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     ssgBranch *tile = new ssgBranch () ;
 162     tile -> setName ( path.c_str() ) ;
 163
 164     // Attempt to open "path.gz" or "path"
 165     fg_gzifstream in( path );
 166     if ( ! in.is_open() ) {
 167         FG_LOG( FG_TERRAIN, FG_ALERT, "Cannot open file: " << path );
 168         return NULL;
 169     }
 170
 171     shading = current_options.get_shading();
 172
 173     in_fragment = false;
 174     t->ncount = 0;
 175     vncount = 0;
 176     vtcount = 0;
 177     t->bounding_radius = 0.0;
 178     center = t->center;
 179
 180     StopWatch stopwatch;
 181     stopwatch.start();
 182
 183     // ignore initial comments and blank lines. (priming the pump)
 184     // in >> skipcomment;
 185     string line;
 186
 187     while ( ! in.eof() ) {
 188         string token;
 189         char c;
 190
 191 #if defined( MACOS )
 192         in >> ::skipws;
 193 #else
 194         in >> skipws;
 195 #endif
 196
 197         if ( in.get( c ) && c == '#' ) {
 198             // process a comment line
 199
 200             // getline( in, line );
 201             // cout << "comment = " << line << endl;
 202
 203             in >> token;
 204
 205             if ( token == "gbs" ) {
 206                 // reference point (center offset)
 207                 in >> t->center >> t->bounding_radius;
 208                 center = t->center;
 209                 // cout << "center = " << center
 210                 //      << " radius = " << t->bounding_radius << endl;
 211             } else if ( token == "bs" ) {
 212                 // reference point (center offset)
 213                 in >> fragment.center;
 214                 in >> fragment.bounding_radius;
 215
 216                 // cout << "center = " << fragment.center
 217                 //      << " radius = " << fragment.bounding_radius << endl;
 218             } else if ( token == "usemtl" ) {
 219                 // material property specification
 220
 221                 // if first usemtl with shared_done = false, then set
 222                 // shared_done true and build the ssg shared lists
 223                 if ( ! shared_done ) {
 224                     // sanity check
 225                     if ( nodes.size() != vncount ) {
 226                         FG_LOG( FG_TERRAIN, FG_ALERT,
 227                                 "Tile has mismatched nodes and normals: "
 228                                 << path );
 229                         // exit(-1);
 230                     }
 231                     shared_done = true;
 232
 233                     t->vtlist = new sgVec3 [ nodes.size() ];
 234                     t->vnlist = new sgVec3 [ vncount ];
 235                     t->tclist = new sgVec2 [ vtcount ];
 236
 237                     for ( i = 0; i < (int)nodes.size(); ++i ) {
 238                         sgSetVec3( t->vtlist[i],
 239                                    nodes[i][0], nodes[i][1], nodes[i][2] );
 240                     }
 241                     for ( i = 0; i < vncount; ++i ) {
 242                         sgSetVec3( t->vnlist[i],
 243                                    normals[i][0],
 244                                    normals[i][1],
 245                                    normals[i][2] );
 246                     }
 247                     for ( i = 0; i < vtcount; ++i ) {
 248                         sgSetVec2( t->tclist[i],
 249                                    tex_coords[i][0], tex_coords[i][1] );
 250                     }
 251                 }
 252
 253                 // series of individual triangles
 254                 if ( in_faces ) {
 255                     xglEnd();
 256                 }
 257
 258                 // this also signals the start of a new fragment
 259                 if ( in_fragment ) {
 260                     // close out the previous structure and start the next
 261                     xglEndList();
 262                     // printf("xglEnd(); xglEndList();\n");
 263
 264                     // update fragment
 265                     fragment.display_list = display_list;
 266
 267                     // push this fragment onto the tile's object list
 268                     t->fragment_list.push_back(fragment);
 269                 } else {
 270                     in_fragment = true;
 271                 }
 272
 273                 // printf("start of fragment (usemtl)\n");
 274
 275                 display_list = xglGenLists(1);
 276                 xglNewList(display_list, GL_COMPILE);
 277                 // printf("xglGenLists(); xglNewList();\n");
 278                 in_faces = false;
 279
 280                 // reset the existing face list
 281                 // printf("cleaning a fragment with %d faces\n",
 282                 //        fragment.faces.size());
 283                 fragment.init();
 284
 285                 // scan the material line
 286                 string material;
 287                 in >> material;
 288                 fragment.tile_ptr = t;
 289
 290                 // find this material in the properties list
 291                 if ( ! material_mgr.find( material, fragment.material_ptr )) {
 292                     FG_LOG( FG_TERRAIN, FG_ALERT,
 293                             "Ack! unknown usemtl name = " << material
 294                             << " in " << path );
 295                 }
 296
 297                 // set the texture width and height values for this
 298                 // material
 299                 FGMaterial m = fragment.material_ptr->get_m();
 300                 tex_width = m.get_xsize();
 301                 tex_height = m.get_ysize();
 302                 state = fragment.material_ptr->get_state();
 303                 // cout << "(w) = " << tex_width << " (h) = "
 304                 //      << tex_width << endl;
 305
 306                 // initialize the fragment transformation matrix
 307                 /*
 308                  for ( i = 0; i < 16; i++ ) {
 309                    fragment.matrix[i] = 0.0;
 310                  }
 311                  fragment.matrix[0] = fragment.matrix[5] =
 312                  fragment.matrix[10] = fragment.matrix[15] = 1.0;
 313                 */
 314             } else {
 315                 // unknown comment, just gobble the input untill the
 316                 // end of line
 317
 318                 in >> skipeol;
 319             }
 320         } else {
 321             in.putback( c );
 322
 323             in >> token;
 324
 325             // cout << "token = " << token << endl;
 326
 327             if ( token == "vn" ) {
 328                 // vertex normal
 329                 if ( vncount < FG_MAX_NODES ) {
 330                     in >> normals[vncount][0]
 331                        >> normals[vncount][1]
 332                        >> normals[vncount][2];
 333                     vncount++;
 334                 } else {
 335                     FG_LOG( FG_TERRAIN, FG_ALERT,
 336                             "Read too many vertex normals in " << path
 337                             << " ... dying :-(" );
 338                     exit(-1);
 339                 }
 340             } else if ( token == "vt" ) {
 341                 // vertex texture coordinate
 342                 if ( vtcount < FG_MAX_NODES*3 ) {
 343                     in >> tex_coords[vtcount][0]
 344                        >> tex_coords[vtcount][1];
 345                     vtcount++;
 346                 } else {
 347                     FG_LOG( FG_TERRAIN, FG_ALERT,
 348                             "Read too many vertex texture coords in " << path
 349                             << " ... dying :-("
 350                             );
 351                     exit(-1);
 352                 }
 353             } else if ( token == "v" ) {
 354                 // node (vertex)
 355                 if ( t->ncount < FG_MAX_NODES ) {
 356                     /* in >> nodes[t->ncount][0]
 357                        >> nodes[t->ncount][1]
 358                        >> nodes[t->ncount][2]; */
 359                     in >> node;
 360                     nodes.push_back(node);
 361                     t->ncount++;
 362                 } else {
 363                     FG_LOG( FG_TERRAIN, FG_ALERT,
 364                             "Read too many nodes in " << path
 365                             << " ... dying :-(");
 366                     exit(-1);
 367                 }
 368             } else if ( token == "t" ) {
 369                 // start a new triangle strip
 370
 371                 n1 = n2 = n3 = n4 = 0;
 372
 373                 // fgPrintf( FG_TERRAIN, FG_DEBUG,
 374                 //           "    new tri strip = %s", line);
 375                 in >> n1 >> n2 >> n3;
 376                 fragment.add_face(n1, n2, n3);
 377
 378                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
 379
 380                 xglBegin(GL_TRIANGLE_STRIP);
 381                 // printf("xglBegin(tristrip) %d %d %d\n", n1, n2, n3);
 382
 383                 odd = 1;
 384                 // scale = 1.0;
 385
 386                 if ( shading ) {
 387                     // Shading model is "GL_SMOOTH" so use precalculated
 388                     // (averaged) normals
 389                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 390                     xglNormal3dv(normal);
 391                     pp = calc_tex_coords(nodes[n1], center);
 392                     xglTexCoord2f(pp.lon(), pp.lat());
 393                     xglVertex3dv(nodes[n1].get_n());
 394
 395                     // MAT3_SCALE_VEC(normal, normals[n2], scale);
 396                     xglNormal3dv(normal);
 397                     pp = calc_tex_coords(nodes[n2], center);
 398                     xglTexCoord2f(pp.lon(), pp.lat());
 399                     xglVertex3dv(nodes[n2].get_n());
 400
 401                     // MAT3_SCALE_VEC(normal, normals[n3], scale);
 402                     xglNormal3dv(normal);
 403                     pp = calc_tex_coords(nodes[n3], center);
 404                     xglTexCoord2f(pp.lon(), pp.lat());
 405                     xglVertex3dv(nodes[n3].get_n());
 406                 } else {
 407                     // Shading model is "GL_FLAT" so calculate per face
 408                     // normals on the fly.
 409                     if ( odd ) {
 410                         calc_normal(nodes[n1], nodes[n2],
 411                                     nodes[n3], approx_normal);
 412                     } else {
 413                         calc_normal(nodes[n2], nodes[n1],
 414                                     nodes[n3], approx_normal);
 415                     }
 416                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 417                     xglNormal3dv(normal);
 418
 419                     pp = calc_tex_coords(nodes[n1], center);
 420                     xglTexCoord2f(pp.lon(), pp.lat());
 421                     xglVertex3dv(nodes[n1].get_n());
 422
 423                     pp = calc_tex_coords(nodes[n2], center);
 424                     xglTexCoord2f(pp.lon(), pp.lat());
 425                     xglVertex3dv(nodes[n2].get_n());
 426
 427                     pp = calc_tex_coords(nodes[n3], center);
 428                     xglTexCoord2f(pp.lon(), pp.lat());
 429                     xglVertex3dv(nodes[n3].get_n());
 430                 }
 431                 // printf("some normals, texcoords, and vertices\n");
 432
 433                 odd = 1 - odd;
 434                 last1 = n2;
 435                 last2 = n3;
 436
 437                 // There can be three or four values
 438                 char c;
 439                 while ( in.get(c) ) {
 440                     if ( c == '\n' ) {
 441                         break; // only the one
 442                     }
 443                     if ( isdigit(c) ){
 444                         in.putback(c);
 445                         in >> n4;
 446                         break;
 447                     }
 448                 }
 449
 450                 if ( n4 > 0 ) {
 451                     fragment.add_face(n3, n2, n4);
 452
 453                     if ( shading ) {
 454                         // Shading model is "GL_SMOOTH"
 455                         // MAT3_SCALE_VEC(normal, normals[n4], scale);
 456                     } else {
 457                         // Shading model is "GL_FLAT"
 458                         calc_normal(nodes[n3], nodes[n2], nodes[n4],
 459                                     approx_normal);
 460                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 461                     }
 462                     xglNormal3dv(normal);
 463                     pp = calc_tex_coords(nodes[n4], center);
 464                     xglTexCoord2f(pp.lon(), pp.lat());
 465                     xglVertex3dv(nodes[n4].get_n());
 466
 467                     odd = 1 - odd;
 468                     last1 = n3;
 469                     last2 = n4;
 470                     // printf("a normal, texcoord, and vertex (4th)\n");
 471                 }
 472             } else if ( token == "tf" ) {
 473                 // triangle fan
 474                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new fan");
 475
 476                 fan_vertices.clear();
 477                 fan_tex_coords.clear();
 478
 479                 xglBegin(GL_TRIANGLE_FAN);
 480
 481                 in >> n1;
 482                 fan_vertices.push_back( n1 );
 483                 xglNormal3dv(normals[n1]);
 484                 if ( in.get( c ) && c == '/' ) {
 485                     in >> tex;
 486                     fan_tex_coords.push_back( tex );
 487                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 488                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 489                 } else {
 490                     in.putback( c );
 491                     pp = calc_tex_coords(nodes[n1], center);
 492                 }
 493                 xglTexCoord2f(pp.x(), pp.y());
 494                 xglVertex3dv(nodes[n1].get_n());
 495
 496                 in >> n2;
 497                 fan_vertices.push_back( n2 );
 498                 xglNormal3dv(normals[n2]);
 499                 if ( in.get( c ) && c == '/' ) {
 500                     in >> tex;
 501                     fan_tex_coords.push_back( tex );
 502                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 503                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 504                 } else {
 505                     in.putback( c );
 506                     pp = calc_tex_coords(nodes[n2], center);
 507                 }
 508                 xglTexCoord2f(pp.x(), pp.y());
 509                 xglVertex3dv(nodes[n2].get_n());
 510
 511                 // read all subsequent numbers until next thing isn't a number
 512                 while ( true ) {
 513 #if defined( MACOS )
 514                     in >> ::skipws;
 515 #else
 516                     in >> skipws;
 517 #endif
 518
 519                     char c;
 520                     in.get(c);
 521                     in.putback(c);
 522                     if ( ! isdigit(c) || in.eof() ) {
 523                         break;
 524                     }
 525
 526                     in >> n3;
 527                     fan_vertices.push_back( n3 );
 528                     // cout << "  triangle = "
 529                     //      << n1 << "," << n2 << "," << n3
 530                     //      << endl;
 531                     xglNormal3dv(normals[n3]);
 532                     if ( in.get( c ) && c == '/' ) {
 533                         in >> tex;
 534                         fan_tex_coords.push_back( tex );
 535                         pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 536                         pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 537                     } else {
 538                         in.putback( c );
 539                         pp = calc_tex_coords(nodes[n3], center);
 540                     }
 541                     xglTexCoord2f(pp.x(), pp.y());
 542                     xglVertex3dv(nodes[n3].get_n());
 543
 544                     fragment.add_face(n1, n2, n3);
 545                     n2 = n3;
 546                 }
 547
 548                 xglEnd();
 549
 550                 // build the ssg entity
 551                 unsigned short *vindex =
 552                     new unsigned short [ fan_vertices.size() ];
 553                 unsigned short *tindex =
 554                     new unsigned short [ fan_tex_coords.size() ];
 555                 for ( i = 0; i < (int)fan_vertices.size(); ++i ) {
 556                     vindex[i] = fan_vertices[i];
 557                 }
 558                 for ( i = 0; i < (int)fan_tex_coords.size(); ++i ) {
 559                     tindex[i] = fan_tex_coords[i];
 560                 }
 561                 ssgLeaf *leaf =
 562                     new ssgVTable ( GL_TRIANGLE_FAN,
 563                                     fan_vertices.size(), vindex, t->vtlist,
 564                                     fan_vertices.size(), vindex, t->vnlist,
 565                                     fan_tex_coords.size(), tindex, t->tclist,
 566                                     0, NULL, NULL ) ;
 567                 leaf->setState( state );
 568
 569                 tile->addKid( leaf );
 570
 571             } else if ( token == "f" ) {
 572                 // unoptimized face
 573
 574                 if ( !in_faces ) {
 575                     xglBegin(GL_TRIANGLES);
 576                     // printf("xglBegin(triangles)\n");
 577                     in_faces = true;
 578                 }
 579
 580                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
 581                 in >> n1 >> n2 >> n3;
 582                 fragment.add_face(n1, n2, n3);
 583
 584                 // xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
 585                 xglNormal3dv(normals[n1]);
 586                 pp = calc_tex_coords(nodes[n1], center);
 587                 xglTexCoord2f(pp.lon(), pp.lat());
 588                 xglVertex3dv(nodes[n1].get_n());
 589
 590                 xglNormal3dv(normals[n2]);
 591                 pp = calc_tex_coords(nodes[n2], center);
 592                 xglTexCoord2f(pp.lon(), pp.lat());
 593                 xglVertex3dv(nodes[n2].get_n());
 594
 595                 xglNormal3dv(normals[n3]);
 596                 pp = calc_tex_coords(nodes[n3], center);
 597                 xglTexCoord2f(pp.lon(), pp.lat());
 598                 xglVertex3dv(nodes[n3].get_n());
 599                 // printf("some normals, texcoords, and vertices (tris)\n");
 600             } else if ( token == "q" ) {
 601                 // continue a triangle strip
 602                 n1 = n2 = 0;
 603
 604                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
 605                 //           line);
 606                 in >> n1;
 607
 608                 // There can be one or two values
 609                 char c;
 610                 while ( in.get(c) ) {
 611                     if ( c == '\n' ) {
 612                         break; // only the one
 613                     }
 614
 615                     if ( isdigit(c) ) {
 616                         in.putback(c);
 617                         in >> n2;
 618                         break;
 619                     }
 620                 }
 621                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
 622
 623                 if ( odd ) {
 624                     fragment.add_face(last1, last2, n1);
 625                 } else {
 626                     fragment.add_face(last2, last1, n1);
 627                 }
 628
 629                 if ( shading ) {
 630                     // Shading model is "GL_SMOOTH"
 631                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 632                 } else {
 633                     // Shading model is "GL_FLAT"
 634                     if ( odd ) {
 635                         calc_normal(nodes[last1], nodes[last2],
 636                                     nodes[n1], approx_normal);
 637                     } else {
 638                         calc_normal(nodes[last2], nodes[last1],
 639                                     nodes[n1], approx_normal);
 640                     }
 641                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 642                 }
 643                 xglNormal3dv(normal);
 644
 645                 pp = calc_tex_coords(nodes[n1], center);
 646                 xglTexCoord2f(pp.lon(), pp.lat());
 647                 xglVertex3dv(nodes[n1].get_n());
 648                 // printf("a normal, texcoord, and vertex (4th)\n");
 649
 650                 odd = 1 - odd;
 651                 last1 = last2;
 652                 last2 = n1;
 653
 654                 if ( n2 > 0 ) {
 655                     // fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
 656
 657                     if ( odd ) {
 658                         fragment.add_face(last1, last2, n2);
 659                     } else {
 660                         fragment.add_face(last2, last1, n2);
 661                     }
 662
 663                     if ( shading ) {
 664                         // Shading model is "GL_SMOOTH"
 665                         // MAT3_SCALE_VEC(normal, normals[n2], scale);
 666                     } else {
 667                         // Shading model is "GL_FLAT"
 668                         if ( odd ) {
 669                             calc_normal(nodes[last1], nodes[last2],
 670                                         nodes[n2], approx_normal);
 671                         } else {
 672                             calc_normal(nodes[last2], nodes[last1],
 673                                         nodes[n2], approx_normal);
 674                         }
 675                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 676                     }
 677                     xglNormal3dv(normal);
 678
 679                     pp = calc_tex_coords(nodes[n2], center);
 680                     xglTexCoord2f(pp.lon(), pp.lat());
 681                     xglVertex3dv(nodes[n2].get_n());
 682                     // printf("a normal, texcoord, and vertex (4th)\n");
 683
 684                     odd = 1 -odd;
 685                     last1 = last2;
 686                     last2 = n2;
 687                 }
 688             } else {
 689                 FG_LOG( FG_TERRAIN, FG_WARN, "Unknown token in "
 690                         << path << " = " << token );
 691             }
 692
 693             // eat white space before start of while loop so if we are
 694             // done with useful input it is noticed before hand.
 695 #if defined( MACOS )
 696             in >> ::skipws;
 697 #else
 698             in >> skipws;
 699 #endif
 700         }
 701     }
 702
 703     if ( in_fragment ) {
 704         // close out the previous structure and start the next
 705         xglEnd();
 706         xglEndList();
 707         // printf("xglEnd(); xglEndList();\n");
 708
 709         // update fragment
 710         fragment.display_list = display_list;
 711
 712         // push this fragment onto the tile's object list
 713         t->fragment_list.push_back(fragment);
 714     }
 715
 716 #if 0
 717     // Draw normal vectors (for visually verifying normals)
 718     xglBegin(GL_LINES);
 719     xglColor3f(0.0, 0.0, 0.0);
 720     for ( i = 0; i < t->ncount; i++ ) {
 721         xglVertex3d(nodes[i][0],
 722                     nodes[i][1] ,
 723                     nodes[i][2]);
 724         xglVertex3d(nodes[i][0] + 500*normals[i][0],
 725                     nodes[i][1] + 500*normals[i][1],
 726                     nodes[i][2] + 500*normals[i][2]);
 727     }
 728     xglEnd();
 729 #endif
 730
 731     t->nodes = nodes;
 732
 733     stopwatch.stop();
 734     FG_LOG( FG_TERRAIN, FG_INFO,
 735             "Loaded " << path << " in "
 736             << stopwatch.elapsedSeconds() << " seconds" );
 737
 738     return tile;
 739 }
 740
 741