jhladmin/node_modules/zrender/lib/contain/cubic.js

var curve = require("../core/curve");

/**
 * 三次贝塞尔曲线描边包含判断
 * @param  {number}  x0
 * @param  {number}  y0
 * @param  {number}  x1
 * @param  {number}  y1
 * @param  {number}  x2
 * @param  {number}  y2
 * @param  {number}  x3
 * @param  {number}  y3
 * @param  {number}  lineWidth
 * @param  {number}  x
 * @param  {number}  y
 * @return {boolean}
 */
function containStroke(x0, y0, x1, y1, x2, y2, x3, y3, lineWidth, x, y) {
  if (lineWidth === 0) {
    return false;
  }

  var _l = lineWidth; // Quick reject

  if (y > y0 + _l && y > y1 + _l && y > y2 + _l && y > y3 + _l || y < y0 - _l && y < y1 - _l && y < y2 - _l && y < y3 - _l || x > x0 + _l && x > x1 + _l && x > x2 + _l && x > x3 + _l || x < x0 - _l && x < x1 - _l && x < x2 - _l && x < x3 - _l) {
    return false;
  }

  var d = curve.cubicProjectPoint(x0, y0, x1, y1, x2, y2, x3, y3, x, y, null);
  return d <= _l / 2;
}

exports.containStroke = containStroke;