@cquiroz/aladin-lite/lib/js/HealpixCache.js

AladinLite module

// Copyright 2013 - UDS/CNRS
// The Aladin Lite program is distributed under the terms
// of the GNU General Public License version 3.
//
// This file is part of Aladin Lite.
//
//    Aladin Lite is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, version 3 of the License.
//
//    Aladin Lite is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    The GNU General Public License is available in COPYING file
//    along with Aladin Lite.
//

/******************************************************************************
 * Aladin Lite project
 *
 * File HealpixCache
 *
 * Author: Thomas Boch[CDS]
 *
 *****************************************************************************/
import { HealpixIndex } from './HealpixIndex'; // class holding some HEALPix computations for better performances
//
// it is made of :
// - a static cache for HEALPix corners at nside=8
// - a dynamic cache for

var HealpixCache = function () {
  var HealpixCache = {};
  HealpixCache.staticCache = {
    corners: {
      nside8: []
    }
  }; // TODO : utilisation du dynamicCache

  HealpixCache.dynamicCache = {};
  HealpixCache.lastNside = 8;
  HealpixCache.hpxIdxCache = null; // TODO : conserver en cache le dernier résultat ?

  HealpixCache.init = function () {
    // pre-compute corners position for nside=8
    var hpxIdx = new HealpixIndex(8);
    var npix = HealpixIndex.nside2Npix(8);
    var corners;

    for (var ipix = 0; ipix < npix; ipix++) {
      corners = hpxIdx.corners_nest(ipix, 1);
      HealpixCache.staticCache.corners.nside8.push(corners);
    }

    HealpixCache.hpxIdxCache = hpxIdx;
  };

  HealpixCache.init();

  HealpixCache.corners_nest = function (ipix, nside) {
    if (nside === 8) {
      return HealpixCache.staticCache.corners.nside8[ipix];
    }

    if (nside !== HealpixCache.lastNside) {
      HealpixCache.hpxIdxCache = new HealpixIndex(nside);
      HealpixCache.lastNside = nside;
    }

    return HealpixCache.hpxIdxCache.corners_nest(ipix, 1);
  };

  return HealpixCache;
}();

export default HealpixCache;