game-dev-starter-pack/main.cpp

#define _USE_MATH_DEFINES
#include <math.h>
#include <fmt/core.h>
#include <box2d/box2d.h>
#include <SFML/Graphics/Sprite.hpp>
#include <SFML/Graphics/Texture.hpp>
#include <SFML/Graphics/RenderWindow.hpp>
#include <SFML/System.hpp>
#include <SFML/Audio.hpp>
#include <SFML/Window/Event.hpp>
#include "dbc.hpp"

void Window_update(sf::RenderWindow &window, sf::Sprite &player) {
  window.clear();
  window.draw(player);
  window.display();
}

struct BoxTest {
  b2Body *groundBody;
  b2Body *body;
};

struct BoxTest Box2d_setup(b2World &world) {
  b2BodyDef groundBodyDef;
  groundBodyDef.position.Set(0.0f, -10.0f);
  b2Body *groundBody = world.CreateBody(&groundBodyDef);

  b2PolygonShape groundBox;
  groundBox.SetAsBox(50.0f, 10.0f);
  groundBody->CreateFixture(&groundBox, 0.0f);

  b2BodyDef bodyDef;
  bodyDef.type = b2_dynamicBody;
  bodyDef.position.Set(3.0f, 4.0f);
  b2Body *body = world.CreateBody(&bodyDef);

  b2PolygonShape dynamicBox;
  dynamicBox.SetAsBox(1.0f, 1.0f);
  b2FixtureDef fixtureDef;
  fixtureDef.shape = &dynamicBox;

  fixtureDef.density = 1.0f;
  fixtureDef.friction = 0.3f;

  body->CreateFixture(&fixtureDef);

  BoxTest box {groundBody, body};
  return box;
}


void Handle_events(sf::RenderWindow &window, BoxTest &box, sf::Sound &click) {
  // is this a main event loop
  while (const auto event = window.pollEvent()) {
    if(event->is<sf::Event::Closed>()) {
      fmt::print("Exiting...\n");
      window.close();
    } else if (const auto* key = event->getIf<sf::Event::KeyPressed>()) {
      if(key->scancode == sf::Keyboard::Scan::Left) {
        b2Vec2 force(-200, 1000);
        box.body->ApplyForceToCenter(force, true);
        box.body->ApplyTorque(100.0f, true);
        click.play();
      } else if(key->scancode == sf::Keyboard::Scan::Right) {
        b2Vec2 force(200, 1000);
        box.body->ApplyForceToCenter(force, true);
        box.body->ApplyTorque(-100.0f, true);
        click.play();
      }
    } else if(const auto* mouse = event->getIf<sf::Event::MouseButtonPressed>()) {
      if(mouse->button == sf::Mouse::Button::Left) {
        b2Vec2 force(-200, 1000);
        box.body->ApplyForceToCenter(force, true);
        box.body->ApplyTorque(100.0f, true);
        click.play();
      } else if(mouse->button == sf::Mouse::Button::Right) {
        b2Vec2 force(200, 1000);
        box.body->ApplyForceToCenter(force, true);
        box.body->ApplyTorque(-100.0f, true);
        click.play();
      }
    }
  }
}

sf::Time Update_entities(sf::RenderWindow &window, b2World &world, sf::Clock &clock, sf::Time &tick, BoxTest &box,  sf::Sprite &player) {
  sf::Vector2u winSize = window.getSize();
  float timeStep = 1.0f / 60.0f;
  int velocityIterations = 6;
  int positionIterations = 2;
  sf::Time since = clock.getElapsedTime();
  sf::Time nextTick = since - tick > sf::seconds(1) ? since : tick;

  world.Step(timeStep, velocityIterations, positionIterations);
  b2Vec2 position = box.body->GetPosition();
  float angle = box.body->GetAngle();

  player.setPosition({position.x * 100.0f, winSize.y - position.y * 100.0f});
  player.setRotation(sf::degrees(angle * 180.0f / M_PI));

  Window_update(window, player);

  return nextTick;
}


sf::Sprite Create_player(sf::RenderWindow &window, sf::Texture &texture) {

  if(!texture.loadFromFile("sprite.png")) {
    fmt::print("Error loading sprite!");
  }

  texture.setSmooth(true);

  sf::Sprite player(texture);

  player.setTexture(texture);

  // position the prite
  sf::Vector2u winSize = window.getSize();
  player.setPosition({float(winSize.x) / 2, float(winSize.y) / 2});
  player.setOrigin({50.f, 50.f});

  return player;
}

int main() {
  fmt::print("Setting up a window for you...\n");

  sf::RenderWindow window(sf::VideoMode({1280, 720}), "Simple Game Demo");
  window.setFramerateLimit(60);
  window.setVerticalSyncEnabled(true);

  sf::SoundBuffer buffer;
  if(!buffer.loadFromFile("click.mp3")) {
    fmt::print("Failed to load click.ogg!\n");
  }
  sf::Sound click(buffer);

  sf::Clock deltaClock;
  sf::Clock clock;
  sf::Time tick = clock.getElapsedTime();

  sf::Texture texture;
  auto player = Create_player(window, texture);

  b2Vec2 gravity(0.0f, -10.0f);
  b2World world(gravity);
  BoxTest box = Box2d_setup(world);

  while (window.isOpen()) {
    Handle_events(window, box, click);
    // preparing for refactoring this into a class or struct for everything
    tick = Update_entities(window, world, clock, tick, box, player);
  }
}