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Diffstat (limited to 'examples/game_of_life/src/main.rs')
| -rw-r--r-- | examples/game_of_life/src/main.rs | 803 |
1 files changed, 803 insertions, 0 deletions
diff --git a/examples/game_of_life/src/main.rs b/examples/game_of_life/src/main.rs new file mode 100644 index 00000000..080d55c0 --- /dev/null +++ b/examples/game_of_life/src/main.rs @@ -0,0 +1,803 @@ +//! This example showcases an interactive version of the Game of Life, invented +//! by John Conway. It leverages a `Canvas` together with other widgets. +mod style; + +use grid::Grid; +use iced::{ + button::{self, Button}, + executor, + slider::{self, Slider}, + time, Align, Application, Checkbox, Column, Command, Container, Element, + Length, Row, Settings, Subscription, Text, +}; +use std::time::{Duration, Instant}; + +pub fn main() { + GameOfLife::run(Settings { + antialiasing: true, + ..Settings::default() + }) +} + +#[derive(Default)] +struct GameOfLife { + grid: Grid, + controls: Controls, + is_playing: bool, + queued_ticks: usize, + speed: usize, + next_speed: Option<usize>, +} + +#[derive(Debug, Clone)] +enum Message { + Grid(grid::Message), + Tick(Instant), + TogglePlayback, + ToggleGrid(bool), + Next, + Clear, + SpeedChanged(f32), +} + +impl Application for GameOfLife { + type Message = Message; + type Executor = executor::Default; + type Flags = (); + + fn new(_flags: ()) -> (Self, Command<Message>) { + ( + Self { + speed: 1, + ..Self::default() + }, + Command::none(), + ) + } + + fn title(&self) -> String { + String::from("Game of Life - Iced") + } + + fn update(&mut self, message: Message) -> Command<Message> { + match message { + Message::Grid(message) => { + self.grid.update(message); + } + Message::Tick(_) | Message::Next => { + self.queued_ticks = (self.queued_ticks + 1).min(self.speed); + + if let Some(task) = self.grid.tick(self.queued_ticks) { + if let Some(speed) = self.next_speed.take() { + self.speed = speed; + } + + self.queued_ticks = 0; + + return Command::perform(task, Message::Grid); + } + } + Message::TogglePlayback => { + self.is_playing = !self.is_playing; + } + Message::ToggleGrid(show_grid_lines) => { + self.grid.toggle_lines(show_grid_lines); + } + Message::Clear => { + self.grid.clear(); + } + Message::SpeedChanged(speed) => { + if self.is_playing { + self.next_speed = Some(speed.round() as usize); + } else { + self.speed = speed.round() as usize; + } + } + } + + Command::none() + } + + fn subscription(&self) -> Subscription<Message> { + if self.is_playing { + time::every(Duration::from_millis(1000 / self.speed as u64)) + .map(Message::Tick) + } else { + Subscription::none() + } + } + + fn view(&mut self) -> Element<Message> { + let selected_speed = self.next_speed.unwrap_or(self.speed); + let controls = self.controls.view( + self.is_playing, + self.grid.are_lines_visible(), + selected_speed, + ); + + let content = Column::new() + .push(self.grid.view().map(Message::Grid)) + .push(controls); + + Container::new(content) + .width(Length::Fill) + .height(Length::Fill) + .style(style::Container) + .into() + } +} + +mod grid { + use iced::{ + canvas::{ + self, Cache, Canvas, Cursor, Event, Frame, Geometry, Path, Text, + }, + mouse, Color, Element, HorizontalAlignment, Length, Point, Rectangle, + Size, Vector, VerticalAlignment, + }; + use rustc_hash::{FxHashMap, FxHashSet}; + use std::future::Future; + use std::ops::RangeInclusive; + use std::time::{Duration, Instant}; + + pub struct Grid { + state: State, + interaction: Interaction, + life_cache: Cache, + grid_cache: Cache, + translation: Vector, + scaling: f32, + show_lines: bool, + last_tick_duration: Duration, + last_queued_ticks: usize, + version: usize, + } + + #[derive(Debug, Clone)] + pub enum Message { + Populate(Cell), + Unpopulate(Cell), + Ticked { + result: Result<Life, TickError>, + tick_duration: Duration, + version: usize, + }, + } + + #[derive(Debug, Clone)] + pub enum TickError { + JoinFailed, + } + + impl Default for Grid { + fn default() -> Self { + Self { + state: State::default(), + interaction: Interaction::None, + life_cache: Cache::default(), + grid_cache: Cache::default(), + translation: Vector::default(), + scaling: 1.0, + show_lines: true, + last_tick_duration: Duration::default(), + last_queued_ticks: 0, + version: 0, + } + } + } + + impl Grid { + const MIN_SCALING: f32 = 0.1; + const MAX_SCALING: f32 = 2.0; + + pub fn tick( + &mut self, + amount: usize, + ) -> Option<impl Future<Output = Message>> { + let version = self.version; + let tick = self.state.tick(amount)?; + + self.last_queued_ticks = amount; + + Some(async move { + let start = Instant::now(); + let result = tick.await; + let tick_duration = start.elapsed() / amount as u32; + + Message::Ticked { + result, + version, + tick_duration, + } + }) + } + + pub fn update(&mut self, message: Message) { + match message { + Message::Populate(cell) => { + self.state.populate(cell); + self.life_cache.clear(); + } + Message::Unpopulate(cell) => { + self.state.unpopulate(&cell); + self.life_cache.clear(); + } + Message::Ticked { + result: Ok(life), + version, + tick_duration, + } if version == self.version => { + self.state.update(life); + self.life_cache.clear(); + + self.last_tick_duration = tick_duration; + } + Message::Ticked { + result: Err(error), .. + } => { + dbg!(error); + } + Message::Ticked { .. } => {} + } + } + + pub fn view<'a>(&'a mut self) -> Element<'a, Message> { + Canvas::new(self) + .width(Length::Fill) + .height(Length::Fill) + .into() + } + + pub fn clear(&mut self) { + self.state = State::default(); + self.version += 1; + + self.life_cache.clear(); + } + + pub fn toggle_lines(&mut self, enabled: bool) { + self.show_lines = enabled; + } + + pub fn are_lines_visible(&self) -> bool { + self.show_lines + } + + fn visible_region(&self, size: Size) -> Region { + let width = size.width / self.scaling; + let height = size.height / self.scaling; + + Region { + x: -self.translation.x - width / 2.0, + y: -self.translation.y - height / 2.0, + width, + height, + } + } + + fn project(&self, position: Point, size: Size) -> Point { + let region = self.visible_region(size); + + Point::new( + position.x / self.scaling + region.x, + position.y / self.scaling + region.y, + ) + } + } + + impl<'a> canvas::Program<Message> for Grid { + fn update( + &mut self, + event: Event, + bounds: Rectangle, + cursor: Cursor, + ) -> Option<Message> { + if let Event::Mouse(mouse::Event::ButtonReleased(_)) = event { + self.interaction = Interaction::None; + } + + let cursor_position = cursor.position_in(&bounds)?; + let cell = Cell::at(self.project(cursor_position, bounds.size())); + let is_populated = self.state.contains(&cell); + + let (populate, unpopulate) = if is_populated { + (None, Some(Message::Unpopulate(cell))) + } else { + (Some(Message::Populate(cell)), None) + }; + + match event { + Event::Mouse(mouse_event) => match mouse_event { + mouse::Event::ButtonPressed(button) => match button { + mouse::Button::Left => { + self.interaction = if is_populated { + Interaction::Erasing + } else { + Interaction::Drawing + }; + + populate.or(unpopulate) + } + mouse::Button::Right => { + self.interaction = Interaction::Panning { + translation: self.translation, + start: cursor_position, + }; + + None + } + _ => None, + }, + mouse::Event::CursorMoved { .. } => { + match self.interaction { + Interaction::Drawing => populate, + Interaction::Erasing => unpopulate, + Interaction::Panning { translation, start } => { + self.translation = translation + + (cursor_position - start) + * (1.0 / self.scaling); + + self.life_cache.clear(); + self.grid_cache.clear(); + + None + } + _ => None, + } + } + mouse::Event::WheelScrolled { delta } => match delta { + mouse::ScrollDelta::Lines { y, .. } + | mouse::ScrollDelta::Pixels { y, .. } => { + if y < 0.0 && self.scaling > Self::MIN_SCALING + || y > 0.0 && self.scaling < Self::MAX_SCALING + { + let old_scaling = self.scaling; + + self.scaling = (self.scaling + * (1.0 + y / 30.0)) + .max(Self::MIN_SCALING) + .min(Self::MAX_SCALING); + + if let Some(cursor_to_center) = + cursor.position_from(bounds.center()) + { + let factor = self.scaling - old_scaling; + + self.translation = self.translation + - Vector::new( + cursor_to_center.x * factor + / (old_scaling * old_scaling), + cursor_to_center.y * factor + / (old_scaling * old_scaling), + ); + } + + self.life_cache.clear(); + self.grid_cache.clear(); + } + + None + } + }, + _ => None, + }, + } + } + + fn draw(&self, bounds: Rectangle, cursor: Cursor) -> Vec<Geometry> { + let center = Vector::new(bounds.width / 2.0, bounds.height / 2.0); + + let life = self.life_cache.draw(bounds.size(), |frame| { + let background = Path::rectangle(Point::ORIGIN, frame.size()); + frame.fill(&background, Color::from_rgb8(0x40, 0x44, 0x4B)); + + frame.with_save(|frame| { + frame.translate(center); + frame.scale(self.scaling); + frame.translate(self.translation); + frame.scale(Cell::SIZE as f32); + + let region = self.visible_region(frame.size()); + + for cell in region.cull(self.state.cells()) { + frame.fill_rectangle( + Point::new(cell.j as f32, cell.i as f32), + Size::UNIT, + Color::WHITE, + ); + } + }); + }); + + let overlay = { + let mut frame = Frame::new(bounds.size()); + + let hovered_cell = + cursor.position_in(&bounds).map(|position| { + Cell::at(self.project(position, frame.size())) + }); + + if let Some(cell) = hovered_cell { + frame.with_save(|frame| { + frame.translate(center); + frame.scale(self.scaling); + frame.translate(self.translation); + frame.scale(Cell::SIZE as f32); + + frame.fill_rectangle( + Point::new(cell.j as f32, cell.i as f32), + Size::UNIT, + Color { + a: 0.5, + ..Color::BLACK + }, + ); + }); + } + + let text = Text { + color: Color::WHITE, + size: 14.0, + position: Point::new(frame.width(), frame.height()), + horizontal_alignment: HorizontalAlignment::Right, + vertical_alignment: VerticalAlignment::Bottom, + ..Text::default() + }; + + if let Some(cell) = hovered_cell { + frame.fill_text(Text { + content: format!("({}, {})", cell.j, cell.i), + position: text.position - Vector::new(0.0, 16.0), + ..text + }); + } + + let cell_count = self.state.cell_count(); + + frame.fill_text(Text { + content: format!( + "{} cell{} @ {:?} ({})", + cell_count, + if cell_count == 1 { "" } else { "s" }, + self.last_tick_duration, + self.last_queued_ticks + ), + ..text + }); + + frame.into_geometry() + }; + + if self.scaling < 0.2 || !self.show_lines { + vec![life, overlay] + } else { + let grid = self.grid_cache.draw(bounds.size(), |frame| { + frame.translate(center); + frame.scale(self.scaling); + frame.translate(self.translation); + frame.scale(Cell::SIZE as f32); + + let region = self.visible_region(frame.size()); + let rows = region.rows(); + let columns = region.columns(); + let (total_rows, total_columns) = + (rows.clone().count(), columns.clone().count()); + let width = 2.0 / Cell::SIZE as f32; + let color = Color::from_rgb8(70, 74, 83); + + frame.translate(Vector::new(-width / 2.0, -width / 2.0)); + + for row in region.rows() { + frame.fill_rectangle( + Point::new(*columns.start() as f32, row as f32), + Size::new(total_columns as f32, width), + color, + ); + } + + for column in region.columns() { + frame.fill_rectangle( + Point::new(column as f32, *rows.start() as f32), + Size::new(width, total_rows as f32), + color, + ); + } + }); + + vec![life, grid, overlay] + } + } + + fn mouse_interaction( + &self, + bounds: Rectangle, + cursor: Cursor, + ) -> mouse::Interaction { + match self.interaction { + Interaction::Drawing => mouse::Interaction::Crosshair, + Interaction::Erasing => mouse::Interaction::Crosshair, + Interaction::Panning { .. } => mouse::Interaction::Grabbing, + Interaction::None if cursor.is_over(&bounds) => { + mouse::Interaction::Crosshair + } + _ => mouse::Interaction::default(), + } + } + } + + #[derive(Default)] + struct State { + life: Life, + births: FxHashSet<Cell>, + is_ticking: bool, + } + + impl State { + fn cell_count(&self) -> usize { + self.life.len() + self.births.len() + } + + fn contains(&self, cell: &Cell) -> bool { + self.life.contains(cell) || self.births.contains(cell) + } + + fn cells(&self) -> impl Iterator<Item = &Cell> { + self.life.iter().chain(self.births.iter()) + } + + fn populate(&mut self, cell: Cell) { + if self.is_ticking { + self.births.insert(cell); + } else { + self.life.populate(cell); + } + } + + fn unpopulate(&mut self, cell: &Cell) { + if self.is_ticking { + let _ = self.births.remove(cell); + } else { + self.life.unpopulate(cell); + } + } + + fn update(&mut self, mut life: Life) { + self.births.drain().for_each(|cell| life.populate(cell)); + + self.life = life; + self.is_ticking = false; + } + + fn tick( + &mut self, + amount: usize, + ) -> Option<impl Future<Output = Result<Life, TickError>>> { + if self.is_ticking { + return None; + } + + self.is_ticking = true; + + let mut life = self.life.clone(); + + Some(async move { + tokio::task::spawn_blocking(move || { + for _ in 0..amount { + life.tick(); + } + + life + }) + .await + .map_err(|_| TickError::JoinFailed) + }) + } + } + + #[derive(Clone, Default)] + pub struct Life { + cells: FxHashSet<Cell>, + } + + impl Life { + fn len(&self) -> usize { + self.cells.len() + } + + fn contains(&self, cell: &Cell) -> bool { + self.cells.contains(cell) + } + + fn populate(&mut self, cell: Cell) { + self.cells.insert(cell); + } + + fn unpopulate(&mut self, cell: &Cell) { + let _ = self.cells.remove(cell); + } + + fn tick(&mut self) { + let mut adjacent_life = FxHashMap::default(); + + for cell in &self.cells { + let _ = adjacent_life.entry(*cell).or_insert(0); + + for neighbor in Cell::neighbors(*cell) { + let amount = adjacent_life.entry(neighbor).or_insert(0); + + *amount += 1; + } + } + + for (cell, amount) in adjacent_life.iter() { + match amount { + 2 => {} + 3 => { + let _ = self.cells.insert(*cell); + } + _ => { + let _ = self.cells.remove(cell); + } + } + } + } + + pub fn iter(&self) -> impl Iterator<Item = &Cell> { + self.cells.iter() + } + } + + impl std::fmt::Debug for Life { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + f.debug_struct("Life") + .field("cells", &self.cells.len()) + .finish() + } + } + + #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] + pub struct Cell { + i: isize, + j: isize, + } + + impl Cell { + const SIZE: usize = 20; + + fn at(position: Point) -> Cell { + let i = (position.y / Cell::SIZE as f32).ceil() as isize; + let j = (position.x / Cell::SIZE as f32).ceil() as isize; + + Cell { + i: i.saturating_sub(1), + j: j.saturating_sub(1), + } + } + + fn cluster(cell: Cell) -> impl Iterator<Item = Cell> { + use itertools::Itertools; + + let rows = cell.i.saturating_sub(1)..=cell.i.saturating_add(1); + let columns = cell.j.saturating_sub(1)..=cell.j.saturating_add(1); + + rows.cartesian_product(columns).map(|(i, j)| Cell { i, j }) + } + + fn neighbors(cell: Cell) -> impl Iterator<Item = Cell> { + Cell::cluster(cell).filter(move |candidate| *candidate != cell) + } + } + + pub struct Region { + x: f32, + y: f32, + width: f32, + height: f32, + } + + impl Region { + fn rows(&self) -> RangeInclusive<isize> { + let first_row = (self.y / Cell::SIZE as f32).floor() as isize; + + let visible_rows = + (self.height / Cell::SIZE as f32).ceil() as isize; + + first_row..=first_row + visible_rows + } + + fn columns(&self) -> RangeInclusive<isize> { + let first_column = (self.x / Cell::SIZE as f32).floor() as isize; + + let visible_columns = + (self.width / Cell::SIZE as f32).ceil() as isize; + + first_column..=first_column + visible_columns + } + + fn cull<'a>( + &self, + cells: impl Iterator<Item = &'a Cell>, + ) -> impl Iterator<Item = &'a Cell> { + let rows = self.rows(); + let columns = self.columns(); + + cells.filter(move |cell| { + rows.contains(&cell.i) && columns.contains(&cell.j) + }) + } + } + + enum Interaction { + None, + Drawing, + Erasing, + Panning { translation: Vector, start: Point }, + } +} + +#[derive(Default)] +struct Controls { + toggle_button: button::State, + next_button: button::State, + clear_button: button::State, + speed_slider: slider::State, +} + +impl Controls { + fn view<'a>( + &'a mut self, + is_playing: bool, + is_grid_enabled: bool, + speed: usize, + ) -> Element<'a, Message> { + let playback_controls = Row::new() + .spacing(10) + .push( + Button::new( + &mut self.toggle_button, + Text::new(if is_playing { "Pause" } else { "Play" }), + ) + .on_press(Message::TogglePlayback) + .style(style::Button), + ) + .push( + Button::new(&mut self.next_button, Text::new("Next")) + .on_press(Message::Next) + .style(style::Button), + ); + + let speed_controls = Row::new() + .width(Length::Fill) + .align_items(Align::Center) + .spacing(10) + .push( + Slider::new( + &mut self.speed_slider, + 1.0..=1000.0, + speed as f32, + Message::SpeedChanged, + ) + .style(style::Slider), + ) + .push(Text::new(format!("x{}", speed)).size(16)); + + Row::new() + .padding(10) + .spacing(20) + .align_items(Align::Center) + .push(playback_controls) + .push(speed_controls) + .push( + Checkbox::new(is_grid_enabled, "Grid", Message::ToggleGrid) + .size(16) + .spacing(5) + .text_size(16), + ) + .push( + Button::new(&mut self.clear_button, Text::new("Clear")) + .on_press(Message::Clear) + .style(style::Clear), + ) + .into() + } +} |