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

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;