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raylib-cs/Examples/Shapes/SimpleParticles.cs

347 lines
12 KiB
C#

/*******************************************************************************************
*
* raylib [shapes] example - simple particles
*
* Example complexity rating: [★★☆☆] 2/4
*
* Example originally created with raylib 5.6, last time updated with raylib 5.6
*
* Example contributed by Jordi Santonja (@JordSant)
*
* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
* BSD-like license that allows static linking with closed source software
*
* Copyright (c) 2025 Jordi Santonja (@JordSant)
*
********************************************************************************************/
namespace Examples.Shapes;
public partial class SimpleParticles : IExample
{
private const int screenWidth = 800;
private const int screenHeight = 450;
private const int MAX_PARTICLES = 3000; // Max number of particles
public string Name => "Shapes / Simple Particles";
public string Title => "raylib [shapes] example - simple particles";
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
private enum ParticleType
{
Water = 0,
Smoke,
Fire
}
private static readonly string[] particleTypeNames = ["WATER", "SMOKE", "FIRE"];
private struct Particle
{
public ParticleType type; // Particle type (WATER, SMOKE, FIRE)
public Vector2 position; // Particle position on screen
public Vector2 velocity; // Particle current speed and direction
public float radius; // Particle radius
public Color color; // Particle color
public float lifeTime; // Particle life time
public bool alive; // Particle alive: inside screen and life time
}
// Circular buffer state
private int head; // Index for the next write
private int tail; // Index for the next read
private Particle[] buffer; // Particle buffer array
// Particle emitter parameters
private int emissionRate; // Negative: on average every -X frames. Positive: particles per frame
private ParticleType currentType;
private Vector2 emitterPosition;
private Random random;
public void Init()
{
// Definition of particles
buffer = new Particle[MAX_PARTICLES]; // Particle array
head = 0;
tail = 0;
// Particle emitter parameters
emissionRate = -2; // Negative: on average every -X frames. Positive: particles per frame
currentType = ParticleType.Water;
emitterPosition = new(screenWidth / 2.0f, screenHeight / 2.0f);
random = new Random();
}
public void Update()
{
// Update
//----------------------------------------------------------------------------------
// Emit new particles: when emissionRate is 1, emit every frame
if (emissionRate < 0)
{
if (random.Next(-emissionRate) == 0)
{
EmitParticle(emitterPosition, currentType);
}
}
else
{
for (int i = 0; i <= emissionRate; i++)
{
EmitParticle(emitterPosition, currentType);
}
}
// Update the parameters of each particle
UpdateParticles(screenWidth, screenHeight);
// Remove dead particles from the circular buffer
UpdateCircularBuffer();
// Change Particle Emission Rate (UP/DOWN arrows)
if (IsKeyPressed(KeyboardKey.Up))
{
emissionRate++;
}
if (IsKeyPressed(KeyboardKey.Down))
{
emissionRate--;
}
// Change Particle Type (LEFT/RIGHT arrows)
if (IsKeyPressed(KeyboardKey.Right))
{
currentType = (currentType == ParticleType.Fire) ? ParticleType.Water : (ParticleType)((int)currentType + 1);
}
if (IsKeyPressed(KeyboardKey.Left))
{
currentType = (currentType == ParticleType.Water) ? ParticleType.Fire : (ParticleType)((int)currentType - 1);
}
if (IsMouseButtonDown(MouseButton.Left))
{
emitterPosition = GetMousePosition();
}
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(Color.RayWhite);
// Call the function with a loop to draw all particles
DrawParticles();
// Draw UI and Instructions
DrawRectangle(5, 5, 315, 75, Fade(Color.SkyBlue, 0.5f));
DrawRectangleLines(5, 5, 315, 75, Color.Blue);
DrawText("CONTROLS:", 15, 15, 10, Color.Black);
DrawText("UP/DOWN: Change Particle Emission Rate", 15, 35, 10, Color.Black);
DrawText("LEFT/RIGHT: Change Particle Type (Water, Smoke, Fire)", 15, 55, 10, Color.Black);
if (emissionRate < 0)
{
DrawText($"Particles every {-emissionRate} frames | Type: {particleTypeNames[(int)currentType]}", 15, 95, 10, Color.DarkGray);
}
else
{
DrawText($"{emissionRate + 1} Particles per frame | Type: {particleTypeNames[(int)currentType]}", 15, 95, 10, Color.DarkGray);
}
DrawFPS(screenWidth - 80, 10);
EndDrawing();
//----------------------------------------------------------------------------------
}
public void Unload()
{
}
//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
private void EmitParticle(Vector2 emitterPosition, ParticleType type)
{
int index = AddToCircularBuffer();
// If buffer is full, index is -1
if (index != -1)
{
ref Particle newParticle = ref buffer[index];
// Fill particle properties
newParticle.position = emitterPosition;
newParticle.alive = true;
newParticle.lifeTime = 0.0f;
newParticle.type = type;
float speed = (float)(random.Next(10)) / 5.0f;
switch (type)
{
case ParticleType.Water:
{
newParticle.radius = 5.0f;
newParticle.color = Color.Blue;
}
break;
case ParticleType.Smoke:
{
newParticle.radius = 7.0f;
newParticle.color = Color.Gray;
}
break;
case ParticleType.Fire:
{
newParticle.radius = 10.0f;
newParticle.color = Color.Yellow;
speed /= 10.0f;
}
break;
default:
break;
}
float direction = (float)(random.Next(360));
newParticle.velocity = new(speed * MathF.Cos(direction * DEG2RAD), speed * MathF.Sin(direction * DEG2RAD));
}
}
private int AddToCircularBuffer()
{
int index = -1;
// Check if buffer full
if (((head + 1) % MAX_PARTICLES) != tail)
{
// Add new particle to the head position and advance head
index = head;
head = (head + 1) % MAX_PARTICLES;
}
return index;
}
private void UpdateParticles(int screenWidth, int screenHeight)
{
for (int i = tail; i != head; i = (i + 1) % MAX_PARTICLES)
{
// Update particle life and positions
buffer[i].lifeTime += 1.0f / 60.0f; // 60 FPS -> 1/60 seconds per frame
switch (buffer[i].type)
{
case ParticleType.Water:
{
buffer[i].position.X += buffer[i].velocity.X;
buffer[i].velocity.Y += 0.2f; // Gravity
buffer[i].position.Y += buffer[i].velocity.Y;
}
break;
case ParticleType.Smoke:
{
buffer[i].position.X += buffer[i].velocity.X;
buffer[i].velocity.Y -= 0.05f; // Upwards
buffer[i].position.Y += buffer[i].velocity.Y;
buffer[i].radius += 0.5f; // Increment radius: smoke expands
buffer[i].color.A -= 4; // Decrement alpha: smoke fades
// If alpha transparent, particle dies
if (buffer[i].color.A < 4)
{
buffer[i].alive = false;
}
}
break;
case ParticleType.Fire:
{
// Add a little horizontal oscillation to fire particles
buffer[i].position.X += buffer[i].velocity.X + MathF.Cos(buffer[i].lifeTime * 215.0f);
buffer[i].velocity.Y -= 0.05f; // Upwards
buffer[i].position.Y += buffer[i].velocity.Y;
buffer[i].radius -= 0.15f; // Decrement radius: fire shrinks
buffer[i].color.G -= 3; // Decrement green: fire turns reddish starting from yellow
// If radius too small, particle dies
if (buffer[i].radius <= 0.02f)
{
buffer[i].alive = false;
}
}
break;
default:
break;
}
// Disable particle when out of screen
Vector2 center = buffer[i].position;
float radius = buffer[i].radius;
if ((center.X < -radius) || (center.X > (screenWidth + radius)) ||
(center.Y < -radius) || (center.Y > (screenHeight + radius)))
{
buffer[i].alive = false;
}
}
}
private void UpdateCircularBuffer()
{
// Update circular buffer: advance tail over dead particles
while ((tail != head) && !buffer[tail].alive)
{
tail = (tail + 1) % MAX_PARTICLES;
}
}
private void DrawParticles()
{
for (int i = tail; i != head; i = (i + 1) % MAX_PARTICLES)
{
if (buffer[i].alive)
{
DrawCircleV(buffer[i].position,
buffer[i].radius,
buffer[i].color);
}
}
}
public static int Main()
{
// Initialization
//--------------------------------------------------------------------------------------
InitWindow(screenWidth, screenHeight, "raylib [shapes] example - simple particles");
SetTargetFPS(60); // Set our game to run at 60 frames-per-second
//--------------------------------------------------------------------------------------
var game = new SimpleParticles();
game.Init();
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
game.Update();
}
game.Unload();
// De-Initialization
//--------------------------------------------------------------------------------------
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
}