kepler.gl/src/utils/layer-utils/layer-utils.js

kepler.gl is a webgl based application to visualize large scale location data in the browser

// Copyright (c) 2018 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import {DEFAULT_LIGHT_SETTINGS} from 'constants/default-settings';

/**
 * Find default layers from fields
 *
 * @param {Object} dataset
 * @param {Object} layerClasses
 * @returns {Array} found layers
 */
export function findDefaultLayer(dataset, layerClasses) {
  if (!dataset) {
    return [];
  }

  let layers = [];
  Object.keys(layerClasses).forEach(lc => {
    const layerProps = layerClasses[lc].findDefaultLayerProps(dataset);
    if (layerProps) {
      const found = (Array.isArray(layerProps) ? layerProps : [layerProps])
        .map(props => new layerClasses[lc]({...props, dataId: dataset.id}));
      layers = layers.concat(found);
    }
  });

  return layers;
}

/**
 * calculate layer data based on layer type, col Config,
 * return updated layer if colorDomain, dataMap has changed
 * @param {object} layer
 * @param {object} state
 * @param {object} oldLayerData
 * @param {object} opt
 * @returns {object} {layerData: {}, layer: {} || undefined}
 */
export function calculateLayerData(layer, state, oldLayerData, opt = {}) {
  const {type} = layer;
  const {datasets} = state;

  const {data, filteredIndex, allData} = datasets[layer.config.dataId] || {};

  if (!type || !layer.hasAllColumns()) {
    return {layer, layerData: {}};
  }

  const layerData = layer.formatLayerData(
    data,
    allData,
    filteredIndex,
    oldLayerData,
    opt
  );
  return {layerData, layer};
}

export function getLightSettingsFromBounds(bounds) {
  return Array.isArray(bounds) && bounds.length >= 4
    ? {
        ...DEFAULT_LIGHT_SETTINGS,
        lightsPosition: [
          ...bounds.slice(0, 2),
          DEFAULT_LIGHT_SETTINGS.lightsPosition[2],
          ...bounds.slice(2, 4),
          DEFAULT_LIGHT_SETTINGS.lightsPosition[5]
        ]
      }
    : DEFAULT_LIGHT_SETTINGS;
}