skia2/resources/particles/variable_rate.json

{
   "MaxCount": 4000,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 3
   },
   "EffectCode": [
      "void effectUpdate(inout Effect effect) {",
      "  effect.rate = (sin(radians(effect.age * 720)) + 0.7) * 200;",
      "}",
      ""
   ],
   "Code": [
      "void spawn(inout Particle p) {",
      "  p.lifetime = 6;",
      "  float a = radians(rand * 360);",
      "  float2 ofs = float2(cos(a), sin(a)) * 40;",
      "  p.pos += ofs;",
      "  p.vel = ofs;",
      "  p.scale = 0.5;",
      "}",
      ""
   ],
   "Bindings": []
}