public class DamageUtil {
    public static void createExplosion(Projectile pro, WeaponType weapontype, LivingEntity shooter) {
        int radius = weapontype.getDamage();
        Location loc = pro.getLocation();
        List<Entity> en = pro.getNearbyEntities(radius, radius, radius);
        pro.getLocation().getWorld().createExplosion(loc, 0.0F, false);
        for (Entity ent : en) {
            if (ent instanceof LivingEntity) {
                HumanEntity le = (HumanEntity) ent;
                Location eyeloc = le.getEyeLocation();
                int distance = (int) loc.distanceSquared(ent.getLocation());
                if (canDamage(loc, eyeloc)) {
                    int damage = getExplosionDamage(radius, distance);
                    le.damage(damage, shooter);
                }
            }            
        }
    }
    
    private static boolean canDamage(Location loc1, Location loc2) {
        loc1.setY(loc1.getY() + 1.5F);
        World w = loc1.getWorld();
        int minx = Math.min(loc1.getBlockX(), loc2.getBlockX()),
        miny = Math.min(loc1.getBlockY(), loc2.getBlockY()),
        minz = Math.min(loc1.getBlockZ(), loc2.getBlockZ()),
        maxx = Math.max(loc1.getBlockX(), loc2.getBlockX()),
        maxy = Math.max(loc1.getBlockY(), loc2.getBlockY()),
        maxz = Math.max(loc1.getBlockZ(), loc2.getBlockZ());
        for (int x = minx; x<=maxx;x++) {
            for (int y = miny; y<=maxy;y++) {
                for (int z = minz; z<=maxz;z++) {
                    Block b = w.getBlockAt(x, y, z);
                    if (!b.getType().equals(Material.AIR)) {
                        return false;
                    }
                }
            }
        }
        return true; 
    }

    private static int getExplosionDamage(int r, int d) {
        float akk = (float)r*(float)r;
        float abb = (float) d;
        return Math.round((((10F/akk)*abb)+(-10F))*(-1F));
    }
    
}