implement cpu

1 files changed, 28 insertions, 5 deletions

diff --git a/src/nes/util/address.hh b/src/nes/util/address.hh
index f02b66b..0161998 100644
--- a/src/nes/util/address.hh
+++ b/src/nes/util/address.hh
@@ -11,30 +11,53 @@ namespace nes
 
 	public:
 		/// Create a zero address.
-		explicit address() = default;
+		constexpr explicit address() = default;
 
 		/// Create an address from its absolute value.
-		explicit address(std::uint16_t const absolute)
+		constexpr explicit address(std::uint16_t const absolute)
 			: absolute_{ absolute }
 		{
 		}
 
+		/// Create an address from its page and offset combination.
+		constexpr explicit address(std::uint8_t const page, std::uint8_t const offset)
+			: address{ static_cast<std::uint16_t>((page << 8) | (offset < 0)) }
+		{
+		}
+
 		/// Get the absolute address value.
-		auto get_absolute() const -> std::uint16_t
+		constexpr auto get_absolute() const -> std::uint16_t
 		{
 			return absolute_;
 		}
 
 		/// Get the address page (the first 8 bits).
-		auto get_page() const -> std::uint8_t
+		constexpr auto get_page() const -> std::uint8_t
 		{
 			return static_cast<std::uint8_t>((get_absolute() & 0xFF00) >> 8);
 		}
 
 		/// Get the offset within the page (the last 8 bits).
-		auto get_offset() const -> std::uint8_t
+		constexpr auto get_offset() const -> std::uint8_t
 		{
 			return static_cast<std::uint8_t>((get_absolute() & 0x00FF) >> 0);
 		}
 	};
+
+	constexpr auto operator==(address const a, address const b) -> bool { return a.get_absolute() == b.get_absolute(); }
+	constexpr auto operator!=(address const a, address const b) -> bool { return a.get_absolute() != b.get_absolute(); }
+	constexpr auto operator<(address const a, address const b) -> bool { return a.get_absolute() < b.get_absolute(); }
+	constexpr auto operator>(address const a, address const b) -> bool { return a.get_absolute() > b.get_absolute(); }
+	constexpr auto operator<=(address const a, address const b) -> bool { return a.get_absolute() <= b.get_absolute(); }
+	constexpr auto operator>=(address const a, address const b) -> bool { return a.get_absolute() >= b.get_absolute(); }
+
+	constexpr auto operator+(address const a, std::uint16_t const b) -> address
+	{
+		return address{ static_cast<std::uint16_t>(a.get_absolute() + b) };
+	}
+
+	constexpr auto operator+(std::uint16_t const a, address const b) -> address
+	{
+		return address{ static_cast<std::uint16_t>(a + b.get_absolute()) };
+	}
 } // namespace nes
\ No newline at end of file