1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2016 Joseph Helm and Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | *
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5 | * This file is part of HeuristicLab.
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6 | *
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7 | * HeuristicLab is free software: you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation, either version 3 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * HeuristicLab is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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19 | */
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20 | #endregion
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21 |
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22 | using HeuristicLab.Core;
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23 | using HeuristicLab.Encodings.PermutationEncoding;
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24 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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25 | using System;
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26 | using System.Collections.Generic;
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27 | using System.Linq;
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28 | using System.Text;
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29 | using System.Threading.Tasks;
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30 |
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31 | namespace HeuristicLab.Problems.BinPacking3D.Packer {
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32 | [Item("BinPackerResidualSpaceBestFit", "A class for packing bins for the 3D bin-packer problem. It uses a best fit algortihm depending on the residual space.")]
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33 | [StorableClass]
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34 | public class BinPackerResidualSpaceBestFit : BinPacker {
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35 |
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36 | public BinPackerResidualSpaceBestFit() : base() { }/*
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37 | public BinPackerResidualSpaceBestFit(Permutation permutation, PackingShape binShape, IList<PackingItem> items, bool useStackingConstraints)
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38 | : base(permutation, binShape, items, useStackingConstraints) { }
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39 | */
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40 | /// <summary>
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41 | /// Packs the items into the bins by using a best fit residual space algorithm.
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42 | /// The order of the chosen items depends on the merit function.
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43 | /// Each residual space belongs to an extreme point.
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44 | /// </summary>
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45 | /// <returns></returns>
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46 | public override IList<BinPacking3D> PackItems(Permutation sortedItems, PackingShape binShape, IList<PackingItem> items, bool useStackingConstraints) {
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47 | IList<BinPacking3D> packingList = new List<BinPacking3D>();
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48 | IList<int> remainingIds = new List<int>(sortedItems);
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49 | bool rotated = false;
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50 |
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51 | foreach (var remainingId in remainingIds) {
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52 | PackingItem item = items[remainingId];
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53 | var residualSpacePoints = GetResidualSpaceForAllPoints(packingList, item);
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54 | var sortedPoints = residualSpacePoints.OrderBy(x => x.Item3);
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55 | var packed = false;
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56 |
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57 | foreach (var point in sortedPoints) {
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58 | if (point.Item1.IsPositionFeasible(item, point.Item2, useStackingConstraints)) {
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59 | var binPacking = point.Item1;
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60 | PackItem(ref binPacking, remainingId, item, point.Item2, useStackingConstraints);
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61 | packed = true;
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62 | break;
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63 | }
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64 | }
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65 |
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66 | if (!packed) {
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67 | BinPacking3D binPacking = new BinPacking3D(binShape);
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68 | var position = FindPackingPositionForItem(binPacking, item, useStackingConstraints, rotated);
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69 | if (position != null) {
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70 | PackItem(ref binPacking, remainingId, item, position, useStackingConstraints);
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71 | } else {
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72 | throw new InvalidOperationException("Item " + remainingId + " cannot be packed in an empty bin.");
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73 | }
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74 | packingList.Add(binPacking);
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75 | }
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76 | }
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77 |
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78 | return packingList;
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79 | }
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80 |
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81 | /// <summary>
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82 | /// This method returns a list with all bins and their residual space where a given item can be placed.
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83 | /// It is nessecary to get all bins and their residaul space because this list will be sortet later.
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84 | /// </summary>
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85 | /// <param name="packingList"></param>
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86 | /// <param name="item"></param>
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87 | /// <returns></returns>
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88 | public static IList<Tuple<BinPacking3D, PackingPosition, int>> GetResidualSpaceForAllPoints(IList<BinPacking3D> packingList, PackingItem item) {
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89 | var residualSpacePoints = new List<Tuple<BinPacking3D, PackingPosition, int>>();
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90 | foreach (BinPacking3D bp in packingList) {
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91 | foreach (var ep in bp.ExtremePoints) {
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92 | var rs = bp.ResidualSpace[ep];
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93 | if (rs.Item1 < item.Width || rs.Item2 < item.Height || rs.Item3 < item.Depth) {
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94 | continue;
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95 | }
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96 | residualSpacePoints.Add(Tuple.Create(bp, ep, CalculateResidualMerit(rs, item, ep)));
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97 | }
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98 | }
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99 | return residualSpacePoints;
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100 | }
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101 |
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102 | /// <summary>
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103 | /// The merit function puts an item on the EP that minimizes the difference between its residual space an the item dimension
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104 | /// </summary>
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105 | /// <param name="rs"></param>
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106 | /// <param name="item"></param>
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107 | /// <param name="ep"></param>
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108 | /// <returns></returns>
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109 | private static int CalculateResidualMerit(Tuple<int, int, int> rs, PackingItem item, PackingPosition ep) {
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110 | return ((rs.Item1 - item.Width) +
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111 | (rs.Item2 - item.Height) +
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112 | (rs.Item3 - item.Depth));
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113 | }
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114 |
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115 | }
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116 | }
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