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|
mod rand;
mod sc;
use rand::Gen;
use sc::{Key, Screen};
use std::error::Error;
use std::io::{stderr, stdout, Write};
use std::time::{Duration, SystemTime};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Pos {
row: u16,
col: u16,
}
#[derive(Debug)]
struct Snake {
body: Vec<Pos>,
direction: Key,
growing: i64,
}
impl Snake {
fn next(&self) -> Pos {
let mut pos = self.body[0];
match self.direction {
Key::Up => pos.row -= 1,
Key::Down => pos.row += 1,
Key::Left => pos.col -= 1,
Key::Right => pos.col += 1,
}
pos
}
fn erase(&self, screen: &Screen) -> Result<(), Box<dyn Error>> {
let pos = self.next();
if screen.in_bounds(pos.row, pos.col) {
sc::move_cursor(pos.row, pos.col)?;
write!(stdout(), " ")?;
}
for &pos in self.body.iter() {
sc::move_cursor(pos.row, pos.col)?;
write!(stdout(), " ")?;
}
Ok(())
}
fn print(&self, g: &mut Gen, screen: &Screen) -> Result<(), Box<dyn Error>> {
let next = self.next();
if (self.direction == Key::Left || self.direction == Key::Right)
&& screen.in_bounds(next.row, next.col)
&& g.rand(40) == 0
{
sc::move_cursor(next.row, next.col)?;
write!(stdout(), "~")?;
}
for (i, &pos) in self.body.iter().enumerate() {
sc::move_cursor(pos.row, pos.col)?;
if i == 0 {
write!(stdout(), "O")?;
continue;
}
let prev = self.body[i - 1];
if i == self.body.len() - 1 {
if prev.row < pos.row {
write!(stdout(), "v")?;
continue;
}
if prev.row > pos.row {
write!(stdout(), "^")?;
continue;
}
if prev.col < pos.col {
write!(stdout(), ">")?;
continue;
}
write!(stdout(), "<")?;
continue;
}
let next = self.body[i + 1];
if prev.col == next.col {
write!(stdout(), "|")?;
continue;
}
if prev.row == next.row {
write!(stdout(), "=")?;
continue;
}
let (a, b) = if prev.row == pos.row {
(prev, next)
} else {
(next, prev)
};
if (a.col < pos.col) == (b.row < pos.row) {
write!(stdout(), "/")?;
continue;
}
write!(stdout(), "\\")?;
}
Ok(())
}
fn step(&mut self) {
let pos = self.next();
if self.growing > 0 {
self.body.push(self.body[self.body.len() - 1]);
self.growing -= 1;
}
for i in (1..self.body.len()).rev() {
self.body[i] = self.body[i - 1];
}
self.body[0] = pos;
}
}
struct Fruit {
pos: Pos,
}
impl Fruit {
fn print(&self) -> Result<(), Box<dyn Error>> {
sc::move_cursor(self.pos.row, self.pos.col)?;
write!(stdout(), "@")?;
Ok(())
}
fn new_pos(&mut self, g: &mut Gen, screen: &Screen) {
self.pos.row = g.rand(i32::from(screen.rows) - 4) as u16 + 2;
self.pos.col = g.rand(i32::from(screen.cols) - 4) as u16 + 2;
}
}
fn snake() -> Result<i64, Box<dyn Error>> {
let screen = Screen::init()?;
let mut g = rand::new(
SystemTime::now()
.duration_since(SystemTime::UNIX_EPOCH)
.unwrap()
.as_nanos() as i64,
);
let mut snake = Snake {
body: vec![Pos {
row: screen.rows / 2,
col: screen.cols / 2,
}],
direction: Key::Right,
growing: 0,
};
let mut fruit = Fruit {
pos: Pos { row: 0, col: 0 },
};
fruit.new_pos(&mut g, &screen);
let mut score: i64 = 0;
let mut real_score: i64 = 0;
let mut delay = Duration::from_millis(200);
loop {
sc::move_cursor(0, 3)?;
write!(stdout(), " Score: {} ", score)?;
snake.print(&mut g, &screen)?;
fruit.print()?;
sc::move_cursor(screen.rows - 1, screen.cols - 1)?;
stdout().flush()?;
let mut d = delay;
if snake.direction == Key::Up || snake.direction == Key::Down {
d = d * 5 / 4;
}
std::thread::sleep(d);
snake.erase(&screen)?;
if let Some(key) = screen.read_key() {
if !(snake.direction == Key::Up && key == Key::Down
|| snake.direction == Key::Down && key == Key::Up
|| snake.direction == Key::Left && key == Key::Right
|| snake.direction == Key::Right && key == Key::Left)
|| snake.body.len() == 1
{
snake.direction = key;
}
};
snake.step();
if snake.body[0] == fruit.pos {
snake.growing += 6;
loop {
fruit.new_pos(&mut g, &screen);
if !snake.body.contains(&fruit.pos) {
break;
}
}
let h = real_score / 2;
score += h * h * h * h * h - h + 1;
real_score += 1;
delay = delay * 14 / 15;
}
if !screen.in_bounds(snake.body[0].row, snake.body[0].col)
|| snake.body[1..].contains(&snake.body[0])
{
return Ok(score);
}
}
}
fn main() {
let score = match snake() {
Ok(s) => s,
Err(err) => {
let _ = writeln!(stderr(), "FAIL: {}", err);
std::process::exit(1);
}
};
let _ = sc::clear();
let _ = sc::move_cursor(0, 0);
let _ = writeln!(stdout(), "Score: {}", score);
}
|
