		{
-			int32_t s = (value >> 16) & 0x00008000;
-			int32_t e = ((value >> 23) & 0X000000FF) - (127 - 15);
-			int32_t m = value & 0X007FFFFF;
+			int32_t s = (tmp >> 16) & 0x00008000;
+			int32_t e = ((tmp >> 23) & 0X000000FF) - (127 - 15);
+			int32_t m = tmp & 0X007FFFFF;
 
 			if (e <= 0) {
 				if (e < -10)
@@ -94,7 +81,7 @@ namespace bitstream
 
 		inline static float dequantize(uint16_t value)
 		{
-			uint32_t result;
+			uint32_t tmp;
 			uint32_t mantissa = (uint32_t)(value & 1023);
 			uint32_t exponent = 0XFFFFFFF2;
 
@@ -106,22 +93,22 @@ namespace bitstream
 					}
 
 					mantissa &= 0XFFFFFBFF;
-					result = (((uint32_t)value & 0x8000) << 16) | ((exponent + 127) << 23) | (mantissa << 13);
+					tmp = (((uint32_t)value & 0x8000) << 16) | ((exponent + 127) << 23) | (mantissa << 13);
 				}
 				else
 				{
-					result = (uint32_t)((value & 0x8000) << 16);
+					tmp = (uint32_t)((value & 0x8000) << 16);
 				}
 			}
 			else
 			{
-				result = ((((uint32_t)value & 0x8000) << 16) | ((((((uint32_t)value >> 10) & 0X1F) - 15) + 127) << 23)) | (mantissa << 13);
+				tmp = ((((uint32_t)value & 0x8000) << 16) | ((((((uint32_t)value >> 10) & 0X1F) - 15) + 127) << 23)) | (mantissa << 13);
 			}
 
-			Values values;
-			values.i = result;
+			float result;
+			std::memcpy(&result, &tmp, sizeof(float));
 
-			return values.f;
+			return result;
 		}
 	};
 }

include/bitstream/quantization/smallest_three.h

@@ -1,8 +1,5 @@
 #pragma once
 
-#include <cstdint>
-#include <cmath>
-
 /*
  *  Copyright (c) 2020 Stanislav Denisov, Maxim Munning, Davin Carten
  *
@@ -25,6 +22,9 @@
  *  SOFTWARE.
  */
 
+#include <cstdint>
+#include <cmath>
+
 namespace bitstream
 {
 	/**

include/bitstream/stream/bit_reader.h

@@ -36,28 +36,28 @@ namespace bitstream
 			m_WordIndex(0) {}
 
 		/**
-		 * @brief Construct a reader pointing to the given byte array with @p num_bytes size
+		 * @brief Construct a reader pointing to the given byte array with @p num_bits
 		 * @param bytes The byte array to read from. Should be 4-byte aligned if possible. The size of the array must be a multiple of 4
-		 * @param num_bytes The maximum number of bytes that we can read
+		 * @param num_bits The maximum number of bits that we can read
 		*/
-		explicit bit_reader(const void* bytes, uint32_t num_bytes) noexcept :
+		explicit bit_reader(const void* bytes, uint32_t num_bits) noexcept :
 			m_Buffer(static_cast<const uint32_t*>(bytes)),
 			m_NumBitsRead(0),
-			m_TotalBits(num_bytes * 8),
+			m_TotalBits(num_bits),
 			m_Scratch(0),
 			m_ScratchBits(0),
 			m_WordIndex(0) {}
 
 		/**
 		 * @brief Construct a reader pointing to the given @p buffer
 		 * @param buffer The buffer to read from
-		 * @param num_bytes The maximum number of bytes that we can read
+		 * @param num_bits The maximum number of bits that we can read
 		*/
 		template<size_t Size>
-		explicit bit_reader(byte_buffer<Size>& buffer, uint32_t num_bytes) noexcept :
+		explicit bit_reader(byte_buffer<Size>& buffer, uint32_t num_bits) noexcept :
 			m_Buffer(reinterpret_cast<uint32_t*>(buffer.Bytes)),
 			m_NumBitsRead(0),
-			m_TotalBits(num_bytes * 8),
+			m_TotalBits(num_bits),
 			m_Scratch(0),
 			m_ScratchBits(0),
 			m_WordIndex(0) {}
@@ -113,6 +113,12 @@ namespace bitstream
 		*/
 		uint32_t get_num_bits_serialized() const noexcept { return m_NumBitsRead; }
 
+		/**
+		 * @brief Returns the number of bytes which have been read from the buffer
+		 * @return The number of bytes which have been read
+		*/
+		uint32_t get_num_bytes_serialized() const noexcept { return m_NumBitsRead > 0U ? ((m_NumBitsRead - 1U) / 8U + 1U) : 0U; }
+
 		/**
 		 * @brief Returns whether the @p num_bits be read from the buffer
 		 * @param num_bits The number of bits to test
@@ -178,24 +184,23 @@ namespace bitstream
 
 			BS_ASSERT(num_bytes * 8U >= m_NumBitsRead);
 
-			uint32_t offset = m_NumBitsRead / 32;
+			uint32_t remainder = (num_bytes * 8U - m_NumBitsRead) % 32U;
 			uint32_t zero;
 
-			// Test for zeros in padding
-			for (uint32_t i = offset; i < num_bytes / 4; i++)
+			// Test the last word more carefully, as it may have data
+			if (remainder != 0U)
 			{
-				bool status = serialize_bits(zero, 32);
-
+				bool status = serialize_bits(zero, remainder);
 				BS_ASSERT(status && zero == 0);
 			}
 
-			uint32_t remainder = num_bytes * 8U - m_NumBitsRead;
+			uint32_t offset = m_NumBitsRead / 32;
+            uint32_t max = num_bytes / 4;
 
-			// Test the last word more carefully, as it may have data
-			if (remainder % 32U != 0U)
+			// Test for zeros in padding
+			for (uint32_t i = offset; i < max; i++)
 			{
-				bool status = serialize_bits(zero, remainder);
-
+				bool status = serialize_bits(zero, 32);
 				BS_ASSERT(status && zero == 0);
 			}
 
@@ -329,9 +334,10 @@ namespace bitstream
 		 * @brief Reads from the buffer, by trying to deduce the trait.
 		 * @note The Trait type in this function is always implicit and will be deduced from the first argument if possible.
 		 * If the trait cannot be deduced it will not compile.
-		 * @tparam Trait A template specialization of serialize_trait<>
+		 * @tparam Trait The type of the first argument, which will be used to deduce the trait specialization
 		 * @tparam ...Args The types of the arguments to pass to the serialize function
-		 * @param ...args The arguments to pass to the serialize function
+		 * @param arg The first argument to pass to the serialize function
+		 * @param ...args The rest of the arguments to pass to the serialize function
 		 * @return Whether successful or not
 		*/
 		template<typename Trait, typename... Args>