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     string token;
 188     char c;
 189
 190 #ifdef __MWERKS__
 191     while ( in.get(c) && c  != '\0' ) {
 192         in.putback(c);
 193 #else
 194     while ( ! in.eof() ) {
 195 #endif
 196
 197 #if defined( MACOS )
 198         in >> ::skipws;
 199 #else
 200         in >> skipws;
 201 #endif
 202
 203         if ( in.get( c ) && c == '#' ) {
 204             // process a comment line
 205
 206             // getline( in, line );
 207             // cout << "comment = " << line << endl;
 208
 209             in >> token;
 210
 211             if ( token == "gbs" ) {
 212                 // reference point (center offset)
 213                 in >> t->center >> t->bounding_radius;
 214                 center = t->center;
 215                 // cout << "center = " << center
 216                 //      << " radius = " << t->bounding_radius << endl;
 217             } else if ( token == "bs" ) {
 218                 // reference point (center offset)
 219                 in >> fragment.center;
 220                 in >> fragment.bounding_radius;
 221
 222                 // cout << "center = " << fragment.center
 223                 //      << " radius = " << fragment.bounding_radius << endl;
 224             } else if ( token == "usemtl" ) {
 225                 // material property specification
 226
 227                 // if first usemtl with shared_done = false, then set
 228                 // shared_done true and build the ssg shared lists
 229                 if ( ! shared_done ) {
 230                     // sanity check
 231                     if ( nodes.size() != vncount ) {
 232                         FG_LOG( FG_TERRAIN, FG_ALERT,
 233                                 "Tile has mismatched nodes and normals: "
 234                                 << path );
 235                         // exit(-1);
 236                     }
 237                     shared_done = true;
 238
 239                     t->vtlist = new sgVec3 [ nodes.size() ];
 240                     t->vnlist = new sgVec3 [ vncount ];
 241                     t->tclist = new sgVec2 [ vtcount ];
 242
 243                     for ( i = 0; i < (int)nodes.size(); ++i ) {
 244                         sgSetVec3( t->vtlist[i],
 245                                    nodes[i][0], nodes[i][1], nodes[i][2] );
 246                     }
 247                     for ( i = 0; i < vncount; ++i ) {
 248                         sgSetVec3( t->vnlist[i],
 249                                    normals[i][0],
 250                                    normals[i][1],
 251                                    normals[i][2] );
 252                     }
 253                     for ( i = 0; i < vtcount; ++i ) {
 254                         sgSetVec2( t->tclist[i],
 255                                    tex_coords[i][0], tex_coords[i][1] );
 256                     }
 257                 }
 258
 259                 // series of individual triangles
 260                 if ( in_faces ) {
 261                     xglEnd();
 262                 }
 263
 264                 // this also signals the start of a new fragment
 265                 if ( in_fragment ) {
 266                     // close out the previous structure and start the next
 267                     xglEndList();
 268                     // printf("xglEnd(); xglEndList();\n");
 269
 270                     // update fragment
 271                     fragment.display_list = display_list;
 272
 273                     // push this fragment onto the tile's object list
 274                     t->fragment_list.push_back(fragment);
 275                 } else {
 276                     in_fragment = true;
 277                 }
 278
 279                 // printf("start of fragment (usemtl)\n");
 280
 281                 display_list = xglGenLists(1);
 282                 xglNewList(display_list, GL_COMPILE);
 283                 // printf("xglGenLists(); xglNewList();\n");
 284                 in_faces = false;
 285
 286                 // reset the existing face list
 287                 // printf("cleaning a fragment with %d faces\n",
 288                 //        fragment.faces.size());
 289                 fragment.init();
 290
 291                 // scan the material line
 292                 string material;
 293                 in >> material;
 294                 fragment.tile_ptr = t;
 295
 296                 // find this material in the properties list
 297                 if ( ! material_mgr.find( material, fragment.material_ptr )) {
 298                     FG_LOG( FG_TERRAIN, FG_ALERT,
 299                             "Ack! unknown usemtl name = " << material
 300                             << " in " << path );
 301                 }
 302
 303                 // set the texture width and height values for this
 304                 // material
 305                 FGMaterial m = fragment.material_ptr->get_m();
 306                 tex_width = m.get_xsize();
 307                 tex_height = m.get_ysize();
 308                 state = fragment.material_ptr->get_state();
 309                 // cout << "(w) = " << tex_width << " (h) = "
 310                 //      << tex_width << endl;
 311
 312                 // initialize the fragment transformation matrix
 313                 /*
 314                  for ( i = 0; i < 16; i++ ) {
 315                    fragment.matrix[i] = 0.0;
 316                  }
 317                  fragment.matrix[0] = fragment.matrix[5] =
 318                  fragment.matrix[10] = fragment.matrix[15] = 1.0;
 319                 */
 320             } else {
 321                 // unknown comment, just gobble the input untill the
 322                 // end of line
 323
 324                 in >> skipeol;
 325             }
 326         } else {
 327             in.putback( c );
 328
 329             in >> token;
 330
 331             // cout << "token = " << token << endl;
 332
 333             if ( token == "vn" ) {
 334                 // vertex normal
 335                 if ( vncount < FG_MAX_NODES ) {
 336                     in >> normals[vncount][0]
 337                        >> normals[vncount][1]
 338                        >> normals[vncount][2];
 339                     vncount++;
 340                 } else {
 341                     FG_LOG( FG_TERRAIN, FG_ALERT,
 342                             "Read too many vertex normals in " << path
 343                             << " ... dying :-(" );
 344                     exit(-1);
 345                 }
 346             } else if ( token == "vt" ) {
 347                 // vertex texture coordinate
 348                 if ( vtcount < FG_MAX_NODES*3 ) {
 349                     in >> tex_coords[vtcount][0]
 350                        >> tex_coords[vtcount][1];
 351                     vtcount++;
 352                 } else {
 353                     FG_LOG( FG_TERRAIN, FG_ALERT,
 354                             "Read too many vertex texture coords in " << path
 355                             << " ... dying :-("
 356                             );
 357                     exit(-1);
 358                 }
 359             } else if ( token == "v" ) {
 360                 // node (vertex)
 361                 if ( t->ncount < FG_MAX_NODES ) {
 362                     /* in >> nodes[t->ncount][0]
 363                        >> nodes[t->ncount][1]
 364                        >> nodes[t->ncount][2]; */
 365                     in >> node;
 366                     nodes.push_back(node);
 367                     t->ncount++;
 368                 } else {
 369                     FG_LOG( FG_TERRAIN, FG_ALERT,
 370                             "Read too many nodes in " << path
 371                             << " ... dying :-(");
 372                     exit(-1);
 373                 }
 374             } else if ( token == "t" ) {
 375                 // start a new triangle strip
 376
 377                 n1 = n2 = n3 = n4 = 0;
 378
 379                 // fgPrintf( FG_TERRAIN, FG_DEBUG,
 380                 //           "    new tri strip = %s", line);
 381                 in >> n1 >> n2 >> n3;
 382                 fragment.add_face(n1, n2, n3);
 383
 384                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
 385
 386                 xglBegin(GL_TRIANGLE_STRIP);
 387                 // printf("xglBegin(tristrip) %d %d %d\n", n1, n2, n3);
 388
 389                 odd = 1;
 390                 // scale = 1.0;
 391
 392                 if ( shading ) {
 393                     // Shading model is "GL_SMOOTH" so use precalculated
 394                     // (averaged) normals
 395                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 396                     xglNormal3dv(normal);
 397                     pp = calc_tex_coords(nodes[n1], center);
 398                     xglTexCoord2f(pp.lon(), pp.lat());
 399                     xglVertex3dv(nodes[n1].get_n());
 400
 401                     // MAT3_SCALE_VEC(normal, normals[n2], scale);
 402                     xglNormal3dv(normal);
 403                     pp = calc_tex_coords(nodes[n2], center);
 404                     xglTexCoord2f(pp.lon(), pp.lat());
 405                     xglVertex3dv(nodes[n2].get_n());
 406
 407                     // MAT3_SCALE_VEC(normal, normals[n3], scale);
 408                     xglNormal3dv(normal);
 409                     pp = calc_tex_coords(nodes[n3], center);
 410                     xglTexCoord2f(pp.lon(), pp.lat());
 411                     xglVertex3dv(nodes[n3].get_n());
 412                 } else {
 413                     // Shading model is "GL_FLAT" so calculate per face
 414                     // normals on the fly.
 415                     if ( odd ) {
 416                         calc_normal(nodes[n1], nodes[n2],
 417                                     nodes[n3], approx_normal);
 418                     } else {
 419                         calc_normal(nodes[n2], nodes[n1],
 420                                     nodes[n3], approx_normal);
 421                     }
 422                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 423                     xglNormal3dv(normal);
 424
 425                     pp = calc_tex_coords(nodes[n1], center);
 426                     xglTexCoord2f(pp.lon(), pp.lat());
 427                     xglVertex3dv(nodes[n1].get_n());
 428
 429                     pp = calc_tex_coords(nodes[n2], center);
 430                     xglTexCoord2f(pp.lon(), pp.lat());
 431                     xglVertex3dv(nodes[n2].get_n());
 432
 433                     pp = calc_tex_coords(nodes[n3], center);
 434                     xglTexCoord2f(pp.lon(), pp.lat());
 435                     xglVertex3dv(nodes[n3].get_n());
 436                 }
 437                 // printf("some normals, texcoords, and vertices\n");
 438
 439                 odd = 1 - odd;
 440                 last1 = n2;
 441                 last2 = n3;
 442
 443                 // There can be three or four values
 444                 char c;
 445                 while ( in.get(c) ) {
 446                     if ( c == '\n' ) {
 447                         break; // only the one
 448                     }
 449                     if ( isdigit(c) ){
 450                         in.putback(c);
 451                         in >> n4;
 452                         break;
 453                     }
 454                 }
 455
 456                 if ( n4 > 0 ) {
 457                     fragment.add_face(n3, n2, n4);
 458
 459                     if ( shading ) {
 460                         // Shading model is "GL_SMOOTH"
 461                         // MAT3_SCALE_VEC(normal, normals[n4], scale);
 462                     } else {
 463                         // Shading model is "GL_FLAT"
 464                         calc_normal(nodes[n3], nodes[n2], nodes[n4],
 465                                     approx_normal);
 466                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 467                     }
 468                     xglNormal3dv(normal);
 469                     pp = calc_tex_coords(nodes[n4], center);
 470                     xglTexCoord2f(pp.lon(), pp.lat());
 471                     xglVertex3dv(nodes[n4].get_n());
 472
 473                     odd = 1 - odd;
 474                     last1 = n3;
 475                     last2 = n4;
 476                     // printf("a normal, texcoord, and vertex (4th)\n");
 477                 }
 478             } else if ( token == "tf" ) {
 479                 // triangle fan
 480                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new fan");
 481
 482                 fan_vertices.clear();
 483                 fan_tex_coords.clear();
 484
 485                 xglBegin(GL_TRIANGLE_FAN);
 486
 487                 in >> n1;
 488                 fan_vertices.push_back( n1 );
 489                 xglNormal3dv(normals[n1]);
 490                 if ( in.get( c ) && c == '/' ) {
 491                     in >> tex;
 492                     fan_tex_coords.push_back( tex );
 493                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 494                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 495                 } else {
 496                     in.putback( c );
 497                     pp = calc_tex_coords(nodes[n1], center);
 498                 }
 499                 xglTexCoord2f(pp.x(), pp.y());
 500                 xglVertex3dv(nodes[n1].get_n());
 501
 502                 in >> n2;
 503                 fan_vertices.push_back( n2 );
 504                 xglNormal3dv(normals[n2]);
 505                 if ( in.get( c ) && c == '/' ) {
 506                     in >> tex;
 507                     fan_tex_coords.push_back( tex );
 508                     pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 509                     pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 510                 } else {
 511                     in.putback( c );
 512                     pp = calc_tex_coords(nodes[n2], center);
 513                 }
 514                 xglTexCoord2f(pp.x(), pp.y());
 515                 xglVertex3dv(nodes[n2].get_n());
 516
 517                 // read all subsequent numbers until next thing isn't a number
 518                 while ( true ) {
 519 #if defined( MACOS )
 520                     in >> ::skipws;
 521 #else
 522                     in >> skipws;
 523 #endif
 524
 525                     char c;
 526                     in.get(c);
 527                     in.putback(c);
 528                     if ( ! isdigit(c) || in.eof() ) {
 529                         break;
 530                     }
 531
 532                     in >> n3;
 533                     fan_vertices.push_back( n3 );
 534                     // cout << "  triangle = "
 535                     //      << n1 << "," << n2 << "," << n3
 536                     //      << endl;
 537                     xglNormal3dv(normals[n3]);
 538                     if ( in.get( c ) && c == '/' ) {
 539                         in >> tex;
 540                         fan_tex_coords.push_back( tex );
 541                         pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
 542                         pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
 543                     } else {
 544                         in.putback( c );
 545                         pp = calc_tex_coords(nodes[n3], center);
 546                     }
 547                     xglTexCoord2f(pp.x(), pp.y());
 548                     xglVertex3dv(nodes[n3].get_n());
 549
 550                     fragment.add_face(n1, n2, n3);
 551                     n2 = n3;
 552                 }
 553
 554                 xglEnd();
 555
 556                 // build the ssg entity
 557                 unsigned short *vindex =
 558                     new unsigned short [ fan_vertices.size() ];
 559                 unsigned short *tindex =
 560                     new unsigned short [ fan_tex_coords.size() ];
 561                 for ( i = 0; i < (int)fan_vertices.size(); ++i ) {
 562                     vindex[i] = fan_vertices[i];
 563                 }
 564                 for ( i = 0; i < (int)fan_tex_coords.size(); ++i ) {
 565                     tindex[i] = fan_tex_coords[i];
 566                 }
 567                 ssgLeaf *leaf =
 568                     new ssgVTable ( GL_TRIANGLE_FAN,
 569                                     fan_vertices.size(), vindex, t->vtlist,
 570                                     fan_vertices.size(), vindex, t->vnlist,
 571                                     fan_tex_coords.size(), tindex, t->tclist,
 572                                     0, NULL, NULL ) ;
 573                 leaf->setState( state );
 574
 575                 tile->addKid( leaf );
 576
 577             } else if ( token == "f" ) {
 578                 // unoptimized face
 579
 580                 if ( !in_faces ) {
 581                     xglBegin(GL_TRIANGLES);
 582                     // printf("xglBegin(triangles)\n");
 583                     in_faces = true;
 584                 }
 585
 586                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
 587                 in >> n1 >> n2 >> n3;
 588                 fragment.add_face(n1, n2, n3);
 589
 590                 // xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
 591                 xglNormal3dv(normals[n1]);
 592                 pp = calc_tex_coords(nodes[n1], center);
 593                 xglTexCoord2f(pp.lon(), pp.lat());
 594                 xglVertex3dv(nodes[n1].get_n());
 595
 596                 xglNormal3dv(normals[n2]);
 597                 pp = calc_tex_coords(nodes[n2], center);
 598                 xglTexCoord2f(pp.lon(), pp.lat());
 599                 xglVertex3dv(nodes[n2].get_n());
 600
 601                 xglNormal3dv(normals[n3]);
 602                 pp = calc_tex_coords(nodes[n3], center);
 603                 xglTexCoord2f(pp.lon(), pp.lat());
 604                 xglVertex3dv(nodes[n3].get_n());
 605                 // printf("some normals, texcoords, and vertices (tris)\n");
 606             } else if ( token == "q" ) {
 607                 // continue a triangle strip
 608                 n1 = n2 = 0;
 609
 610                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
 611                 //           line);
 612                 in >> n1;
 613
 614                 // There can be one or two values
 615                 char c;
 616                 while ( in.get(c) ) {
 617                     if ( c == '\n' ) {
 618                         break; // only the one
 619                     }
 620
 621                     if ( isdigit(c) ) {
 622                         in.putback(c);
 623                         in >> n2;
 624                         break;
 625                     }
 626                 }
 627                 // fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
 628
 629                 if ( odd ) {
 630                     fragment.add_face(last1, last2, n1);
 631                 } else {
 632                     fragment.add_face(last2, last1, n1);
 633                 }
 634
 635                 if ( shading ) {
 636                     // Shading model is "GL_SMOOTH"
 637                     // MAT3_SCALE_VEC(normal, normals[n1], scale);
 638                 } else {
 639                     // Shading model is "GL_FLAT"
 640                     if ( odd ) {
 641                         calc_normal(nodes[last1], nodes[last2],
 642                                     nodes[n1], approx_normal);
 643                     } else {
 644                         calc_normal(nodes[last2], nodes[last1],
 645                                     nodes[n1], approx_normal);
 646                     }
 647                     // MAT3_SCALE_VEC(normal, approx_normal, scale);
 648                 }
 649                 xglNormal3dv(normal);
 650
 651                 pp = calc_tex_coords(nodes[n1], center);
 652                 xglTexCoord2f(pp.lon(), pp.lat());
 653                 xglVertex3dv(nodes[n1].get_n());
 654                 // printf("a normal, texcoord, and vertex (4th)\n");
 655
 656                 odd = 1 - odd;
 657                 last1 = last2;
 658                 last2 = n1;
 659
 660                 if ( n2 > 0 ) {
 661                     // fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
 662
 663                     if ( odd ) {
 664                         fragment.add_face(last1, last2, n2);
 665                     } else {
 666                         fragment.add_face(last2, last1, n2);
 667                     }
 668
 669                     if ( shading ) {
 670                         // Shading model is "GL_SMOOTH"
 671                         // MAT3_SCALE_VEC(normal, normals[n2], scale);
 672                     } else {
 673                         // Shading model is "GL_FLAT"
 674                         if ( odd ) {
 675                             calc_normal(nodes[last1], nodes[last2],
 676                                         nodes[n2], approx_normal);
 677                         } else {
 678                             calc_normal(nodes[last2], nodes[last1],
 679                                         nodes[n2], approx_normal);
 680                         }
 681                         // MAT3_SCALE_VEC(normal, approx_normal, scale);
 682                     }
 683                     xglNormal3dv(normal);
 684
 685                     pp = calc_tex_coords(nodes[n2], center);
 686                     xglTexCoord2f(pp.lon(), pp.lat());
 687                     xglVertex3dv(nodes[n2].get_n());
 688                     // printf("a normal, texcoord, and vertex (4th)\n");
 689
 690                     odd = 1 -odd;
 691                     last1 = last2;
 692                     last2 = n2;
 693                 }
 694             } else {
 695                 FG_LOG( FG_TERRAIN, FG_WARN, "Unknown token in "
 696                         << path << " = " << token );
 697             }
 698
 699             // eat white space before start of while loop so if we are
 700             // done with useful input it is noticed before hand.
 701 #if defined( MACOS )
 702             in >> ::skipws;
 703 #else
 704             in >> skipws;
 705 #endif
 706         }
 707     }
 708
 709     if ( in_fragment ) {
 710         // close out the previous structure and start the next
 711         xglEnd();
 712         xglEndList();
 713         // printf("xglEnd(); xglEndList();\n");
 714
 715         // update fragment
 716         fragment.display_list = display_list;
 717
 718         // push this fragment onto the tile's object list
 719         t->fragment_list.push_back(fragment);
 720     }
 721
 722 #if 0
 723     // Draw normal vectors (for visually verifying normals)
 724     xglBegin(GL_LINES);
 725     xglColor3f(0.0, 0.0, 0.0);
 726     for ( i = 0; i < t->ncount; i++ ) {
 727         xglVertex3d(nodes[i][0],
 728                     nodes[i][1] ,
 729                     nodes[i][2]);
 730         xglVertex3d(nodes[i][0] + 500*normals[i][0],
 731                     nodes[i][1] + 500*normals[i][1],
 732                     nodes[i][2] + 500*normals[i][2]);
 733     }
 734     xglEnd();
 735 #endif
 736
 737     t->nodes = nodes;
 738
 739     stopwatch.stop();
 740     FG_LOG( FG_TERRAIN, FG_INFO,
 741             "Loaded " << path << " in "
 742             << stopwatch.elapsedSeconds() << " seconds" );
 743
 744     return tile;
 745 }
 746
 747