Added R key to reset game

examples/invaders/README.md

@@ -18,6 +18,10 @@ cargo run --release --package invaders
 
 <kbd>Pause</kbd> <kbd>P</kbd>: Pause
 
+<kbd>R</kbd>: Reset Game
+
+<kbd>escape</kbd>: Quit
+
 ## GamePad Controls
 
 `D-Pad 🡰` `D-Pad 🡲`: Move tank

examples/invaders/simple-invaders/src/lib.rs

@@ -459,6 +459,43 @@ impl World {
             });
         }
     }
+
+    pub fn reset_game(&mut self) {
+        // Recreate the alien
+        self.invaders = Invaders {
+            grid: make_invader_grid(&self.assets),
+            stepper: Point::new(COLS - 1, 0),
+            direction: Direction::Right,
+            descend: false,
+            bounds: Bounds::default(),
+        };
+
+        // Empty laser
+        self.lasers.clear();
+
+        // Recreate the shield
+        self.shields = (0..4)
+            .map(|i| Shield {
+                sprite: Sprite::new(&self.assets, Frame::Shield1),
+                pos: Point::new(i * 45 + 32, 192),
+            })
+            .collect();
+
+        // Reset player position
+        self.player.pos = PLAYER_START;
+
+        // Remove bullet
+        self.bullet = None;
+
+        // Reset collision state
+        self.collision.clear();
+
+        // Reset game score
+        self._score = 0;
+
+        // Set gameover to false
+        self.gameover = false;
+    }
 }
 
 /// Create a default `World` with a static PRNG seed.
@@ -501,23 +538,15 @@ impl Invaders {
 
         // Scan through the entire grid
         for (y, row) in self.grid.iter().enumerate() {
-            for (x, col) in row.iter().enumerate() {
-                if col.is_some() {
-                    // Build a boundary box of invaders in the grid
-                    if top > y {
-                        top = y;
-                    }
-                    if bottom < y {
-                        bottom = y;
-                    }
-                    if left > x {
-                        left = x;
-                    }
-                    if right < x {
-                        right = x;
-                    }
-                }
-            }
+            row.iter()
+                .enumerate()
+                .filter(|(_, col)| col.is_some())
+                .for_each(|(x, _)| {
+                    top = top.min(y);
+                    bottom = bottom.max(y);
+                    left = left.min(x);
+                    right = right.max(x);
+                });
         }
 
         if top > bottom || left > right {

examples/invaders/src/main.rs

@@ -95,6 +95,10 @@ impl Game {
             Controls { direction, fire }
         };
     }
+
+    fn reset_game(&mut self) {
+        self.world.reset_game();
+    }
 }
 
 fn main() -> Result<(), Error> {
@@ -165,6 +169,11 @@ fn main() -> Result<(), Error> {
                     return;
                 }
 
+                // Reset game
+                if g.game.input.key_pressed(VirtualKeyCode::R) {
+                    g.game.reset_game();
+                }
+
                 // Resize the window
                 if let Some(size) = g.game.input.window_resized() {
                     if let Err(err) = g.game.pixels.resize_surface(size.width, size.height) {