Circle loading animation

Question

I'm trying to create Apple's OS X circle loading animation.

What I have tried so far:

.animation-wrapper {
  width: 200px;
  height: 200px;
  border: 1px solid black;
  border-radius: 50%;
  position: relative;
  overflow: hidden;
  filter: brightness(0.8);
  -webkit-filter: brightness(0.8);
}
.pie-piece1 {
  position: absolute;
  width: 50%;
  height: 50%;
  bottom: 0;
  left: 0;
  background: linear-gradient(to right, rgba(255, 0, 0, 1) 0%, rgba(255, 255, 0, 1) 100%);
}
.pie-piece2 {
  position: absolute;
  width: 50%;
  height: 50%;
  bottom: 0;
  right: 0;
  background: linear-gradient(to right, rgba(255, 255, 0, 1) 0%, rgba(0, 255, 0, 1) 100%);
}
.pie-piece3 {
  position: absolute;
  width: 50%;
  height: 50%;
  top: 0;
  left: 0;
  background: linear-gradient(to right, rgba(255, 0, 0, 1) 0%, rgba(255, 0, 255, 1) 100%);
}
.pie-piece4 {
  position: absolute;
  width: 50%;
  height: 50%;
  top: 0;
  right: 0;
  background: linear-gradient(to right, rgba(255, 0, 255, 1) 0%, rgba(0, 0, 255, 1) 100%);
}
.rotating-spinners {
  position: absolute;
}
.spike {
  fill: rgba(22, 22, 22, 0.5);
}

<figure class="animation-wrapper">
  <div class="pie-piece1"></div>
  <div class="pie-piece2"></div>
  <div class="pie-piece3"></div>
  <div class="pie-piece4"></div>
  <svg class="rotating-spinners" width="100%" height="100%" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <defs>
      <path id="spin-part" class="spike" d="M 65,-40 C 65,-40 80,20 50,50 60,40 50,-40 50,-40Z" />
    </defs>
    <use x="0" y="0" xlink:href="#spin-part" />
    <use x="0" y="0" xlink:href="#spin-part" transform="rotate(60, 50, 50)" />
    <use x="0" y="0" xlink:href="#spin-part" transform="rotate(120, 50, 50)" />
    <use x="0" y="0" xlink:href="#spin-part" transform="rotate(180, 50, 50)" />
    <use x="0" y="0" xlink:href="#spin-part" transform="rotate(240, 50, 50)" />
    <use x="0" y="0" xlink:href="#spin-part" transform="rotate(300, 50, 50)" />
  </svg>
</figure>

The linear gradients don't seem to line up correctly since i couldn't find a way to make the gradients go in two directions.

Is there a way to create this using only CSS or SVG without mixing them like I have done?

Or are there other solutions I can use like canvas or some kind of image magic?

Answer 1

Here's my effort. The conical gradient is an embedded bitmap image extracted by calculating the maximum value of each pixel in the animated GIF posted by the OP. A semi-opaque black windmill pattern is superimposed on top of that and animated, and a blur filter gets rid of the JPEG artefacts.

(Edit: Added a reflective highlight to make it look a bit more 3D)

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"
  width="121" height="121" viewBox="0 0 121 121">
  <defs>
    <clipPath id="circ">
      <circle r="60" cx="60.5" cy="60.5"/>
    </clipPath>
    <linearGradient id="shine" x1="0%" y1="0%" x2="0%" y2="100%">
      <stop offset="0%" style="stop-color:#fff;stop-opacity:0.6" />
      <stop offset="10%" style="stop-color:#fff;stop-opacity:0.3" />
      <stop offset="20%" style="stop-color:#fff;stop-opacity:0.1" />
      <stop offset="40%" style="stop-color:#fff;stop-opacity:0" />
    </linearGradient>
    <filter id="blur">
      <feGaussianBlur in="SourceGraphic" stdDeviation="2"/>
    </filter>
  </defs>
  <image width="121" height="121" filter="url(#blur)" xlink:href="data:image/jpeg;base64,
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  hIYYg5SFtM/cMbbeoFFHwc04MnGHKcXl/9k=" clip-path="url(#circ)" />
  <g transform="translate(60.5,60.5)">
    <path d="M0 0A56 56 0 0 0 0 56 56 56 0 0 0 32.916 45.305 56 56 0 0 1 0 0 56
        56 0 0 0 53.259 17.305 56 56 0 0 0 53.259-17.305 56 56 0 0 1 0 0 56 56
        0 0 0 32.916-45.305 56 56 0 0 0 0-56 56 56 0 0 1 0 0 56 56 0 0 0
        -32.916-45.305 56 56 0 0 0-53.259-17.305 56 56 0 0 1 0 0 56 56 0 0 0
        -53.259 17.305 56 56 0 0 0-32.916 45.305 56 56 0 0 1 0 0Z"
        stroke="none" fill="#000" opacity="0.25" transform="rotate(0)">
      <animateTransform attributeName="transform" type="rotate" from="0"
          to="72" begin="0s" dur="0.6s" repeatCount="indefinite" />
    </path>
    <circle r="59" stroke="#000" stroke-width="2" fill="none" opacity="0.25" />
    <circle r="55" fill="url(#shine)" stroke="none" />
  </g>
</svg>