zh/builder/src/zrender/graphic/shape/Line.js

/**
 * 直线
 * @module zrender/graphic/shape/Line
 */
import Path from '../Path';
import { subPixelOptimizeLine } from '../helper/subPixelOptimize'; // Avoid create repeatly.

var subPixelOptimizeOutputShape = {};
export default Path.extend({
  type: 'line',
  shape: {
    // Start point
    x1: 0,
    y1: 0,
    // End point
    x2: 0,
    y2: 0,
    percent: 1
  },
  style: {
    stroke: '#000',
    fill: null
  },
  buildPath: function (ctx, shape) {
    var x1;
    var y1;
    var x2;
    var y2;

    if (this.subPixelOptimize) {
      subPixelOptimizeLine(subPixelOptimizeOutputShape, shape, this.style);
      x1 = subPixelOptimizeOutputShape.x1;
      y1 = subPixelOptimizeOutputShape.y1;
      x2 = subPixelOptimizeOutputShape.x2;
      y2 = subPixelOptimizeOutputShape.y2;
    } else {
      x1 = shape.x1;
      y1 = shape.y1;
      x2 = shape.x2;
      y2 = shape.y2;
    }

    var percent = shape.percent;

    if (percent === 0) {
      return;
    }

    ctx.moveTo(x1, y1);

    if (percent < 1) {
      x2 = x1 * (1 - percent) + x2 * percent;
      y2 = y1 * (1 - percent) + y2 * percent;
    }

    ctx.lineTo(x2, y2);
  },

  /**
   * Get point at percent
   * @param  {number} percent
   * @return {Array.<number>}
   */
  pointAt: function (p) {
    var shape = this.shape;
    return [shape.x1 * (1 - p) + shape.x2 * p, shape.y1 * (1 - p) + shape.y2 * p];
  }
});