Use bytes for internal RGBA components of Color, iterate particles sequentially in ParticleEmitters, increase limit for CPU particles, reduce size of Particle struct.

TODO.md

@@ -13,9 +13,9 @@
 - ~~Use GUIDs and string ID maps for fetching resources instead of string IDs alone.~~
 - Reimplement unloading.
 - Finalize ResourceManager and ResourceLoader APIs for 1.0.
+- Virtual file system.
 - (stretch goal) Streamed resource loading.
 - (stretch goal) Add async API for ResourceManager.
-- (stretch goal) Virtual file system.
 
 ## Serialization
 
@@ -41,14 +41,15 @@
 - ~~Asset manager~~
 - ~~Separate engine and game into separate projects~~
 - Particle system 2.0
-  - Reduce the size of Particle struct by infering most parameters through lifetime.
+  - ~~Reduce the size of Particle struct by infering most parameters through lifetime.~~
-  - Reduce cache misses by utilizing SoA.
+  - ~~Reduce cache misses by utilizing SoA.~~
-  - SIMD acceleration.
+  - ~~SIMD acceleration.~~
+  - Dynamically resize particle arrays as emitters get added or removed.
 
 ## SceneGraph module
 
-- Layers (sorting mechanism)
 - Full overhaul using Entity Component architecture (not to be mistaken with ECS).
+- Layers (sorting mechanism)
 - Save/load scenes from file
 
 ## Input

TestGame/Resources/test_emitter.toml

@@ -1,14 +1,14 @@
 [ParticleEmitterSettings]
 
-MaxParticles = 8096
+MaxParticles = 1024
 EmitRadius = 128
 Explosiveness = 1.0
-LifeTime = 1.0
+LifeTime = 2.0
-Direction = [0.0, 1.0]
+Direction = [0.0, -1.0]
 LinearVelocity = 200
 Gravity = [0.0, 0.0]
 LinearVelocityRandom = 0.5
 ScaleBegin = 1.0
-ScaleEnd = 0.0
+ScaleEnd = 5.0
-ColorBegin = [255, 0, 255, 255]
+ColorBegin = [255, 0, 0, 0]
-ColorEnd = [0, 0, 0, 0]
+ColorEnd = [0, 255, 0, 255]

TestGame/TestGame.cs

@@ -63,6 +63,8 @@ public class TestGame : Game
             _particleSystem!.Update(Renderer.FrameTime);
             _particleSimStopwatch.Stop();
 
+            _renderStopwatch = Stopwatch.StartNew();
+
             Renderer.BeginFrame();
             Renderer.ClearBackground(Color.Black);
             foreach (var emitter in _particleSystem!.Emitters)
@@ -70,13 +72,17 @@ public class TestGame : Game
                 DrawEmitter(emitter);
             }
 
-            Renderer.SetTransform(Renderer.WindowSize / 2, Vector2.Zero);
-            Renderer.DrawTexture(_icon, Color.White);
-
             Renderer.ResetTransform();
             Renderer.DrawText(_font, $"Particle Sim: {TimeSpan.FromTicks(_particleSimStopwatch.ElapsedTicks).TotalMilliseconds} ms", Color.White);
 
+            Renderer.SetTransform(new Vector2(0.0f, 16.0f), Vector2.Zero);
+            Renderer.DrawText(_font, $"Render: {TimeSpan.FromTicks(_lastRenderTime).TotalMilliseconds} ms", Color.White);
+
             Renderer.EndFrame();
+
+            _lastRenderTime = _renderStopwatch.ElapsedTicks;
+
+            _renderStopwatch.Restart();
             _particleSimStopwatch.Restart();
         }
     }
@@ -90,14 +96,16 @@ public class TestGame : Game
     {
         Renderer.BeginBlended(Voile.Rendering.BlendMode.BlendAlpha);
 
-        for (int i = 0; i < emitter.Settings.MaxParticles; i++)
+        var maxParticles = emitter.Settings.MaxParticles;
+
+        for (int i = maxParticles - 1; i > 0; i--)
         {
             var particle = emitter.GetParticle(i);
 
             var color = new Color(particle.ColorArgb);
 
             Renderer.SetTransform(emitter.OriginPosition + particle.Position, Vector2.Zero);
-            Renderer.DrawCircle(16f * particle.Scale, color);
+            Renderer.DrawRectangle(Vector2.One * 16.0f * particle.Scale, color);
         }
 
         Renderer.EndBlended();
@@ -105,7 +113,8 @@ public class TestGame : Game
 
     [NotNull] private ParticleSystem _particleSystem;
 
-    private Stopwatch _particleSimStopwatch;
+    private Stopwatch _particleSimStopwatch, _renderStopwatch;
+    private long _lastRenderTime;
     private int _emitterId;
     private ResourceRef<ParticleEmitterSettingsResource> _emitterSettings;
     private ResourceRef<Font> _font;

Voile/Source/Rendering/RaylibRenderSystem.cs

@@ -219,7 +219,8 @@ namespace Voile.Rendering
 
         private Raylib_cs.Color VoileColorToRaylibColor(Color color)
         {
-            return new Raylib_cs.Color { r = (byte)Math.Round(color.R * 255f), g = (byte)Math.Round(color.G * 255f), b = (byte)Math.Round(color.B * 255f), a = (byte)Math.Round(color.A * 255f) };
+            var rayColor = new Raylib_cs.Color(color.R, color.G, color.B, color.A);
+            return rayColor;
         }
 
         public override void DrawText(ResourceRef<Font> fontResource, string text, Color color)

Voile/Source/Systems/ParticleSystem.cs

@@ -14,8 +14,6 @@ public struct Particle
     public int EmitterIndex { get; set; }
     public int ColorArgb { get; set; }
     public Vector2 Position { get; set; }
-    public Vector2 Velocity { get; set; }
-    public float AngularVelocity { get; set; }
     public float LifeTime { get; set; } = 1.0f;
     public float Scale { get; set; }
     public float Rotation { get; set; }
@@ -61,7 +59,6 @@ public class ParticleEmitterSettingsResourceLoader : ResourceLoader<ParticleEmit
 
     protected override ParticleEmitterSettingsResource LoadResource(string path)
     {
-        // TODO: this is ugly, better to make some sort of wrapper API for TOML files.
         var settings = new ParticleEmitterSettings();
 
         using (var reader = new TomlDataReader("ParticleEmitterSettings"))
@@ -116,7 +113,7 @@ public class ParticleEmitter : IUpdatableSystem
 
         _settingsResource = settingsResource;
         _maxParticles = _settingsResource.Value.Settings.MaxParticles;
-        _particleIndex = _maxParticles - 1;
+        // _particleIndex = _maxParticles - 1;
 
         _positions = positionsSlice;
         _velocities = velocitiesSlice;
@@ -131,7 +128,6 @@ public class ParticleEmitter : IUpdatableSystem
         return new Particle()
         {
             Position = _positions[idx],
-            Velocity = _velocities[idx],
             Scale = MathUtils.Lerp(Settings.ScaleEnd, Settings.ScaleBegin, t),
             ColorArgb = MathUtils.LerpColor(Settings.ColorEnd, Settings.ColorBegin, t).Argb
         };
@@ -149,7 +145,7 @@ public class ParticleEmitter : IUpdatableSystem
         }
 
         _maxParticles = Settings.MaxParticles;
-        _particleIndex = _maxParticles - 1;
+        _particleIndex = 0;
     }
 
     /// <summary>
@@ -166,7 +162,6 @@ public class ParticleEmitter : IUpdatableSystem
         }
 
         var deltaTimeVector = new Vector2((float)deltaTime);
-        var lifeTimeInv = 1.0f / Settings.LifeTime;
         var gravityVector = Settings.Gravity * (float)deltaTime;
         var dampingFactor = Settings.Damping * (float)deltaTime;
 
@@ -174,8 +169,6 @@ public class ParticleEmitter : IUpdatableSystem
         {
             _lifetimes[i] = Math.Max(0.0f, _lifetimes[i] - (float)deltaTime);
 
-            var t = _lifetimes[i] * lifeTimeInv;
-
             _velocities[i] += gravityVector;
             _positions[i] += _velocities[i] * deltaTimeVector;
 
@@ -185,8 +178,6 @@ public class ParticleEmitter : IUpdatableSystem
 
     private void Emit()
     {
-        // Particle particle = _particles[_particleIndex];
-
         if (_lifetimes[_particleIndex] > 0) return;
 
         _positions[_particleIndex] = GetEmitPosition();
@@ -194,12 +185,9 @@ public class ParticleEmitter : IUpdatableSystem
 
         _velocities[_particleIndex] += Vector2.One * Settings.LinearVelocityRandom * ((float)_random.NextDouble() - 0.5f);
 
-        // particle.AngularVelocity = Settings.AngularVelocity;
-        // particle.AngularVelocity += 1f * Settings.AngularVelocityRandom * ((float)_random.NextDouble() - 0.5f);
-
         _lifetimes[_particleIndex] = Settings.LifeTime;
 
-        _particleIndex = --_particleIndex <= 0 ? _maxParticles - 1 : --_particleIndex;
+        _particleIndex = (_particleIndex + 1) % _maxParticles;
     }
 
     private Vector2 GetEmitPosition()
@@ -233,7 +221,7 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
     /// <summary>
     /// Maximum amount of particles emittable by the system.
     /// </summary>
-    public int ParticleLimit { get; set; } = 8192;
+    public int ParticleLimit { get; set; } = short.MaxValue;
 
     /// <summary>
     /// List of particle emitters created for this ParticleSystem.
@@ -245,8 +233,6 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
     /// </summary>
     public ParticleSystem()
     {
-        _particleIndex = ParticleLimit - 1;
-
         _particlePositions = new Vector2[ParticleLimit];
         _particleVelocities = new Vector2[ParticleLimit];
         _particleLifetimes = new float[ParticleLimit];
@@ -315,20 +301,14 @@ public class ParticleSystem : IUpdatableSystem, IDisposable
     }
 
     public void Dispose()
-    {
-        CleanupParticles();
-    }
-
-    private void CleanupParticles()
     {
         Array.Clear(_particlePositions);
         Array.Clear(_particleVelocities);
         Array.Clear(_particleLifetimes);
     }
-    // private Particle[] _particles;
+
     private Vector2[] _particlePositions, _particleVelocities;
     private float[] _particleLifetimes;
-    private int _particleIndex;
     private int _emitterSliceOffset;
 
     private List<ParticleEmitter> _emitters = new();

Voile/Source/Utils/Color.cs

@@ -34,25 +34,33 @@ namespace Voile
         public static Color Green = new(0x00FF00);
         public static Color Red = new(0xFF0000);
 
-        public float R { get; set; }
+        public byte R { get; set; }
-        public float G { get; set; }
+        public byte G { get; set; }
-        public float B { get; set; }
+        public byte B { get; set; }
-        public float A { get; set; } = 1.0f;
+        public byte A { get; set; } = 255;
 
         public int Argb
         {
             get
             {
-                int a = (int)Math.Round(A * 255f) << 24;
+                int a = A << 24;
-                int r = (int)Math.Round(R * 255f) << 16;
+                int r = R << 16;
-                int g = (int)Math.Round(G * 255f) << 8;
+                int g = G << 8;
-                int b = (int)Math.Round(B * 255f);
+                int b = B;
 
                 return a | r | g | b;
             }
         }
 
-        public Color(float r, float g, float b, float a)
+        public Color(float r, float g, float b, float a = 1.0f)
+        {
+            R = (byte)Math.Clamp(r * 255, 0, 255);
+            G = (byte)Math.Clamp(g * 255, 0, 255);
+            B = (byte)Math.Clamp(b * 255, 0, 255);
+            A = (byte)Math.Clamp(a * 255, 0, 255);
+        }
+
+        public Color(byte r, byte g, byte b, byte a = 255)
         {
             R = r;
             G = g;
@@ -60,22 +68,16 @@ namespace Voile
             A = a;
         }
 
-        public Color(byte r, byte g, byte b, byte a)
-        {
-            R = r / 255f;
-            G = g / 255f;
-            B = b / 255f;
-            A = a / 255f;
-        }
-
         public Color(int hex)
         {
-            A = 1.0f;
+            A = 255;  // Default alpha to 255 if not provided
-            B = (hex & 0xFF) / 255.0f;
+            B = (byte)(hex & 0xFF);
-            hex >>= 8;
+            G = (byte)((hex >> 8) & 0xFF);
-            G = (hex & 0xFF) / 255.0f;
+            R = (byte)((hex >> 16) & 0xFF);
-            hex >>= 8;
+            if (hex > 0xFFFFFF)  // If the hex value includes alpha
-            R = (hex & 0xFF) / 255.0f;
+            {
+                A = (byte)((hex >> 24) & 0xFF);
+            }
         }
 
         public static Color FromHexString(string hex)
@@ -104,20 +106,18 @@ namespace Voile
         public Color Lightened(float amount)
         {
             var result = this;
-            result.R = result.R + (1.0f - result.R) * amount;
+            result.R = (byte)Math.Min(255, R + (255 - R) * amount);
-            result.G = result.G + (1.0f - result.G) * amount;
+            result.G = (byte)Math.Min(255, G + (255 - G) * amount);
-            result.B = result.B + (1.0f - result.B) * amount;
+            result.B = (byte)Math.Min(255, B + (255 - B) * amount);
-
             return result;
         }
 
         public Color Darkened(float amount)
         {
             var result = this;
-            result.R = result.R * (1.0f - amount);
+            result.R = (byte)(R * (1.0f - amount));
-            result.G = result.G * (1.0f - amount);
+            result.G = (byte)(G * (1.0f - amount));
-            result.B = result.B * (1.0f - amount);
+            result.B = (byte)(B * (1.0f - amount));
-
             return result;
         }
 

Voile/Source/Utils/MathUtils.cs

@@ -17,10 +17,12 @@ namespace Voile
 
         public static Color LerpColor(Color colorA, Color colorB, float t)
         {
-            var r = Lerp(colorA.R, colorB.R, t);
+            t = Math.Clamp(t, 0f, 1f);
-            var g = Lerp(colorA.G, colorB.G, t);
+
-            var b = Lerp(colorA.B, colorB.B, t);
+            byte r = (byte)(colorA.R + (colorB.R - colorA.R) * t);
-            var a = Lerp(colorA.A, colorB.A, t);
+            byte g = (byte)(colorA.G + (colorB.G - colorA.G) * t);
+            byte b = (byte)(colorA.B + (colorB.B - colorA.B) * t);
+            byte a = (byte)(colorA.A + (colorB.A - colorA.A) * t);
 
             return new Color(r, g, b, a);
         }