ctaza/game.cpp

#include "game.hpp"

Game::Game()
:
    running(true),
    fullscreen(false),
    wireframe(false),
    rotation(0.0f),
    camera(glm::vec3(0.0f, 0.0f, 5.0f))
{
    if (SDL_Init(SDL_INIT_EVERYTHING)) {
        fprintf(stderr, "Error initializing SDL2: %s\n", SDL_GetError());
        exit(1);
    }

    if (SDL_SetRelativeMouseMode(SDL_TRUE)) {
        fprintf(stderr, "Error initializing SDL2: %s\n", SDL_GetError());
        exit(1);
    }

    SDL_GL_LoadLibrary(NULL);

    /* GL version 3.3 */
    SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);

    /* depth buffer */
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);

    win_flags = SDL_WINDOW_OPENGL;
    win_width = 640;
    win_height = 640;
    window = SDL_CreateWindow(
        "lukin",
        0, 0,
        win_width, win_height,
        win_flags);
    assert(window);
    context = SDL_GL_CreateContext(window);

    /* gives us access to the opengl functions */
    gladLoadGLLoader(SDL_GL_GetProcAddress);

    /* depth testing is good */
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
}

Game::~Game()
{
    for (auto ent : entities)
        delete ent;
}

void
Game::update(float dt)
{
    // rotation += 0.03; //tmp
    float speed = 5; //tmp
    float sensitivity = 0.001f; //tmp
    float effspeed = speed * dt;

    int offset_x, offset_y;
    SDL_GetRelativeMouseState(&offset_x, &offset_y);

    camera.yaw   += offset_x * sensitivity;
    camera.pitch -= offset_y * sensitivity;

    if (camera.pitch >= M_PI / 2)
        camera.pitch = M_PI / 2 - 0.01f;
    if (camera.pitch <= -M_PI / 2)
        camera.pitch = -M_PI / 2 + 0.01f;

    SDL_Event ev;
    while (SDL_PollEvent(&ev)) {
        if (ev.type == SDL_KEYDOWN) {
            switch (ev.key.keysym.sym) {
            case SDLK_F1:
                toggle_wireframe();
                break;
            case SDLK_F11:
                toggle_fullscreen();
                break;
            default:
                break;
            }
        }


        if (ev.type == SDL_QUIT) {
            running = false;
        }
    }

#define if_key(key) if (key_states[SDL_SCANCODE_##key])
    const u8 *key_states = SDL_GetKeyboardState(NULL);

    if_key(ESCAPE)
        running = false;
    if_key(W)
        camera.position += effspeed * camera.get_flat_front();
    if_key(S)
        camera.position -= effspeed * camera.get_flat_front();
    if_key(A)
        camera.position += effspeed * camera.get_right();
    if_key(D)
        camera.position -= effspeed * camera.get_right();
    if_key(SPACE)
        camera.position += effspeed * glm::vec3(0.0f, 1.0f, 0.0f);
    if_key(LCTRL)
        camera.position -= effspeed * glm::vec3(0.0f, 1.0f, 0.0f);
}

void
Game::render() const
{
    glViewport(0, 0, win_width, win_height);
    glClearColor(0.2, 0.2, 0.2, 0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    for (auto &e : entities) {
        // tmp
        e->mesh.mesh->shader->set_mat4("model", glm::rotate(
                                     glm::mat4(1.0f),
                                     rotation,
                                     glm::vec3(0.6f, 0.9f, 0.4f)));

        e->mesh.mesh->shader->set_mat4("view", camera.get_view());
        e->mesh.mesh->draw();
    }

    SDL_GL_SwapWindow(window);
}

Entity *
Game::add_entity()
{
    Entity *ent = new Entity;

    entities.push_back(ent);
    return ent;
}

void
Game::toggle_fullscreen()
{
    fullscreen = !fullscreen;
    if (fullscreen)
        SDL_SetWindowFullscreen(window, win_flags |
                                SDL_WINDOW_FULLSCREEN_DESKTOP);
    else
        SDL_SetWindowFullscreen(window, win_flags);
}

void
Game::toggle_wireframe()
{
    wireframe = !wireframe;
    if (wireframe)
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    else
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}