init

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.lock

@@ -0,0 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "bouncy"
+version = "0.1.0"

Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "bouncy"
+version = "0.1.0"
+authors = ["Sridhar Ratnakumar <srid@srid.ca>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/main.rs

@@ -0,0 +1,117 @@
+use std::fmt::{Display, Formatter};
+
+enum VertDir {
+    Up,
+    Down,
+}
+
+enum HorizDir {
+    Left,
+    Right,
+}
+
+struct Ball {
+    x: u32,
+    y: u32,
+    vert_dir: VertDir,
+    horiz_dir: HorizDir,
+}
+
+struct Frame {
+    width: u32,
+    height: u32,
+}
+
+struct Game {
+    frame: Frame,
+    ball: Ball,
+}
+
+impl Game {
+    fn new() -> Game {
+        let frame = Frame {
+            width: 60,
+            height: 30,
+        };
+        let ball = Ball {
+            x: 2,
+            y: 4,
+            vert_dir: VertDir::Up,
+            horiz_dir: HorizDir::Left,
+        };
+        Game {frame, ball}
+    }
+
+    fn step(&mut self) {
+        self.ball.bounce(&self.frame);
+        self.ball.mv();
+    }
+}
+
+impl Ball {
+    fn bounce(&mut self, frame: &Frame) {
+        if self.x == 0 {
+            self.horiz_dir = HorizDir::Right;
+        } else if self.x == frame.width - 1 {
+            self.horiz_dir = HorizDir::Left;
+        }
+
+        if self.y == 0 {
+            self.vert_dir = VertDir::Down;
+        } else if self.y == frame.height - 1 {
+            self.vert_dir = VertDir::Up;
+        }
+    }
+
+    fn mv(&mut self) {
+        match self.horiz_dir {
+            HorizDir::Left => self.x -= 1,
+            HorizDir::Right => self.x += 1,
+        }
+        match self.vert_dir {
+            VertDir::Up => self.y -= 1,
+            VertDir::Down => self.y += 1,
+        }
+    }
+}
+
+impl Display for Game {
+    fn fmt(&self, fmt: &mut Formatter) -> std::fmt::Result {
+        let top_bottom = |fmt: &mut Formatter| {
+            write!(fmt, "+");
+            for _ in 0..self.frame.width {
+                write!(fmt, "-");
+            }
+            write!(fmt, "+\n")
+        };
+
+        top_bottom(fmt)?;
+
+        for row in 0..self.frame.height {
+            write!(fmt, "|");
+
+            for column in 0..self.frame.width {
+                let c = if row == self.ball.y && column == self.ball.x {
+                    'o'
+                } else {
+                    ' '
+                };
+                write!(fmt, "{}", c);
+            }
+
+            write!(fmt, "|\n");
+        }
+
+        top_bottom(fmt)
+    }
+}
+
+fn main () {
+    let mut game = Game::new();
+    let sleep_duration = std::time::Duration::from_millis(33);
+    loop {
+        println!("{}", game);
+        game.step();
+        std::thread::sleep(sleep_duration);
+    }
+}