game of life (torus)

gistfile1.h

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdbool.h>
#include <unistd.h>

#define WIDTH  40
#define HEIGHT 20
int grid[HEIGHT][WIDTH];
int new_generation[HEIGHT][WIDTH];

int adjacency_cell(int y, int x)
{
	if (y < 0)
		y += HEIGHT;
	if (x < 0)
		x += WIDTH;
	return (grid[y%HEIGHT][x%WIDTH]);
}
int live_or_die(int y, int x)
{
	if (y >= HEIGHT) {
		for (int y=0; y < HEIGHT; y++) {
			for (int x=0; x < WIDTH; x++) {
				grid[y][x] = new_generation[y][x];
			}
		}
		return 0;
	}
	int state = adjacency_cell(y-1, x-1)
		+ adjacency_cell(y-1, x)
		+ adjacency_cell(y-1, x+1)
		+ adjacency_cell(y, x-1)
		+ adjacency_cell(y, x+1)
		+ adjacency_cell(y+1, x-1)
		+ adjacency_cell(y+1, x)
		+ adjacency_cell(y+1, x+1);

	switch (grid[y][x]) {
		case 0:
			if (state == 3)
				new_generation[y][x] = 1;
			else
				new_generation[y][x] = 0;
			break;
		case 1:
			if (state == 2 || state == 3)
				new_generation[y][x] = 1;
			else
				new_generation[y][x] = 0;
			break;
		default:
			break;
	}
	if (x >= WIDTH-1) {
		x=0;
		y++;
	} else {
		x++;
	}
	return live_or_die(y, x);
}

void screen_clear(void)
{
	printf("\x1b[2J");	// 画面をクリア
	fflush(stdout);		// 標準出力のバッファをフラッシュ
	printf("\x1b[1;1H");	// カーソルを左上隅に設定
}

void draw(void)
{
	screen_clear();
	for (int y=0; y < HEIGHT; y++) {
		for (int x=0; x < WIDTH; x++) {
			if (grid[y][x] == 0)
				printf("□");
			else
				printf("■");
		}
		printf("\n");
	}
	printf("\n");
}

void grid_init()
{
	srand(time(0));
	for (int y=0;y < HEIGHT; y++) {
		for (int x=0; x < WIDTH; x++) {
			grid[y][x] = (int)(rand() * (1 - 0 + 1.0) / (1.0 + RAND_MAX));
		}
	}
}

int main(void)
{
	grid_init();

	draw();
	getc(stdin);
	for (;;) {
		live_or_die(0, 0);
		draw();
		sleep(1);
	}
	return 0;
}