src/symmetry/symmetry-utils.js

/**
 * @file Symmetry Utils
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 * @private
 */

import { Matrix4 } from '../../lib/three.es6.js'

import { Log } from '../globals.js'
import { EncodedSymOp, SymOpCode } from './symmetry-constants.js'

function getSymmetryOperations (spacegroup) {
  var encodedSymopList = EncodedSymOp[ spacegroup ]
  var matrixDict = {}

  if (encodedSymopList === undefined) {
    console.warn(
      "getSymmetryOperations: spacegroup '" +
      spacegroup + "' not found in symop library"
    )
    return matrixDict
  }

  var symopList = []

  for (var i = 0, il = encodedSymopList.length; i < il; i += 3) {
    var symop = []
    for (var j = 0; j < 3; ++j) {
      symop.push(SymOpCode[ encodedSymopList[ i + j ] ])
    }
    symopList.push(symop)
  }

  var reInteger = /^[1-9]$/

  symopList.forEach(function (symop) {
    // console.log( "symop", symop );

    var row = 0
    var matrix = new Matrix4().set(
      0, 0, 0, 0,
      0, 0, 0, 0,
      0, 0, 0, 0,
      0, 0, 0, 1
    )
    var me = matrix.elements

    matrixDict[ symop ] = matrix

    symop.forEach(function (elm) {
      // console.log( "row", row );

      var negate = false
      var denominator = false

      for (var i = 0, n = elm.length; i < n; ++i) {
        var c = elm[ i ]

        if (c === '-') {
          negate = true
        } else if (c === '+') {
          negate = false
        } else if (c === '/') {
          denominator = true
        } else if (c === 'X') {
          me[ 0 + row ] = negate ? -1 : 1
        } else if (c === 'Y') {
          me[ 4 + row ] = negate ? -1 : 1
        } else if (c === 'Z') {
          me[ 8 + row ] = negate ? -1 : 1
        } else if (reInteger.test(c)) {
          var integer = parseInt(c)
          if (denominator) {
            me[ 12 + row ] /= integer
          } else {
            me[ 12 + row ] = integer
          }
        } else {
          Log.warn('getSymmetryOperations: unknown token "' + c + '"')
        }
        // console.log( "token", c )
      }

      row += 1
    })

    // console.log( "matrix", me )
  })

  return matrixDict
}

export {
    getSymmetryOperations
}