message: fix(morph): optimize morphing effect by adding an extra rotation
diff: <script type="text/javascript">
  const zr = zrender.init(document.getElementById('main'));
  const shapes = [
  + new zrender.Rect({
  + shape: {
  + x: 100,
  + y: 100,
  + width: 100,
  + height: 200
  + },
  + style: {
  + fill: 'red',
  + opacity: 0.5,
  + stroke: 'red'
  + }
  + }),
  new zrender.Circle({
  shape: {
  cx: 200,
  cy: 200,
  r: 90
  + },
  + style: {
  + fill: 'red',
  + opacity: 0.5,
  + stroke: 'red'
  }
  }),
  new zrender.Isogon({
  x: 200,
  y: 200,
  r: 100,
  - n: 10
  + n: 6
  + },
  + style: {
  + fill: 'red',
  + opacity: 0.5,
  + stroke: 'red'
  }
  }),
  new zrender.Sector({
  r: 100,
  startAngle: 1,
  endAngle: 3
  - }
  - }),
  - new zrender.Rect({
  - shape: {
  - x: 100,
  - y: 100,
  - width: 50,
  - height: 200
  + },
  + style: {
  + fill: 'red',
  + opacity: 0.5,
  + stroke: 'red'
  }
  })
  ];
  