third_party/skia/resources/particles/warp.json

{
   "MaxCount": 4096,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 2
   },
   "Code": [
      "void effectSpawn(inout Effect effect) {",
      "  effect.rate = 90;",
      "}",
      "",
      "float2 circle(inout float seed) {",
      "  float r = sqrt(rand(seed));",
      "  float a = rand(seed) * 6.283185;",
      "  return r * float2(sin(a), cos(a));",
      "}",
      "",
      "void spawn(inout Particle p) {",
      "  p.lifetime = 30;",
      "  p.pos += circle(p.seed) * 40;",
      "}",
      "",
      "void update(inout Particle p) {",
      "  p.vel += normalize(p.pos - effect.pos) * dt * 10;",
      "  p.scale = mix(0.25, 3, p.age);",
      "}",
      ""
   ],
   "Bindings": []
}