#include "grid.h"
#include "tiles.h"
#include <gint/std/stdlib.h>

void
grid_random_walker(struct Grid *restrict grid)
{
	int x;
	int y;
	int i;
	int roll;

	/* fill with walls */
	i = grid->width * grid->height;
	while (i-- > 0)
		grid->data[i] = TILE_SOLID;

	/* dig our way to the right */
	x = 0;
	y = grid->height / 2;
	while (x < grid->width) {
		roll = rand() % 8;
		grid_set(grid, x, y, roll ? TILE_VOID : TILE_OBSTACLE_3);
		roll = rand() % 9;
		switch (roll) {
		case 0:
		case 1:
		case 2:
			/* right */
			x += 1;
			break;
		case 3:
		case 4:
			/* up */
			y -= 1;
			if (y < 0)
				y = grid->height - 1;
			break;
		case 5:
		case 6:
			/* down */
			y += 1;
			if (y >= grid->height)
				y = 0;
			break;
		case 7:
		case 8:
			/* left */
			x -= 1;
			if (x < 0)
				x = 0;
			break;
		default:
			break;
		}
	}
}