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

/**
 * 矩形
 * @module zrender/graphic/shape/Rect
 */
import Path from '../Path';
import * as roundRectHelper from '../helper/roundRect';
import { subPixelOptimizeRect } from '../helper/subPixelOptimize'; // Avoid create repeatly.

var subPixelOptimizeOutputShape = {};
export default Path.extend({
  type: 'rect',
  shape: {
    // 左上、右上、右下、左下角的半径依次为r1、r2、r3、r4
    // r缩写为1         相当于 [1, 1, 1, 1]
    // r缩写为[1]       相当于 [1, 1, 1, 1]
    // r缩写为[1, 2]    相当于 [1, 2, 1, 2]
    // r缩写为[1, 2, 3] 相当于 [1, 2, 3, 2]
    r: 0,
    x: 0,
    y: 0,
    width: 0,
    height: 0
  },
  buildPath: function (ctx, shape) {
    var x;
    var y;
    var width;
    var height;

    if (this.subPixelOptimize) {
      subPixelOptimizeRect(subPixelOptimizeOutputShape, shape, this.style);
      x = subPixelOptimizeOutputShape.x;
      y = subPixelOptimizeOutputShape.y;
      width = subPixelOptimizeOutputShape.width;
      height = subPixelOptimizeOutputShape.height;
      subPixelOptimizeOutputShape.r = shape.r;
      shape = subPixelOptimizeOutputShape;
    } else {
      x = shape.x;
      y = shape.y;
      width = shape.width;
      height = shape.height;
    }

    if (!shape.r) {
      ctx.rect(x, y, width, height);
    } else {
      roundRectHelper.buildPath(ctx, shape);
    }

    ctx.closePath();
    return;
  }
});