en/builder/src/zrender/graphic/shape/Arc.js

/**
 * 圆弧
 * @module zrender/graphic/shape/Arc
 */
import Path from '../Path';
export default Path.extend({
  type: 'arc',
  shape: {
    cx: 0,
    cy: 0,
    r: 0,
    startAngle: 0,
    endAngle: Math.PI * 2,
    clockwise: true
  },
  style: {
    stroke: '#000',
    fill: null
  },
  buildPath: function (ctx, shape) {
    var x = shape.cx;
    var y = shape.cy;
    var r = Math.max(shape.r, 0);
    var startAngle = shape.startAngle;
    var endAngle = shape.endAngle;
    var clockwise = shape.clockwise;
    var unitX = Math.cos(startAngle);
    var unitY = Math.sin(startAngle);
    ctx.moveTo(unitX * r + x, unitY * r + y);
    ctx.arc(x, y, r, startAngle, endAngle, !clockwise);
  }
});