resources/particles/default.json

{
   "MaxCount": 4096,
   "Duration": 1,
   "Rate": 1000,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 1
   },
   "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;",
      "};",
      "",
      "void spawn(inout Particle p) {",
      "  p.lifetime = mix(1, 3, rand);",
      "  float a = radians(mix(250, 290, rand));",
      "  float s = mix(10, 30, rand);",
      "  p.vel.x = cos(a) * s;",
      "  p.vel.y = sin(a) * s;",
      "  p.pos = text(rand).xy;",
      "}",
      "",
      "void update(inout Particle p) {",
      "  float4 startColor = float4(1, 0.196, 0.078, 1);",
      "  float4 endColor   = float4(1, 0.784, 0.078, 1);",
      "  p.color = mix(startColor, endColor, p.age);",
      "}",
      ""
   ],
   "Bindings": [
      {
         "Type": "SkTextBinding",
         "Name": "text",
         "Text": "SKIA",
         "FontSize": 96
      }
   ]
}