particle system refactor, allowing particles to spawn more particles

Author: BenMakesGames

BenMakesGames.PlayPlayMini.GraphicsExtensions/BenMakesGames.PlayPlayMini.GraphicsExtensions.csproj

@@ -5,7 +5,7 @@
         <Company>Ben Hendel-Doying</Company>
         <Description>Some GraphicsManager extensions for PlayPlayMini.</Description>
         <Copyright>2023-2025 Ben Hendel-Doying</Copyright>
-        <Version>6.1.0</Version>
+        <Version>6.2.0</Version>
 
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
         <PackageTags>monogame playplaymini graphics extensions animations text</PackageTags>

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/FlashOfInsight.cs

@@ -3,6 +3,10 @@
 
 namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
 
+/// <summary>
+/// The entire screen goes white; the white then parts in half, each half receding to the top and bottom of the screen.
+/// The total effect takes only a tenth of a second.
+/// </summary>
 public sealed class FlashOfInsight: IParticle
 {
     private Color Color { get; }
@@ -17,7 +21,7 @@ public FlashOfInsight(Color color)
     }
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         TTL -= gameTime.ElapsedGameTime.TotalSeconds;
     }

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/FloatAwayPicture.cs

@@ -21,7 +21,7 @@ public sealed class FloatAwayPicture: IParticle
     public int Y => (int)(StartingY - Math.Sin(Angle) * TimeAlive * Speed);
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         TimeAlive += gameTime.ElapsedGameTime.TotalSeconds;
     }

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/FloatAwayText.cs

@@ -4,6 +4,9 @@
 
 namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
 
+/// <summary>
+/// A piece of text that floats away from a starting position at a specified angle and speed.
+/// </summary>
 public sealed class FloatAwayText: IParticle
 {
     public required string Text { get; init; }
@@ -23,7 +26,7 @@ public sealed class FloatAwayText: IParticle
     public int Y => (int)(StartingY - Math.Sin(Angle) * TimeAlive * Speed);
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         TimeAlive += gameTime.ElapsedGameTime.TotalSeconds;
     }

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/GlassShard.cs

@@ -4,6 +4,9 @@
 
 namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
 
+/// <summary>
+/// A tumbling shard of glass that launches away from its starting point, and falls under gravity.
+/// </summary>
 public sealed class GlassShard : IParticle
 {
     /// <inheritdoc />
@@ -74,7 +77,7 @@ public void Draw(GraphicsManager graphics)
     }
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         YSpeed += 0.2 * gameTime.ElapsedGameTime.TotalSeconds * 60;
 

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/IParticle.cs

@@ -1,4 +1,5 @@
-using BenMakesGames.PlayPlayMini.Services;
+using System.Collections.Generic;
+using BenMakesGames.PlayPlayMini.Services;
 using Microsoft.Xna.Framework;
 
 namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
@@ -26,8 +27,9 @@ public interface IParticle
     /// <summary>
     /// Update the particle's state.
     /// </summary>
+    /// <param name="particleSpawner"></param>
     /// <param name="gameTime"></param>
-    void Update(GameTime gameTime);
+    void Update(IParticleSpawner particleSpawner, GameTime gameTime);
 
     /// <summary>
     /// Draw the particle.

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/ParticleCollection.cs

@@ -0,0 +1,73 @@
+using System.Collections.Generic;
+using BenMakesGames.PlayPlayMini.Services;
+using Microsoft.Xna.Framework;
+
+namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
+
+public interface IParticleSpawner
+{
+    /// <summary>
+    /// Queues particles to be added in the next Update cycle.
+    /// </summary>
+    /// <param name="particle"></param>
+    void AddParticles(params IEnumerable<IParticle> particle);
+}
+
+/// <summary>
+/// For updating and drawing a collection of particles.
+/// </summary>
+/// <remarks>
+/// If you want different layers of particles (e.g. background, foreground), create multiple instances of this class,
+/// update them all, and draw them in the desired order.
+/// </remarks>
+public sealed class ParticleCollection: IParticleSpawner
+{
+    private const int InitialParticleCapacity = 256;
+    private const int InitialSpawnQueueCapacity = 128;
+
+    private List<IParticle> Particles { get; } = new(InitialParticleCapacity);
+    private List<IParticle> SpawnQueue { get; } = new(InitialSpawnQueueCapacity);
+
+    /// <inheritdoc />
+    public void AddParticles(params IEnumerable<IParticle> particle)
+    {
+        SpawnQueue.AddRange(particle);
+    }
+
+    /// <summary>
+    /// Updates all particles in the collection.
+    /// </summary>
+    /// <remarks>
+    /// For better performance, call this in your GameState's FixedUpdate method rather than its Update method.
+    /// </remarks>
+    /// <param name="gameTime"></param>
+    public void Update(GameTime gameTime)
+    {
+        Particles.AddRange(SpawnQueue);
+
+        SpawnQueue.Clear();
+
+        for(int i = Particles.Count - 1; i >= 0; i--)
+        {
+            var particle = Particles[i];
+
+            if (particle.IsAlive)
+                particle.Update(this, gameTime);
+            else
+                Particles.RemoveAt(i);
+        }
+    }
+
+    /// <summary>
+    /// Draws all particles in the collection.
+    /// </summary>
+    /// <remarks>
+    /// Call in your GameState's Draw method.
+    /// </remarks>
+    /// <param name="graphics"></param>
+    public void Draw(GraphicsManager graphics)
+    {
+        foreach (var particle in Particles)
+            particle.Draw(graphics);
+    }
+}

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/Particles.cs

@@ -4,6 +4,9 @@
 
 namespace BenMakesGames.PlayPlayMini.GraphicsExtensions.ParticleEffects;
 
+/// <summary>
+/// A particle of snow that falls to the ground, waving slightly as it falls.
+/// </summary>
 public sealed class Snow: IParticle
 {
     private Color Color { get; }
@@ -29,7 +32,7 @@ public Snow(Color color, int maxY, int graphicsWidth)
     }
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         X -= gameTime.ElapsedGameTime.TotalSeconds * 4 * Size * Speed;
         Y += gameTime.ElapsedGameTime.TotalSeconds * 16 * Size * Speed;

BenMakesGames.PlayPlayMini.GraphicsExtensions/ParticleEffects/Snow.cs

@@ -38,7 +38,7 @@ public void Draw(GraphicsManager graphics)
     }
 
     /// <inheritdoc />
-    public void Update(GameTime gameTime)
+    public void Update(IParticleSpawner particleSpawner, GameTime gameTime)
     {
         CenterX += XVelocity * gameTime.ElapsedGameTime.TotalSeconds * 60;
         CenterY += YVelocity * gameTime.ElapsedGameTime.TotalSeconds * 60;