Particles

PixelStorm's particle system creates lightweight entities for visual effects. The implementation is simple on purpose: particles are just engine entities with their own transform, sprite, and particle state.

Particle

Particle stores the state of a live particle.

Field	Use
Velocity	current velocity
Lifetime	total lifetime
Age	time already lived
StartColor / EndColor	color interpolation
StartScale / EndScale	scale interpolation
GravityScale	per-particle gravity

Defaults

Field	Default
Lifetime	1.0f
Age	0.0f
StartColor	opaque white
EndColor	transparent white
StartScale	(4, 4)
EndScale	(1, 1)
GravityScale	0.0f

ParticleEmitter

ParticleEmitter defines how particles are spawned.

Field	Default	Use
Active	true	whether it can emit
Loop	false	whether it auto-emits cyclically
AutoEmit	false	whether it emits over time
BurstCount	8	particles per burst
EmitRate	0.0f	bursts per second
Lifetime	0.75f	lifetime of each particle
Speed	80.0f	base speed
SpeedVariation	20.0f	random variation
Spread	180.0f	angular spread
RenderOrder	0	draw layer

ParticleEmitterProxy

Entity::Particles() returns the emitter control proxy.

Method	Use
Play()	enables automatic emission
Pause()	pauses without clearing pending bursts
Stop()	stops and clears pending bursts
IsPlaying()	active state
IsLooping() / SetLoop()	auto-emission loop
IsAutoEmitting() / SetAutoEmit()	continuous emission
GetBurstCount() / SetBurstCount()	burst size
GetEmitRate() / SetEmitRate()	emission rate
GetLifetime() / SetLifetime()	lifetime
GetSpeed() / SetSpeed()	base speed
GetSpeedVariation() / SetSpeedVariation()	variation
GetSpread() / SetSpread()	spread
GetStartColor() / SetStartColor()	start color
GetEndColor() / SetEndColor()	end color
GetStartScale() / SetStartScale()	start scale
GetEndScale() / SetEndScale()	end scale
GetGravityScale() / SetGravityScale()	gravity
GetTexture() / SetTexture()	texture name
GetRenderOrder() / SetRenderOrder()	draw order
EmitBurst(count)	requests extra bursts

EmitBurst

• count <= 0 is ignored
• bursts are accumulated in PendingBursts
• the system consumes them on the next update

System

ParticleSystem:

• spawns particles from active emitters
• animates color, scale, and position
• destroys expired particles

Example

Entity fx = GetWorld().CreateParticleEmitter(
    "Dust",
    Vec2(200.0f, 180.0f),
    "spark",
    8,
    0.5f,
    90.0f,
    20.0f,
    180.0f,
    Vec4(1.0f, 0.8f, 0.2f, 1.0f),
    Vec4(1.0f, 0.2f, 0.0f, 0.0f));

fx.Particles().EmitBurst(12);

note

Particles are rendered as normal entities with Transform, SpriteRenderer, and Particle. That makes them easy to integrate with the existing renderer.