public ParticleEmitter(ParticleEmitterConfig emitterConfig, bool playOnAwake = true)
{
_emitterConfig = emitterConfig;
_playOnAwake = playOnAwake;
_particles = new List <Particle>((int)_emitterConfig.maxParticles);
Pool <Particle> .warmCache((int)_emitterConfig.maxParticles);
// set some sensible defaults
collisionConfig.elasticity = 0.5f;
collisionConfig.friction = 0.5f;
collisionConfig.collidesWithLayers = Physics.allLayers;
collisionConfig.gravity = _emitterConfig.gravity;
collisionConfig.lifetimeLoss = 0f;
collisionConfig.minKillSpeedSquared = float.MinValue;
collisionConfig.radiusScale = 0.8f;
init();
}
public ParticleEmitter( ParticleEmitterConfig emitterConfig, bool playOnAwake = true )
{
_emitterConfig = emitterConfig;
_playOnAwake = playOnAwake;
_particles = new List<Particle>( (int)_emitterConfig.maxParticles );
Pool<Particle>.warmCache( (int)_emitterConfig.maxParticles );
// set some sensible defaults
collisionConfig.elasticity = 0.5f;
collisionConfig.friction = 0.5f;
collisionConfig.collidesWithLayers = Physics.allLayers;
collisionConfig.gravity = _emitterConfig.gravity;
collisionConfig.lifetimeLoss = 0f;
collisionConfig.minKillSpeedSquared = float.MinValue;
collisionConfig.radiusScale = 0.8f;
initialize();
}
public void initialize(ParticleEmitterConfig emitterConfig, Vector2 spawnPosition)
{
_collided = false;
// init the position of the Particle. This is based on the source position of the particle emitter
// plus a configured variance. The Random.minusOneToOne method allows the number to be both positive
// and negative
position.X = emitterConfig.sourcePositionVariance.X * Random.minusOneToOne();
position.Y = emitterConfig.sourcePositionVariance.Y * Random.minusOneToOne();
this.spawnPosition = spawnPosition;
// init the direction of the The newAngle is calculated using the angle passed in and the
// angle variance.
var newAngle = MathHelper.ToRadians(emitterConfig.angle + emitterConfig.angleVariance * Random.minusOneToOne());
// create a new Vector2 using the newAngle
var vector = new Vector2(Mathf.cos(newAngle), Mathf.sin(newAngle));
// calculate the vectorSpeed using the speed and speedVariance which has been passed in
var vectorSpeed = emitterConfig.speed + emitterConfig.speedVariance * Random.minusOneToOne();
// the particles direction vector is calculated by taking the vector calculated above and
// multiplying that by the speed
_direction = vector * vectorSpeed;
// calculate the particles life span using the life span and variance passed in
_timeToLive = MathHelper.Max(0, emitterConfig.particleLifespan + emitterConfig.particleLifespanVariance * Random.minusOneToOne());
_particleLifetime = _timeToLive;
var startRadius = emitterConfig.maxRadius + emitterConfig.maxRadiusVariance * Random.minusOneToOne();
var endRadius = emitterConfig.minRadius + emitterConfig.minRadiusVariance * Random.minusOneToOne();
// set the default diameter of the particle from the source position
_radius = startRadius;
_radiusDelta = (endRadius - startRadius) / _timeToLive;
_angle = MathHelper.ToRadians(emitterConfig.angle + emitterConfig.angleVariance * Random.minusOneToOne());
_degreesPerSecond = MathHelper.ToRadians(emitterConfig.rotatePerSecond + emitterConfig.rotatePerSecondVariance * Random.minusOneToOne());
_radialAcceleration = emitterConfig.radialAcceleration + emitterConfig.radialAccelVariance * Random.minusOneToOne();
_tangentialAcceleration = emitterConfig.tangentialAcceleration + emitterConfig.tangentialAccelVariance * Random.minusOneToOne();
// calculate the particle size using the start and finish particle sizes
var particleStartSize = emitterConfig.startParticleSize + emitterConfig.startParticleSizeVariance * Random.minusOneToOne();
var particleFinishSize = emitterConfig.finishParticleSize + emitterConfig.finishParticleSizeVariance * Random.minusOneToOne();
_particleSizeDelta = (particleFinishSize - particleStartSize) / _timeToLive;
particleSize = MathHelper.Max(0, particleStartSize);
// calculate the color the particle should have when it starts its life. All the elements
// of the start color passed in along with the variance are used to calculate the start color
_startColor = new Color
(
(int)(emitterConfig.startColor.R + emitterConfig.startColorVariance.R * Random.minusOneToOne()),
(int)(emitterConfig.startColor.G + emitterConfig.startColorVariance.G * Random.minusOneToOne()),
(int)(emitterConfig.startColor.B + emitterConfig.startColorVariance.B * Random.minusOneToOne()),
(int)(emitterConfig.startColor.A + emitterConfig.startColorVariance.A * Random.minusOneToOne())
);
color = _startColor;
// calculate the color the particle should be when its life is over. This is done the same
// way as the start color above
_finishColor = new Color
(
(int)(emitterConfig.finishColor.R + emitterConfig.finishColorVariance.R * Random.minusOneToOne()),
(int)(emitterConfig.finishColor.G + emitterConfig.finishColorVariance.G * Random.minusOneToOne()),
(int)(emitterConfig.finishColor.B + emitterConfig.finishColorVariance.B * Random.minusOneToOne()),
(int)(emitterConfig.finishColor.A + emitterConfig.finishColorVariance.A * Random.minusOneToOne())
);
// calculate the rotation
var startA = MathHelper.ToRadians(emitterConfig.rotationStart + emitterConfig.rotationStartVariance * Random.minusOneToOne());
var endA = MathHelper.ToRadians(emitterConfig.rotationEnd + emitterConfig.rotationEndVariance * Random.minusOneToOne());
rotation = startA;
_rotationDelta = (endA - startA) / _timeToLive;
}
/// <summary>
/// updates the particle. Returns true when the particle is no longer alive
/// </summary>
/// <param name="emitterConfig">Emitter config.</param>
public bool update(ParticleEmitterConfig emitterConfig, ref ParticleCollisionConfig collisionConfig, Vector2 rootPosition)
{
// PART 1: reduce the life span of the particle
_timeToLive -= Time.deltaTime;
// if the current particle is alive then update it
if (_timeToLive > 0)
{
// only update the particle position if it has not collided. If it has, physics takes over
if (!_collided)
{
// if maxRadius is greater than 0 then the particles are going to spin otherwise they are affected by speed and gravity
if (emitterConfig.emitterType == ParticleEmitterType.Radial)
{
// PART 2: update the angle of the particle from the radius. This is only done if the particles are rotating
_angle += _degreesPerSecond * Time.deltaTime;
_radius += _radiusDelta * Time.deltaTime;
Vector2 tmp;
tmp.X = -Mathf.cos(_angle) * _radius;
tmp.Y = -Mathf.sin(_angle) * _radius;
_velocity = tmp - position;
position = tmp;
}
else
{
Vector2 tmp, radial, tangential;
radial = Vector2.Zero;
if (position.X != 0 || position.Y != 0)
{
Vector2.Normalize(ref position, out radial);
}
tangential = radial;
radial = radial * _radialAcceleration;
var newy = tangential.X;
tangential.X = -tangential.Y;
tangential.Y = newy;
tangential = tangential * _tangentialAcceleration;
tmp = radial + tangential + emitterConfig.gravity;
tmp = tmp * Time.deltaTime;
_direction = _direction + tmp;
tmp = _direction * Time.deltaTime;
_velocity = tmp / Time.deltaTime;
position = position + tmp;
}
}
// update the particles color. we do the lerp from finish-to-start because timeToLive counts from particleLifespan to 0
var t = (_particleLifetime - _timeToLive) / _particleLifetime;
ColorExt.lerp(ref _startColor, ref _finishColor, out color, t);
// update the particle size
particleSize += _particleSizeDelta * Time.deltaTime;
particleSize = MathHelper.Max(0, particleSize);
// update the rotation of the particle
rotation += _rotationDelta * Time.deltaTime;
if (collisionConfig.enabled)
{
// if we already collided we have to handle the collision response
if (_collided)
{
// handle after collision movement. we need to track velocity for this
_velocity += collisionConfig.gravity * Time.deltaTime;
position += _velocity * Time.deltaTime;
// if we move too slow we die
if (_velocity.LengthSquared() < collisionConfig.minKillSpeedSquared)
{
return(true);
}
}
// should we use our spawnPosition as a reference or the parent Transforms position?
var pos = emitterConfig.simulateInWorldSpace ? spawnPosition : rootPosition;
_circleCollisionShape.recalculateBounds(particleSize * 0.5f * collisionConfig.radiusScale, pos + position);
var neighbors = Physics.boxcastBroadphase(ref _circleCollisionShape.bounds, collisionConfig.collidesWithLayers);
foreach (var neighbor in neighbors)
{
CollisionResult result;
if (_circleCollisionShape.collidesWithShape(neighbor.shape, out result))
{
// handle the overlap
position -= result.minimumTranslationVector;
calculateCollisionResponseVelocity(collisionConfig.friction, collisionConfig.elasticity, ref result.minimumTranslationVector);
// handle collision config props
_timeToLive -= _timeToLive * collisionConfig.lifetimeLoss;
_collided = true;
}
}
}
}
else
{
// timeToLive expired. were done
return(true);
}
return(false);
}
public void initialize( ParticleEmitterConfig emitterConfig, Vector2 spawnPosition )
{
_collided = false;
// init the position of the Particle. This is based on the source position of the particle emitter
// plus a configured variance. The Random.minusOneToOne method allows the number to be both positive
// and negative
position.X = emitterConfig.sourcePositionVariance.X * Random.minusOneToOne();
position.Y = emitterConfig.sourcePositionVariance.Y * Random.minusOneToOne();
this.spawnPosition = spawnPosition;
// init the direction of the The newAngle is calculated using the angle passed in and the
// angle variance.
var newAngle = MathHelper.ToRadians( emitterConfig.angle + emitterConfig.angleVariance * Random.minusOneToOne() );
// create a new Vector2 using the newAngle
var vector = new Vector2( Mathf.cos( newAngle ), Mathf.sin( newAngle ) );
// calculate the vectorSpeed using the speed and speedVariance which has been passed in
var vectorSpeed = emitterConfig.speed + emitterConfig.speedVariance * Random.minusOneToOne();
// the particles direction vector is calculated by taking the vector calculated above and
// multiplying that by the speed
_direction = vector * vectorSpeed;
// calculate the particles life span using the life span and variance passed in
_timeToLive = MathHelper.Max( 0, emitterConfig.particleLifespan + emitterConfig.particleLifespanVariance * Random.minusOneToOne() );
_particleLifetime = _timeToLive;
var startRadius = emitterConfig.maxRadius + emitterConfig.maxRadiusVariance * Random.minusOneToOne();
var endRadius = emitterConfig.minRadius + emitterConfig.minRadiusVariance * Random.minusOneToOne();
// set the default diameter of the particle from the source position
_radius = startRadius;
_radiusDelta = (endRadius - startRadius) / _timeToLive;
_angle = MathHelper.ToRadians( emitterConfig.angle + emitterConfig.angleVariance * Random.minusOneToOne() );
_degreesPerSecond = MathHelper.ToRadians( emitterConfig.rotatePerSecond + emitterConfig.rotatePerSecondVariance * Random.minusOneToOne() );
_radialAcceleration = emitterConfig.radialAcceleration + emitterConfig.radialAccelVariance * Random.minusOneToOne();
_tangentialAcceleration = emitterConfig.tangentialAcceleration + emitterConfig.tangentialAccelVariance * Random.minusOneToOne();
// calculate the particle size using the start and finish particle sizes
var particleStartSize = emitterConfig.startParticleSize + emitterConfig.startParticleSizeVariance * Random.minusOneToOne();
var particleFinishSize = emitterConfig.finishParticleSize + emitterConfig.finishParticleSizeVariance * Random.minusOneToOne();
_particleSizeDelta = ( particleFinishSize - particleStartSize ) / _timeToLive;
particleSize = MathHelper.Max( 0, particleStartSize );
// calculate the color the particle should have when it starts its life. All the elements
// of the start color passed in along with the variance are used to calculate the start color
_startColor = new Color
(
(int)( emitterConfig.startColor.R + emitterConfig.startColorVariance.R * Random.minusOneToOne() ),
(int)( emitterConfig.startColor.G + emitterConfig.startColorVariance.G * Random.minusOneToOne() ),
(int)( emitterConfig.startColor.B + emitterConfig.startColorVariance.B * Random.minusOneToOne() ),
(int)( emitterConfig.startColor.A + emitterConfig.startColorVariance.A * Random.minusOneToOne() )
);
color = _startColor;
// calculate the color the particle should be when its life is over. This is done the same
// way as the start color above
_finishColor = new Color
(
(int)( emitterConfig.finishColor.R + emitterConfig.finishColorVariance.R * Random.minusOneToOne() ),
(int)( emitterConfig.finishColor.G + emitterConfig.finishColorVariance.G * Random.minusOneToOne() ),
(int)( emitterConfig.finishColor.B + emitterConfig.finishColorVariance.B * Random.minusOneToOne() ),
(int)( emitterConfig.finishColor.A + emitterConfig.finishColorVariance.A * Random.minusOneToOne() )
);
// calculate the rotation
var startA = MathHelper.ToRadians( emitterConfig.rotationStart + emitterConfig.rotationStartVariance * Random.minusOneToOne() );
var endA = MathHelper.ToRadians( emitterConfig.rotationEnd + emitterConfig.rotationEndVariance * Random.minusOneToOne() );
rotation = startA;
_rotationDelta = ( endA - startA ) / _timeToLive;
}
/// <summary>
/// updates the particle. Returns true when the particle is no longer alive
/// </summary>
/// <param name="emitterConfig">Emitter config.</param>
public bool update( ParticleEmitterConfig emitterConfig, ref ParticleCollisionConfig collisionConfig, Vector2 rootPosition )
{
// PART 1: reduce the life span of the particle
_timeToLive -= Time.deltaTime;
// if the current particle is alive then update it
if( _timeToLive > 0 )
{
// only update the particle position if it has not collided. If it has, physics takes over
if( !_collided )
{
// if maxRadius is greater than 0 then the particles are going to spin otherwise they are affected by speed and gravity
if( emitterConfig.emitterType == ParticleEmitterType.Radial )
{
// PART 2: update the angle of the particle from the radius. This is only done if the particles are rotating
_angle += _degreesPerSecond * Time.deltaTime;
_radius += _radiusDelta * Time.deltaTime;
Vector2 tmp;
tmp.X = -Mathf.cos( _angle ) * _radius;
tmp.Y = -Mathf.sin( _angle ) * _radius;
_velocity = tmp - position;
position = tmp;
}
else
{
Vector2 tmp, radial, tangential;
radial = Vector2.Zero;
if( position.X != 0 || position.Y != 0 )
Vector2.Normalize( ref position, out radial );
tangential = radial;
radial = radial * _radialAcceleration;
var newy = tangential.X;
tangential.X = -tangential.Y;
tangential.Y = newy;
tangential = tangential * _tangentialAcceleration;
tmp = radial + tangential + emitterConfig.gravity;
tmp = tmp * Time.deltaTime;
_direction = _direction + tmp;
tmp = _direction * Time.deltaTime;
_velocity = tmp / Time.deltaTime;
position = position + tmp;
}
}
// update the particles color. we do the lerp from finish-to-start because timeToLive counts from particleLifespan to 0
var t = ( _particleLifetime - _timeToLive ) / _particleLifetime;
ColorExt.lerp( ref _startColor, ref _finishColor, out color, t );
// update the particle size
particleSize += _particleSizeDelta * Time.deltaTime;
particleSize = MathHelper.Max( 0, particleSize );
// update the rotation of the particle
rotation += _rotationDelta * Time.deltaTime;
if( collisionConfig.enabled )
{
// if we already collided we have to handle the collision response
if( _collided )
{
// handle after collision movement. we need to track velocity for this
_velocity += collisionConfig.gravity * Time.deltaTime;
position += _velocity * Time.deltaTime;
// if we move too slow we die
if( _velocity.LengthSquared() < collisionConfig.minKillSpeedSquared )
return true;
}
// should we use our spawnPosition as a reference or the parent Transforms position?
var pos = emitterConfig.simulateInWorldSpace ? spawnPosition : rootPosition;
_circleCollisionShape.recalculateBounds( particleSize * 0.5f * collisionConfig.radiusScale, pos + position );
var neighbors = Physics.boxcastBroadphase( ref _circleCollisionShape.bounds, collisionConfig.collidesWithLayers );
foreach( var neighbor in neighbors )
{
CollisionResult result;
if( _circleCollisionShape.collidesWithShape( neighbor.shape, out result ) )
{
// handle the overlap
position -= result.minimumTranslationVector;
calculateCollisionResponseVelocity( collisionConfig.friction, collisionConfig.elasticity, ref result.minimumTranslationVector );
// handle collision config props
_timeToLive -= _timeToLive * collisionConfig.lifetimeLoss;
_collided = true;
}
}
}
}
else
{
// timeToLive expired. were done
return true;
}
return false;
}
