1
0
mirror of https://github.com/lefticus/6502-cpp.git synced 2024-10-31 14:07:53 +00:00
6502-cpp/examples/simple_game/commodore64.hpp
2021-06-10 21:08:27 -06:00

58 lines
1.6 KiB
C++

#ifndef INC_6502_C_C64_HPP
#define INC_6502_C_C64_HPP
#include <algorithm>
#include <array>
#include <chrono>
#include "6502.hpp"
#include "petscii.hpp"
#include "vicii.hpp"
namespace c64 {
struct Joystick
{
std::uint8_t state{};
[[nodiscard]] constexpr bool up() const noexcept { return (state & 1) == 0; }
[[nodiscard]] constexpr bool left() const noexcept { return (state & 4) == 0; }
[[nodiscard]] constexpr bool fire() const noexcept { return (state & 16) == 0; }
[[nodiscard]] constexpr bool right() const noexcept { return (state & 8) == 0; }
[[nodiscard]] constexpr bool down() const noexcept { return (state & 2) == 0; }
};
struct Clock
{
using milliseconds = std::chrono::duration<std::uint16_t, std::milli>;
static constexpr std::uint16_t TimerAControl = 0xDC0E;
static constexpr std::uint16_t TimerALowByte = 0xDC04;
static constexpr std::uint16_t TimerAHighByte = 0xDC05;
// return elapsed time since last restart
[[nodiscard]] milliseconds restart() noexcept
{
// stop Timer A
mos6502::poke(TimerAControl, 0b00000000);
// last value
const auto previous_value = static_cast<std::uint16_t>(
mos6502::peek(TimerALowByte) | (static_cast<uint16_t>(mos6502::peek(TimerAHighByte)) << 8));
// reset timer
mos6502::poke(TimerALowByte, 0xFF);
mos6502::poke(TimerAHighByte, 0xFF);
// restart timer A
mos6502::poke(TimerAControl, 0b00010001);
return milliseconds{ 0xFFFF - previous_value };
}
Clock() noexcept { [[maybe_unused]] const auto value = restart(); }
};
}// namespace c64
#endif// INC_6502_C_C64_HPP