orbum/liborbum/src/Common/Types/Register/WordRegister.hpp

#pragma once

#include <cstddef>

#include "Common/Types/Primitive.hpp"
#include "Common/Types/Bus/ByteBusMappable.hpp"
#include "Common/Types/Bitfield.hpp"

/// Word register.
class WordRegister : public ByteBusMappable
{
public:
	/// Initialise register.
	virtual void initialise() = 0;

	/// Read/write functions to access the register, with subclassed functionality. 
    virtual ubyte read_ubyte(const size_t offset) = 0;
	virtual void write_ubyte(const size_t offset, const ubyte value) = 0;
	virtual uhword read_uhword(const size_t offset) = 0;
	virtual void write_uhword(const size_t offset, const uhword value) = 0;
	virtual uword read_uword() = 0;
	virtual void write_uword(const uword value) = 0;
	
	/// Read/write floats - wrappers around read/write uword.
	f32 read_float()
	{
		return static_cast<f32>(read_uword());
	}

	void write_float(const f32 value)
	{
		write_uword(static_cast<uword>(value));
	}

	/// Bitfield extraction/insertion.
	uword extract_field(const Bitfield field)
	{
		return field.extract_from(read_uword());
	}

	void insert_field(const Bitfield field, const uword value)
	{
		write_uword(field.insert_into(read_uword(), value));
	}

	/// Offsets the register by the specified (signed) value.
	void offset(const sword value)
	{
		write_uword(read_uword() + value);
	}
	
	/// ByteBusMappable overrides.
	usize byte_bus_map_size() const override
	{
		return static_cast<usize>(NUMBER_BYTES_IN_WORD);
	}

	ubyte byte_bus_read_ubyte(const BusContext context, const usize offset) override
	{
		return read_ubyte(offset);
	}

	void byte_bus_write_ubyte(const BusContext context, const usize offset, const ubyte value) override
	{
		write_ubyte(offset, value);
	}

	uhword byte_bus_read_uhword(const BusContext context, const usize offset) override
	{
		return read_uhword(offset / NUMBER_BYTES_IN_HWORD);
	}

	void byte_bus_write_uhword(const BusContext context, const usize offset, const uhword value) override
	{
		write_uhword(offset / NUMBER_BYTES_IN_HWORD, value);
	}

	uword byte_bus_read_uword(const BusContext context, const usize offset) override
	{
		return read_uword();
	}

	void byte_bus_write_uword(const BusContext context, const usize offset, const uword value) override
	{
		write_uword(value);
	}
};