public/zh/builder/src/echarts/chart/candlestick/candlestickLayout.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.
*/

/* global Float32Array */
import { subPixelOptimize } from '../../util/graphic';
import createRenderPlanner from '../helper/createRenderPlanner';
import { parsePercent } from '../../util/number';
import { retrieve2 } from 'zrender/src/core/util';
var LargeArr = typeof Float32Array !== 'undefined' ? Float32Array : Array;
export default {
  seriesType: 'candlestick',
  plan: createRenderPlanner(),
  reset: function (seriesModel) {
    var coordSys = seriesModel.coordinateSystem;
    var data = seriesModel.getData();
    var candleWidth = calculateCandleWidth(seriesModel, data);
    var cDimIdx = 0;
    var vDimIdx = 1;
    var coordDims = ['x', 'y'];
    var cDim = data.mapDimension(coordDims[cDimIdx]);
    var vDims = data.mapDimension(coordDims[vDimIdx], true);
    var openDim = vDims[0];
    var closeDim = vDims[1];
    var lowestDim = vDims[2];
    var highestDim = vDims[3];
    data.setLayout({
      candleWidth: candleWidth,
      // The value is experimented visually.
      isSimpleBox: candleWidth <= 1.3
    });

    if (cDim == null || vDims.length < 4) {
      return;
    }

    return {
      progress: seriesModel.pipelineContext.large ? largeProgress : normalProgress
    };

    function normalProgress(params, data) {
      var dataIndex;

      while ((dataIndex = params.next()) != null) {
        var axisDimVal = data.get(cDim, dataIndex);
        var openVal = data.get(openDim, dataIndex);
        var closeVal = data.get(closeDim, dataIndex);
        var lowestVal = data.get(lowestDim, dataIndex);
        var highestVal = data.get(highestDim, dataIndex);
        var ocLow = Math.min(openVal, closeVal);
        var ocHigh = Math.max(openVal, closeVal);
        var ocLowPoint = getPoint(ocLow, axisDimVal);
        var ocHighPoint = getPoint(ocHigh, axisDimVal);
        var lowestPoint = getPoint(lowestVal, axisDimVal);
        var highestPoint = getPoint(highestVal, axisDimVal);
        var ends = [];
        addBodyEnd(ends, ocHighPoint, 0);
        addBodyEnd(ends, ocLowPoint, 1);
        ends.push(subPixelOptimizePoint(highestPoint), subPixelOptimizePoint(ocHighPoint), subPixelOptimizePoint(lowestPoint), subPixelOptimizePoint(ocLowPoint));
        data.setItemLayout(dataIndex, {
          sign: getSign(data, dataIndex, openVal, closeVal, closeDim),
          initBaseline: openVal > closeVal ? ocHighPoint[vDimIdx] : ocLowPoint[vDimIdx],
          // open point.
          ends: ends,
          brushRect: makeBrushRect(lowestVal, highestVal, axisDimVal)
        });
      }

      function getPoint(val, axisDimVal) {
        var p = [];
        p[cDimIdx] = axisDimVal;
        p[vDimIdx] = val;
        return isNaN(axisDimVal) || isNaN(val) ? [NaN, NaN] : coordSys.dataToPoint(p);
      }

      function addBodyEnd(ends, point, start) {
        var point1 = point.slice();
        var point2 = point.slice();
        point1[cDimIdx] = subPixelOptimize(point1[cDimIdx] + candleWidth / 2, 1, false);
        point2[cDimIdx] = subPixelOptimize(point2[cDimIdx] - candleWidth / 2, 1, true);
        start ? ends.push(point1, point2) : ends.push(point2, point1);
      }

      function makeBrushRect(lowestVal, highestVal, axisDimVal) {
        var pmin = getPoint(lowestVal, axisDimVal);
        var pmax = getPoint(highestVal, axisDimVal);
        pmin[cDimIdx] -= candleWidth / 2;
        pmax[cDimIdx] -= candleWidth / 2;
        return {
          x: pmin[0],
          y: pmin[1],
          width: vDimIdx ? candleWidth : pmax[0] - pmin[0],
          height: vDimIdx ? pmax[1] - pmin[1] : candleWidth
        };
      }

      function subPixelOptimizePoint(point) {
        point[cDimIdx] = subPixelOptimize(point[cDimIdx], 1);
        return point;
      }
    }

    function largeProgress(params, data) {
      // Structure: [sign, x, yhigh, ylow, sign, x, yhigh, ylow, ...]
      var points = new LargeArr(params.count * 5);
      var offset = 0;
      var point;
      var tmpIn = [];
      var tmpOut = [];
      var dataIndex;

      while ((dataIndex = params.next()) != null) {
        var axisDimVal = data.get(cDim, dataIndex);
        var openVal = data.get(openDim, dataIndex);
        var closeVal = data.get(closeDim, dataIndex);
        var lowestVal = data.get(lowestDim, dataIndex);
        var highestVal = data.get(highestDim, dataIndex);

        if (isNaN(axisDimVal) || isNaN(lowestVal) || isNaN(highestVal)) {
          points[offset++] = NaN;
          offset += 4;
          continue;
        }

        points[offset++] = getSign(data, dataIndex, openVal, closeVal, closeDim);
        tmpIn[cDimIdx] = axisDimVal;
        tmpIn[vDimIdx] = lowestVal;
        point = coordSys.dataToPoint(tmpIn, null, tmpOut);
        points[offset++] = point ? point[0] : NaN;
        points[offset++] = point ? point[1] : NaN;
        tmpIn[vDimIdx] = highestVal;
        point = coordSys.dataToPoint(tmpIn, null, tmpOut);
        points[offset++] = point ? point[1] : NaN;
      }

      data.setLayout('largePoints', points);
    }
  }
};

function getSign(data, dataIndex, openVal, closeVal, closeDim) {
  var sign;

  if (openVal > closeVal) {
    sign = -1;
  } else if (openVal < closeVal) {
    sign = 1;
  } else {
    sign = dataIndex > 0 // If close === open, compare with close of last record
    ? data.get(closeDim, dataIndex - 1) <= closeVal ? 1 : -1 : // No record of previous, set to be positive
    1;
  }

  return sign;
}

function calculateCandleWidth(seriesModel, data) {
  var baseAxis = seriesModel.getBaseAxis();
  var extent;
  var bandWidth = baseAxis.type === 'category' ? baseAxis.getBandWidth() : (extent = baseAxis.getExtent(), Math.abs(extent[1] - extent[0]) / data.count());
  var barMaxWidth = parsePercent(retrieve2(seriesModel.get('barMaxWidth'), bandWidth), bandWidth);
  var barMinWidth = parsePercent(retrieve2(seriesModel.get('barMinWidth'), 1), bandWidth);
  var barWidth = seriesModel.get('barWidth');
  return barWidth != null ? parsePercent(barWidth, bandWidth) // Put max outer to ensure bar visible in spite of overlap.
  : Math.max(Math.min(bandWidth / 2, barMaxWidth), barMinWidth);
}