From 10c789f5690ed69a97b708d15270506a40cdac39 Mon Sep 17 00:00:00 2001
From: Rekai Musuka <rekai@musuka.dev>
Date: Tue, 6 Apr 2021 23:53:54 -0500
Subject: [PATCH] feat: add fps and frametime ui information

---
 README.md   |   2 +-
 src/main.rs | 124 +++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 118 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 30a354b..80508d7 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ Key             | Action
 <kbd>R</kbd>    | Increase Scale
 <kbd>F</kbd>    | Decrease Scale
 
-#### Mandelbrot Iteration Limit (Max 512 by default)
+#### Mandelbrot Iteration Limit (Can go up to 1024)
 Key             | Action
 ---             | ---
 <kbd>T</kbd>    | Increment by a factor of 2
diff --git a/src/main.rs b/src/main.rs
index d728941..bbdb168 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,19 +1,35 @@
+use bevy::diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin};
 use bevy::prelude::*;
 use bevy::render::texture::{Extent3d, TextureDimension, TextureFormat};
 use mandelbrot::{Bounds, Mandelbrot, TEXTURE_HEIGHT, TEXTURE_WIDTH};
 use std::time::Instant;
 
+const MAX_ITERATION_COUNT: u32 = 1024;
+
 fn main() {
-    // Mandelbrot::escape_time_image();
+    let window_settings = WindowDescriptor {
+        width: TEXTURE_WIDTH as f32,
+        height: TEXTURE_HEIGHT as f32,
+        title: "Mandelbrot".to_string(),
+        vsync: false,
+        resizable: false,
+        ..Default::default()
+    };
+
     App::build()
+        .insert_resource(window_settings)
         .add_plugins(DefaultPlugins)
-        .add_startup_system(startup.system())
+        .add_plugin(FrameTimeDiagnosticsPlugin)
+        .add_startup_system(setup.system())
         .insert_resource(TextureOptions::default())
+        .add_system(performance_info_system.system())
         .add_system(mandelbrot_render_system.system())
-        .add_system(transform_mandelbrot_system.system())
+        .add_system(user_input_system.system())
         .run();
 }
 
+struct PerformanceInfo;
+
 struct TextureOptions {
     zoom: f64,
     horizontal: f64,
@@ -34,7 +50,7 @@ impl Default for TextureOptions {
     }
 }
 
-fn transform_mandelbrot_system(input: Res<Input<KeyCode>>, mut scale: ResMut<TextureOptions>) {
+fn user_input_system(input: Res<Input<KeyCode>>, mut scale: ResMut<TextureOptions>) {
     // Zoom: E to Zoom In, Q to Zoom Out
     // Horizontal Movement: D to move right, A to move left
     // Vertical Movement: W to move up, S to move Down
@@ -54,8 +70,8 @@ fn transform_mandelbrot_system(input: Res<Input<KeyCode>>, mut scale: ResMut<Tex
     if limit_change == 1 {
         scale.iteration_limit *= 2;
 
-        if scale.iteration_limit > 512 {
-            scale.iteration_limit = 512;
+        if scale.iteration_limit > MAX_ITERATION_COUNT {
+            scale.iteration_limit = MAX_ITERATION_COUNT;
         }
     } else if limit_change == -1 {
         scale.iteration_limit /= 2;
@@ -74,6 +90,35 @@ fn transform_mandelbrot_system(input: Res<Input<KeyCode>>, mut scale: ResMut<Tex
     }
 }
 
+fn performance_info_system(
+    // time: Res<Time>,
+    diag: Res<Diagnostics>,
+    mut query: Query<&mut Text, With<PerformanceInfo>>,
+) {
+    for mut text in query.iter_mut() {
+        let mut fps = 0.00;
+        let mut frametime = 0.00;
+
+        if let Some(fps_diag) = diag.get(FrameTimeDiagnosticsPlugin::FPS) {
+            if let Some(average) = fps_diag.average() {
+                fps = average;
+            }
+        }
+
+        if let Some(frametime_diag) = diag.get(FrameTimeDiagnosticsPlugin::FRAME_TIME) {
+            if let Some(average) = frametime_diag.average() {
+                frametime = average;
+            }
+        }
+
+        // FPS Number
+        text.sections[1].value = format!("{:.1}", fps);
+
+        // Frametime Number
+        text.sections[3].value = format!("{:.3}", frametime * 1000.0);
+    }
+}
+
 fn mandelbrot_render_system(
     materials: Res<Assets<ColorMaterial>>,
     mut textures: ResMut<Assets<Texture>>,
@@ -106,11 +151,14 @@ fn mandelbrot_render_system(
     }
 }
 
-fn startup(
+fn setup(
     mut commands: Commands,
     mut textures: ResMut<Assets<Texture>>,
     mut materials: ResMut<Assets<ColorMaterial>>,
+    asset_server: Res<AssetServer>,
 ) {
+    let ui_font = asset_server.load("fonts/vcr_osd_mono.ttf");
+    let white = Color::rgb(1.0, 1.0, 1.0);
     let mut fractal = Mandelbrot::default();
 
     let texture_size = Extent3d::new(TEXTURE_WIDTH as u32, TEXTURE_HEIGHT as u32, 1);
@@ -124,10 +172,72 @@ fn startup(
     ));
 
     commands.spawn_bundle(OrthographicCameraBundle::new_2d());
+    commands.spawn_bundle(UiCameraBundle::default());
+
     commands
         .spawn_bundle(SpriteBundle {
             material: materials.add(texture_handle.into()),
             ..Default::default()
         })
         .insert(fractal);
+
+    commands
+        .spawn_bundle(TextBundle {
+            text: Text {
+                sections: vec![
+                    TextSection {
+                        value: "FPS: ".to_string(),
+                        style: TextStyle {
+                            font: ui_font.clone(),
+                            font_size: 40.0,
+                            color: white,
+                        },
+                        ..Default::default()
+                    },
+                    TextSection {
+                        value: "".to_string(),
+                        style: TextStyle {
+                            font: ui_font.clone(),
+                            font_size: 40.0,
+                            color: white,
+                        },
+                        ..Default::default()
+                    },
+                    TextSection {
+                        value: "\nFrametime: ".to_string(),
+                        style: TextStyle {
+                            font: ui_font.clone(),
+                            font_size: 40.0,
+                            color: white,
+                        },
+                        ..Default::default()
+                    },
+                    TextSection {
+                        value: "".to_string(),
+                        style: TextStyle {
+                            font: ui_font.clone(),
+                            font_size: 40.0,
+                            color: white,
+                        },
+                        ..Default::default()
+                    },
+                    TextSection {
+                        value: "ms".to_string(),
+                        style: TextStyle {
+                            font: ui_font.clone(),
+                            font_size: 40.0,
+                            color: white,
+                        },
+                        ..Default::default()
+                    },
+                ],
+                ..Default::default()
+            },
+            style: Style {
+                ..Default::default()
+            },
+
+            ..Default::default()
+        })
+        .insert(PerformanceInfo);
 }