particle_core 0.0.2

Core engine for particle effects in Flutter. High-performance physics, single GPU draw call rendering via drawRawAtlas, and full customization.

particle_core

Core engine for particle effects in Flutter. High-performance physics, single GPU draw call rendering, and full customization.

You probably want particle_text or particle_image instead — they provide ready-to-use widgets built on this engine.

What's inside

• ParticleSystem — physics engine with spring forces, pointer repulsion, and text/image rasterization
• ParticleConfig — full configuration: colors, density, physics, fonts, presets
• ParticlePainter — high-performance renderer using Canvas.drawRawAtlas (single GPU draw call)
• Particle — data model for individual particles

Use this package if

• You want to build a custom particle widget on top of the engine
• You need direct access to the physics system
• You're creating a new particle effect type beyond text and images

Getting started

dependencies:
  particle_core: ^0.0.1

ParticleConfig options

Parameter	Type	Default	Description
particleDensity	double	2000	Particles per 100k px² of screen area (auto-scales)
particleCount	int?	null	Fixed count — overrides density when set
maxParticleCount	int	50000	Upper cap for density scaling
minParticleCount	int	1000	Lower floor for density scaling
mouseRadius	double	80.0	Pointer repulsion radius (logical px)
returnSpeed	double	0.04	Spring return speed (0.01–0.1)
friction	double	0.88	Velocity damping (0.8–0.95)
repelForce	double	8.0	Pointer repulsion strength (1.0–20.0)
backgroundColor	Color	#020308	Canvas background
particleColor	Color	#8CAADE	Particle color at rest
displacedColor	Color	#DCE5FF	Particle color when scattered
pointerGlowColor	Color	#C8D2F0	Glow orb color
minParticleSize	double	0.4	Min particle radius
maxParticleSize	double	2.2	Max particle radius
minAlpha	double	0.5	Min particle opacity
maxAlpha	double	1.0	Max particle opacity
sampleGap	int	2	Pixel sampling density (lower = more targets)
fontWeight	FontWeight	bold	Text rendering weight
fontFamily	String?	null	Custom font family
showPointerGlow	bool	true	Show pointer glow orb
pointerDotRadius	double	4.0	Center dot radius

Built-in presets

Preset	Density	Style
ParticleConfig()	2000	Default blue-white glow
ParticleConfig.cosmic()	2800	Dense cosmic blue dust
ParticleConfig.fire()	2400	Fiery warm orange
ParticleConfig.matrix()	2000	Neon green
ParticleConfig.pastel()	1700	Soft pastel pink
ParticleConfig.minimal()	900	Fewer, larger particles

Responsive particle count

Particle count scales automatically with screen size:

Mobile  (360×800)   → ~5,760 particles
Tablet  (768×1024)  → ~15,729 particles
Desktop (1920×1080) → ~41,472 particles
4K      (3840×2160) → ~50,000 particles (capped)

Performance

particle_core renders all particles in a single GPU draw call using Canvas.drawRawAtlas. This means 10,000+ particles run smoothly at 60fps — compared to traditional drawCircle -per-particle approaches that start lagging at 1,000.

Other optimizations:

• Pre-allocated Float32List/Int32List buffers — zero GC pressure per frame
• Squared-distance checks — avoids sqrt in physics hot loops
• ChangeNotifier-driven repainting — no setState, no widget tree rebuilds
• RepaintBoundary isolation — only the canvas layer repaints
• Pre-rendered sprite texture — 32×32 soft glow circle created once, reused every frame

License

MIT License. See LICENSE for details.