main.cpp

#include "chip8.h"

#include <SFML\Graphics.hpp>

void drawDisplay(const Chip8 &emu, sf::RenderWindow &window);
void updateKeyState(Chip8 &emu, sf::Keyboard::Key key, unsigned char value);

int main(int argc, char **argv) {
    if(argc < 2)
    {
        std::cerr << "Usage: myChip8.exe \"file\"\n\n" << std::endl;
        return -1;
    }

    // initialize the Chip8 system and load the game into the memory
    Chip8 emu;
    emu.initialize();
    if(!emu.loadGame("tetris.c8")) {
        std::cerr << "Error: Could open the game file " << argv[1] << std::endl;
        return -1;
    }

    // set up render system and register input callbacks
    sf::RenderWindow window(sf::VideoMode(832, 416), "rChip-8", sf::Style::Titlebar | sf::Style::Close);
    //sf::RenderWindow window(sf::VideoMode(1664, 832), "rChip-8", sf::Style::Titlebar | sf::Style::Close);
    //window.setVerticalSyncEnabled(true);
    //window.setFramerateLimit(60);

    sf::Clock clock;
    sf::Time elapsedTime = sf::Time::Zero;
    const sf::Time updateFrequency = sf::seconds(1.0f / 60.0f);

    // start the game loop
    sf::Event event;
    while(window.isOpen()) {
        //if(emu.extendedScreenEnabled())
        //    emu.drawFlag = true;

        //if(emu.forceExitEnabled())
        //    window.close();

        // variant 1
        while(window.pollEvent(event)) {
            switch(event.type) {
                case sf::Event::Closed:
                    window.close();
                break;
                case sf::Event::KeyPressed:
                    if(event.key.code == sf::Keyboard::Escape)
                        window.close();

                    updateKeyState(emu, event.key.code, 1);
                break;
                case sf::Event::KeyReleased:
                    updateKeyState(emu, event.key.code, 0);
                break;
            }
        }

        elapsedTime += clock.restart();
        while(elapsedTime >= updateFrequency) {
            emu.emulateCycle();



            emu.updateTimers();

            elapsedTime -= updateFrequency;
        }
             if(emu.drawFlag) {
                window.clear();
                drawDisplay(emu, window);
                window.display();

                emu.drawFlag = false;
            }
        // variant 2
        /*while(window.pollEvent(event)) {
            switch(event.type) {
                case sf::Event::Closed:
                    window.close();
                break;
                case sf::Event::KeyPressed:
                    if(event.key.code == sf::Keyboard::Escape)
                        window.close();

                    updateKeyState(emu, event.key.code, 1);
                break;
                case sf::Event::KeyReleased:
                    updateKeyState(emu, event.key.code, 0);
                break;
            }
        }

        if(clock.getElapsedTime() > updateFrequency) {
            emu.emulateCycle();
            emu.updateTimers();
            clock.restart();
        }

        if(emu.drawFlag) {
            window.clear();
            drawDisplay(emu, window);
            window.display();

            emu.drawFlag = false;
        }*/

        // variant 3
        /*while(window.pollEvent(event)) {
            switch(event.type) {
               case sf::Event::Closed:
                   window.close();
               break;
               case sf::Event::KeyPressed:
                   if(event.key.code == sf::Keyboard::Escape)
                       window.close();

                   updateKeyState(emu, event.key.code, 1);
               break;
               case sf::Event::KeyReleased:
                   updateKeyState(emu, event.key.code, 0);
               break;
           }
        }

        elapsedTime += clock.restart();
        while(elapsedTime >= updateFrequency) {
            emu.emulateCycle();
            emu.updateTimers();

            elapsedTime -= updateFrequency;
        }

        if(emu.drawFlag) {
            window.clear();
            drawDisplay(emu, window);
            window.display();

            emu.drawFlag = false;
        }*/
    };

    return 0;
}

void drawDisplay(const Chip8 &emu, sf::RenderWindow &window) {
    //define pixel size. since resolution is constant, variables won't be used
    sf::RectangleShape rectangle(sf::Vector2f(13, 13));
    for(int y = 0; y < 32; ++y) {
        for(int x = 0; x < 64; ++x) {
            unsigned char gfx = emu.gfxValueAt(x + (64 * y));
            if(gfx > 0) {
                rectangle.setPosition((float)(x * 13), (float)(y * 13));
                window.draw(rectangle);
            }
        }
    }
}

void updateKeyState(Chip8 &emu, sf::Keyboard::Key key, unsigned char value) {
    /*emu.mapKey(0x1, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Num1));
    emu.mapKey(0x2, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Num2));
    emu.mapKey(0x3, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Num3));
    emu.mapKey(0xC, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Num4));

    emu.mapKey(0x4, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Q));
    emu.mapKey(0x5, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::W));
    emu.mapKey(0x6, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::E));
    emu.mapKey(0xD, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::R));

    emu.mapKey(0x7, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::A));
    emu.mapKey(0x8, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::S));
    emu.mapKey(0x9, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::D));
    emu.mapKey(0xE, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::F));

    emu.mapKey(0xA, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::Z));
    emu.mapKey(0x0, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::X));
    emu.mapKey(0xB, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::C));
    emu.mapKey(0xF, sf::Keyboard::isKeyPressed(sf::Keyboard::Key::V));*/
    int index = -1;

    switch(key) {
        case sf::Keyboard::Key::Num1: index = 0x1; break;
        case sf::Keyboard::Key::Num2: index = 0x2; break;
        case sf::Keyboard::Key::Num3: index = 0x3; break;
        case sf::Keyboard::Key::Num4: index = 0xC; break;
        case sf::Keyboard::Key::Q: index = 0x4; break;
        case sf::Keyboard::Key::W: index = 0x5; break;
        case sf::Keyboard::Key::E: index = 0x6; break;
        case sf::Keyboard::Key::R: index = 0xD; break;
        case sf::Keyboard::Key::A: index = 0x7; break;
        case sf::Keyboard::Key::S: index = 0x8; break;
        case sf::Keyboard::Key::D: index = 0x9; break;
        case sf::Keyboard::Key::F: index = 0xE; break;
        case sf::Keyboard::Key::Y: index = 0xA; break;
        case sf::Keyboard::Key::X: index = 0x0; break;
        case sf::Keyboard::Key::C: index = 0xB; break;
        case sf::Keyboard::Key::V: index = 0xF; break;
    }

    if(index >= 0)
        emu.mapKey(index, value);
}