selector.js

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

var polygonContain = require("zrender/lib/contain/polygon");

var BoundingRect = require("zrender/lib/core/BoundingRect");

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/
// Key of the first level is brushType: `line`, `rect`, `polygon`.
// Key of the second level is chart element type: `point`, `rect`.
// See moudule:echarts/component/helper/BrushController
// function param:
//      {Object} itemLayout fetch from data.getItemLayout(dataIndex)
//      {Object} selectors {point: selector, rect: selector, ...}
//      {Object} area {range: [[], [], ..], boudingRect}
// function return:
//      {boolean} Whether in the given brush.
var selector = {
  lineX: getLineSelectors(0),
  lineY: getLineSelectors(1),
  rect: {
    point: function (itemLayout, selectors, area) {
      return itemLayout && area.boundingRect.contain(itemLayout[0], itemLayout[1]);
    },
    rect: function (itemLayout, selectors, area) {
      return itemLayout && area.boundingRect.intersect(itemLayout);
    }
  },
  polygon: {
    point: function (itemLayout, selectors, area) {
      return itemLayout && area.boundingRect.contain(itemLayout[0], itemLayout[1]) && polygonContain.contain(area.range, itemLayout[0], itemLayout[1]);
    },
    rect: function (itemLayout, selectors, area) {
      var points = area.range;

      if (!itemLayout || points.length <= 1) {
        return false;
      }

      var x = itemLayout.x;
      var y = itemLayout.y;
      var width = itemLayout.width;
      var height = itemLayout.height;
      var p = points[0];

      if (polygonContain.contain(points, x, y) || polygonContain.contain(points, x + width, y) || polygonContain.contain(points, x, y + height) || polygonContain.contain(points, x + width, y + height) || BoundingRect.create(itemLayout).contain(p[0], p[1]) || lineIntersectPolygon(x, y, x + width, y, points) || lineIntersectPolygon(x, y, x, y + height, points) || lineIntersectPolygon(x + width, y, x + width, y + height, points) || lineIntersectPolygon(x, y + height, x + width, y + height, points)) {
        return true;
      }
    }
  }
};

function getLineSelectors(xyIndex) {
  var xy = ['x', 'y'];
  var wh = ['width', 'height'];
  return {
    point: function (itemLayout, selectors, area) {
      if (itemLayout) {
        var range = area.range;
        var p = itemLayout[xyIndex];
        return inLineRange(p, range);
      }
    },
    rect: function (itemLayout, selectors, area) {
      if (itemLayout) {
        var range = area.range;
        var layoutRange = [itemLayout[xy[xyIndex]], itemLayout[xy[xyIndex]] + itemLayout[wh[xyIndex]]];
        layoutRange[1] < layoutRange[0] && layoutRange.reverse();
        return inLineRange(layoutRange[0], range) || inLineRange(layoutRange[1], range) || inLineRange(range[0], layoutRange) || inLineRange(range[1], layoutRange);
      }
    }
  };
}

function inLineRange(p, range) {
  return range[0] <= p && p <= range[1];
}

function lineIntersectPolygon(lx, ly, l2x, l2y, points) {
  for (var i = 0, p2 = points[points.length - 1]; i < points.length; i++) {
    var p = points[i];

    if (lineIntersect(lx, ly, l2x, l2y, p[0], p[1], p2[0], p2[1])) {
      return true;
    }

    p2 = p;
  }
} // Code from <http://blog.csdn.net/rickliuxiao/article/details/6259322> with some fix.
// See <https://en.wikipedia.org/wiki/Line%E2%80%93line_intersection>


function lineIntersect(a1x, a1y, a2x, a2y, b1x, b1y, b2x, b2y) {
  var delta = determinant(a2x - a1x, b1x - b2x, a2y - a1y, b1y - b2y);

  if (nearZero(delta)) {
    // parallel
    return false;
  }

  var namenda = determinant(b1x - a1x, b1x - b2x, b1y - a1y, b1y - b2y) / delta;

  if (namenda < 0 || namenda > 1) {
    return false;
  }

  var miu = determinant(a2x - a1x, b1x - a1x, a2y - a1y, b1y - a1y) / delta;

  if (miu < 0 || miu > 1) {
    return false;
  }

  return true;
}

function nearZero(val) {
  return val <= 1e-6 && val >= -1e-6;
}

function determinant(v1, v2, v3, v4) {
  return v1 * v4 - v2 * v3;
}

var _default = selector;
module.exports = _default;