notedeck

commit 800ab26cb48a05c558742f226ad4128305600286
parent ce6f5c6c1174729f955a753b69916722854d4364
Author: William Casarin <jb55@jb55.com>
Date:   Sun,  9 Jul 2023 14:08:25 -0700

add frame_history helper from egui

Diffstat:
A
src/frame_history.rs
 | 
126
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 126 insertions(+), 0 deletions(-)
diff --git a/src/frame_history.rs b/src/frame_history.rs
@@ -0,0 +1,126 @@
+use egui::util::History;
+
+pub struct FrameHistory {
+    frame_times: History<f32>,
+}
+
+impl Default for FrameHistory {
+    fn default() -> Self {
+        let max_age: f32 = 1.0;
+        let max_len = (max_age * 300.0).round() as usize;
+        Self {
+            frame_times: History::new(0..max_len, max_age),
+        }
+    }
+}
+
+impl FrameHistory {
+    // Called first
+    pub fn on_new_frame(&mut self, now: f64, previous_frame_time: Option<f32>) {
+        let previous_frame_time = previous_frame_time.unwrap_or_default();
+        if let Some(latest) = self.frame_times.latest_mut() {
+            *latest = previous_frame_time; // rewrite history now that we know
+        }
+        self.frame_times.add(now, previous_frame_time); // projected
+    }
+
+    pub fn mean_frame_time(&self) -> f32 {
+        self.frame_times.average().unwrap_or_default()
+    }
+
+    pub fn fps(&self) -> f32 {
+        1.0 / self.frame_times.mean_time_interval().unwrap_or_default()
+    }
+
+    pub fn ui(&mut self, ui: &mut egui::Ui) {
+        ui.label(format!(
+            "Mean CPU usage: {:.2} ms / frame",
+            1e3 * self.mean_frame_time()
+        ))
+        .on_hover_text(
+            "Includes egui layout and tessellation time.\n\
+            Does not include GPU usage, nor overhead for sending data to GPU.",
+        );
+        egui::warn_if_debug_build(ui);
+
+        if !cfg!(target_arch = "wasm32") {
+            egui::CollapsingHeader::new("📊 CPU usage history")
+                .default_open(false)
+                .show(ui, |ui| {
+                    self.graph(ui);
+                });
+        }
+    }
+
+    fn graph(&mut self, ui: &mut egui::Ui) -> egui::Response {
+        use egui::*;
+
+        ui.label("egui CPU usage history");
+
+        let history = &self.frame_times;
+
+        // TODO(emilk): we should not use `slider_width` as default graph width.
+        let height = ui.spacing().slider_width;
+        let size = vec2(ui.available_size_before_wrap().x, height);
+        let (rect, response) = ui.allocate_at_least(size, Sense::hover());
+        let style = ui.style().noninteractive();
+
+        let graph_top_cpu_usage = 0.010;
+        let graph_rect = Rect::from_x_y_ranges(history.max_age()..=0.0, graph_top_cpu_usage..=0.0);
+        let to_screen = emath::RectTransform::from_to(graph_rect, rect);
+
+        let mut shapes = Vec::with_capacity(3 + 2 * history.len());
+        shapes.push(Shape::Rect(epaint::RectShape {
+            rect,
+            rounding: style.rounding,
+            fill: ui.visuals().extreme_bg_color,
+            stroke: ui.style().noninteractive().bg_stroke,
+        }));
+
+        let rect = rect.shrink(4.0);
+        let color = ui.visuals().text_color();
+        let line_stroke = Stroke::new(1.0, color);
+
+        if let Some(pointer_pos) = response.hover_pos() {
+            let y = pointer_pos.y;
+            shapes.push(Shape::line_segment(
+                [pos2(rect.left(), y), pos2(rect.right(), y)],
+                line_stroke,
+            ));
+            let cpu_usage = to_screen.inverse().transform_pos(pointer_pos).y;
+            let text = format!("{:.1} ms", 1e3 * cpu_usage);
+            shapes.push(ui.fonts(|f| {
+                Shape::text(
+                    f,
+                    pos2(rect.left(), y),
+                    egui::Align2::LEFT_BOTTOM,
+                    text,
+                    TextStyle::Monospace.resolve(ui.style()),
+                    color,
+                )
+            }));
+        }
+
+        let circle_color = color;
+        let radius = 2.0;
+        let right_side_time = ui.input(|i| i.time); // Time at right side of screen
+
+        for (time, cpu_usage) in history.iter() {
+            let age = (right_side_time - time) as f32;
+            let pos = to_screen.transform_pos_clamped(Pos2::new(age, cpu_usage));
+
+            shapes.push(Shape::line_segment(
+                [pos2(pos.x, rect.bottom()), pos],
+                line_stroke,
+            ));
+
+            if cpu_usage < graph_top_cpu_usage {
+                shapes.push(Shape::circle_filled(pos, radius, circle_color));
+            }
+        }
+
+        ui.painter().extend(shapes);
+
+        response
+    }
+}