Finalize ParticleSystem, add angular velocity, multiple emitters, GetBool for IDataReader, use Lerp in LerpColor.

TestGame/Resources/fire_effect.toml

@@ -0,0 +1,20 @@
+# Fire effect example
+[ParticleEmitterSettings]
+
+Local = true
+MaxParticles = 128
+EmitRadius = 8
+Explosiveness = 0
+LifeTime = 1.0
+Direction = [0.0, -1.0]
+LinearVelocity = 200
+LinearVelocityDamping = 0.0
+AngularVelocity = 230
+AngularVelocityDamping = 0.0
+AngularVelocityRandom = 1.0
+Gravity = [0.0, 0.0]
+LinearVelocityRandom = 0.5
+ScaleBegin = 0.1
+ScaleEnd = 5.0
+ColorBegin = [255, 162, 0]
+ColorEnd = [64, 64, 64, 0]

TestGame/Resources/test_emitter.toml

@@ -1,14 +0,0 @@
-[ParticleEmitterSettings]
-
-MaxParticles = 1024
-EmitRadius = 128
-Explosiveness = 1.0
-LifeTime = 2.0
-Direction = [0.0, -1.0]
-LinearVelocity = 200
-Gravity = [0.0, 0.0]
-LinearVelocityRandom = 0.5
-ScaleBegin = 1.0
-ScaleEnd = 5.0
-ColorBegin = [255, 0, 0, 0]
-ColorEnd = [0, 255, 0, 255]

TestGame/TestGame.cs

@@ -26,11 +26,6 @@ public class TestGame : Game
 
     protected override void LoadResources()
     {
-        // if (!ResourceManager.TryLoad("my_sound", "sounds/test_sound.ogg", out Sound? _testSound))
-        // {
-
-        // }
-
         if (!ResourceManager.TryLoad("fonts/Inter-Regular.ttf", out _font))
         {
 
@@ -38,7 +33,7 @@ public class TestGame : Game
 
         ResourceManager.TryLoad("icon.png", out _icon);
 
-        if (!ResourceManager.TryLoad("test_emitter.toml", out _emitterSettings))
+        if (!ResourceManager.TryLoad("fire_effect.toml", out _fireEffect))
         {
             throw new Exception("Failed to load emitter settings!");
         }
@@ -46,7 +41,7 @@ public class TestGame : Game
 
     protected override void Ready()
     {
-        _emitterId = _particleSystem.CreateEmitter(Renderer.WindowSize / 2, _emitterSettings);
+        _emitterId = _particleSystem.CreateEmitter(Renderer.WindowSize / 2, _fireEffect);
     }
 
     protected override void Run()
@@ -59,6 +54,16 @@ public class TestGame : Game
                 _particleSystem!.RestartEmitter(_emitterId);
             }
 
+            if (Input.KeyboardKeyJustPressed(KeyboardKey.One))
+            {
+                _particleSystem.CreateEmitter(Input.GetMousePosition(), _fireEffect);
+            }
+
+            if (Input.IsMouseButtonDown(MouseButton.Left))
+            {
+                _particleSystem.SetEmitterPosition(_emitterId, Input.GetMousePosition());
+            }
+
             _particleSimStopwatch = Stopwatch.StartNew();
             _particleSystem!.Update(Renderer.FrameTime);
             _particleSimStopwatch.Stop();
@@ -97,15 +102,15 @@ public class TestGame : Game
         Renderer.BeginBlended(Voile.Rendering.BlendMode.BlendAlpha);
 
         var maxParticles = emitter.Settings.MaxParticles;
+        var particleSize = new Vector2(16.0f, 16.0f);
+        var pivot = particleSize / 2;
 
-        for (int i = maxParticles - 1; i > 0; i--)
+        for (int i = maxParticles - 1; i >= 0; i--)
         {
             var particle = emitter.GetParticle(i);
 
-            var color = new Color(particle.ColorArgb);
+            Renderer.SetTransform(particle.Position, pivot, particle.Rotation);
-
+            Renderer.DrawRectangle(particleSize * particle.Scale, particle.Color);
-            Renderer.SetTransform(emitter.OriginPosition + particle.Position, Vector2.Zero);
-            Renderer.DrawRectangle(Vector2.One * 16.0f * particle.Scale, color);
         }
 
         Renderer.EndBlended();
@@ -116,7 +121,7 @@ public class TestGame : Game
     private Stopwatch _particleSimStopwatch, _renderStopwatch;
     private long _lastRenderTime;
     private int _emitterId;
-    private ResourceRef<ParticleEmitterSettingsResource> _emitterSettings;
+    private ResourceRef<ParticleEmitterSettingsResource> _fireEffect;
     private ResourceRef<Font> _font;
     private ResourceRef<Texture2d> _icon;
     private Logger _logger = new(nameof(TestGame));

Voile/Source/Resources/DataReaders/IDataReader.cs

@@ -30,6 +30,13 @@ namespace Voile.Resources.DataReaders
     /// </summary>
     public interface IStreamKeyValueGetter
     {
+        /// <summary>
+        /// Get a boolean from this data getter.
+        /// </summary>
+        /// <param name="key">Key of the value.</param>
+        /// <param name="defaultValue">Default value in case this getter fails to get data.</param>
+        /// <returns></returns>
+        bool GetBool(string key, bool defaultValue = false);
         /// <summary>
         /// Get an int from this data getter.
         /// </summary>

Voile/Source/Resources/DataReaders/TomlDataReader.cs

@@ -31,6 +31,30 @@ public class TomlDataReader : IStreamDataReader, IDataValidator, IStreamKeyValue
         }
     }
 
+    public bool GetBool(string key, bool defaultValue = false)
+    {
+        if (_table is null)
+        {
+            return defaultValue;
+        }
+
+        var dataTable = _table[ExpectedHeader];
+
+        if (!dataTable.HasKey(key))
+        {
+            return defaultValue;
+        }
+
+        var tableValue = dataTable[key];
+
+        if (!tableValue.IsBoolean)
+        {
+            return defaultValue;
+        }
+
+        return tableValue.AsBoolean;
+    }
+
     public int GetInt(string key, int defaultValue = 0)
     {
         if (_table is null)

Voile/Source/Systems/ParticleSystem.cs

@@ -12,7 +12,7 @@ public struct Particle
     }
 
     public int EmitterIndex { get; set; }
-    public int ColorArgb { get; set; }
+    public Color Color { get; set; }
     public Vector2 Position { get; set; }
     public float LifeTime { get; set; } = 1.0f;
     public float Scale { get; set; }
@@ -21,6 +21,7 @@ public struct Particle
 
 public class ParticleEmitterSettings
 {
+    public bool Local { get; set; } = true;
     public int MaxParticles { get; set; } = 16;
     public float EmitRadius { get; set; }
     public float LifeTime { get; set; } = 1.0f;
@@ -28,14 +29,15 @@ public class ParticleEmitterSettings
     public Vector2 Direction { get; set; } = -Vector2.UnitY;
     public float LinearVelocity { get; set; } = 980.0f;
     public float AngularVelocity { get; set; }
-    public float AngularVelocityRandom { get; set; }
+    public float AngularVelocityRandom { get; set; } = 0.5f;
     public float LinearVelocityRandom { get; set; } = 0.5f;
     public Vector2 Gravity { get; set; } = Vector2.UnitY * 980f;
     public float ScaleBegin { get; set; } = 1.0f;
     public float ScaleEnd { get; set; } = 0.0f;
     public Color ColorBegin { get; set; } = Color.White;
     public Color ColorEnd { get; set; } = Color.Black;
-    public float Damping { get; set; } = 1.0f;
+    public float LinearVelocityDamping { get; set; } = 1.0f;
+    public float AngularVelocityDamping { get; set; } = 0.1f;
 }
 
 public class ParticleEmitterSettingsResource : Resource
@@ -45,7 +47,6 @@ public class ParticleEmitterSettingsResource : Resource
     {
         Settings = settings;
     }
-
 }
 
 /// <summary>
@@ -65,6 +66,7 @@ public class ParticleEmitterSettingsResourceLoader : ResourceLoader<ParticleEmit
         {
             reader.Read(File.Open(path, FileMode.Open));
 
+            settings.Local = reader.GetBool("Local", true);
             settings.MaxParticles = reader.GetInt("MaxParticles");
             settings.EmitRadius = reader.GetInt("EmitRadius");
             settings.LifeTime = reader.GetFloat("LifeTime", 1.0f);
@@ -79,7 +81,8 @@ public class ParticleEmitterSettingsResourceLoader : ResourceLoader<ParticleEmit
             settings.ScaleEnd = reader.GetFloat("ScaleEnd");
             settings.ColorBegin = reader.GetColor("ColorBegin", Color.White);
             settings.ColorEnd = reader.GetColor("ColorEnd", Color.Black);
-            settings.Damping = reader.GetFloat("Damping", 1.0f);
+            settings.LinearVelocityDamping = reader.GetFloat("LinearVelocityDamping", 1.0f);
+            settings.AngularVelocityDamping = reader.GetFloat("AngularVelocityDamping", 1.0f);
         }
 
         return new ParticleEmitterSettingsResource(path, settings);
@@ -94,12 +97,11 @@ public class ParticleEmitter : IUpdatableSystem
     /// <summary>
     /// Origin position in the world of this emitter.
     /// </summary>
-    public Vector2 OriginPosition => _originPosition;
+    public Vector2 OriginPosition { get; set; }
     /// <summary>
     /// <see cref="ParticleEmitterSettings"/> for this emitter.
     /// </summary>
     public ParticleEmitterSettings Settings => _settingsResource.Value.Settings;
-    public int ArrayOffset => _lifetimes.Offset;
 
     /// <summary>
     /// Constructs a new <see cref="ParticleEmitter"/>.
@@ -107,29 +109,39 @@ public class ParticleEmitter : IUpdatableSystem
     /// <param name="originPosition">World origin position.</param>
     /// <param name="settingsResource">Emitter settings resource.</param>
     /// <param name="particles">Particle segment that this emitter will simulate.</param>
-    public ParticleEmitter(Vector2 originPosition, ResourceRef<ParticleEmitterSettingsResource> settingsResource, ArraySegment<Vector2> positionsSlice, ArraySegment<Vector2> velocitiesSlice, ArraySegment<float> lifetimesSlice)
+    public ParticleEmitter(Vector2 originPosition, ResourceRef<ParticleEmitterSettingsResource> settingsResource)
     {
-        _originPosition = originPosition;
+        OriginPosition = originPosition;
 
         _settingsResource = settingsResource;
         _maxParticles = _settingsResource.Value.Settings.MaxParticles;
-        // _particleIndex = _maxParticles - 1;
 
-        _positions = positionsSlice;
+        _positions = new Vector2[_maxParticles];
-        _velocities = velocitiesSlice;
+        _velocities = new Vector2[_maxParticles];
-        _lifetimes = lifetimesSlice;
+        _angularVelocities = new float[_maxParticles];
+        _lifetimes = new float[_maxParticles];
+        _rotations = new float[_maxParticles];
 
         _random = new LehmerRandom();
     }
 
     public Particle GetParticle(int idx)
     {
+        if (idx > _lifetimes.Length)
+        {
+            return new Particle();
+        }
+
         var t = _lifetimes[idx] / Settings.LifeTime;
+        var scale = MathUtils.Lerp(Settings.ScaleEnd, Settings.ScaleBegin, t);
+        var color = MathUtils.LerpColor(Settings.ColorEnd, Settings.ColorBegin, t);
+
         return new Particle()
         {
             Position = _positions[idx],
-            Scale = MathUtils.Lerp(Settings.ScaleEnd, Settings.ScaleBegin, t),
+            Scale = scale,
-            ColorArgb = MathUtils.LerpColor(Settings.ColorEnd, Settings.ColorBegin, t).Argb
+            Color = color,
+            Rotation = _rotations[idx]
         };
     }
 
@@ -139,12 +151,14 @@ public class ParticleEmitter : IUpdatableSystem
     /// <param name="particles">New particle segment.</param>
     public void Restart()
     {
-        for (int i = 0; i < _lifetimes.Count; i++)
-        {
-            _lifetimes[i] = 0.0f;
-        }
-
         _maxParticles = Settings.MaxParticles;
+
+        _positions = new Vector2[_maxParticles];
+        _velocities = new Vector2[_maxParticles];
+        _angularVelocities = new float[_maxParticles];
+        _lifetimes = new float[_maxParticles];
+        _rotations = new float[_maxParticles];
+
         _particleIndex = 0;
     }
 
@@ -156,23 +170,28 @@ public class ParticleEmitter : IUpdatableSystem
     {
         var rate = (int)MathUtils.Lerp(1, _maxParticles, Settings.Explosiveness);
 
-        for (int i = 0; i < rate; i++)
-        {
-            Emit();
-        }
-
         var deltaTimeVector = new Vector2((float)deltaTime);
         var gravityVector = Settings.Gravity * (float)deltaTime;
-        var dampingFactor = Settings.Damping * (float)deltaTime;
+
+        var linearVelocityDampingFactor = Settings.LinearVelocityDamping * (float)deltaTime;
+        var angularVelocityDampingFactor = Settings.AngularVelocityDamping * (float)deltaTime;
 
         for (int i = 0; i < _maxParticles; i++)
         {
             _lifetimes[i] = Math.Max(0.0f, _lifetimes[i] - (float)deltaTime);
 
             _velocities[i] += gravityVector;
-            _positions[i] += _velocities[i] * deltaTimeVector;
 
-            _velocities[i] -= _velocities[i] * dampingFactor;
+            _positions[i] += _velocities[i] * deltaTimeVector;
+            _rotations[i] += _angularVelocities[i] * (float)deltaTime;
+
+            _velocities[i] -= _velocities[i] * linearVelocityDampingFactor;
+            _angularVelocities[i] -= _angularVelocities[i] * angularVelocityDampingFactor;
+        }
+
+        for (int i = 0; i < rate; i++)
+        {
+            Emit();
         }
     }
 
@@ -184,6 +203,7 @@ public class ParticleEmitter : IUpdatableSystem
         _velocities[_particleIndex] = Settings.Direction * Settings.LinearVelocity;
 
         _velocities[_particleIndex] += Vector2.One * Settings.LinearVelocityRandom * ((float)_random.NextDouble() - 0.5f);
+        _angularVelocities[_particleIndex] = Settings.AngularVelocity * Settings.AngularVelocityRandom * ((float)_random.NextDouble() - 0.5f);
 
         _lifetimes[_particleIndex] = Settings.LifeTime;
 
@@ -193,6 +213,7 @@ public class ParticleEmitter : IUpdatableSystem
     private Vector2 GetEmitPosition()
     {
         var settings = _settingsResource.Value.Settings;
+        Vector2 originOffset = Settings.Local ? OriginPosition : Vector2.Zero;
 
         // https://gamedev.stackexchange.com/questions/26713/calculate-random-points-pixel-within-a-circle-image
         var angle = _random.NextDouble() * Math.PI * 2;
@@ -201,15 +222,16 @@ public class ParticleEmitter : IUpdatableSystem
         float x = radius * (float)Math.Cos(angle);
         float y = radius * (float)Math.Sin(angle);
 
-        return new Vector2(x, y);
+        var point = new Vector2(x, y);
+
+        return point + originOffset;
     }
 
     private LehmerRandom _random;
     private int _maxParticles;
     private int _particleIndex;
-    private Vector2 _originPosition = Vector2.Zero;
+    private Vector2[] _positions, _velocities;
-    private ArraySegment<Vector2> _positions, _velocities;
+    private float[] _lifetimes, _rotations, _angularVelocities;
-    private ArraySegment<float> _lifetimes;
     private ResourceRef<ParticleEmitterSettingsResource> _settingsResource;
 }
 
@@ -218,26 +240,11 @@ public class ParticleEmitter : IUpdatableSystem
 /// </summary>
 public class ParticleSystem : IUpdatableSystem, IDisposable
 {
-    /// <summary>
-    /// Maximum amount of particles emittable by the system.
-    /// </summary>
-    public int ParticleLimit { get; set; } = short.MaxValue;
-
     /// <summary>
     /// List of particle emitters created for this ParticleSystem.
     /// </summary>
     public IReadOnlyList<ParticleEmitter> Emitters => _emitters;
 
-    /// <summary>
-    /// Constructs a new <see cref="ParticleSystem"/>.
-    /// </summary>
-    public ParticleSystem()
-    {
-        _particlePositions = new Vector2[ParticleLimit];
-        _particleVelocities = new Vector2[ParticleLimit];
-        _particleLifetimes = new float[ParticleLimit];
-    }
-
     /// <summary>
     /// Creates an emitter from a <see cref="ParticleEmitterSettingsResource"/>.
     /// </summary>
@@ -246,31 +253,22 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
     /// <returns></returns>
     public int CreateEmitter(Vector2 originPosition, ResourceRef<ParticleEmitterSettingsResource> settingsResource)
     {
-        var settings = settingsResource.Value.Settings;
+        var emitter = new ParticleEmitter(originPosition, settingsResource);
-
-        if (_emitterSliceOffset + settings.MaxParticles >= ParticleLimit - 1)
-        {
-            _logger.Error("Cannot create an emitter! Reached particle limit.");
-            return -1;
-        }
-
-        var positionsSlice = new ArraySegment<Vector2>(_particlePositions, _emitterSliceOffset, settings.MaxParticles);
-        var velocitiesSlice = new ArraySegment<Vector2>(_particleVelocities, _emitterSliceOffset, settings.MaxParticles);
-        var lifetimesSlice = new ArraySegment<float>(_particleLifetimes, _emitterSliceOffset, settings.MaxParticles);
-
-        for (int i = 0; i < lifetimesSlice.Count; i++)
-        {
-            lifetimesSlice[i] = settings.LifeTime;
-        }
-
-        var emitter = new ParticleEmitter(originPosition, settingsResource, positionsSlice, velocitiesSlice, lifetimesSlice);
-
         _emitters.Add(emitter);
-        _emitterSliceOffset += settings.MaxParticles;
-
         return _emitters.Count - 1;
     }
 
+    public void SetEmitterPosition(int emitterIdx, Vector2 position)
+    {
+        if (emitterIdx >= _emitters.Count)
+        {
+            throw new ArgumentException($"Emitter with idx {emitterIdx} is not present!");
+        }
+
+        var emitter = _emitters[emitterIdx];
+        emitter.OriginPosition = position;
+    }
+
     /// <summary>
     /// Restarts an emitter. 
     /// </summary>
@@ -284,7 +282,6 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
         }
 
         var emitter = _emitters[id];
-
         emitter.Restart();
     }
 
@@ -302,16 +299,7 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
 
     public void Dispose()
     {
-        Array.Clear(_particlePositions);
-        Array.Clear(_particleVelocities);
-        Array.Clear(_particleLifetimes);
     }
 
-    private Vector2[] _particlePositions, _particleVelocities;
-    private float[] _particleLifetimes;
-    private int _emitterSliceOffset;
-
     private List<ParticleEmitter> _emitters = new();
-
-    private Logger _logger = new(nameof(ParticleSystem));
 }

Voile/Source/Utils/MathUtils.cs

@@ -19,10 +19,10 @@ namespace Voile
         {
             t = Math.Clamp(t, 0f, 1f);
 
-            byte r = (byte)(colorA.R + (colorB.R - colorA.R) * t);
+            byte r = (byte)Lerp(colorA.R, colorB.R, t);
-            byte g = (byte)(colorA.G + (colorB.G - colorA.G) * t);
+            byte g = (byte)Lerp(colorA.G, colorB.G, t);
-            byte b = (byte)(colorA.B + (colorB.B - colorA.B) * t);
+            byte b = (byte)Lerp(colorA.B, colorB.B, t);
-            byte a = (byte)(colorA.A + (colorB.A - colorA.A) * t);
+            byte a = (byte)Lerp(colorA.A, colorB.A, t);
 
             return new Color(r, g, b, a);
         }