Create particle effects

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@pibbl/core/particles provides deterministic 2D effects for UI-scale sparks, confetti, click feedback, trails, and other Canvas composition. An immutable effect describes a population; Particles2D binds it into ordinary Pibbl layout, events, filters, lifecycle, and scheduling.

Define, then mount

import {
  Particles2D,
  useParticleSystem,
  defineParticleEffect2D,
  particleChoice,
  particleCurve,
  particleRange,
} from "@pibbl/core/particles";

const celebration = defineParticleEffect2D({
  emitters: [
    {
      name: "confetti",
      capacity: 240,
      overflow: "recycle-oldest",
      emission: [{ type: "manual", count: 48 }],
      shape: { type: "circle", radius: 5, sample: "interior" },
      initial: {
        lifetimeMilliseconds: particleRange(700, 1_100),
        velocity: [particleRange(-160, 160), particleRange(-220, -90)],
        size: particleRange(5, 10),
        color: particleChoice([
          { value: "#fb7185", weight: 1 },
          { value: "#34d399", weight: 1 },
          { value: "#f7c948", weight: 1 },
        ]),
      },
      motion: [{ type: "acceleration", value: [0, 280] }],
      appearance: {
        opacity: particleCurve([
          [0, 1],
          [0.8, 1],
          [1, 0],
        ]),
      },
      renderer: { type: "rectangle", blend: "source-over" },
      bounds: { min: [-180, -240], max: [180, 180] },
    },
  ],
});

function Celebration() {
  const system = useParticleSystem(celebration, { autoplay: false, seed: 42 });
  return (
    <Particles2D
      system={system}
      pointerEvents="auto"
      style={{ width: 640, height: 360, cursor: "crosshair" }}
      onPointerDown={(event) =>
        system.emit("confetti", { position: [event.x, event.y] })
      }
    />
  );
}

The direct descriptor functions do not sample immediately. They build frozen, particle-specific values that compile into deterministic random channels, parameter registers, and curve or gradient tables.

Motion, capacity, and bounds

acceleration, gravity, drag, and the other motion modules calculate particle motion analytically at its logical age. They do not replace Pibbl animation: continue to drive component transforms and ordinary application values with signals plus tween, keyframes, spring, defineAnimation, or stepper.

Capacity is allocated up front in fixed typed arrays. Choose a realistic ceiling rather than an unbounded safety number. Bounds should conservatively contain shape, velocity, acceleration, and size for the full lifetime so Canvas can perform coarse paint culling.

Start with Particle effects.

Fire, smoke, and shared flow

A convincing flame needs coherent internal detail as well as moving particles. The Fire and Flow example combines a small animated procedural flame texture, sparse embers, and soft smoke sprites. Its artwork is generated locally. Shape selection and manipulation use ordinary Pibbl controls; decorative effects opt out of pointer targeting.

For interacting smoke, create one field with useFlowField2D, add force/heat sources with useFlowSource2D, and pass it to useParticleSystem(effect, { flow }). Many particles can sample that shared field without owning rigid bodies. With optional @pibbl/core/physics/2d, physicsObstacles2D(pibblPhysicsWorld2D()) provides committed box, ellipse, and polygon geometry and motion. Both systems must use the same coordinates. The adapter copies numerical data and does not depend on shared WASM memory or apply smoke forces back to the physics world.

Flow-bound particles use the field for translation. Put wind and upward force on the flow source, rather than adding particle initial velocity or translational motion modules. Angular motion, deterministic random appearance, and lifetime curves remain available. Ordinary particles keep analytical motion; flow adds stateful transport with explicit timing and replay limits.

Effect recipes belong to the application. A helper such as useFireAndSmoke can compose these hooks and return the systems and controls its scene needs; Pibbl does not export a growing catalog of named fire/smoke presets. Canvas paint order determines which whole elements appear in front. Soft particle pixels can cross an obstacle boundary even when their centers cannot; this is not volumetric lighting or depth-aware sprite clipping.

Implementation guidance for agents

Read the Canvas particles companion for ownership, adaptation, failure modes, and verification. Agent start provides the version-selection workflow.

Documentation version

Documentation built with @pibbl/core 0.0.2, revision c321a83. ALPHA — NOT FOR PRODUCTION USE.