gameoflife.pde

/* conway's game of life
 *
 * todo:
 *
 * - predict next step and fill color
 * - improve neighbour calculating speed 
 */

int FPS = 4;
int COUNT = 20;
int SIZE = 10;
int MAP_WIDTH = COUNT * SIZE;
int MAP_HEIGHT = COUNT * SIZE;
color BACKGROUND_COLOR = color(255, 255, 255, 0);

/* cells */
bool DEAD = false;
bool ALIVE = true;
color dead_color = BACKGROUND_COLOR;
color alive_color = color(222, 222, 222, 75);
/* for toggling cell's status randomly */
float TOTAL_RANGE = 100;
float TOGGLE_RATE = 0.15;
Square[][] cells;

void setup()
{
    frameRate(FPS);
    size(MAP_WIDTH, MAP_HEIGHT);
    background(BACKGROUND_COLOR);

    cells = new Square[COUNT][COUNT];
    for (int i = 0;i < COUNT;i++)
        for (int j = 0;j < COUNT;j++)
            cells[i][j] = new Square((j * SIZE), (i * SIZE), SIZE, alive_color, dead_color);
    random_status();
}

void draw()
{
    background(BACKGROUND_COLOR);
    draw_cells();
    update_cells();
    if (is_stable())
        noLoop();
}

void draw_cells()
{
    for (int i = 0;i < COUNT;i++)
        for (int j = 0;j < COUNT;j++)
            cells[i][j].draw();
}

int get_status(int dirx, int diry, int x, int y)
{
    int i = (x + dirx + COUNT) % COUNT;
    int j = (y + diry + COUNT) % COUNT;
    /* center */
    if (dirx == 0 && diry == 0)
        return 0;
    /* upper part */
    if (dirx == -1 || (dirx == 0 && diry == -1))
        return (cells[i][j].prev_status == ALIVE) ? 1 : 0;
    /* down part */
    else
        return (cells[i][j].status == ALIVE) ? 1 : 0;
}


bool calculate(int x, int y, bool current)
{
    int alive_neighbour = 0;
    int rdirs[] = {-1, 0, 1}, cdirs[] = {-1, 0, 1};
    for (int i = 0;i < 3;i++)
        for (int j = 0;j < 3;j++)
            alive_neighbour += get_status(cdirs[i], rdirs[j], x, y);
    if (current == DEAD && alive_neighbour == 3)
        return ALIVE;
    if (current == ALIVE && (alive_neighbour == 2 || alive_neighbour == 3))
        return ALIVE;
    return DEAD;
}

void update_cells()
{
    for (int i = 0;i < COUNT;i++)
        for (int j = 0;j < COUNT;j++) {
        cells[i][j].prev_status = cells[i][j].status;
        cells[i][j].status = calculate(i, j, cells[i][j].status);
    }
}

void is_stable()
{
    for (int i = 0;i < COUNT;i++)
        for (int j = 0;j < COUNT;j++)
            if (cells[i][j].prev_status != cells[i][j].status)
                return false;
    return true;
}

void random_status()
{
    for (int i = 0;i < COUNT;i++)
        for (int j = 0;j < COUNT;j++)
            if (random(0, TOTAL_RANGE) <= (TOTAL_RANGE * TOGGLE_RATE))
                cells[i][j].toggle();
}

class Square {
    int x, y;
    int size;
    bool status, prev_status;
    color alive, dead;

    Square(int _x, int _y, int _size, color _alive, color _dead) {
        x = _x; y = _y;
        size = _size;
        alive = _alive;
        dead = _dead;
        status = DEAD;
        prev_status = DEAD;
    }

    void draw() {
        if (status)
            fill(alive);
        else
            fill(dead);
        noStroke();
        rect(x, y, size, size);
    }

    void toggle() {
        status = !status;
    }

    void kill() {
        status = DEAD;
    }

    void born() {
        status = ALIVE;
    }

    bool is_dead() {
        return (status == DEAD);
    }
}