Added particle system

Sandbox/src/GameLayer.bf

@@ -172,7 +172,7 @@ namespace Sandbox
 			{
 				float f = (float)Math.Cos(gameTime.TotalTime.TotalSeconds) * 0.5f + 0.55f;
 
-				FontRenderer.DrawText(pressSpaceToRestart, -pressSpaceToStart.AdvanceX / 2f, 0, .(1, 0, 0, f));
+				FontRenderer.DrawText(pressSpaceToRestart, -pressSpaceToRestart.AdvanceX / 2f, 0, .(1, 0, 0, f));
 			}
 
 			Renderer2D.EndScene();

Sandbox/src/ParticleSystem.bf

@@ -0,0 +1,133 @@
+using GlitchyEngine.Math;
+using GlitchyEngine;
+using System;
+using GlitchyEngine.Renderer;
+namespace Sandbox
+{
+	class ParticleSystem
+	{
+		struct Particle
+		{
+			public bool IsAlive;
+			public Vector2 Position;
+			public float Rotation;
+			public float Scale;
+			public Vector2 Velocity;
+			public float AngularVelocity;
+			public float LiveTime;
+			public Color Color;
+		}
+
+		private Random _random = new .() ~ delete _;
+
+		private Particle[] _particles ~ delete _;
+		private int _freeParticles;
+
+		public float EmissionRate;
+		public float EmissionAngle;
+		public Vector2 EmissionDirection;
+		public float EmissionVelocity;
+
+		public float EmissionSize;
+		public float EmissionSizeVariance;
+
+		public float LiveTime;
+		public float LiveTimeVariance;
+
+		public Vector2 Position;
+
+		public bool Emit;
+
+		public Color EmmisionColor = .White;
+
+		public this(int maxParticles)
+		{
+			_particles = new Particle[maxParticles];
+			_freeParticles = maxParticles;
+		}
+
+		private float _emission = 0.0f;
+
+		public void Update(GameTime gameTime)
+		{
+			for (var particle in ref _particles)
+			{
+				if (!particle.IsAlive)
+					continue;
+
+				particle.LiveTime -= gameTime.DeltaTime;
+
+				if (particle.LiveTime < 0.0f)
+				{
+					particle.IsAlive = false;
+					_freeParticles++;
+				}
+
+				particle.Position += particle.Velocity * gameTime.DeltaTime;
+				particle.Rotation += particle.AngularVelocity * gameTime.DeltaTime;
+			}
+
+			if (Emit)
+			{
+				_emission += gameTime.DeltaTime * EmissionRate;
+	
+				while (_emission >= 1.0f)
+				{
+					Emit();
+	
+					_emission--;
+				}
+			}
+		}
+
+		public void Draw()
+		{
+			for (let particle in _particles)
+			{
+				if(particle.IsAlive)
+					Renderer2D.DrawQuad(particle.Position, .(particle.Scale), particle.Rotation, particle.Color);
+			}
+		}
+
+		private Particle* GetFreeParticle()
+		{
+			for (ref Particle particle in ref _particles)
+			{
+				if (!particle.IsAlive)
+					return &particle;
+			}
+
+			return null;
+		}
+
+		private void Emit()
+		{
+			if (_freeParticles == 0)
+				return;
+
+			Particle* particle = GetFreeParticle();
+
+			if (particle == null)
+				return;
+
+			particle.IsAlive = true;
+			particle.Position = Position;
+			particle.Rotation = 0;
+			particle.Scale = EmissionSize + (float)_random.NextDoubleSigned() * EmissionSizeVariance;
+
+			float angle = Math.Atan2(EmissionDirection.Y, EmissionDirection.X);
+
+			angle += (float)_random.NextDoubleSigned() * EmissionAngle;
+
+			Vector2 direction = .(Math.Cos(angle), Math.Sin(angle));
+
+			particle.Velocity = direction * EmissionVelocity;
+			particle.AngularVelocity = 0;//EmissionVelocity;
+			particle.LiveTime = LiveTime + (float)_random.NextDoubleSigned() * LiveTimeVariance;
+
+			particle.Color = EmmisionColor;
+
+			_freeParticles--;
+		}
+	}
+}

Sandbox/src/Rocket.bf

@@ -20,6 +20,9 @@ namespace Sandbox
 		private Vector2 _speed;
 
 		private Vector2 _position;
+		private Vector2 _direction;
+
+		private Line2D _rocketLine;
 
 		private float _rotation = -MathHelper.PiOverTwo;
 
@@ -31,45 +34,93 @@ namespace Sandbox
 
 		public int Score = 0;
 
+		public Vector2 Position => _position;
+		public Vector2 Direction => _direction;
+
+		ParticleSystem _particleSystem ~ delete _;
+
 		public this()
 		{
 			_rocketTexture = new Texture2D("content/RocketGame/Rocket.dds");
 			_rocketTexture.SamplerState = SamplerStateManager.PointClamp;
+
+			_particleSystem = new ParticleSystem(1024)
+			{
+				LiveTime = 1.0f,
+				LiveTimeVariance = 0.5f,
+				Emit = true,
+			};
 		}
 
 		public void Update(GameTime gameTime)
 		{
-			FlightSpeed = Dead ? 0.0f : 2.0f;
-			
-			if (Dead && Input.IsKeyPressing(Key.Space))
+			do
 			{
-				Dead = false;
-				Started = false;
-				_speed = .Zero;
-				Score = 0;
-			}
-			else if (!Started)
-			{
-				_position = .Zero;
+				FlightSpeed = Dead ? 0.0f : 2.0f;
 				
-				if (Input.IsKeyPressing(Key.Space))
-					Started = true;
-				else
-					return;
+				if (Dead && Input.IsKeyPressing(Key.Space))
+				{
+					Dead = false;
+					Started = false;
+					_speed = .Zero;
+					Score = 0;
+				}
+				else if (!Started)
+				{
+					_position = .Zero;
+					
+					if (Input.IsKeyPressing(Key.Space))
+						Started = true;
+					else
+						break;
+				}
+	
+				UpdatePosition(gameTime);
+	
+				if (Started)
+					CheckDead();
+			}
+			
+			UpdateParticles(gameTime);
+		}
+
+		private void UpdateParticles(GameTime gameTime)
+		{
+			
+			_particleSystem.Position = Position - Direction * 0.4f;
+			_particleSystem.EmissionDirection = -Direction;
+			_particleSystem.EmissionVelocity = FlightSpeed * 2;
+			_particleSystem.EmissionAngle = MathHelper.PiOverFour / 2;
+
+			_particleSystem.Emit = !Dead;
+
+			if (Input.IsKeyPressing(Key.Space))
+			{
+				_particleSystem.EmissionRate = 100;
+				_particleSystem.EmissionSize = 0.125f;
+				_particleSystem.EmissionSizeVariance = 0.025f;
+
+				_particleSystem.EmmisionColor = .(255, 106, 0);
+			}
+			else if (Input.IsKeyReleasing(Key.Space))
+			{
+				_particleSystem.EmissionRate = 10;
+				_particleSystem.EmissionSize = 0.075f;
+				_particleSystem.EmissionSizeVariance = 0.025f;
+
+				_particleSystem.EmmisionColor = .(140, 126, 93);
 			}
 
-			UpdatePosition(gameTime);
+			_particleSystem.Update(gameTime);
 
-			if (Started)
-				CheckDead();
 		}
 
 		public void Draw()
 		{
-			Renderer2D.DrawQuad(_position, .One, _rotation, _rocketTexture, .White);
-		}
+			_particleSystem.Draw();
 
-		Line2D rocketLine;
+			Renderer2D.DrawQuad(Vector3(_position, 5), .One, _rotation, _rocketTexture, .White);
+		}
 
 		private void UpdatePosition(GameTime gameTime)
 		{
@@ -91,8 +142,8 @@ namespace Sandbox
 
 			_rotation = ang;
 
-			Vector2 dir = Vector2.Normalize(_speed + .(10, 0));
-			rocketLine = .(_position - dir / 2.8f, _position + dir / 2.4f);
+			_direction = Vector2.Normalize(_speed + .(10, 0));
+			_rocketLine = .(_position - _direction / 2.8f, _position + _direction / 2.4f);
 		}
 
 		const float worldBorder = 2.1f;
@@ -136,17 +187,17 @@ namespace Sandbox
 				Line2D topR = .(topTip, topRight);
 				Line2D topL = .(topTip, topLeft);
 
-				if ((bottomR.Intersects(rocketLine) case .Intersection) ||
-					(bottomL.Intersects(rocketLine) case .Intersection) ||
-					(topR.Intersects(rocketLine) case .Intersection) ||
-					(topL.Intersects(rocketLine) case .Intersection))
+				if ((bottomR.Intersects(_rocketLine) case .Intersection) ||
+					(bottomL.Intersects(_rocketLine) case .Intersection) ||
+					(topR.Intersects(_rocketLine) case .Intersection) ||
+					(topL.Intersects(_rocketLine) case .Intersection))
 				{
 					Dead = true;
 				}
 
 				if (!Dead)
 				{
-					if (Line2D(bottomTip, topTip).Intersects(rocketLine) case .Intersection)
+					if (Line2D(bottomTip, topTip).Intersects(_rocketLine) case .Intersection)
 					{
 						scoreLine = @obs.Index;
 					}