Moved from threads to tasks

Author: SamusAranX

DoomFire/DoomFireSim.cs

@@ -1,14 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics;
-using System.Drawing;
-using System.Drawing.Drawing2D;
-using System.Drawing.Imaging;
 using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-using System.Security.Cryptography;
-using System.Threading.Tasks;
 
 namespace DoomFire {
 	public class DoomFireSim: INotifyPropertyChanged {
@@ -153,8 +146,10 @@ public void DoFire() {
 		}
 
 		private void SpreadFire(int x, int row, int nextRow) {
+			var pixels = this.Pixels;
+
 			var idx = row + x;
-			var pixel = this.Pixels[idx];
+			var pixel = pixels[idx];
 
 			var rnd = this.GetRandomFloat();
 			var randomRemapped = (rnd - 0.5f) * 2; // 0.0 - 1.0 remapped to -1.0 - 1.0
@@ -166,11 +161,13 @@ private void SpreadFire(int x, int row, int nextRow) {
 			var nextIdx = nextRow + newX;
 
 			if (pixel == 0) {
-				this.Pixels[nextIdx] = 0;
+				pixels[nextIdx] = 0;
 				return;
 			}
 
-			this.Pixels[nextIdx] = (byte)Math.Max(0, Math.Round(pixel - rnd * this.FadeSpeedBase));
+			pixels[nextIdx] = (byte)Math.Max(0, Math.Round(pixel - rnd * this.FadeSpeedBase));
+
+			this.Pixels = pixels;
 		}
 	}
 }

DoomFireGUI/MainWindow.xaml

@@ -103,15 +103,22 @@
 			</Grid>
 
 			<Button Content="Initialize" Padding="10,4" Click="InitButton_OnClick" />
-			<Grid>
-				<Grid.ColumnDefinitions>
-					<ColumnDefinition />
-					<ColumnDefinition Width="5" />
-					<ColumnDefinition />
-				</Grid.ColumnDefinitions>
-				<Button Content="Start" Padding="10,4" Click="StartButton_OnClick" />
-				<Button Grid.Column="2" Content="Pause" Padding="10,4" Click="PauseButton_OnClick" />
-			</Grid>
+
+			<Button Padding="10,4" Margin="0,5,0,0"
+				        Click="StartButton_OnClick">
+				<Button.Style>
+					<Style TargetType="Button">
+						<Style.Triggers>
+							<DataTrigger Binding="{Binding DFIsRunning}" Value="True">
+								<Setter Property="Content" Value="Stop"/>
+							</DataTrigger>
+							<DataTrigger Binding="{Binding DFIsRunning}" Value="False">
+								<Setter Property="Content" Value="Start"/>
+							</DataTrigger>
+						</Style.Triggers>
+					</Style>
+				</Button.Style>
+			</Button>
 
 			<CheckBox Content="Use Palette" 
 			          IsChecked="{Binding UsePalette}" />
@@ -172,7 +179,7 @@
 
 			<StackPanel DataContext="{Binding DF}">
 				<TextBlock>
-					<Run>Bits:</Run>
+					<Run>Randomness Bits:</Run>
 					<Run Text="{Binding CutoffBits, FallbackValue=N/A}" />
 				</TextBlock>
 				<Slider Value="{Binding CutoffBits}"

DoomFireGUI/MainWindow.xaml.cs

@@ -4,9 +4,9 @@
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Threading;
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Media;
-using System.Windows.Media.Animation;
 using System.Windows.Media.Imaging;
 using DoomFire;
 using DColor = System.Drawing.Color;
@@ -32,6 +32,8 @@ private void SetField<T>(ref T field, T value, [CallerMemberName] string propert
 
 		#endregion
 
+		#region Properties
+
 		private DoomFireSim _df;
 		public DoomFireSim DF {
 			get => this._df;
@@ -92,9 +94,12 @@ public int ActualFrameRate {
 			set => this.SetField(ref this._actualFrameRate, value);
 		}
 
+		#endregion
+
 		private readonly DColor[] firePalette;
 
-		private Thread simThread;
+		private CancellationTokenSource tokenSource = new CancellationTokenSource();
+		private Task simulationTask;
 
 		public MainWindow() {
 			this.firePalette = DoomFire.Colors.PopulatePalette(256);
@@ -107,7 +112,7 @@ private void MainWindow_OnLoaded(object sender, RoutedEventArgs e) {
 		}
 
 		private void MainWindow_OnClosing(object sender, CancelEventArgs e) {
-			this.DFIsRunning = false;
+			this.tokenSource.Cancel();
 		}
 
 		private void InitButton_OnClick(object sender, RoutedEventArgs e) {
@@ -127,32 +132,42 @@ private void InitButton_OnClick(object sender, RoutedEventArgs e) {
 		}
 
 		private void StartButton_OnClick(object sender, RoutedEventArgs e) {
-			if (this.DFIsRunning)
-				return;
+			if (this.DFIsRunning) {
+				this.ResizeMode = ResizeMode.CanResizeWithGrip;
 
-			this.ResizeMode = ResizeMode.NoResize;
-			this.DFIsRunning = true;
+				this.tokenSource.Cancel();
+				this.DFIsRunning = false;
 
-			this.simThread = new Thread(this.ThreadLoop);
-			this.simThread.Start();
-		}
+			} else {
+				this.ResizeMode = ResizeMode.NoResize;
+
+				this.tokenSource = new CancellationTokenSource();
+				this.simulationTask = Task.Run(() => {
+					this.ThreadLoop(this.tokenSource.Token);
+				});
 
-		private void PauseButton_OnClick(object sender, RoutedEventArgs e) {
-			this.DFIsRunning = false;
-			this.ResizeMode = ResizeMode.CanResizeWithGrip;
+				this.DFIsRunning = true;
+			}
 		}
 
-		private void ThreadLoop() {
+		private void ThreadLoop(CancellationToken token) {
 			var sw = new Stopwatch();
 			sw.Start();
 
-			while (this.DF != null && this.DFIsRunning) {
+			while (true) {
+				if (token.IsCancellationRequested)
+					break;
+
 				var curTime = sw.ElapsedMilliseconds;
+
 				this.SimulationStep();
 				this.UpdateImage();
 
-				var targetSleep = 1000 / this._targetFrameRate;
+				// another check for good measure
+				if (token.IsCancellationRequested)
+					break;
 
+				var targetSleep = 1000 / this._targetFrameRate;
 				var frameElapsed = (int)(sw.ElapsedMilliseconds - curTime);
 				var sleepElapsed = (int)Math.Round(targetSleep - frameElapsed);
 
@@ -168,12 +183,12 @@ private void ThreadLoop() {
 			}
 
 			sw.Stop();
+			Debug.WriteLine("Task completed");
 		}
 
 		private void SimulationStep() {
-			if (this.DFIsProcessing) {
+			if (this.DFIsProcessing)
 				return;
-			}
 
 			this.DFIsProcessing = true;