skia2/resources/particles/confetti.json

{
   "MaxCount": 200,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 8
   },
   "Code": [
      "void effectSpawn(inout Effect effect) {",
      "  effect.lifetime = 2;",
      "}",
      "",
      "void effectUpdate(inout Effect effect) {",
      "  if (effect.age < 0.25 || effect.age > 0.75) { effect.rate = 0; }",
      "  else { effect.rate = 200; }",
      "}",
      "",
      "void spawn(inout Particle p) {",
      "  int idx = int(rand(p.seed) * 4);",
      "  p.color.rgb = (idx == 0) ? float3(0.87, 0.24, 0.11)",
      "              : (idx == 1) ? float3(1.00, 0.90, 0.20)",
      "              : (idx == 2) ? float3(0.44, 0.73, 0.24)",
      "              :              float3(0.38, 0.54, 0.95);",
      "",
      "  p.lifetime = (1 - effect.age) * effect.lifetime;",
      "  p.scale = mix(0.6, 1, rand(p.seed));",
      "}",
      "",
      "void update(inout Particle p) {",
      "  p.color.a = 1 - p.age;",
      "",
      "  float a = radians(rand(p.seed) * 360);",
      "  float invAge = 1 - p.age;",
      "  p.vel = float2(cos(a), sin(a)) * mix(250, 550, rand(p.seed)) * invAge * invAge;",
      "}",
      ""
   ],
   "Bindings": []
}