init

src/client/game/demonware/bit_buffer.cpp

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+#include <std_include.hpp>
+#include "bit_buffer.hpp"
+
+namespace demonware
+{
+	bool bit_buffer::read_bytes(const unsigned int bytes, unsigned char* output)
+	{
+		return this->read(bytes * 8, output);
+	}
+
+	bool bit_buffer::read_bool(bool* output)
+	{
+		if (!this->read_data_type(1))
+		{
+			return false;
+		}
+
+		return this->read(1, output);
+	}
+
+	bool bit_buffer::read_uint32(unsigned int* output)
+	{
+		if (!this->read_data_type(8))
+		{
+			return false;
+		}
+
+		return this->read(32, output);
+	}
+
+	bool bit_buffer::read_data_type(const char expected)
+	{
+		char data_type = 0;
+
+		if (!this->use_data_types_) return true;
+		if (this->read(5, &data_type))
+		{
+			return (data_type == expected);
+		}
+
+		return false;
+	}
+
+	bool bit_buffer::write_bytes(const size_t bytes, const char* data)
+	{
+		return this->write_bytes(bytes, reinterpret_cast<const unsigned char*>(data));
+	}
+
+	bool bit_buffer::write_bytes(const size_t bytes, const unsigned char* data)
+	{
+		return this->write(static_cast<unsigned>(bytes) * 8, data);
+	}
+
+	bool bit_buffer::write_bool(bool data)
+	{
+		if (this->write_data_type(1))
+		{
+			return this->write(1, &data);
+		}
+
+		return false;
+	}
+
+	bool bit_buffer::write_int32(int data)
+	{
+		if (this->write_data_type(7))
+		{
+			return this->write(32, &data);
+		}
+
+		return false;
+	}
+
+	bool bit_buffer::write_uint32(unsigned int data)
+	{
+		if (this->write_data_type(8))
+		{
+			return this->write(32, &data);
+		}
+
+		return false;
+	}
+
+	bool bit_buffer::write_data_type(char data)
+	{
+		if (!this->use_data_types_)
+		{
+			return true;
+		}
+
+		return this->write(5, &data);
+	}
+
+	bool bit_buffer::read(unsigned int bits, void* output)
+	{
+		if (bits == 0) return false;
+		if ((this->current_bit_ + bits) > (this->buffer_.size() * 8)) return false;
+
+		int cur_byte = this->current_bit_ >> 3;
+		auto cur_out = 0;
+
+		const char* bytes = this->buffer_.data();
+		const auto output_bytes = reinterpret_cast<unsigned char*>(output);
+
+		while (bits > 0)
+		{
+			const int min_bit = (bits < 8) ? bits : 8;
+			const auto this_byte = bytes[cur_byte++] & 0xFF;
+			const int remain = this->current_bit_ & 7;
+
+			if ((min_bit + remain) <= 8)
+			{
+				output_bytes[cur_out] = BYTE((0xFF >> (8 - min_bit)) & (this_byte >> remain));
+			}
+			else
+			{
+				output_bytes[cur_out] = BYTE(
+					(0xFF >> (8 - min_bit)) & (bytes[cur_byte] << (8 - remain)) | (this_byte >> remain));
+			}
+
+			cur_out++;
+			this->current_bit_ += min_bit;
+			bits -= min_bit;
+		}
+
+		return true;
+	}
+
+	bool bit_buffer::write(const unsigned int bits, const void* data)
+	{
+		if (bits == 0) return false;
+		this->buffer_.resize(this->buffer_.size() + (bits >> 3) + 1);
+
+		int bit = bits;
+		const auto bytes = const_cast<char*>(this->buffer_.data());
+		const auto* input_bytes = reinterpret_cast<const unsigned char*>(data);
+
+		while (bit > 0)
+		{
+			const int bit_pos = this->current_bit_ & 7;
+			auto rem_bit = 8 - bit_pos;
+			const auto this_write = (bit < rem_bit) ? bit : rem_bit;
+
+			const BYTE mask = ((0xFF >> rem_bit) | (0xFF << (bit_pos + this_write)));
+			const int byte_pos = this->current_bit_ >> 3;
+
+			const BYTE temp_byte = (mask & bytes[byte_pos]);
+			const BYTE this_bit = ((bits - bit) & 7);
+			const auto this_byte = (bits - bit) >> 3;
+
+			auto this_data = input_bytes[this_byte];
+
+			const auto next_byte = (((bits - 1) >> 3) > this_byte) ? input_bytes[this_byte + 1] : 0;
+
+			this_data = BYTE((next_byte << (8 - this_bit)) | (this_data >> this_bit));
+
+			const BYTE out_byte = (~mask & (this_data << bit_pos) | temp_byte);
+			bytes[byte_pos] = out_byte;
+
+			this->current_bit_ += this_write;
+			bit -= this_write;
+		}
+
+		return true;
+	}
+
+	void bit_buffer::set_use_data_types(const bool use_data_types)
+	{
+		this->use_data_types_ = use_data_types;
+	}
+
+	unsigned int bit_buffer::size() const
+	{
+		return this->current_bit_ / 8 + (this->current_bit_ % 8 ? 1 : 0);
+	}
+
+	std::string& bit_buffer::get_buffer()
+	{
+		this->buffer_.resize(this->size());
+		return this->buffer_;
+	}
+}