Phyllotaxis Spiral

// 002 - Phyllotaxis Spiral (organic)
// 1:1 Original algorithm engine source
function createPhyllotaxisSpiral() {
  return {
    setup() {
    },
    render(context, timeState, params) {
      const { ctx, width, height } = context;
      const count = Number(params.pointCount || 1200);
      const c = Number(params.scaleFactor || 6);
      const speed = Number(params.rotationSpeed || 0.5);
      const divergence = Number(params.divergenceAngle || 137.508) * (Math.PI / 180);
      ctx.fillStyle = "#08090d";
      ctx.fillRect(0, 0, width, height);
      const cx = width * 0.5;
      const cy = height * 0.5;
      const t = timeState.time * speed;
      for (let n = 0; n < count; n++) {
        const theta = n * divergence + t * (1 + n * 2e-4);
        const r = c * Math.sqrt(n) * (1 + 0.05 * Math.sin(t * 2 + n * 0.02));
        const x = cx + r * Math.cos(theta);
        const y = cy + r * Math.sin(theta);
        if (x < -20 || x > width + 20 || y < -20 || y > height + 20) continue;
        const size = Math.max(1, r / (width * 0.5) * 4 + 1.2);
        const hue = (n * 0.35 + t * 40) % 360;
        ctx.fillStyle = hsla(hue, 90, 65, 0.85);
        ctx.beginPath();
        ctx.arc(x, y, size, 0, Math.PI * 2);
        ctx.fill();
      }
    }
  };
}

// Default parameters from content metadata
const defaultParams = [
  {
    "key": "divergenceAngle",
    "label": "Divergence Angle (°)",
    "type": "range",
    "min": 137,
    "max": 138,
    "step": 0.001,
    "defaultValue": 137.508,
    "description": "Golden ratio packing angle"
  },
  {
    "key": "scaleFactor",
    "label": "Scale Factor (c)",
    "type": "range",
    "min": 2,
    "max": 12,
    "step": 0.2,
    "defaultValue": 6,
    "description": "Radial distribution density"
  },
  {
    "key": "rotationSpeed",
    "label": "Rotation Speed",
    "type": "range",
    "min": 0.1,
    "max": 2,
    "step": 0.05,
    "defaultValue": 0.5,
    "description": "Temporal rotation multiplier"
  },
  {
    "key": "pointCount",
    "label": "Seed Count",
    "type": "range",
    "min": 300,
    "max": 2400,
    "step": 50,
    "defaultValue": 1200,
    "description": "Total seed floret points"
  }
];

if (!window.__art_instances) window.__art_instances = {};
if (!window.__art_instances['phyllotaxis-spiral']) {
  const inst = typeof createPhyllotaxisSpiral === 'function' ? createPhyllotaxisSpiral() : null;
  if (inst && inst.setup) {
    inst.setup({ ctx, width, height, dpr: 1, aspectRatio: width / height }, defaultParams);
  }
  window.__art_instances['phyllotaxis-spiral'] = inst;
}

const instance = window.__art_instances['phyllotaxis-spiral'];
if (instance && instance.render) {
  instance.render(
    { ctx, width, height, dpr: 1, aspectRatio: width / height },
    { time, deltaTime: dt, frameCount: Math.floor(time * 60), fps: 60 },
    defaultParams
  );
}