More work on iced-tetris

.gitignore

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+target

iced-tetris/Cargo.toml

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+[package]
+name = "iced-tetris"
+version = "0.1.0"
+edition = "2018"
+resolver = "2"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+iced = { git = "https://github.com/hecrj/iced", rev = "099981cfc2f61a1f37e84100592d65babb94fb82", features = ["tokio", "canvas"] }
+iced_native = { git = "https://github.com/hecrj/iced", rev = "099981cfc2f61a1f37e84100592d65babb94fb82"}
+chrono = "0.4.19"
+rand = "0.8.4"

iced-tetris/src/main.rs

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+use iced::widget::canvas::{self, Path};
+use iced::{
+    executor, keyboard, time, Application, Color, Command, Element, Length, Point, Rectangle,
+    Settings, Size, Subscription,
+};
+use iced_native::{event, subscription, Event};
+use rand::distributions::{Distribution, Standard};
+
+fn main() -> iced::Result {
+    Tetris::run(Settings::default())
+}
+
+struct Tetris {
+    background_cache: canvas::Cache,
+    blocks: BlockGrid,
+    ticks: usize,
+    paused: bool,
+}
+
+impl Tetris {
+    fn new() -> Tetris {
+        Tetris {
+            background_cache: canvas::Cache::default(),
+            blocks: BlockGrid::new(),
+            ticks: 0,
+            paused: false,
+        }
+    }
+}
+
+impl Application for Tetris {
+    type Executor = executor::Default;
+    type Message = Message;
+    type Flags = ();
+
+    fn new(_flags: ()) -> (Self, Command<Message>) {
+        (Tetris::new(), Command::none())
+    }
+
+    fn title(&self) -> String {
+        String::from("Tetris - Iced")
+    }
+
+    fn update(&mut self, message: Self::Message) -> Command<Message> {
+        match message {
+            Message::Pause => self.paused = !self.paused,
+            Message::Tick(_) => {
+                if !self.paused {
+                    self.ticks += 1
+                }
+            }
+            Message::Up => (),
+            Message::Down => {
+                self.blocks.move_active_piece(MoveDirection::HardDrop);
+            }
+            Message::Left => {
+                self.blocks.move_active_piece(MoveDirection::Left);
+            }
+            Message::Right => {
+                self.blocks.move_active_piece(MoveDirection::Right);
+            }
+        };
+
+        match self.blocks.active_piece {
+            None => {
+                let piece: Tetromino = rand::random();
+                self.blocks.drop_piece(piece);
+            }
+            Some(_) => {
+                if self.ticks % 10 == 0 {
+                    self.blocks.move_active_piece(MoveDirection::SoftDrop);
+                }
+            }
+        };
+        Command::none()
+    }
+
+    fn subscription(&self) -> Subscription<Message> {
+        let keyboard_subscription = subscription::events_with(|event, status| {
+            if let event::Status::Captured = status {
+                return None;
+            }
+
+            match event {
+                Event::Keyboard(keyboard::Event::KeyPressed { key_code, .. }) => {
+                    handle_keypress(key_code)
+                }
+                _ => None,
+            }
+        });
+
+        let time_subscription = time::every(std::time::Duration::from_millis(50))
+            .map(|_| Message::Tick(chrono::Local::now()));
+        Subscription::batch([time_subscription, keyboard_subscription])
+    }
+
+    fn view(&mut self) -> Element<Self::Message> {
+        canvas::Canvas::new(self)
+            .width(Length::Fill)
+            .height(Length::Fill)
+            .into()
+    }
+}
+
+impl<'a> canvas::Program<Message> for Tetris {
+    fn draw(&self, bounds: Rectangle, _cursor: canvas::Cursor) -> Vec<canvas::Geometry> {
+        let game_width = bounds.width / 3.0;
+        let block_length = game_width / 10.0;
+        let center = bounds.center();
+        let top_left = Point::new(center.x - game_width / 2.0, 0.0);
+
+        let background = self.background_cache.draw(bounds.size(), |frame| {
+            let game_size = Size::new(block_length * 10.0, block_length * 20.0);
+            let game_bg = Path::rectangle(top_left, game_size);
+            frame.fill(&game_bg, Color::BLACK);
+        });
+
+        let block_size = Size::new(block_length, block_length);
+        let mut frame = canvas::Frame::new(bounds.size());
+
+        for (i, j, tetronimo) in self.blocks.iter() {
+            let point = Point::new(
+                i as f32 * block_length + top_left.x,
+                j as f32 * block_length + top_left.y,
+            );
+            let block = Path::rectangle(point, block_size);
+            let color = tetronimo.color();
+            frame.fill(&block, color);
+        }
+
+        vec![background, frame.into_geometry()]
+    }
+}
+
+fn handle_keypress(key_code: keyboard::KeyCode) -> Option<Message> {
+    use keyboard::KeyCode;
+
+    Some(match key_code {
+        KeyCode::Up => Message::Up,
+        KeyCode::Down => Message::Down,
+        KeyCode::Right => Message::Right,
+        KeyCode::Left => Message::Left,
+        KeyCode::Space => Message::Pause,
+        _ => return None,
+    })
+}
+
+#[derive(Debug)]
+enum Message {
+    Up,
+    Down,
+    Left,
+    Right,
+    Pause,
+    Tick(chrono::DateTime<chrono::Local>),
+}
+
+struct BlockGrid {
+    state: [[Option<Block>; 20]; 10],
+    active_piece: Option<ActivePiece>,
+}
+
+#[derive(Debug, Copy, Clone)]
+struct ActivePiece {
+    location: (u8, u8),
+    tetromino: Tetromino,
+}
+
+impl ActivePiece {
+    fn move_piece(&self, direction: &MoveDirection) -> ActivePiece {
+        use MoveDirection::*;
+        let (cur_x, cur_y) = self.location;
+        ActivePiece {
+            tetromino: self.tetromino,
+            location: match direction {
+                Left => (cur_x.checked_sub(1).unwrap_or(0), cur_y),
+                Right => (cur_x + 1, cur_y),
+                SoftDrop => (cur_x, cur_y + 1),
+                HardDrop => (cur_x, cur_y),
+            },
+        }
+    }
+}
+
+impl BlockGrid {
+    fn new() -> BlockGrid {
+        let mut state = [[None; 20]; 10];
+        BlockGrid {
+            state,
+            active_piece: None,
+        }
+    }
+
+    /// If it's impossible to drop a piece, return false
+    fn drop_piece(&mut self, tetromino: Tetromino) -> bool {
+        if let None = self.active_piece {
+            let piece = ActivePiece {
+                location: (4, 0),
+                tetromino,
+            };
+            let piece_blocks = Self::piece_blocks(&piece);
+            if self.piece_blocks_in_bounds(&piece_blocks) {
+                self.active_piece = Some(piece);
+                true
+            } else {
+                false
+            }
+        } else {
+            false
+        }
+    }
+
+    fn piece_blocks_in_bounds(&self, piece_blocks: &[(u8, u8); 4]) -> bool {
+        piece_blocks.iter().all(|(x, y)| {
+            let x = *x;
+            let y = *y;
+            x < 10 && y < 20 && self.state[x as usize][y as usize].is_none()
+        })
+    }
+
+    /// If there is an active piece, and the move is legal, move it. Return true if it was possible
+    /// to move an active piece, false otherwise.
+    fn move_active_piece(&mut self, direction: MoveDirection) -> bool {
+        let active = self.active_piece;
+        match (active, direction) {
+            (None, _) => false,
+            (Some(piece), MoveDirection::Left | MoveDirection::Right) => {
+                let new_piece = piece.move_piece(&direction);
+                let new_blocks = Self::piece_blocks(&new_piece);
+                if self.piece_blocks_in_bounds(&new_blocks) {
+                    self.active_piece = Some(new_piece);
+                    true
+                } else {
+                    false
+                }
+            }
+            (Some(ref piece), MoveDirection::HardDrop) => {
+                let mut new_piece = *piece;
+                loop {
+                    let p = new_piece.move_piece(&MoveDirection::SoftDrop);
+                    let new_blocks = Self::piece_blocks(&p);
+                    if self.piece_blocks_in_bounds(&new_blocks) {
+                        new_piece = p;
+                    } else {
+                        break;
+                    }
+                }
+
+                self.active_piece = Some(new_piece);
+                self.place_active_piece();
+                true
+            }
+            (Some(ref piece), MoveDirection::SoftDrop) => {
+                let new_piece = piece.move_piece(&MoveDirection::SoftDrop);
+                let new_blocks = Self::piece_blocks(&new_piece);
+                if self.piece_blocks_in_bounds(&new_blocks) {
+                    self.active_piece = Some(new_piece);
+                    true
+                } else {
+                    self.place_active_piece();
+                    false
+                }
+            }
+        }
+    }
+
+    /// Remove the currently active piece and place its blocks onto the board.
+    fn place_active_piece(&mut self) {
+        if let Some(piece) = self.active_piece {
+            let cur_blocks = Self::piece_blocks(&piece);
+            for (x, y) in cur_blocks.iter() {
+                self.state[*x as usize][*y as usize] = Some(Block {
+                    source: piece.tetromino,
+                });
+            }
+            self.active_piece = None;
+        }
+    }
+
+    fn piece_blocks(piece: &ActivePiece) -> [(u8, u8); 4] {
+        use Tetromino::*;
+        let (x, y) = piece.location;
+
+        match piece.tetromino {
+            I => [(x, y), (x, y + 1), (x, y + 2), (x, y + 3)],
+            J => [(x, y), (x, y + 1), (x, y + 2), (x - 1, y + 2)],
+            L => [(x, y), (x, y + 1), (x, y + 2), (x + 1, y + 2)],
+            O => [(x, y), (x + 1, y), (x, y + 1), (x + 1, y + 1)],
+            S => [(x, y + 1), (x + 1, y + 1), (x + 1, y), (x + 2, y)],
+            T => [(x, y), (x + 1, y), (x + 2, y), (x + 1, y + 1)],
+            Z => [(x, y), (x + 1, y), (x + 1, y + 1), (x + 2, y + 1)],
+        }
+    }
+
+    fn active_piece_blocks(&self) -> Option<(Tetromino, [(u8, u8); 4])> {
+        self.active_piece
+            .as_ref()
+            .map(|piece| (piece.tetromino, Self::piece_blocks(&piece)))
+    }
+
+    fn iter<'a>(&'a self) -> BlockGridIter<'a> {
+        BlockGridIter::new(&self.state, self.active_piece_blocks())
+    }
+}
+
+struct BlockGridIter<'a> {
+    outer_state: &'a [[Option<Block>; 20]; 10],
+    outer_active: Option<(Tetromino, [(u8, u8); 4])>,
+    idx: usize,
+    active_pice_idx: usize,
+}
+
+impl<'a> BlockGridIter<'a> {
+    fn new(
+        state: &'a [[Option<Block>; 20]; 10],
+        outer_active: Option<(Tetromino, [(u8, u8); 4])>,
+    ) -> Self {
+        BlockGridIter {
+            outer_state: state,
+            idx: 0,
+            active_pice_idx: 0,
+            outer_active,
+        }
+    }
+}
+
+impl<'a> std::iter::Iterator for BlockGridIter<'a> {
+    type Item = (u8, u8, Tetromino);
+    fn next(&mut self) -> Option<Self::Item> {
+        loop {
+            if self.idx >= 200 {
+                return self.outer_active.and_then(|(tetromino, block_array)| {
+                    let i = self.active_pice_idx;
+                    self.active_pice_idx += 1;
+                    block_array.get(i).map(|(x, y)| (*x, *y, tetromino))
+                });
+            }
+            let i = self.idx % 10;
+            let j = self.idx / 10;
+            match self.outer_state[i][j] {
+                Some(block) => {
+                    self.idx += 1;
+                    return Some((i as u8, j as u8, block.source));
+                }
+                None => {
+                    self.idx += 1;
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Block {
+    source: Tetromino,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq)]
+enum MoveDirection {
+    Left,
+    Right,
+    HardDrop,
+    SoftDrop,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+enum Tetromino {
+    I,
+    J,
+    L,
+    O,
+    S,
+    T,
+    Z,
+}
+
+impl Tetromino {
+    fn color(self) -> Color {
+        use Tetromino::*;
+        match self {
+            I => Color::from_rgb8(0, 255, 255),
+            J => Color::from_rgb8(0, 0, 255),
+            L => Color::from_rgb8(255, 165, 0),
+            O => Color::from_rgb8(255, 255, 0),
+            S => Color::from_rgb8(0, 255, 0),
+            T => Color::from_rgb8(255, 255, 0),
+            Z => Color::from_rgb8(128, 0, 128),
+        }
+    }
+}
+
+impl Distribution<Tetromino> for Standard {
+    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> Tetromino {
+        let index: u8 = rng.gen_range(0..=6);
+        match index {
+            0 => Tetromino::I,
+            1 => Tetromino::J,
+            2 => Tetromino::L,
+            3 => Tetromino::O,
+            4 => Tetromino::S,
+            5 => Tetromino::T,
+            6 => Tetromino::Z,
+            _ => unreachable!(),
+        }
+    }
+}