[frame_stats] Key binding to clear min/max frame time; address review comments

examples/with_winit/README.md

@@ -19,4 +19,5 @@ $ cargo run -p with_winit --release -- [SVG FILES]
 - Arrow keys switch between SVG images in the current set.
 - Space resets the position and zoom of the image.
 - S toggles the frame statistics layer
+- C resets the min/max frame time tracked by statistics
 - Escape exits the program.

examples/with_winit/src/lib.rs

@@ -99,7 +99,7 @@ fn run(
     let mut simple_text = SimpleText::new();
     let mut images = ImageCache::new();
     let mut stats = stats::Stats::new();
-    let mut stats_toggle = true;
+    let mut stats_shown = true;
     let start = Instant::now();
 
     let mut touch_state = multi_touch::TouchState::new();
@@ -146,7 +146,10 @@ fn run(
                                 transform = Affine::IDENTITY;
                             }
                             Some(VirtualKeyCode::S) => {
-                                stats_toggle = !stats_toggle;
+                                stats_shown = !stats_shown;
+                            }
+                            Some(VirtualKeyCode::C) => {
+                                stats.clear_min_and_max();
                             }
                             Some(VirtualKeyCode::Escape) => {
                                 *control_flow = ControlFlow::Exit;
@@ -304,7 +307,7 @@ fn run(
                 transform = transform * Affine::scale(scale_factor);
             }
             builder.append(&fragment, Some(transform));
-            if stats_toggle {
+            if stats_shown {
                 snapshot.draw_layer(
                     &mut builder,
                     &mut scene_params.text,

examples/with_winit/src/stats.rs

@@ -168,6 +168,11 @@ impl Stats {
         }
     }
 
+    pub fn clear_min_and_max(&mut self) {
+        self.min = u64::MAX;
+        self.max = u64::MIN;
+    }
+
     pub fn add_sample(&mut self, sample: Sample) {
         let oldest = if self.count < SLIDING_WINDOW_SIZE {
             self.count += 1;
@@ -181,11 +186,7 @@ impl Stats {
         if let Some(oldest) = oldest {
             self.sum -= oldest;
         }
-        if micros < self.min {
-            self.min = micros;
-        }
-        if micros > self.max {
-            self.max = micros;
-        }
+        self.min = self.min.min(micros);
+        self.max = self.max.max(micros);
     }
 }