Game Dev

[Thumper]

I decided a few days ago that i wanted to create a console-based version of that old game Snakes. The one where you're a little snake and you go around and eat orbs and get bigger and bigger, and the object of the game is to avoid yourself, as when you run into your body its game over.

I've already ran into an issue. I can't figure a robust way to limit the console to say.. 30 frames per seconds.
suggestions, or hints?

Thanks a bunch
-Thumper

[Disch]

The console sucks for this kind of thing. Why not just use a graphics lib? It's much easier and looks better.

[Thumper]

I've got zero experience with any graphics library. I know the console sucks for it, but that's what I'm comfortable with.

If you could give me the name of, or link me to a user friendly graphics lib, I'll give it a shot.

[Disch]

I've got zero experience with any graphics library. I know the console sucks for it, but that's what I'm comfortable with.

This is the bane of so many people on these forums. Every time I see another post about a console game I die a little inside.

And I've been seeing so many of them lately.

If you could give me the name of, or link me to a user friendly graphics lib, I'll give it a shot.

SFML is very simple. Installing it on your machine is a little work, but you only have to do that once, and it's well worth it.

http://www.sfml-dev.org/

[m4ster r0shi]

Here is something you can work on. I've written this to be an installer for a keylogger, so don't expect much.
SFML is a good library for games, google it.

#include <iostream>
#include <string>
#include <list>
#include <cstdlib>
#include <ctime>
#include <process.h>
#include <windows.h>
using namespace std;

class GameConsole
{
private:
    HANDLE console;

public:
    GameConsole()
    {
        console=GetStdHandle(STD_OUTPUT_HANDLE);
        CONSOLE_CURSOR_INFO cursor_status;

        GetConsoleCursorInfo(console,&cursor_status);

        cursor_status.bVisible=false;

        SetConsoleCursorInfo(console,&cursor_status);
    }

    void CharOutXY(int x, int y, char c)
    {
        COORD pos; pos.X=x; pos.Y=y;

        SetConsoleCursorPosition(console,pos);

        std::cout << c << std::flush;
    }

    void CharOutXYC(int x, int y, WORD color, char c)
    {
        COORD pos; pos.X=x; pos.Y=y;

        SetConsoleCursorPosition(console,pos);
        SetConsoleTextAttribute(console,color);

        std::cout << c << std::flush;
    }

    void TextOutXY(int x, int y, const std::string & str)
    {
        COORD pos; pos.X=x; pos.Y=y;

        WORD color=FOREGROUND_BLUE|FOREGROUND_GREEN;
        color|=FOREGROUND_RED|FOREGROUND_INTENSITY;

        SetConsoleCursorPosition(console,pos);
        SetConsoleTextAttribute(console,color);

        std::cout << str << std::flush;
    }
};

class GameInput
{
public:
    enum MoveDirection
    {
        MD_NONE,
        MD_UP,
        MD_DOWN,
        MD_RIGHT,
        MD_LEFT
    };

private:
    volatile MoveDirection move_dir;
    volatile bool polling;
    volatile bool stopped_polling;

    static void poll(void * p)
    {
        GameInput * gi = (GameInput*)p;

        while (true)
        {
            if (!gi->polling) break;

            if (GetAsyncKeyState(VK_UP)>>15)
                {gi->move_dir=MD_UP;}

            if (GetAsyncKeyState(VK_DOWN)>>15)
                {gi->move_dir=MD_DOWN;}

            if (GetAsyncKeyState(VK_LEFT)>>15)
                {gi->move_dir=MD_LEFT;}

            if (GetAsyncKeyState(VK_RIGHT)>>15)
                {gi->move_dir=MD_RIGHT;}

            Sleep(25);
        }

        gi->stopped_polling=true;
    }

public:
    GameInput():move_dir(MD_NONE),polling(false){}

    void StartPolling()
    {
        if (polling) return;

        polling=true;
        stopped_polling=false;
        _beginthread(poll,0,this);
    }

    void StopPolling()
    {
        if (!polling) return;

        polling=false;
        while (!stopped_polling) Sleep(100);
    }

    MoveDirection GetInput()
    {
        return move_dir;
    }
};

class GameMap
{
public:
    enum TileType
    {
        TT_EMPTY,
        TT_SNAKE,
        TT_BERRY
    };

private:
    TileType map[80][25];

public:
    GameMap()
    {
        for (int x=0; x<80; x++)
            for (int y=0; y<25; y++)
                map[x][y]=TT_EMPTY;
    }

    TileType & At(int x, int y)
    {
        return map[x][y];
    }
};

class Snake
{
private:
    std::list<COORD> snake_pos;

public:
    Snake(){}

    void init(int x, int y)
    {
        COORD head;
        head.X=x;
        head.Y=y;

        snake_pos.push_front(head);
    }

    COORD GetHead()
    {
        return snake_pos.front();
    }

    COORD GetTail()
    {
        return snake_pos.back();
    }

    void Grow(COORD new_head)
    {
        snake_pos.push_front(new_head);
    }

    void Move(COORD new_head)
    {
        Grow(new_head);
        snake_pos.pop_back();
    }
};

class Game
{
private:
    GameConsole game_console;
    GameInput game_input;
    GameMap game_map;
    Snake snake;

    static const char snake_char='*';
    static const char berry_char='@';

    std::list<COORD> need_redraw;
    GameInput::MoveDirection move_dir;
    COORD new_head;
    COORD old_tail;
    int berry_count;

    void find_good_berry_pos(int & x, int & y)
    {
        while (true)
        {
            x=rand()%80;
            y=rand()%25;

            if (game_map.At(x,y)==GameMap::TT_EMPTY) break;
        }
    }

    void need_redraw_xy(int x, int y)
    {
        COORD pos;
        pos.X=x;
        pos.Y=y;

        need_redraw.push_back(pos);
    }

    void spawn_berries()
    {
        if (berry_count>=3) return;

        int spawn_prob=berry_count+1;
        spawn_prob*=berry_count+1;
        spawn_prob*=2;
        spawn_prob=20-spawn_prob;

        bool spawn=rand()%100+1<=spawn_prob;

        int x, y;

        if (spawn)
        {
            find_good_berry_pos(x,y);

            game_map.At(x,y)=GameMap::TT_BERRY;
            need_redraw_xy(x,y);
            berry_count++;
        }
    }

    void get_input()
    {
        new_head=snake.GetHead();
        move_dir=game_input.GetInput();

        switch(move_dir)
        {
            case GameInput::MD_UP:
                new_head.Y--;

            break;
            case GameInput::MD_DOWN:
                new_head.Y++;

            break;
            case GameInput::MD_RIGHT:
                new_head.X++;

            break;
            case GameInput::MD_LEFT:
                new_head.X--;

            break;
            default:;
        }

        new_head.X+=80;
        new_head.X%=80;
        new_head.Y+=25;
        new_head.Y%=25;
    }

    bool defeat()
    {
        if (game_map.At(new_head.X,new_head.Y)==GameMap::TT_SNAKE) return true;

        return false;
    }

    void move_snake()
    {
        old_tail=snake.GetTail();

        switch(game_map.At(new_head.X,new_head.Y))
        {
            case GameMap::TT_BERRY:
                game_map.At(new_head.X,new_head.Y)=GameMap::TT_SNAKE;
                snake.Grow(new_head);
                need_redraw_xy(new_head.X,new_head.Y);

                berry_count--;

            break;
            default:
                game_map.At(old_tail.X,old_tail.Y)=GameMap::TT_EMPTY;
                need_redraw_xy(old_tail.X,old_tail.Y);
                snake.Move(new_head);
                game_map.At(new_head.X,new_head.Y)=GameMap::TT_SNAKE;
                need_redraw_xy(new_head.X,new_head.Y);
        }
    }

    void draw()
    {
        COORD pos;
        std::list<COORD>::iterator it;
        for (it=need_redraw.begin(); it!=need_redraw.end(); it++)
        {
            pos=*it;

            switch(game_map.At(pos.X,pos.Y))
            {
                case GameMap::TT_EMPTY:
                game_console.CharOutXY(pos.X,pos.Y,' ');

                break;
                case GameMap::TT_SNAKE:
                game_console.CharOutXYC(pos.X,pos.Y,
                    FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_INTENSITY,snake_char);

                break;
                case GameMap::TT_BERRY:
                game_console.CharOutXYC(pos.X,pos.Y,
                    FOREGROUND_RED|FOREGROUND_INTENSITY,berry_char);
            }
        }
    }

    void main_game_loop()
    {
        while (move_dir==GameInput::MD_NONE)
        {
            get_input();

            Sleep(100);
        }

        game_console.TextOutXY(0,0,"                                        ");
        game_console.TextOutXY(0,1,"                                        ");

        while (true)
        {
            if (GetAsyncKeyState(VK_ESCAPE)>>15) break;

            need_redraw.clear();
            spawn_berries();
            get_input();
            if (defeat()) return;
            move_snake();
            draw();

            Sleep(200);
        }
    }

    void init()
    {
        srand(time(0));

        move_dir=GameInput::MD_NONE;
        berry_count=0;

        snake.init(40,12);
        game_console.CharOutXYC(40,12,
            FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_INTENSITY,snake_char);
    }

public:
    Game()
    {
        init();
    }

    void Play()
    {
        game_console.TextOutXY(0,0,"(hit an arrow key to start...)");
        game_console.TextOutXY(0,1,"(hold esc to quit...)");

        game_input.StartPolling();
        main_game_loop();
        game_input.StopPolling();
    }
};

int main(int argc, char * argv[])
{
    Game().Play();

    return 0;
}

[m4ster r0shi]

Disch wrote:

Every time I see another post about a console game I die a little inside.

Oh... Sorry... :/ (I couldn't edit the previous post... max chars reached...)

[Thumper]

@Disch
My apologies. After all, i joined this forum to improve my code. Your input is greatly appreciated.

@m4sterr0shi
Well damn, you just totally obliterated what i was trying to do. I think I'll have to pass on reading your code before i give it a go myself. Thanks, though.