lab 03

labs/03/src/lib.rs

@@ -0,0 +1,137 @@
+use rand::Rng;
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+#[derive(Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum Cell {
+    Dead = 0,
+    Alive = 1,
+    Dying = 2,
+}
+
+impl Cell {
+    pub fn toggle(&mut self) {
+        *self = if *self == Cell::Alive {
+            Cell::Dead
+        } else {
+            Cell::Alive
+        };
+    }
+}
+
+#[wasm_bindgen]
+pub struct Universe {
+    width: u32,
+    height: u32,
+    cells: Vec<Cell>,
+}
+
+#[wasm_bindgen]
+impl Universe {
+    pub fn new() -> Self {
+        let (width, height) = (64, 64);
+        let mut rng = rand::thread_rng();
+        let cells = (0..width * height)
+            .map(|_| {
+                if rng.gen_range(0..2) == 0 {
+                    Cell::Dead
+                } else {
+                    Cell::Alive
+                }
+            })
+            .collect();
+
+        Self {
+            width,
+            height,
+            cells,
+        }
+    }
+
+    pub fn width(&self) -> u32 {
+        self.width
+    }
+
+    pub fn height(&self) -> u32 {
+        self.height
+    }
+
+    pub fn cells(&self) -> *const Cell {
+        self.cells.as_ptr()
+    }
+
+    fn get_index(&self, row: u32, col: u32) -> usize {
+        (row * self.width + col) as usize
+    }
+
+    fn count_live_neighbours(&self, row: u32, col: u32) -> u8 {
+        let mut count = 0;
+        for i in [self.height - 1, 0, 1] {
+            for j in [self.width - 1, 0, 1] {
+                if i == 0 && j == 0 {
+                    continue;
+                }
+                let idx = self.get_index((row + i) % self.height, (col + j) % self.width);
+                count += self.cells[idx] as u8;
+            }
+        }
+        count
+    }
+
+    pub fn tick(&mut self) {
+        let mut cells = self.cells.clone();
+        for row in 0..self.height {
+            for col in 0..self.width {
+                let idx = self.get_index(row, col);
+                cells[idx] = match (self.cells[idx], self.count_live_neighbours(row, col)) {
+                    (Cell::Alive, _) => Cell::Dying,
+                    (Cell::Dying, _) => Cell::Dead,
+                    (Cell::Dead, 2) => Cell::Alive,
+                    _ => Cell::Dead,
+                }
+            }
+        }
+        self.cells = cells;
+    }
+
+    pub fn render(&self) -> String {
+        self.to_string()
+    }
+
+    pub fn toggle_cell(&mut self, row: u32, col: u32) {
+        let idx = self.get_index(row, col);
+        self.cells[idx].toggle();
+    }
+
+    pub fn set_alive(&mut self, row: u32, col: u32) {
+        let idx = self.get_index(row, col);
+        self.cells[idx] = Cell::Alive;
+    }
+
+    pub fn clear(&mut self) {
+        for cell in self.cells.iter_mut() {
+            *cell = Cell::Dead;
+        }
+    }
+}
+
+use std::fmt;
+
+impl fmt::Display for Universe {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        for row in 0..self.height {
+            for col in 0..self.width {
+                let idx = self.get_index(row, col);
+                let glyph = if self.cells[idx] == Cell::Alive {
+                    '⬛'
+                } else {
+                    '🔳'
+                };
+                write!(f, "{glyph}");
+            }
+            write!(f, "\n");
+        }
+        Ok(())
+    }
+}