Merge pull request #9 from VGVentures/feat/vehicle-sim

feat: vehicle simulation

lib/dashboard/game/gauge_game.dart

@@ -4,14 +4,20 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:vehicle_cockpit/dashboard/dashboard.dart';
 import 'package:vehicle_cockpit/l10n/l10n.dart';
+import 'package:vehicle_sim/vehicle_sim.dart';
 
 class GaugeGame extends FlameGame with KeyboardEvents {
   GaugeGame({
+    required this.sim,
     required this.onSpeedChanged,
     required this.appTheme,
     required this.l10n,
+    this.timeScale = 2.5,
   });
 
+  /// Speeds vehicle simulation up by this factor to adjust fun factor.
+  final double timeScale;
+  final VehicleSim sim;
   final ThemeData appTheme;
   final AppLocalizations l10n;
   final ValueChanged<double> onSpeedChanged;
@@ -24,24 +30,29 @@ class GaugeGame extends FlameGame with KeyboardEvents {
   @override
   Color backgroundColor() => Colors.transparent;
 
-  void accelerate() => hittingGas = true;
+  void acceleratorPedalPushed() => hittingGas = true;
 
-  void release() => hittingGas = false;
+  void acceleratorPedalReleased() => hittingGas = false;
 
   @override
   KeyEventResult onKeyEvent(
     KeyEvent event,
     Set<LogicalKeyboardKey> keysPressed,
   ) {
-    final isKeyDown = event is KeyDownEvent || event is KeyRepeatEvent;
+    final isPressed = event is KeyDownEvent || event is KeyRepeatEvent;
+    final wasReleased = event is KeyUpEvent;
 
-    final isSpace = keysPressed.contains(LogicalKeyboardKey.space);
+    if (event.logicalKey != LogicalKeyboardKey.space ||
+        (!isPressed && !wasReleased)) {
+      return KeyEventResult.ignored;
+    }
 
-    if (isSpace && isKeyDown) {
-      accelerate();
+    if (isPressed) {
+      acceleratorPedalPushed();
     } else {
-      release();
+      acceleratorPedalReleased();
     }
+
     return KeyEventResult.handled;
   }
 
@@ -51,8 +62,8 @@ class GaugeGame extends FlameGame with KeyboardEvents {
       gauge = GaugeComponent(
         size: Vector2.all(340),
         position: size / 2,
-        maxRpm: 9,
-        dangerZone: 8,
+        maxRpm: (sim.vehicle.engineRpmMaximum / 1000).round(),
+        dangerZone: (sim.vehicle.engineRpmRedline / 1000).round(),
         appTheme: appTheme,
       ),
     );
@@ -74,18 +85,16 @@ class GaugeGame extends FlameGame with KeyboardEvents {
 
   @override
   void update(double dt) {
-    var rpm = gauge.progress;
-    var speed = speedometer.speed;
-    if (hittingGas) {
-      rpm += .008;
-      speed += rpm / 8;
-    } else {
-      rpm -= .008;
-      speed -= (speed / 500) + .02;
-    }
-    onSpeedChanged(speed);
-    gauge.progress = rpm;
-    speedometer.speed = speed;
+    sim.simulate(dt * timeScale, hittingGas ? 1.0 : -1.3);
+
+    gauge.setProgress(
+      sim.engineRpm / sim.vehicle.engineRpmMaximum,
+      dt,
+    );
+    speedometer.speed = sim.speed;
+    gear.gearText.text = sim.gear.toString();
+
+    onSpeedChanged(sim.speed);
 
     super.update(dt);
   }

lib/dashboard/game/gear.dart

@@ -55,26 +55,6 @@ class Gear extends PositionComponent with HasGameRef<GaugeGame> {
     size.addListener(_buildPath);
   }
 
-  @override
-  void update(double dt) {
-    final speed = gameRef.speedometer.speed;
-    if (speed <= 0) {
-      gearText.text = 'N';
-    } else if (speed <= 10) {
-      gearText.text = '1';
-    } else if (speed <= 15) {
-      gearText.text = '2';
-    } else if (speed <= 35) {
-      gearText.text = '3';
-    } else if (speed <= 55) {
-      gearText.text = '4';
-    } else if (speed <= 65) {
-      gearText.text = '5';
-    } else {
-      gearText.text = '6';
-    }
-  }
-
   void _buildPath() {
     final dimensions = size.toRect();
     const curveOffset = 15.0;

lib/dashboard/game/rpm_gauge/gauge_component.dart

@@ -3,6 +3,7 @@ import 'dart:math' as math;
 import 'package:flame/components.dart';
 import 'package:flutter/material.dart';
 import 'package:vehicle_cockpit/dashboard/dashboard.dart';
+import 'package:vehicle_cockpit/util/math_utils.dart';
 
 class GaugeComponent extends PositionComponent {
   GaugeComponent({
@@ -18,19 +19,22 @@ class GaugeComponent extends PositionComponent {
   final int dangerZone;
   final ThemeData appTheme;
   double _progress = 0;
+  double _targetProgress = 0;
 
   final _rng = math.Random();
 
   double get progress => _progress;
 
-  set progress(double value) {
-    if (value < 0) {
-      _progress = 0;
+  void setProgress(double value, double delta) {
+    var current = value;
+    if (current < 0) {
+      current = 0;
     } else if (value >= 1) {
-      _progress = 1 - _rng.nextDouble() * 0.02;
-    } else {
-      _progress = value;
+      current = 1 - _rng.nextDouble() * 0.02;
     }
+
+    _targetProgress = current;
+    _progress = _progress.expDecay(_targetProgress, 16, delta);
   }
 
   @override

lib/dashboard/game/speedometer.dart

@@ -8,7 +8,7 @@ class Speedometer extends TextComponent with HasGameRef<GaugeGame> {
     super.position,
   }) : super(
           anchor: Anchor.center,
-          text: speed.clamp(0, 160).round().toString(),
+          text: speed.round().toString(),
         );
 
   double speed;
@@ -57,7 +57,6 @@ class Speedometer extends TextComponent with HasGameRef<GaugeGame> {
 
   @override
   void update(double dt) {
-    speed = speed.clamp(0, 160);
     text = speed.round().toString();
     _mph.position = Vector2(size.x / 2, size.y);
     if (speed >= 120) {

lib/dashboard/view/dashboard_page.dart

@@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
 import 'package:vehicle_cockpit/dashboard/dashboard.dart';
 import 'package:vehicle_cockpit/l10n/l10n.dart';
 import 'package:vehicle_cockpit/ui/ui.dart';
+import 'package:vehicle_sim/vehicle_sim.dart';
 
 class Dashboard extends StatefulWidget {
   const Dashboard({
@@ -23,13 +24,17 @@ class DashboardState extends State<Dashboard>
   late final AnimationController _controller;
 
   void onSpeedChanged(double speed) {
+    if (speed <= 0) {
+      _controller.stop();
+      return;
+    }
+
     // Based on the max speed of 160mph, 0.222222 miles would be the distance
     // covered in 5000 milliseconds if going max speed.
+
     const distance = 0.222222;
     final timeInMilliseconds = (distance / speed) * 3600 * 1000;
 
-    if (speed <= 0) _controller.stop();
-
     _controller
       ..duration = Duration(
         milliseconds: timeInMilliseconds.round().abs(),
@@ -59,6 +64,7 @@ class DashboardState extends State<Dashboard>
     final l10n = context.l10n;
     final theme = Theme.of(context);
     final game = GaugeGame(
+      sim: VehicleSim(vehicle: Vehicles.compactCrossoverSUV),
       appTheme: theme,
       l10n: l10n,
       onSpeedChanged: onSpeedChanged,

lib/dashboard/widgets/accelerator_button.dart

@@ -16,12 +16,12 @@ class _AcceleratorButtonState extends State<AcceleratorButton> {
   bool _isPressed = false;
 
   void _accelerate(_) {
-    _game.accelerate();
+    _game.acceleratorPedalPushed();
     setState(() => _isPressed = true);
   }
 
   void _release([_]) {
-    _game.release();
+    _game.acceleratorPedalReleased();
     setState(() => _isPressed = false);
   }
 

lib/dashboard/widgets/lap_section.dart

@@ -77,20 +77,22 @@ class LapSectionState extends State<LapSection> {
   }
 
   void newLap(AnimationStatus status) {
-    if (status == AnimationStatus.completed) {
-      setState(() {
-        if (stopwatch.elapsed < bestTime || bestLap == 0) {
-          bestTime = stopwatch.elapsed;
-          bestLap = currentLap;
-        }
-        currentLap++;
-        stopwatch.reset();
-        setLapTime();
-        widget.controller
-          ..reset()
-          ..forward();
-      });
+    if (status != AnimationStatus.completed) {
+      return;
     }
+
+    setState(() {
+      if (stopwatch.elapsed < bestTime || bestLap == 0) {
+        bestTime = stopwatch.elapsed;
+        bestLap = currentLap;
+      }
+      currentLap++;
+      stopwatch.reset();
+      setLapTime();
+      widget.controller
+        ..reset()
+        ..forward();
+    });
   }
 
   String _lapTime(Duration duration) {

lib/util/math_utils.dart

@@ -0,0 +1,15 @@
+import 'dart:math' as math;
+
+extension DoubleExtensions on double {
+  /// Exponential decay function. Use this instead of linear interpolation since
+  /// it is framerate-independent!
+  ///
+  /// e.g., `myValue.expDecay(toValue, decay, delta);`
+  ///
+  /// Note that useful [decay] values are typically between 1 (slow) to 25
+  /// (fast).
+  ///
+  /// Thanks, Freya! https://youtu.be/LSNQuFEDOyQ?t=2981
+  double expDecay(double b, double decay, double delta) =>
+      b + (this - b) * math.exp(-decay * delta);
+}

lib/util/util.dart

@@ -0,0 +1 @@
+export 'math_utils.dart';

packages/vehicle_sim/.gitignore

@@ -0,0 +1,7 @@
+# See https://www.dartlang.org/guides/libraries/private-files
+
+# Files and directories created by pub
+.dart_tool/
+.packages
+build/
+pubspec.lock

packages/vehicle_sim/README.md

@@ -0,0 +1,8 @@
+# Vehicle Sim
+
+[![style: very good analysis][very_good_analysis_badge]][very_good_analysis_link]
+
+A very simple vehicle simulation model.
+
+[very_good_analysis_badge]: https://img.shields.io/badge/style-very_good_analysis-B22C89.svg
+[very_good_analysis_link]: https://pub.dev/packages/very_good_analysis

packages/vehicle_sim/analysis_options.yaml

@@ -0,0 +1 @@
+include: package:very_good_analysis/analysis_options.6.0.0.yaml