From 93bf728475e82dadc04225d7ced89171306a9801 Mon Sep 17 00:00:00 2001
From: Carter Anderson <mcanders1@gmail.com>
Date: Fri, 27 Mar 2020 15:03:47 -0700
Subject: [PATCH] new Diagnostics system

---
 examples/instancing.rs        |   3 +-
 examples/instancing_old.rs    |   1 -
 examples/spawner.rs           |   3 +-
 examples/ui_bench.rs          |   3 +-
 src/app/app_builder.rs        |  17 ++++-
 src/core/time.rs              |   7 +-
 src/diagnostic/diagnostics.rs |  94 ++++++++++++++++++++++++++
 src/diagnostic/mod.rs         | 124 ++++++++++++++++++++++++++++++++++
 src/diagnostics/mod.rs        |  32 ---------
 src/lib.rs                    |   2 +-
 10 files changed, 245 insertions(+), 41 deletions(-)
 create mode 100644 src/diagnostic/diagnostics.rs
 create mode 100644 src/diagnostic/mod.rs
 delete mode 100644 src/diagnostics/mod.rs

diff --git a/examples/instancing.rs b/examples/instancing.rs
index c5472643f3..ead3faf417 100644
--- a/examples/instancing.rs
+++ b/examples/instancing.rs
@@ -5,7 +5,8 @@ fn main() {
     App::build()
         .add_defaults()
         .add_system(build_move_system())
-        .add_system(bevy::diagnostics::build_fps_printer_system())
+        .add_default_diagnostics()
+        .print_diagnostics(std::time::Duration::from_secs_f64(1.0))
         .setup_world(setup)
         .run();
 }
diff --git a/examples/instancing_old.rs b/examples/instancing_old.rs
index 1792cf9441..890c819221 100644
--- a/examples/instancing_old.rs
+++ b/examples/instancing_old.rs
@@ -24,7 +24,6 @@ fn main() {
         .add_system(build_wander_system())
         .add_system(build_navigate_system())
         .add_system(build_move_system())
-        .add_system(bevy::diagnostics::build_fps_printer_system())
         .run();
 }
 
diff --git a/examples/spawner.rs b/examples/spawner.rs
index f52e99a7da..e5750d375f 100644
--- a/examples/spawner.rs
+++ b/examples/spawner.rs
@@ -5,7 +5,8 @@ fn main() {
     App::build()
         .add_defaults()
         .add_system(build_move_system())
-        .add_system(bevy::diagnostics::build_fps_printer_system())
+        .add_default_diagnostics()
+        .print_diagnostics(std::time::Duration::from_secs_f64(1.0))
         .setup_world(setup)
         .run();
 }
diff --git a/examples/ui_bench.rs b/examples/ui_bench.rs
index 3e135620de..825bcf8ad1 100644
--- a/examples/ui_bench.rs
+++ b/examples/ui_bench.rs
@@ -5,7 +5,8 @@ fn main() {
         .add_defaults()
         .setup_world(setup)
         .add_system(build_move_system())
-        .add_system(bevy::diagnostics::build_fps_printer_system())
+        .add_default_diagnostics()
+        .print_diagnostics(std::time::Duration::from_secs_f64(1.0))
         .run();
 }
 
diff --git a/src/app/app_builder.rs b/src/app/app_builder.rs
index d642d75e11..793987ddb3 100644
--- a/src/app/app_builder.rs
+++ b/src/app/app_builder.rs
@@ -9,7 +9,7 @@ use crate::{
         draw_target::draw_targets::*, mesh::Mesh, pass::passes::*, pipeline::pipelines::*,
         render_resource::resource_providers::*, renderer::Renderer, texture::Texture, *,
     },
-    ui,
+    ui, diagnostic::{Diagnostics, diagnostics},
 };
 
 use bevy_transform::{prelude::LocalToWorld, transform_system_bundle};
@@ -20,7 +20,7 @@ use render_resource::{
     EntityRenderResourceAssignments, RenderResourceAssignments,
 };
 use shader::Shader;
-use std::collections::HashMap;
+use std::{time::Duration, collections::HashMap};
 
 pub struct AppBuilder {
     pub world: Option<World>,
@@ -160,6 +160,7 @@ impl AppBuilder {
     pub fn add_default_resources(&mut self) -> &mut Self {
         let resources = self.resources.as_mut().unwrap();
         resources.insert(Time::new());
+        resources.insert(Diagnostics::default());
         resources.insert(AssetStorage::<Mesh>::new());
         resources.insert(AssetStorage::<Texture>::new());
         resources.insert(AssetStorage::<Shader>::new());
@@ -173,6 +174,18 @@ impl AppBuilder {
         self
     }
 
+    pub fn add_default_diagnostics(&mut self) -> &mut Self {
+        let frame_time_diagnostic_system = {
+            let resources = self.resources.as_mut().unwrap();
+            diagnostics::frame_time_diagnostic_system(resources, 10)
+        };
+        self.add_system(frame_time_diagnostic_system)
+    }
+
+    pub fn print_diagnostics(&mut self, wait: Duration) -> &mut Self {
+        self.add_system(diagnostics::print_diagnostics_system(wait))
+    }
+
     pub fn batch_types2<T1, T2>(&mut self) -> &mut Self
     where
         T1: 'static,
diff --git a/src/core/time.rs b/src/core/time.rs
index 2070f58a55..ff7711bf5f 100644
--- a/src/core/time.rs
+++ b/src/core/time.rs
@@ -3,6 +3,7 @@ use std::time::{Duration, Instant};
 pub struct Time {
     pub delta: Duration,
     pub instant: Instant,
+    pub delta_seconds_f64: f64,
     pub delta_seconds: f32,
 }
 
@@ -11,6 +12,7 @@ impl Time {
         Time {
             delta: Duration::from_secs(0),
             instant: Instant::now(),
+            delta_seconds_f64: 0.0,
             delta_seconds: 0.0,
         }
     }
@@ -21,7 +23,8 @@ impl Time {
 
     pub fn stop(&mut self) {
         self.delta = Instant::now() - self.instant;
-        self.delta_seconds =
-            self.delta.as_secs() as f32 + (self.delta.subsec_nanos() as f32 / 1.0e9);
+        self.delta_seconds_f64 =
+            self.delta.as_secs() as f64 + (self.delta.subsec_nanos() as f64 / 1.0e9);
+        self.delta_seconds = self.delta_seconds_f64 as f32;
     }
 }
diff --git a/src/diagnostic/diagnostics.rs b/src/diagnostic/diagnostics.rs
new file mode 100644
index 0000000000..20a684748a
--- /dev/null
+++ b/src/diagnostic/diagnostics.rs
@@ -0,0 +1,94 @@
+use super::{Diagnostic, DiagnosticId, Diagnostics};
+use crate::{
+    core::Time,
+    prelude::{Resources, SystemBuilder},
+};
+use legion::prelude::Schedulable;
+use std::time::Duration;
+use uuid::Uuid;
+
+pub const FPS: DiagnosticId = DiagnosticId(Uuid::from_bytes([
+    157, 191, 0, 72, 223, 223, 70, 128, 137, 117, 54, 177, 132, 13, 170, 124,
+]));
+
+pub const FRAME_TIME: DiagnosticId = DiagnosticId(Uuid::from_bytes([
+    216, 184, 55, 12, 28, 116, 69, 201, 187, 137, 176, 77, 83, 89, 251, 241,
+]));
+
+pub fn frame_time_diagnostic_system(
+    resources: &Resources,
+    max_history_length: usize,
+) -> Box<dyn Schedulable> {
+    let mut diagnostics = resources.get_mut::<Diagnostics>().unwrap();
+    diagnostics.add(Diagnostic::new(
+        FRAME_TIME,
+        "frame_time",
+        max_history_length,
+    ));
+    diagnostics.add(Diagnostic::new(FPS, "fps", max_history_length));
+    SystemBuilder::new("FrameTimeDiagnostic")
+        .read_resource::<Time>()
+        .write_resource::<Diagnostics>()
+        .build(move |_, _world, (time, ref mut diagnostics), _queries| {
+            if time.delta_seconds_f64 == 0.0 {
+                return;
+            }
+
+            diagnostics.add_measurement(FRAME_TIME, time.delta_seconds_f64);
+            if let Some(fps) = diagnostics
+                .get(FRAME_TIME)
+                .and_then(|frame_time_diagnostic| {
+                    frame_time_diagnostic
+                        .average()
+                        .and_then(|frame_time_average| {
+                            if frame_time_average > 0.0 {
+                                Some(1.0 / frame_time_average)
+                            } else {
+                                None
+                            }
+                        })
+                })
+            {
+                diagnostics.add_measurement(FPS, fps);
+            }
+        })
+}
+
+pub fn print_diagnostics_system(wait: Duration) -> Box<dyn Schedulable> {
+    let mut elasped = 0.0;
+    let wait_seconds = wait.as_secs_f64();
+    SystemBuilder::new("PrintDiagnostics")
+        .read_resource::<Time>()
+        .read_resource::<Diagnostics>()
+        .build(move |_, _world, (time, diagnostics), _queries| {
+            elasped += time.delta_seconds_f64;
+            if elasped >= wait_seconds {
+                elasped = 0.0;
+                for diagnostic in diagnostics.iter() {
+                    if let Some(value) = diagnostic.value() {
+                        println!("{}: {}", diagnostic.name, value);
+                        if let Some(average) = diagnostic.average() {
+                            println!("  average: {}", average);
+                        }
+                    }
+                }
+            }
+        })
+}
+
+pub fn print_diagnostics_debug_system(wait: Duration) -> Box<dyn Schedulable> {
+    let mut elasped = 0.0;
+    let wait_seconds = wait.as_secs_f64();
+    SystemBuilder::new("PrintDiagnostics")
+        .read_resource::<Time>()
+        .read_resource::<Diagnostics>()
+        .build(move |_, _world, (time, diagnostics), _queries| {
+            elasped += time.delta_seconds_f64;
+            if elasped >= wait_seconds {
+                elasped = 0.0;
+                for diagnostic in diagnostics.iter() {
+                    println!("{:#?}\n", diagnostic);
+                }
+            }
+        })
+}
\ No newline at end of file
diff --git a/src/diagnostic/mod.rs b/src/diagnostic/mod.rs
new file mode 100644
index 0000000000..766a5d5e63
--- /dev/null
+++ b/src/diagnostic/mod.rs
@@ -0,0 +1,124 @@
+pub mod diagnostics;
+
+use std::{
+    collections::{HashMap, VecDeque},
+    time::{Duration, SystemTime},
+};
+use uuid::Uuid;
+
+#[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]
+pub struct DiagnosticId(Uuid);
+
+#[derive(Debug)]
+pub struct DiagnosticMeasurement {
+    pub time: SystemTime,
+    pub value: f64,
+}
+
+#[derive(Debug)]
+pub struct Diagnostic {
+    pub id: DiagnosticId,
+    pub name: String,
+    history: VecDeque<DiagnosticMeasurement>,
+    sum: f64,
+    max_history_length: usize,
+}
+
+impl Diagnostic {
+    pub fn add_measurement(&mut self, value: f64) {
+        let time = SystemTime::now();
+        if self.history.len() == self.max_history_length {
+            if let Some(removed_diagnostic) = self.history.pop_back() {
+                self.sum -= removed_diagnostic.value;
+            }
+        }
+
+        self.sum += value;
+        self.history.push_front(DiagnosticMeasurement {
+            time,
+            value,
+        });
+    }
+
+    pub fn new(id: DiagnosticId, name: &str, max_history_length: usize) -> Diagnostic {
+        Diagnostic {
+            id,
+            name: name.to_string(),
+            history: VecDeque::with_capacity(max_history_length),
+            max_history_length,
+            sum: 0.0,
+        }
+    }
+
+    pub fn value(&self) -> Option<f64> {
+        self.history.back().map(|measurement| measurement.value)
+    }
+
+    pub fn sum(&self) -> f64 {
+        self.sum
+    }
+
+    pub fn average(&self) -> Option<f64> {
+        if self.history.len() > 0 {
+            Some(self.sum / self.history.len() as f64)
+        } else {
+            None
+        }
+    }
+
+    pub fn history_len(&self) -> usize {
+        self.history.len()
+    }
+
+    pub fn duration(&self) -> Option<Duration> {
+        if self.history.len() < 2 {
+            return None
+        }
+
+        if let Some(oldest) = self.history.back() {
+            if let Some(newest) = self.history.front() {
+                return newest.time.duration_since(oldest.time).ok()
+            }
+        }
+
+        return None
+    }
+
+    pub fn get_max_history_length(&self) -> usize {
+        self.max_history_length
+    }
+
+}
+
+#[derive(Default)]
+pub struct Diagnostics {
+    diagnostics: HashMap<DiagnosticId, Diagnostic>,
+}
+
+impl Diagnostics {
+    pub fn add(&mut self, diagnostic: Diagnostic) {
+        self.diagnostics.insert(diagnostic.id, diagnostic);
+    }
+
+    pub fn get(&self, id: DiagnosticId) -> Option<&Diagnostic> {
+        self.diagnostics.get(&id)
+    }
+
+    pub fn get_mut(&mut self, id: DiagnosticId) -> Option<&mut Diagnostic> {
+        self.diagnostics.get_mut(&id)
+    }
+
+    pub fn get_measurement(&self, id: DiagnosticId) -> Option<&DiagnosticMeasurement> {
+        self.diagnostics.get(&id).and_then(|diagnostic| diagnostic.history.front())
+    }
+
+    pub fn add_measurement(&mut self, id: DiagnosticId, value: f64) {
+        if let Some(diagnostic) = self.diagnostics.get_mut(&id) {
+            diagnostic.add_measurement(value);
+        }
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item=&Diagnostic> {
+        self.diagnostics.values()
+    }
+}
\ No newline at end of file
diff --git a/src/diagnostics/mod.rs b/src/diagnostics/mod.rs
deleted file mode 100644
index 71a5e25e4c..0000000000
--- a/src/diagnostics/mod.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-use crate::{core::Time, prelude::SystemBuilder};
-use legion::prelude::Schedulable;
-use std::collections::VecDeque;
-
-pub fn build_fps_printer_system() -> Box<dyn Schedulable> {
-    let mut elapsed = 0.0;
-    let mut frame_time_total = 0.0;
-    let mut frame_time_count = 0;
-    let frame_time_max = 10;
-    let mut frame_time_values = VecDeque::new();
-    SystemBuilder::new("FpsPrinter")
-        .read_resource::<Time>()
-        .build(move |_, _world, time, _queries| {
-            elapsed += time.delta_seconds;
-            frame_time_values.push_front(time.delta_seconds);
-            frame_time_total += time.delta_seconds;
-            frame_time_count += 1;
-            if frame_time_count > frame_time_max {
-                frame_time_count = frame_time_max;
-                frame_time_total -= frame_time_values.pop_back().unwrap();
-            }
-            if elapsed > 1.0 {
-                if frame_time_count > 0 && frame_time_total > 0.0 {
-                    println!(
-                        "fps: {}",
-                        1.0 / (frame_time_total / frame_time_count as f32)
-                    )
-                }
-                elapsed = 0.0;
-            }
-        })
-}
diff --git a/src/lib.rs b/src/lib.rs
index 8fd6b7cd4f..7e948a7f1d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,7 +2,7 @@
 pub mod app;
 pub mod asset;
 pub mod core;
-pub mod diagnostics;
+pub mod diagnostic;
 pub mod ecs;
 pub mod plugin;
 pub mod prelude;