resources/particles/warp.json

{
   "MaxCount": 4096,
   "Duration": 1,
   "Rate": 90,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 2
   },
   "Code": [
      "",
      "// float rand; Every read returns a random float [0 .. 1)",
      "layout(ctype=float) in uniform float dt;",
      "layout(ctype=float) in uniform float effectAge;",
      "",
      "struct Particle {",
      "  float  age;",
      "  float  lifetime;",
      "  float2 pos;",
      "  float2 dir;",
      "  float  scale;",
      "  float2 vel;",
      "  float  spin;",
      "  float4 color;",
      "  float  frame;",
      "};",
      "",
      "float2 circle() {",
      "  float x;",
      "  float y;",
      "  do {",
      "    x = rand * 2 - 1;",
      "    y = rand * 2 - 1;",
      "  } while (x*x + y*y > 1);",
      "  return float2(x, y);",
      "}",
      "",
      "void spawn(inout Particle p) {",
      "  p.lifetime = 30;",
      "  p.pos = circle() * 40;",
      "}",
      "",
      "void update(inout Particle p) {",
      "  p.vel += normalize(p.pos) * dt * 10;",
      "  p.scale = mix(0.25, 3, p.age);",
      "}",
      ""
   ],
   "Bindings": []
}