sdl-cities/Game.cpp at main · takapro/sdl-cities · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
#include "Game.h"
#include "Cities.h"
#include <stdlib.h>
#include <time.h>

Game::~Game()
{
    SDL_GL_DeleteContext(context);
    SDL_DestroyWindow(window);
    SDL_Quit();
}

bool Game::Initialize()
{
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
        SDL_Log("Unable to initialize SDL: %s", SDL_GetError());
        return false;
    }

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);

    window = SDL_CreateWindow(WINDOW_TITLE,
        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT,
        SDL_WINDOW_OPENGL);
    if (!window) {
        SDL_Log("Failed to create window: %s", SDL_GetError());
        return false;
    }

    context = SDL_GL_CreateContext(window);
    if (!context) {
        SDL_Log("Failed to create context: %s", SDL_GetError());
        return false;
    }

    glewExperimental = GL_TRUE;
    if (glewInit() != GLEW_OK) {
        SDL_Log("Failed to initialize glew");
        return false;
    }
    glGetError();

    isRunning = true;
    ticksCount = SDL_GetTicks();

    srand(time(NULL));

    return true;
}

void Game::RunLoop()
{
    while (isRunning) {
        ProcessInput();
        UpdateGame();
        GenerateOutput();
    }
}

void Game::ProcessInput()
{
    SDL_Event event;
    while (SDL_PollEvent(&event)) {
        switch (event.type) {
            case SDL_QUIT:
                isRunning = false;
                break;

            case SDL_KEYDOWN:
                if (event.key.keysym.sym == SDLK_SPACE) {
                    ResetDestination();
                }
                break;
        }
    }

    const Uint8* state = SDL_GetKeyboardState(NULL);
    if (state[SDL_SCANCODE_ESCAPE]) {
        isRunning = false;
    }

    ProcessKeyboard(state);
}

void Game::UpdateGame()
{
    while (!SDL_TICKS_PASSED(SDL_GetTicks(), ticksCount + 16)) {
    }

    float deltaTime = (SDL_GetTicks() - ticksCount) / 1000.0f;
    if (deltaTime > 0.05f) {
        deltaTime = 0.05f;
    }
    ticksCount = SDL_GetTicks();

    UpdateGame(deltaTime);
}