intern/container/CTR_TaggedSetOps.h

   1 /**
   2  * $Id$
   3  * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version. The Blender
   9  * Foundation also sells licenses for use in proprietary software under
  10  * the Blender License.  See http://www.blender.org/BL/ for information
  11  * about this.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21  *
  22  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
  23  * All rights reserved.
  24  *
  25  * The Original Code is: all of this file.
  26  *
  27  * Contributor(s): none yet.
  28  *
  29  * ***** END GPL/BL DUAL LICENSE BLOCK *****
  30  */
  31
  32 #ifndef NAN_INCLUDED_LOD_TaggedSetOps_h
  33 #define NAN_INCLUDED_LOD_TaggedSetOps_h
  34
  35 #include "MEM_NonCopyable.h"
  36 #include <vector>
  37
  38 /**
  39  * This class contains some utility functions for finding the intersection,
  40  * union, and difference of a collection of stl vector of indices into
  41  * a set of primitives.
  42  *
  43  * These are mainly used as helper functions in the decimation and bsp
  44  * libraries.
  45  *
  46  * This template class assumes that each value of type IndexType encountered
  47  * in the list is a valid index into an array of primitives. This is not
  48  * checked at run-time and is left to the user to insure. Prmitives of
  49  * type ObjectType must have the following public methods to be used by
  50  * this template class:
  51  *
  52  *      int
  53  * OpenTag(void) --- return a persistent tag value for the primitive
  54  *
  55  *      void
  56  * SetOpenTag(int bla) --- set the persistent tag value for this primitive to bla.
  57  *
  58  *      bool
  59  * SelectTag() --- return a persistent boolean tag for this primitive
  60  *
  61  *      void
  62  * SetSelectTag(bool bla) --- set the persistent boolean tag for this primitive to bla.
  63  *
  64  * Here persistent means that the tag should be associated with the object for the
  65  * entire lifetime of the primitive. Again none of this stuff is enforced you have
  66  * to make sure that your primitives do the right thing. Often these tags can be
  67  * cunningly stowed away inside some of the spare bits in the primitive. See
  68  * CTR_TaggedIndex for such a class.
  69  *
  70  */
  71
  72 template
  73 <class IndexType, class ObjectType>
  74 class CTR_TaggedSetOps : public MEM_NonCopyable {
  75
  76 public :
  77
  78         static
  79                 void
  80         Intersect(
  81                 const std::vector< std::vector<IndexType> > &index_list,
  82                 std::vector<ObjectType> &primitives,
  83                 std::vector<IndexType> &output,
  84                 unsigned int mask,
  85                 unsigned int shift
  86         ) {
  87
  88                 // iterate through vectors in index_list
  89                 // iterate through individual members of each vector
  90                 // mark each obejct that the index points to
  91
  92                 std::vector< std::vector<IndexType> >::const_iterator last_vector = index_list.end();
  93                 std::vector< std::vector<IndexType> >::const_iterator start_vector = index_list.begin();
  94
  95                 // FIXME some temporary space
  96
  97                 std::vector<IndexType> temp_union;
  98                 temp_union.reserve(64);
  99
 100                 int tag_num = 0;
 101
 102                 for (; start_vector != last_vector; ++start_vector) {
 103
 104                         std::vector<IndexType>::const_iterator last_index = start_vector->end();
 105                         std::vector<IndexType>::const_iterator start_index = start_vector->begin();
 106
 107                         for (; start_index != last_index; ++start_index) {
 108
 109                                 ObjectType & prim = primitives[*start_index];
 110
 111                                 if (!prim.OpenTag()) {
 112                                         // compute the union
 113                                         temp_union.push_back(*start_index);
 114                                 }
 115                                 int tag = prim.OpenTag();
 116                                 tag = (tag & mask) >> shift;
 117                                 tag += 1;
 118                                 prim.SetOpenTag((prim.OpenTag() & ~mask)| ((tag << shift) & mask));
 119                         }
 120
 121                         ++tag_num;
 122                 }
 123
 124                 // now iterate through the union and pull out all those with the right tag
 125
 126                 std::vector<IndexType>::const_iterator last_index = temp_union.end();
 127                 std::vector<IndexType>::const_iterator start_index = temp_union.begin();
 128
 129                 for (; start_index != last_index; ++start_index) {
 130
 131                         ObjectType & prim = primitives[*start_index];
 132
 133                         if (prim.OpenTag() == tag_num) {
 134                                 //it's part of the intersection!
 135
 136                                 output.push_back(*start_index);
 137                                 // because we're iterating through the union
 138                                 // it's safe to remove the tag at this point
 139
 140                                 prim.SetOpenTag(prim.OpenTag() & ~mask);
 141                         }
 142                 }
 143         };
 144
 145         // note not a strict set intersection!
 146         // if x appears twice in b and is part of the intersection
 147         // it will appear twice in the intersection
 148
 149         static
 150                 void
 151         IntersectPair(
 152                 const std::vector<IndexType> &a,
 153                 const std::vector<IndexType> &b,
 154                 std::vector<ObjectType> &primitives,
 155                 std::vector<IndexType> &output
 156         ) {
 157
 158                 std::vector<IndexType>::const_iterator last_index = a.end();
 159                 std::vector<IndexType>::const_iterator start_index = a.begin();
 160
 161                 for (; start_index != last_index; ++start_index) {
 162                         ObjectType & prim = primitives[*start_index];
 163                         prim.SetSelectTag(true);
 164                 }
 165                 last_index = b.end();
 166                 start_index = b.begin();
 167
 168                 for (; start_index != last_index; ++start_index) {
 169                         ObjectType & prim = primitives[*start_index];
 170                         if (prim.SelectTag()) {
 171                                 output.push_back(*start_index);
 172                         }
 173                 }
 174                 // deselect
 175                 last_index = a.end();
 176                 start_index = a.begin();
 177
 178                 for (; start_index != last_index; ++start_index) {
 179                         ObjectType & prim = primitives[*start_index];
 180                         prim.SetSelectTag(false);
 181                 }
 182         };
 183
 184
 185         static
 186                 void
 187         Union(
 188                 std::vector< std::vector<IndexType> > &index_list,
 189                 std::vector<ObjectType> &primitives,
 190                 std::vector<IndexType> &output
 191         ) {
 192
 193                 // iterate through vectors in index_list
 194                 // iterate through individual members of each vector
 195                 // mark each obejct that the index points to
 196
 197                 std::vector< std::vector<IndexType> >::const_iterator last_vector = index_list.end();
 198                 std::vector< std::vector<IndexType> >::iterator start_vector = index_list.begin();
 199
 200                 for (; start_vector != last_vector; ++start_vector) {
 201
 202                         std::vector<IndexType>::const_iterator last_index = start_vector->end();
 203                         std::vector<IndexType>::iterator start_index = start_vector->begin();
 204
 205                         for (; start_index != last_index; ++start_index) {
 206
 207                                 ObjectType & prim = primitives[*start_index];
 208
 209                                 if (!prim.SelectTag()) {
 210                                         // compute the union
 211                                         output.push_back(*start_index);
 212                                         prim.SetSelectTag(true);
 213                                 }
 214                         }
 215                 }
 216
 217                 // now iterate through the union and reset the tags
 218
 219                 std::vector<IndexType>::const_iterator last_index = output.end();
 220                 std::vector<IndexType>::iterator start_index = output.begin();
 221
 222                 for (; start_index != last_index; ++start_index) {
 223
 224                         ObjectType & prim = primitives[*start_index];
 225                         prim.SetSelectTag(false);
 226                 }
 227         }
 228
 229
 230         static
 231                 void
 232         Difference(
 233                 std::vector< IndexType> &a,
 234                 std::vector< IndexType> &b,
 235                 std::vector<ObjectType> &primitives,
 236                 std::vector< IndexType> &output
 237         ) {
 238
 239                 // iterate through b mark all
 240                 // iterate through a and add to output all unmarked
 241
 242                 std::vector<IndexType>::const_iterator last_index = b.end();
 243                 std::vector<IndexType>::iterator start_index = b.begin();
 244
 245                 for (; start_index != last_index; ++start_index) {
 246
 247                         ObjectType & prim = primitives[*start_index];
 248                         prim.SetSelectTag(true);
 249                 }
 250
 251                 last_index = a.end();
 252                 start_index = a.begin();
 253
 254                 for (; start_index != last_index; ++start_index) {
 255
 256                         ObjectType & prim = primitives[*start_index];
 257                         if (!prim.SelectTag()) {
 258                                 output.push_back(*start_index);
 259                         }
 260                 }
 261
 262                 // clean up the tags
 263
 264                 last_index = b.end();
 265                 start_index = b.begin();
 266
 267                 for (; start_index != last_index; ++start_index) {
 268
 269                         ObjectType & prim = primitives[*start_index];
 270                         prim.SetSelectTag(false);
 271                 }
 272         };
 273
 274 private :
 275
 276         // private constructor - this class is not meant for
 277         // instantiation
 278
 279         CTR_TaggedSetOps();
 280
 281 };
 282
 283 #endif
 284