skia2/resources/particles/fireworks.json

{
   "MaxCount": 1000,
   "Drawable": {
      "Type": "SkCircleDrawable",
      "Radius": 1
   },
   "EffectCode": [
      "void effectSpawn(inout Effect effect) {",
      "  effect.lifetime = 2;",
      "  effect.rate = 120;",
      "  float a = radians(mix(-20, 20, rand) - 90);",
      "  float s = mix(200, 220, rand);",
      "  effect.vel.x = cos(a) * s;",
      "  effect.vel.y = sin(a) * s;",
      "  effect.color.rgb = float3(rand, rand, rand);",
      "  effect.pos.x = 0;",
      "  effect.pos.y = 0;",
      "}",
      "",
      "void effectUpdate(inout Effect effect) {",
      "  effect.vel.y += dt * 90;",
      "}",
      "",
      "void effectDeath(inout Effect effect) {",
      "  explode(false);",
      "}",
      ""
   ],
   "Code": [
      "void spawn(inout Particle p) {",
      "  p.lifetime = 0.5;",
      "  float a = radians(rand * 360);",
      "  float s = mix(5, 10, rand);",
      "  p.vel.x = cos(a) * s;",
      "  p.vel.y = sin(a) * s;",
      "}",
      "",
      "void update(inout Particle p) {",
      "  p.color.a = 1 - p.age;",
      "}",
      ""
   ],
   "Bindings": [
      {
         "Type": "SkEffectBinding",
         "Name": "explode",
         "MaxCount": 50,
         "Drawable": {
            "Type": "SkCircleDrawable",
            "Radius": 3
         },
         "EffectCode": [
            "void effectSpawn(inout Effect effect) {",
            "  effect.burst = 50;",
            "  effect.lifetime = 2.5;",
            "}",
            ""
         ],
         "Code": [
            "void spawn(inout Particle p) {",
            "  p.lifetime = 2 + rand * 0.5;",
            "  float a = radians(rand * 360);",
            "  float s = mix(90, 100, rand);",
            "  p.vel.x = cos(a) * s;",
            "  p.vel.y = sin(a) * s;",
            "}",
            "",
            "void update(inout Particle p) {",
            "  p.color.a = 1 - p.age;",
            "  p.vel.y += dt * 50;",
            "}",
            ""
         ],
         "Bindings": []
      }
   ]
}