src/Objects/obj.cxx

   1 // obj.cxx -- routines to handle "sorta" WaveFront .obj format files.
   2 //
   3 // Written by Curtis Olson, started October 1997.
   4 //
   5 // Copyright (C) 1997  Curtis L. Olson  - curt@infoplane.com
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 //
  21 // $Id$
  22
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include <config.h>
  26 #endif
  27
  28 #ifdef FG_MATH_EXCEPTION_CLASH
  29 #  include <math.h>
  30 #endif
  31
  32 #ifdef HAVE_WINDOWS_H
  33 #  include <windows.h>
  34 #endif
  35
  36 #include <stdio.h>
  37 #include <string.h>
  38 #include <GL/glut.h>
  39 #include <XGL/xgl.h>
  40
  41 // #if defined ( __sun__ )
  42 // extern "C" void *memmove(void *, const void *, size_t);
  43 // extern "C" void *memset(void *, int, size_t);
  44 // #endif
  45
  46 #include <Include/compiler.h>
  47
  48 #include STL_STRING
  49 #include <map>                  // STL
  50 #include <vector>               // STL
  51 #include <ctype.h>              // isdigit()
  52
  53 #include <Debug/logstream.hxx>
  54 #include <Misc/fgstream.hxx>
  55 #include <Include/fg_constants.h>
  56 #include <Main/options.hxx>
  57 #include <Math/mat3.h>
  58 #include <Math/fg_random.h>
  59 #include <Math/point3d.hxx>
  60 #include <Math/polar3d.hxx>
  61 #include <Misc/stopwatch.hxx>
  62 #include <Scenery/tileentry.hxx>
  63
  64 #include "materialmgr.hxx"
  65 #include "obj.hxx"
  66
  67 FG_USING_STD(string);
  68 FG_USING_STD(vector);
  69
  70
  71 typedef vector < int > int_list;
  72 typedef int_list::iterator int_list_iterator;
  73 typedef int_list::const_iterator int_point_list_iterator;
  74
  75
  76 static double normals[FG_MAX_NODES][3];
  77 static double tex_coords[FG_MAX_NODES*3][3];
  78
  79
  80 // given three points defining a triangle, calculate the normal
  81 static void calc_normal(Point3D p1, Point3D p2,
  82                         Point3D p3, double normal[3])
  83 {
  84     double v1[3], v2[3];
  85     double temp;
  86
  87     v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
  88     v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
  89
  90     MAT3cross_product(normal, v1, v2);
  91     MAT3_NORMALIZE_VEC(normal,temp);
  92
  93     // fgPrintf( FG_TERRAIN, FG_DEBUG, "  Normal = %.2f %.2f %.2f\n",
  94     //           normal[0], normal[1], normal[2]);
  95 }
  96
  97
  98 #define FG_TEX_CONSTANT 69.0
  99
 100
 101 // Calculate texture coordinates for a given point.
 102 static Point3D calc_tex_coords(const Point3D& node, const Point3D& ref) {
 103     Point3D cp;
 104     Point3D pp;
 105     // double tmplon, tmplat;
 106
 107     // cout << "-> " << node[0] << " " << node[1] << " " << node[2] << endl;
 108     // cout << "-> " << ref.x() << " " << ref.y() << " " << ref.z() << endl;
 109
 110     cp = Point3D( node[0] + ref.x(),
 111                   node[1] + ref.y(),
 112                   node[2] + ref.z() );
 113
 114     pp = fgCartToPolar3d(cp);
 115
 116     // tmplon = pp.lon() * RAD_TO_DEG;
 117     // tmplat = pp.lat() * RAD_TO_DEG;
 118     // cout << tmplon << " " << tmplat << endl;
 119
 120     pp.setx( fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.x(), 11.0) );
 121     pp.sety( fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.y(), 11.0) );
 122
 123     if ( pp.x() < 0.0 ) {
 124         pp.setx( pp.x() + 11.0 );
 125     }
 126
 127     if ( pp.y() < 0.0 ) {
 128         pp.sety( pp.y() + 11.0 );
 129     }
 130
 131     // cout << pp << endl;
 132
 133     return(pp);
 134 }
 135
 136
 137 // Load a .obj file and build the GL fragment list
 138 ssgBranch *fgObjLoad( const string& path, FGTileEntry *t) {
 139     fgFRAGMENT fragment;
 140     Point3D pp;
 141     double approx_normal[3], normal[3] /*, scale = 0.0 */;
 142     // double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
 143     // GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
 144     GLint display_list = 0;
 145     int shading;
 146     bool in_fragment = false, in_faces = false;
 147     int vncount, vtcount;
 148     int n1 = 0, n2 = 0, n3 = 0, n4 = 0;
 149     int tex;
 150     int last1 = 0, last2 = 0, odd = 0;
 151     point_list nodes;
 152     Point3D node;
 153     Point3D center;
 154     double tex_width = 1000.0, tex_height = 1000.0;
 155     bool shared_done = false;
 156     int_list fan_vertices;
 157     int_list fan_tex_coords;
 158     int i;
 159     ssgSimpleState *state = NULL;
 160
 161     // printf("loading %s\n", path.c_str() );
 162
 163     // Attempt to open "path.gz" or "path"
 164     fg_gzifstream in( path );
 165     if ( ! in.is_open() ) {
 166         FG_LOG( FG_TERRAIN, FG_ALERT, "Cannot open file: " << path );
 167         return 0;
 168     }
 169
 170     shading = current_options.get_shading();
 171
 172     in_fragment = false;
 173     t->ncount = 0;
 174     vncount = 0;
 175     vtcount = 0;
 176     t->bounding_radius = 0.0;
 177     center = t->center;
 178
 179     StopWatch stopwatch;
 180     stopwatch.start();
 181
 182     ssgBranch *tile = new ssgBranch () ;
 183     tile -> setName ( path.c_str() ) ;
 184
 185     // ignore initial comments and blank lines. (priming the pump)
 186     // in >> skipcomment;
 187     string line;
 188
 189     while ( ! in.eof() ) {
 190         string token;
 191         char c;
 192
 193 #if defined( MACOS )
 194         in >> ::skipws;
 195 #else
 196         in >> skipws;
 197 #endif
 198
 199         if ( in.get( c ) && c == '#' ) {
 200             // process a comment line
 201
 202             // getline( in, line );
 203             // cout << "comment = " << line << endl;
 204
 205             in >> token;
 206
 207             if ( token == "gbs" ) {
 208                 // reference point (center offset)
 209                 in >> t->center >> t->bounding_radius;
 210                 center = t->center;
 211                 // cout << "center = " << center
 212                 //      << " radius = " << t->bounding_radius << endl;
 213             } else if ( token == "bs" ) {
 214                 // reference point (center offset)
 215                 in >> fragment.center;
 216                 in >> fragment.bounding_radius;
 217
 218                 // cout << "center = " << fragment.center
 219                 //      << " radius = " << fragment.bounding_radius << endl;
 220             } else if ( token == "usemtl" ) {
 221                 // material property specification
 222
 223                 // if first usemtl with shared_done = false, then set
 224                 // shared_done true and build the ssg shared lists
 225                 if ( ! shared_done ) {
 226                     shared_done = true;
 227
 228                     t->vtlist = new sgVec3 [ nodes.size() ];
 229                     t->vnlist = new sgVec3 [ vncount ];
 230                     t->tclist = new sgVec2 [ vtcount ];
 231
 232                     for ( i = 0; i < (int)nodes.size(); ++i ) {
 233                         sgSetVec3( t->vtlist[i],
 234                                    nodes[i][0], nodes[i][1], nodes[i][2] );
 235                     }
 236                     for ( i = 0; i < vncount; ++i ) {
 237                         sgSetVec3( t->vnlist[i],
 238                                    normals[i][0],
 239                                    normals[i][1],
 240                                    normals[i][2] );
 241                     }
 242                     for ( i = 0; i < vtcount; ++i ) {
 243                         sgSetVec2( t->tclist[i],
 244                                    tex_coords[i][0], tex_coords[i][1] );
 245                     }
 246                 }
 247
 248                 // series of individual triangles
 249                 if ( in_faces ) {
 250                     xglEnd();
 251                 }
 252
 253                 // this also signals the start of a new fragment
 254                 if ( in_fragment ) {
 255                     // close out the previous structure and start the next
 256                     xglEndList();
 257                     // printf("xglEnd(); xglEndList();\n");
 258
 259                     // update fragment
 260                     fragment.display_list = display_list;
 261
 262                     // push this fragment onto the tile's object list
 263                     t->fragment_list.push_back(fragment);
 264                 } else {
 265                     in_fragment = true;
 266                 }
 267
 268                 // printf("start of fragment (usemtl)\n");
 269
 270                 display_list = xglGenLists(1);
 271                 xglNewList(display_list, GL_COMPILE);
 272                 // printf("xglGenLists(); xglNewList();\n");
 273                 in_faces = false;
 274
 275                 // reset the existing face list
 276                 // printf("cleaning a fragment with %d faces\n",
 277                 //        fragment.faces.size());
 278                 fragment.init();
 279
 280                 // scan the material line
 281                 string material;
 282                 in >> material;
 283                 fragment.tile_ptr = t;
 284
 285                 // find this material in the properties list
 286                 if ( ! material_mgr.find( material, fragment.material_ptr )) {
 287                     FG_LOG( FG_TERRAIN, FG_ALERT,
 288                             "Ack! unknown usemtl name = " << material
 289                             << " in " << path );
 290                 }
 291
 292                 // set the texture width and height values for this
 293                 // material
 294                 FGMaterial m = fragment.material_ptr->get_m();
 295                 tex_width = m.get_xsize();
 296                 tex_height = m.get_ysize();
 297                 state = fragment.material_ptr->get_state();
 298                 // cout << "(w) = " << tex_width << " (h) = "
 299                 //      << tex_width << endl;
 300
 301                 // initialize the fragment transformation matrix
 302                 /*
 303                  for ( i = 0; i < 16; i++ ) {
 304                    fragment.matrix[i] = 0.0;
 305                  }
 306                  fragment.matrix[0] = fragment.matrix[5] =
 307                  fragment.matrix[10] = fragment.matrix[15] = 1.0;
 308                 */
 309             } else {
 310                 // unknown comment, just gobble the input untill the
 311                 // end of line
 312
 313                 in >> skipeol;
 314             }
 315         } else {
 316             in.putback( c );
 317
 318             in >> token;
 319
 320             // cout << "token = " << token << endl;
 321
 322             if ( token == "vn" ) {
 323                 // vertex normal
 324                 if ( vncount < FG_MAX_NODES ) {
 325                     in >> normals[vncount][0]
 326                        >> normals[vncount][1]
 327                        >> normals[vncount][2];
 328                     vncount++;
 329                 } else {
 330                     FG_LOG( FG_TERRAIN, FG_ALERT,
 331                             "Read too many vertex normals in " << path
 332                             << " ... dying :-(" );
 333                     exit(-1);
 334                 }
 335             } else if ( token == "vt" ) {
 336                 // vertex texture coordinate
 337                 if ( vtcount < FG_MAX_NODES*3 ) {
 338                     in >> tex_coords[vtcount][0]
 339                        >> tex_coords[vtcount][1];
 340                     vtcount++;
 341                 } else {
 342                     FG_LOG( FG_TERRAIN, FG_ALERT,
 343                             "Read too many vertex texture coords in " << path
 344                             << " ... dying :-("
 345                             );
 346                     exit(-1);
 347                 }
 348             } else if ( token == "v" ) {
 349                 // node (vertex)
 350                 if ( t->ncount < FG_MAX_NODES ) {
 351                     /* in >> nodes[t->ncount][0]
 352                        >> nodes[t->ncount][1]
 353                        >> nodes[t->ncount][2]; */
 354                     in >> node;
 355                     nodes.push_back(node);
 356                     t->ncount++;
 357                 } else {
 358                     FG_LOG( FG_TERRAIN, FG_ALERT,
 359                             "Read too many nodes in " << path
 360                             << " ... dying :-(");
 361                     exit(-1);
 362                 }
 363             } else if ( token == "t" ) {
 364                 // start a new triangle strip
 365
 366                 n1 = n2 = n3 = n4 = 0;
 367
 368                 // fgPrintf( FG_TERRAIN, FG_DEBUG,
 369                 //           "    new tri strip = %s", line);
 370                 in >> n1 >> n2 >> n3;
 371                 fragment.add_face(n1, n2, n3);
 372
 373                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
 374
 375                 xglBegin(GL_TRIANGLE_STRIP);
 376                 // printf("xglBegin(tristrip) %d %d %d\n", n1, n2, n3);
 377
 378                 odd = 1;
 379                 // scale = 1.0;
 380
 381                 if ( shading ) {
 382                     // Shading model is "GL_SMOOTH" so use precalculated
 383                     // (averaged) normals
 384                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 385                     xglNormal3dv(normal);
 386                     pp = calc_tex_coords(nodes[n1], center);
 387                     xglTexCoord2f(pp.lon(), pp.lat());
 388                     xglVertex3dv(nodes[n1].get_n());
 389
 390                     // MAT3_SCALE_VEC(normal, normals[n2], scale);
 391                     xglNormal3dv(normal);
 392                     pp = calc_tex_coords(nodes[n2], center);
 393                     xglTexCoord2f(pp.lon(), pp.lat());
 394                     xglVertex3dv(nodes[n2].get_n());
 395
 396                     // MAT3_SCALE_VEC(normal, normals[n3], scale);
 397                     xglNormal3dv(normal);
 398                     pp = calc_tex_coords(nodes[n3], center);
 399                     xglTexCoord2f(pp.lon(), pp.lat());
 400                     xglVertex3dv(nodes[n3].get_n());
 401                 } else {
 402                     // Shading model is "GL_FLAT" so calculate per face
 403                     // normals on the fly.
 404                     if ( odd ) {
 405                         calc_normal(nodes[n1], nodes[n2],
 406                                     nodes[n3], approx_normal);
 407                     } else {
 408                         calc_normal(nodes[n2], nodes[n1],
 409                                     nodes[n3], approx_normal);
 410                     }
 411                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 412                     xglNormal3dv(normal);
 413
 414                     pp = calc_tex_coords(nodes[n1], center);
 415                     xglTexCoord2f(pp.lon(), pp.lat());
 416                     xglVertex3dv(nodes[n1].get_n());
 417
 418                     pp = calc_tex_coords(nodes[n2], center);
 419                     xglTexCoord2f(pp.lon(), pp.lat());
 420                     xglVertex3dv(nodes[n2].get_n());
 421
 422                     pp = calc_tex_coords(nodes[n3], center);
 423                     xglTexCoord2f(pp.lon(), pp.lat());
 424                     xglVertex3dv(nodes[n3].get_n());
 425                 }
 426                 // printf("some normals, texcoords, and vertices\n");
 427
 428                 odd = 1 - odd;
 429                 last1 = n2;
 430                 last2 = n3;
 431
 432                 // There can be three or four values
 433                 char c;
 434                 while ( in.get(c) ) {
 435                     if ( c == '\n' ) {
 436                         break; // only the one
 437                     }
 438                     if ( isdigit(c) ){
 439                         in.putback(c);
 440                         in >> n4;
 441                         break;
 442                     }
 443                 }
 444
 445                 if ( n4 > 0 ) {
 446                     fragment.add_face(n3, n2, n4);
 447
 448                     if ( shading ) {
 449                         // Shading model is "GL_SMOOTH"
 450                         // MAT3_SCALE_VEC(normal, normals[n4], scale);
 451                     } else {
 452                         // Shading model is "GL_FLAT"
 453                         calc_normal(nodes[n3], nodes[n2], nodes[n4],
 454                                     approx_normal);
 455                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 456                     }
 457                     xglNormal3dv(normal);
 458                     pp = calc_tex_coords(nodes[n4], center);
 459                     xglTexCoord2f(pp.lon(), pp.lat());
 460                     xglVertex3dv(nodes[n4].get_n());
 461
 462                     odd = 1 - odd;
 463                     last1 = n3;
 464                     last2 = n4;
 465                     // printf("a normal, texcoord, and vertex (4th)\n");
 466                 }
 467             } else if ( token == "tf" ) {
 468                 // triangle fan
 469                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new fan");
 470
 471                 fan_vertices.clear();
 472                 fan_tex_coords.clear();
 473
 474                 xglBegin(GL_TRIANGLE_FAN);
 475
 476                 in >> n1;
 477                 fan_vertices.push_back( n1 );
 478                 xglNormal3dv(normals[n1]);
 479                 if ( in.get( c ) && c == '/' ) {
 480                     in >> tex;
 481                     fan_tex_coords.push_back( tex );
 482                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 483                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 484                 } else {
 485                     in.putback( c );
 486                     pp = calc_tex_coords(nodes[n1], center);
 487                 }
 488                 xglTexCoord2f(pp.x(), pp.y());
 489                 xglVertex3dv(nodes[n1].get_n());
 490
 491                 in >> n2;
 492                 fan_vertices.push_back( n2 );
 493                 xglNormal3dv(normals[n2]);
 494                 if ( in.get( c ) && c == '/' ) {
 495                     in >> tex;
 496                     fan_tex_coords.push_back( tex );
 497                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 498                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 499                 } else {
 500                     in.putback( c );
 501                     pp = calc_tex_coords(nodes[n2], center);
 502                 }
 503                 xglTexCoord2f(pp.x(), pp.y());
 504                 xglVertex3dv(nodes[n2].get_n());
 505
 506                 // read all subsequent numbers until next thing isn't a number
 507                 while ( true ) {
 508 #if defined( MACOS )
 509                     in >> ::skipws;
 510 #else
 511                     in >> skipws;
 512 #endif
 513
 514                     char c;
 515                     in.get(c);
 516                     in.putback(c);
 517                     if ( ! isdigit(c) || in.eof() ) {
 518                         break;
 519                     }
 520
 521                     in >> n3;
 522                     fan_vertices.push_back( n3 );
 523                     // cout << "  triangle = "
 524                     //      << n1 << "," << n2 << "," << n3
 525                     //      << endl;
 526                     xglNormal3dv(normals[n3]);
 527                     if ( in.get( c ) && c == '/' ) {
 528                         in >> tex;
 529                         fan_tex_coords.push_back( tex );
 530                         pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 531                         pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 532                     } else {
 533                         in.putback( c );
 534                         pp = calc_tex_coords(nodes[n3], center);
 535                     }
 536                     xglTexCoord2f(pp.x(), pp.y());
 537                     xglVertex3dv(nodes[n3].get_n());
 538
 539                     fragment.add_face(n1, n2, n3);
 540                     n2 = n3;
 541                 }
 542
 543                 xglEnd();
 544
 545                 // build the ssg entity
 546                 unsigned short *vindex =
 547                     new unsigned short [ fan_vertices.size() ];
 548                 unsigned short *tindex =
 549                     new unsigned short [ fan_tex_coords.size() ];
 550                 for ( i = 0; i < (int)fan_vertices.size(); ++i ) {
 551                     vindex[i] = fan_vertices[i];
 552                 }
 553                 for ( i = 0; i < (int)fan_tex_coords.size(); ++i ) {
 554                     tindex[i] = fan_tex_coords[i];
 555                 }
 556                 ssgLeaf *leaf =
 557                     new ssgVTable ( GL_TRIANGLE_FAN,
 558                                     fan_vertices.size(), vindex, t->vtlist,
 559                                     fan_vertices.size(), vindex, t->vnlist,
 560                                     fan_tex_coords.size(), tindex, t->tclist,
 561                                     0, NULL, NULL ) ;
 562                 leaf->setState( state );
 563
 564                 tile->addKid( leaf );
 565
 566             } else if ( token == "f" ) {
 567                 // unoptimized face
 568
 569                 if ( !in_faces ) {
 570                     xglBegin(GL_TRIANGLES);
 571                     // printf("xglBegin(triangles)\n");
 572                     in_faces = true;
 573                 }
 574
 575                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
 576                 in >> n1 >> n2 >> n3;
 577                 fragment.add_face(n1, n2, n3);
 578
 579                 // xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
 580                 xglNormal3dv(normals[n1]);
 581                 pp = calc_tex_coords(nodes[n1], center);
 582                 xglTexCoord2f(pp.lon(), pp.lat());
 583                 xglVertex3dv(nodes[n1].get_n());
 584
 585                 xglNormal3dv(normals[n2]);
 586                 pp = calc_tex_coords(nodes[n2], center);
 587                 xglTexCoord2f(pp.lon(), pp.lat());
 588                 xglVertex3dv(nodes[n2].get_n());
 589
 590                 xglNormal3dv(normals[n3]);
 591                 pp = calc_tex_coords(nodes[n3], center);
 592                 xglTexCoord2f(pp.lon(), pp.lat());
 593                 xglVertex3dv(nodes[n3].get_n());
 594                 // printf("some normals, texcoords, and vertices (tris)\n");
 595             } else if ( token == "q" ) {
 596                 // continue a triangle strip
 597                 n1 = n2 = 0;
 598
 599                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
 600                 //           line);
 601                 in >> n1;
 602
 603                 // There can be one or two values
 604                 char c;
 605                 while ( in.get(c) ) {
 606                     if ( c == '\n' ) {
 607                         break; // only the one
 608                     }
 609
 610                     if ( isdigit(c) ) {
 611                         in.putback(c);
 612                         in >> n2;
 613                         break;
 614                     }
 615                 }
 616                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
 617
 618                 if ( odd ) {
 619                     fragment.add_face(last1, last2, n1);
 620                 } else {
 621                     fragment.add_face(last2, last1, n1);
 622                 }
 623
 624                 if ( shading ) {
 625                     // Shading model is "GL_SMOOTH"
 626                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 627                 } else {
 628                     // Shading model is "GL_FLAT"
 629                     if ( odd ) {
 630                         calc_normal(nodes[last1], nodes[last2],
 631                                     nodes[n1], approx_normal);
 632                     } else {
 633                         calc_normal(nodes[last2], nodes[last1],
 634                                     nodes[n1], approx_normal);
 635                     }
 636                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 637                 }
 638                 xglNormal3dv(normal);
 639
 640                 pp = calc_tex_coords(nodes[n1], center);
 641                 xglTexCoord2f(pp.lon(), pp.lat());
 642                 xglVertex3dv(nodes[n1].get_n());
 643                 // printf("a normal, texcoord, and vertex (4th)\n");
 644
 645                 odd = 1 - odd;
 646                 last1 = last2;
 647                 last2 = n1;
 648
 649                 if ( n2 > 0 ) {
 650                     // fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
 651
 652                     if ( odd ) {
 653                         fragment.add_face(last1, last2, n2);
 654                     } else {
 655                         fragment.add_face(last2, last1, n2);
 656                     }
 657
 658                     if ( shading ) {
 659                         // Shading model is "GL_SMOOTH"
 660                         // MAT3_SCALE_VEC(normal, normals[n2], scale);
 661                     } else {
 662                         // Shading model is "GL_FLAT"
 663                         if ( odd ) {
 664                             calc_normal(nodes[last1], nodes[last2],
 665                                         nodes[n2], approx_normal);
 666                         } else {
 667                             calc_normal(nodes[last2], nodes[last1],
 668                                         nodes[n2], approx_normal);
 669                         }
 670                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 671                     }
 672                     xglNormal3dv(normal);
 673
 674                     pp = calc_tex_coords(nodes[n2], center);
 675                     xglTexCoord2f(pp.lon(), pp.lat());
 676                     xglVertex3dv(nodes[n2].get_n());
 677                     // printf("a normal, texcoord, and vertex (4th)\n");
 678
 679                     odd = 1 -odd;
 680                     last1 = last2;
 681                     last2 = n2;
 682                 }
 683             } else {
 684                 FG_LOG( FG_TERRAIN, FG_WARN, "Unknown token in "
 685                         << path << " = " << token );
 686             }
 687
 688             // eat white space before start of while loop so if we are
 689             // done with useful input it is noticed before hand.
 690 #if defined( MACOS )
 691             in >> ::skipws;
 692 #else
 693             in >> skipws;
 694 #endif
 695         }
 696     }
 697
 698     if ( in_fragment ) {
 699         // close out the previous structure and start the next
 700         xglEnd();
 701         xglEndList();
 702         // printf("xglEnd(); xglEndList();\n");
 703
 704         // update fragment
 705         fragment.display_list = display_list;
 706
 707         // push this fragment onto the tile's object list
 708         t->fragment_list.push_back(fragment);
 709     }
 710
 711 #if 0
 712     // Draw normal vectors (for visually verifying normals)
 713     xglBegin(GL_LINES);
 714     xglColor3f(0.0, 0.0, 0.0);
 715     for ( i = 0; i < t->ncount; i++ ) {
 716         xglVertex3d(nodes[i][0],
 717                     nodes[i][1] ,
 718                     nodes[i][2]);
 719         xglVertex3d(nodes[i][0] + 500*normals[i][0],
 720                     nodes[i][1] + 500*normals[i][1],
 721                     nodes[i][2] + 500*normals[i][2]);
 722     }
 723     xglEnd();
 724 #endif
 725
 726     t->nodes = nodes;
 727
 728     stopwatch.stop();
 729     FG_LOG( FG_TERRAIN, FG_INFO,
 730             "Loaded " << path << " in "
 731             << stopwatch.elapsedSeconds() << " seconds" );
 732
 733     return tile;
 734 }
 735
 736