1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-11-23 03:32:32 +00:00
CLK/Machines/Atari2600/Atari2600.hpp

133 lines
2.8 KiB
C++

//
// Atari2600.hpp
// CLK
//
// Created by Thomas Harte on 14/07/2015.
// Copyright © 2015 Thomas Harte. All rights reserved.
//
#ifndef Atari2600_cpp
#define Atari2600_cpp
#include "../../Processors/6502/CPU6502.hpp"
#include "../../Outputs/CRT/CRT.hpp"
#include <stdint.h>
#include "Atari2600Inputs.h"
namespace Atari2600 {
const unsigned int number_of_upcoming_events = 18;
class Machine: public CPU6502::Processor<Machine> {
public:
Machine();
~Machine();
unsigned int perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value);
void set_rom(size_t length, const uint8_t *data);
void switch_region();
void set_digital_input(Atari2600DigitalInput input, bool state);
Outputs::CRT::CRT *get_crt() { return _crt; }
void setup_output(float aspect_ratio);
void close_output();
private:
uint8_t *_rom, *_romPages[4], _ram[128];
size_t _rom_size;
// the timer
unsigned int _piaTimerValue;
unsigned int _piaTimerShift, _writtenPiaTimerShift;
uint8_t _piaTimerStatus;
// playfield registers
uint8_t _playfieldControl;
uint8_t _playfieldColour;
uint8_t _backgroundColour;
uint8_t _playfield[40];
// delayed clock events
enum OutputState {
Sync,
Blank,
ColourBurst,
Pixel
};
struct Event {
enum Action {
Playfield = 1 << 0,
ResetPixelCounter = 1 << 1,
HMoveCompare = 1 << 2,
HMoveDecrement = 1 << 3,
};
int updates;
int pixelCounterMask;
uint8_t playfieldOutput;
OutputState state;
Event() : updates(0), pixelCounterMask(0) {}
} _upcomingEvents[number_of_upcoming_events];
unsigned int _upcomingEventsPointer;
uint8_t _playfieldOutput;
// player registers
uint8_t _playerColour[2];
uint8_t _playerReflection[2];
uint8_t _playerGraphics[2][2];
uint8_t _playerGraphicsSelector[2];
bool _playerStart[2];
// player + missile registers
uint8_t _playerAndMissileSize[2];
// missile registers
uint8_t _missileGraphicsEnable[2], _missileGraphicsReset[2];
// ball registers
uint8_t _ballGraphicsEnable, _ballGraphicsEnableLatch;
uint8_t _ballGraphicsEnableDelay;
// graphics output
unsigned int _horizontalTimer;
bool _vSyncEnabled, _vBlankEnabled;
bool _vBlankExtend;
// horizontal motion control
uint8_t _hMoveCounter;
uint8_t _hMoveFlags;
uint8_t _objectMotion[5];
// object counters
uint8_t _objectCounter[5];
int _pixelCounter[5];
// joystick state
uint8_t _piaDataDirection[2];
uint8_t _piaDataValue[2];
uint8_t _tiaInputValue[2];
// collisions
uint8_t _collisions[8];
void output_pixels(unsigned int count);
uint8_t get_output_pixel();
void update_timers(int mask);
Outputs::CRT::CRT *_crt;
// latched output state
unsigned int _lastOutputStateDuration;
OutputState _lastOutputState;
uint8_t *_outputBuffer;
};
}
#endif /* Atari2600_cpp */