en/builder/src/echarts3/chart/themeRiver/themeRiverLayout.js

/**
 * @file  Using layout algorithm transform the raw data to layout information.
 * @author Deqing Li(annong035@gmail.com)
 */
import * as zrUtil from 'zrender/src/core/util';
import * as numberUtil from '../../util/number';
export default function (ecModel, api) {
  ecModel.eachSeriesByType('themeRiver', function (seriesModel) {
    var data = seriesModel.getData();
    var single = seriesModel.coordinateSystem;
    var layoutInfo = {}; // use the axis boundingRect for view

    var rect = single.getRect();
    layoutInfo.rect = rect;
    var boundaryGap = seriesModel.get('boundaryGap');
    var axis = single.getAxis();
    layoutInfo.boundaryGap = boundaryGap;

    if (axis.orient === 'horizontal') {
      boundaryGap[0] = numberUtil.parsePercent(boundaryGap[0], rect.height);
      boundaryGap[1] = numberUtil.parsePercent(boundaryGap[1], rect.height);
      var height = rect.height - boundaryGap[0] - boundaryGap[1];
      themeRiverLayout(data, seriesModel, height);
    } else {
      boundaryGap[0] = numberUtil.parsePercent(boundaryGap[0], rect.width);
      boundaryGap[1] = numberUtil.parsePercent(boundaryGap[1], rect.width);
      var width = rect.width - boundaryGap[0] - boundaryGap[1];
      themeRiverLayout(data, seriesModel, width);
    }

    data.setLayout('layoutInfo', layoutInfo);
  });
}
/**
 * The layout information about themeriver
 *
 * @param {module:echarts/data/List} data  data in the series
 * @param {module:echarts/model/Series} seriesModel  the model object of themeRiver series
 * @param {number} height  value used to compute every series height
 */

function themeRiverLayout(data, seriesModel, height) {
  if (!data.count()) {
    return;
  }

  var coordSys = seriesModel.coordinateSystem; // the data in each layer are organized into a series.

  var layerSeries = seriesModel.getLayerSeries(); // the points in each layer.

  var layerPoints = zrUtil.map(layerSeries, function (singleLayer) {
    return zrUtil.map(singleLayer.indices, function (idx) {
      var pt = coordSys.dataToPoint(data.get('time', idx));
      pt[1] = data.get('value', idx);
      return pt;
    });
  });
  var base = computeBaseline(layerPoints);
  var baseLine = base.y0;
  var ky = height / base.max; // set layout information for each item.

  var n = layerSeries.length;
  var m = layerSeries[0].indices.length;
  var baseY0;

  for (var j = 0; j < m; ++j) {
    baseY0 = baseLine[j] * ky;
    data.setItemLayout(layerSeries[0].indices[j], {
      layerIndex: 0,
      x: layerPoints[0][j][0],
      y0: baseY0,
      y: layerPoints[0][j][1] * ky
    });

    for (var i = 1; i < n; ++i) {
      baseY0 += layerPoints[i - 1][j][1] * ky;
      data.setItemLayout(layerSeries[i].indices[j], {
        layerIndex: i,
        x: layerPoints[i][j][0],
        y0: baseY0,
        y: layerPoints[i][j][1] * ky
      });
    }
  }
}
/**
 * Compute the baseLine of the rawdata
 * Inspired by Lee Byron's paper Stacked Graphs - Geometry & Aesthetics
 *
 * @param  {Array.<Array>} data  the points in each layer
 * @return {Object}
 */


function computeBaseline(data) {
  var layerNum = data.length;
  var pointNum = data[0].length;
  var sums = [];
  var y0 = [];
  var max = 0;
  var temp;
  var base = {};

  for (var i = 0; i < pointNum; ++i) {
    for (var j = 0, temp = 0; j < layerNum; ++j) {
      temp += data[j][i][1];
    }

    if (temp > max) {
      max = temp;
    }

    sums.push(temp);
  }

  for (var k = 0; k < pointNum; ++k) {
    y0[k] = (max - sums[k]) / 2;
  }

  max = 0;

  for (var l = 0; l < pointNum; ++l) {
    var sum = sums[l] + y0[l];

    if (sum > max) {
      max = sum;
    }
  }

  base.y0 = y0;
  base.max = max;
  return base;
}