3 // dem.c -- DEM management class
5 // Written by Curtis Olson, started March 1998.
7 // Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
9 // This program is free software; you can redistribute it and/or
10 // modify it under the terms of the GNU General Public License as
11 // published by the Free Software Foundation; either version 2 of the
12 // License, or (at your option) any later version.
14 // This program is distributed in the hope that it will be useful, but
15 // WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 // General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 // (Log is kept at end of this file)
31 #include <Include/compiler.h>
33 #include <ctype.h> // isspace()
34 #include <stdlib.h> // atoi()
35 #include <math.h> // rint()
38 #ifdef HAVE_SYS_STAT_H
39 # include <sys/stat.h> // stat()
41 #ifdef FG_HAVE_STD_INCLUDES
47 # include <unistd.h> // stat()
53 // #include <zlib/zlib.h>
54 #include <Misc/fgstream.hxx>
55 #include <Misc/strutils.hxx>
56 #include <Include/compiler.h>
57 FG_USING_NAMESPACE(std);
60 #include "leastsqs.hxx"
62 #include <Include/fg_constants.h>
65 #define MAX_EX_NODES 10000
71 # define MKDIR(a) mkdir(a)
73 # define MKDIR(a) mkdir(a,S_IRWXU) // I am just guessing at this flag (NHV)
74 # endif // __BORLANDC__
79 fgDEM::fgDEM( void ) {
80 // cout << "class fgDEM CONstructor called." << endl;
81 dem_data = new float[DEM_SIZE_1][DEM_SIZE_1];
82 output_data = new float[DEM_SIZE_1][DEM_SIZE_1];
86 fgDEM::fgDEM( const string &file ) {
87 // cout << "class fgDEM CONstructor called." << endl;
88 dem_data = new float[DEM_SIZE_1][DEM_SIZE_1];
89 output_data = new float[DEM_SIZE_1][DEM_SIZE_1];
96 int fgDEM::open ( const string& file ) {
97 // open input file (or read from stdin)
99 printf("Loading DEM data file: stdin\n");
101 // fd = gzdopen(STDIN_FILENO, "r");
102 printf("Not yet ported ...\n");
105 in = new fg_gzifstream( file );
107 cout << "Cannot open " << file << endl;
110 cout << "Loading DEM data file: " << file << endl;
118 int fgDEM::close () {
119 // the fg_gzifstream doesn't seem to have a close()
127 // return next token from input stream
128 string fgDEM::next_token() {
133 // cout << " returning " + token + "\n";
139 // return next integer from input stream
140 int fgDEM::next_int() {
149 // return next double from input stream
150 double fgDEM::next_double() {
159 // return next exponential num from input stream
160 double fgDEM::next_exp() {
166 token = next_token();
169 const char* p = token.c_str();
173 for ( ; *p != 0; ++p )
181 return ::atof( buf );
183 sscanf(token.c_str(), "%lfD%d", &mantissa, &exp);
185 // cout << " Mantissa = " << mantissa << " Exp = " << exp << "\n";
189 for ( i = 1; i <= exp; i++ ) {
192 } else if ( exp < 0 ) {
193 for ( i = -1; i >= exp; i-- ) {
198 return( (int)rint(mantissa * (double)acc) );
203 // read and parse DEM "A" record
204 int fgDEM::read_a_record() {
211 // get the name field (144 characters)
212 for ( i = 0; i < 144; i++ ) {
217 // clean off the trailing whitespace
219 cout << " Quad name field: " << name << endl;
221 // DEM level code, 3 reflects processing by DMA
223 cout << " DEM level code = " << inum << "\n";
229 // Pattern code, 1 indicates a regular elevation pattern
231 cout << " Pattern code = " << inum << "\n";
233 // Planimetric reference system code, 0 indicates geographic
234 // coordinate system.
236 cout << " Planimetric reference code = " << inum << "\n";
240 cout << " Zone code = " << inum << "\n";
242 // Map projection parameters (ignored)
243 for ( i = 0; i < 15; i++ ) {
245 // printf("%d: %f\n",i,dnum);
248 // Units code, 3 represents arc-seconds as the unit of measure for
249 // ground planimetric coordinates throughout the file.
252 cout << " Unknown (X,Y) units code = " << inum << "!\n";
256 // Units code; 2 represents meters as the unit of measure for
257 // elevation coordinates throughout the file.
260 cout << " Unknown (Z) units code = " << inum << "!\n";
264 // Number (n) of sides in the polygon which defines the coverage of
265 // the DEM file (usually equal to 4).
268 cout << " Unknown polygon dimension = " << inum << "!\n";
272 // Ground coordinates of bounding box in arc-seconds
273 dem_x1 = originx = next_exp();
274 dem_y1 = originy = next_exp();
275 cout << " Origin = (" << originx << "," << originy << ")\n";
286 // Minimum/maximum elevations in meters
289 cout << " Elevation range " << dem_z1 << " to " << dem_z2 << "\n";
291 // Counterclockwise angle from the primary axis of ground
292 // planimetric referenced to the primary axis of the DEM local
294 token = next_token();
296 // Accuracy code; 0 indicates that a record of accuracy does not
297 // exist and that no record type C will follow.
299 // DEM spacial resolution. Usually (3,3,1) (3,6,1) or (3,9,1)
300 // depending on latitude
302 // I will eventually have to do something with this for data at
303 // higher latitudes */
304 token = next_token();
305 cout << " accuracy & spacial resolution string = " << token << endl;
307 cout << " length = " << i << "\n";
310 inum = atoi( token.substr( 0, i - 36 ) );
311 row_step = atof( token.substr( i - 36, 12 ) );
312 col_step = atof( token.substr( i - 24, 12 ) );
313 //token.substr( 25, 12 )
315 ptr = token.c_str() + i - 12;
316 cout << " last field = " << ptr << " = " << atof(ptr) << "\n";
320 col_step = atof(ptr);
321 cout << " last field = " << ptr << " = " << col_step << "\n";
325 row_step = atof(ptr);
326 cout << " last field = " << ptr << " = " << row_step << "\n";
329 // accuracy code = atod(token)
333 cout << " Accuracy code = " << inum << "\n";
335 cout << " column step = " << col_step <<
336 " row step = " << row_step << "\n";
338 // dimension of arrays to follow (1)
339 token = next_token();
341 // number of profiles
342 dem_num_profiles = cols = next_int();
343 cout << " Expecting " << dem_num_profiles << " profiles\n";
349 // read and parse DEM "B" record
350 void fgDEM::read_b_record( ) {
354 // row / column id of this profile
355 prof_row = next_int();
356 prof_col = next_int();
357 // printf("col id = %d row id = %d\n", prof_col, prof_row);
359 // Number of columns and rows (elevations) in this profile
360 prof_num_rows = rows = next_int();
361 prof_num_cols = next_int();
362 // printf(" profile num rows = %d\n", prof_num_rows);
364 // Ground planimetric coordinates (arc-seconds) of the first
365 // elevation in the profile
366 prof_x1 = next_exp();
367 prof_y1 = next_exp();
368 // printf(" Starting at %.2f %.2f\n", prof_x1, prof_y1);
370 // Elevation of local datum for the profile. Always zero for
371 // 1-degree DEM, the reference is mean sea level.
372 token = next_token();
374 // Minimum and maximum elevations for the profile.
375 token = next_token();
376 token = next_token();
378 // One (usually) dimensional array (prof_num_cols,1) of elevations
379 for ( i = 0; i < prof_num_rows; i++ ) {
380 prof_data = next_int();
381 dem_data[cur_col][i] = (float)prof_data;
387 int fgDEM::parse( ) {
392 if ( !read_a_record() ) {
396 for ( i = 0; i < dem_num_profiles; i++ ) {
397 // printf("Ready to read next b record\n");
401 if ( cur_col % 100 == 0 ) {
402 cout << " loaded " << cur_col << " profiles of data\n";
406 cout << " Done parsing\n";
412 // return the current altitude based on mesh data. We should rewrite
413 // this to interpolate exact values, but for now this is good enough
414 double fgDEM::interpolate_altitude( double lon, double lat ) {
415 // we expect incoming (lon,lat) to be in arcsec for now
417 double xlocal, ylocal, dx, dy, zA, zB, elev;
418 int x1, x2, x3, y1, y2, y3;
422 /* determine if we are in the lower triangle or the upper triangle
430 then calculate our end points
433 xlocal = (lon - originx) / col_step;
434 ylocal = (lat - originy) / row_step;
436 xindex = (int)(xlocal);
437 yindex = (int)(ylocal);
439 // printf("xindex = %d yindex = %d\n", xindex, yindex);
441 if ( xindex + 1 == cols ) {
445 if ( yindex + 1 == rows ) {
449 if ( (xindex < 0) || (xindex + 1 >= cols) ||
450 (yindex < 0) || (yindex + 1 >= rows) ) {
454 dx = xlocal - xindex;
455 dy = ylocal - yindex;
459 // printf(" Lower triangle\n");
463 z1 = dem_data[x1][y1];
467 z2 = dem_data[x2][y2];
471 z3 = dem_data[x3][y3];
473 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
474 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
475 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
476 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
478 zA = dx * (z2 - z1) + z1;
479 zB = dx * (z3 - z1) + z1;
481 // printf(" zA = %.2f zB = %.2f\n", zA, zB);
483 if ( dx > FG_EPSILON ) {
484 elev = dy * (zB - zA) / dx + zA;
490 // printf(" Upper triangle\n");
494 z1 = dem_data[x1][y1];
498 z2 = dem_data[x2][y2];
502 z3 = dem_data[x3][y3];
504 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
505 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
506 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
507 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
509 zA = dy * (z2 - z1) + z1;
510 zB = dy * (z3 - z1) + z1;
512 // printf(" zA = %.2f zB = %.2f\n", zA, zB );
513 // printf(" xB - xA = %.2f\n", col_step * dy / row_step);
515 if ( dy > FG_EPSILON ) {
516 elev = dx * (zB - zA) / dy + zA;
526 // Use least squares to fit a simpler data set to dem data
527 void fgDEM::fit( double error, fgBUCKET *p ) {
528 double x[DEM_SIZE_1], y[DEM_SIZE_1];
529 double m, b, ave_error, max_error;
531 int n, row, start, end;
532 int colmin, colmax, rowmin, rowmax;
534 // FILE *dem, *fit, *fit1;
536 printf("Initializing output mesh structure\n");
539 // determine dimensions
540 colmin = p->x * ( (cols - 1) / 8);
541 colmax = colmin + ( (cols - 1) / 8);
542 rowmin = p->y * ( (rows - 1) / 8);
543 rowmax = rowmin + ( (rows - 1) / 8);
544 printf("Fitting region = %d,%d to %d,%d\n", colmin, rowmin, colmax, rowmax);
546 // include the corners explicitly
547 outputmesh_set_pt(colmin, rowmin, dem_data[colmin][rowmin]);
548 outputmesh_set_pt(colmin, rowmax, dem_data[colmin][rowmax]);
549 outputmesh_set_pt(colmax, rowmax, dem_data[colmax][rowmax]);
550 outputmesh_set_pt(colmax, rowmin, dem_data[colmax][rowmin]);
552 printf("Beginning best fit procedure\n");
554 for ( row = rowmin; row <= rowmax; row++ ) {
555 // fit = fopen("fit.dat", "w");
556 // fit1 = fopen("fit1.dat", "w");
560 // printf(" fitting row = %d\n", row);
562 while ( start < colmax ) {
566 x[(end - start) - 1] = 0.0 + ( start * col_step );
567 y[(end - start) - 1] = dem_data[start][row];
569 while ( (end <= colmax) && good_fit ) {
570 n = (end - start) + 1;
571 // printf("Least square of first %d points\n", n);
572 x[end - start] = 0.0 + ( end * col_step );
573 y[end - start] = dem_data[end][row];
574 least_squares(x, y, n, &m, &b);
575 ave_error = least_squares_error(x, y, n, m, b);
576 max_error = least_squares_max_error(x, y, n, m, b);
579 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
580 start, end, ave_error, max_error, m, b);
582 f = fopen("gnuplot.dat", "w");
583 for ( j = 0; j <= end; j++) {
584 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
587 for ( j = start; j <= end; j++) {
588 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
593 printf("Please hit return: "); gets(junk);
596 if ( max_error > error ) {
604 // error exceeded the threshold, back up
605 end -= 2; // back "end" up to the last good enough fit
606 n--; // back "n" up appropriately too
608 // we popped out of the above loop while still within
609 // the error threshold, so we must be at the end of
614 least_squares(x, y, n, &m, &b);
615 ave_error = least_squares_error(x, y, n, m, b);
616 max_error = least_squares_max_error(x, y, n, m, b);
620 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
621 start, end, ave_error, max_error, m, b);
624 fprintf(fit1, "%.2f %.2f\n", x[0], m * x[0] + b);
625 fprintf(fit1, "%.2f %.2f\n", x[end-start], m * x[end-start] + b);
628 if ( start > colmin ) {
629 // skip this for the first line segment
631 outputmesh_set_pt(start, row, (lasty + cury) / 2);
632 // fprintf(fit, "%.2f %.2f\n", x[0], (lasty + cury) / 2);
635 lasty = m * x[end-start] + b;
643 dem = fopen("gnuplot.dat", "w");
644 for ( j = 0; j < DEM_SIZE_1; j++) {
645 fprintf(dem, "%.2f %.2f\n", 0.0 + ( j * col_step ),
651 // NOTICE, this is for testing only. This instance of
652 // output_nodes should be removed. It should be called only
653 // once at the end once all the nodes have been generated.
654 // newmesh_output_nodes(&nm, "mesh.node");
655 // printf("Please hit return: "); gets(junk);
658 // outputmesh_output_nodes(fg_root, p);
662 // Initialize output mesh structure
663 void fgDEM::outputmesh_init( void ) {
666 for ( j = 0; j < DEM_SIZE_1; j++ ) {
667 for ( i = 0; i < DEM_SIZE_1; i++ ) {
668 output_data[i][j] = -9999.0;
674 // Get the value of a mesh node
675 double fgDEM::outputmesh_get_pt( int i, int j ) {
676 return ( output_data[i][j] );
680 // Set the value of a mesh node
681 void fgDEM::outputmesh_set_pt( int i, int j, double value ) {
682 // printf("Setting data[%d][%d] = %.2f\n", i, j, value);
683 output_data[i][j] = value;
687 // Write out a node file that can be used by the "triangle" program.
688 // Check for an optional "index.node.ex" file in case there is a .poly
689 // file to go along with this node file. Include these nodes first
690 // since they are referenced by position from the .poly file.
691 void fgDEM::outputmesh_output_nodes( const string& fg_root, fgBUCKET *p ) {
692 double exnodes[MAX_EX_NODES][3];
693 struct stat stat_buf;
695 char base_path[256], file[256], exfile[256];
702 int colmin, colmax, rowmin, rowmax;
703 int i, j, count, excount, result;
705 // determine dimensions
706 colmin = p->x * ( (cols - 1) / 8);
707 colmax = colmin + ( (cols - 1) / 8);
708 rowmin = p->y * ( (rows - 1) / 8);
709 rowmax = rowmin + ( (rows - 1) / 8);
710 cout << " dumping region = " << colmin << "," << rowmin << " to " <<
711 colmax << "," << rowmax << "\n";
713 // generate the base directory
714 fgBucketGenBasePath(p, base_path);
715 cout << "fg_root = " << fg_root << " Base Path = " << base_path << endl;
716 dir = fg_root + "/Scenery/" + base_path;
717 cout << "Dir = " << dir << endl;
719 // stat() directory and create if needed
721 result = stat(dir.c_str(), &stat_buf);
722 if ( result != 0 && errno == ENOENT ) {
723 cout << "Creating directory\n";
727 command = "mkdir -p " + dir + "\n";
728 system( command.c_str() );
733 // Cygwin crashes when trying to output to node file
734 // explicitly making directory structure seems OK on Win95
736 extract_path (base_path, tmp_path);
738 dir = fg_root + "/Scenery";
739 if (my_mkdir ( dir.c_str() )) { exit (-1); }
741 dir = fg_root + "/Scenery/" + tmp_path;
742 if (my_mkdir ( dir.c_str() )) { exit (-1); }
744 dir = fg_root + "/Scenery/" + base_path;
745 if (my_mkdir ( dir.c_str() )) { exit (-1); }
751 // assume directory exists
754 // get index and generate output file name
755 index = fgBucketGenIndex(p);
756 sprintf(file, "%s/%ld.node", dir.c_str(), index);
758 // get (optional) extra node file name (in case there is matching
760 strcpy(exfile, file);
761 strcat(exfile, ".ex");
763 // load extra nodes if they exist
765 if ( (fd = fopen(exfile, "r")) != NULL ) {
767 fscanf(fd, "%d %d %d %d", &excount, &junki, &junki, &junki);
769 if ( excount > MAX_EX_NODES - 1 ) {
770 printf("Error, too many 'extra' nodes, increase array size\n");
773 printf(" Expecting %d 'extra' nodes\n", excount);
776 for ( i = 1; i <= excount; i++ ) {
777 fscanf(fd, "%d %lf %lf %lf\n", &junki,
778 &exnodes[i][0], &exnodes[i][1], &exnodes[i][2]);
779 printf("(extra) %d %.2f %.2f %.2f\n",
780 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
785 printf("Creating node file: %s\n", file);
786 fd = fopen(file, "w");
788 // first count regular nodes to generate header
790 for ( j = rowmin; j <= rowmax; j++ ) {
791 for ( i = colmin; i <= colmax; i++ ) {
792 if ( output_data[i][j] > -9000.0 ) {
796 // printf(" count = %d\n", count);
798 fprintf(fd, "%d 2 1 0\n", count + excount);
800 // now write out extra node data
801 for ( i = 1; i <= excount; i++ ) {
802 fprintf(fd, "%d %.2f %.2f %.2f\n",
803 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
806 // write out actual node data
808 for ( j = rowmin; j <= rowmax; j++ ) {
809 for ( i = colmin; i <= colmax; i++ ) {
810 if ( output_data[i][j] > -9000.0 ) {
811 fprintf(fd, "%d %.2f %.2f %.2f\n",
813 originx + (double)i * col_step,
814 originy + (double)j * row_step,
818 // printf(" count = %d\n", count);
825 fgDEM::~fgDEM( void ) {
826 // printf("class fgDEM DEstructor called.\n");
828 delete [] output_data;
833 // Revision 1.23 1999/03/10 01:09:12 curt
834 // Tweaks to go along with scenery tools overhaul.
835 // Added a new constructor that accepts the file name.
837 // Revision 1.22 1999/01/19 20:56:56 curt
838 // MacOS portability changes contributed by "Robert Puyol" <puyol@abvent.fr>
840 // Revision 1.21 1998/11/06 14:04:32 curt
841 // Changes due to updates in fgstream.
843 // Revision 1.20 1998/10/28 19:38:20 curt
844 // Elliminate some unnecessary win32 specific stuff (by Norman Vine)
846 // Revision 1.19 1998/10/22 21:59:19 curt
847 // Fixed a couple subtle bugs that resulted from some of my c++ conversions.
848 // One bug could cause a segfault on certain input, and the other bug could
849 // cause the whole procedure to go balistic and generate huge files (also only
850 // on rare input combinations.)
852 // Revision 1.18 1998/10/18 01:17:09 curt
855 // Revision 1.17 1998/10/16 19:08:12 curt
856 // Portability updates from Bernie Bright.
858 // Revision 1.16 1998/10/02 21:41:39 curt
861 // Revision 1.15 1998/09/21 20:53:59 curt
862 // minor tweaks to clean a few additional things up after the rewrite.
864 // Revision 1.14 1998/09/19 17:59:45 curt
865 // Use c++ streams (fg_gzifstream). Also converted many character arrays to
868 // Revision 1.13 1998/09/09 16:24:04 curt
869 // Fixed a bug in the handling of exclude files which was causing
870 // a crash by calling fclose() on an invalid file handle.
872 // Revision 1.12 1998/08/24 20:03:31 curt
873 // Eliminated a possible memory overrun error.
874 // Use the proper free() rather than the incorrect delete().
876 // Revision 1.11 1998/07/20 12:46:11 curt
877 // When outputing to a .node file, first check for an optional
878 // "index.node.ex" file in case there is a .poly file to go along with this
879 // node file. Include these nodes first since they are referenced by position
880 // from the .poly file. This is my first pass at adding an area "cutout"
881 // feature to the terrain generation pipeline.
883 // Revision 1.10 1998/07/13 20:58:02 curt
886 // Revision 1.9 1998/07/13 15:29:49 curt
887 // Added #ifdef HAVE_CONFIG_H
889 // Revision 1.8 1998/07/04 00:47:18 curt
890 // typedef'd struct fgBUCKET.
892 // Revision 1.7 1998/06/05 18:14:39 curt
893 // Abort out early when reading the "A" record if it doesn't look like
894 // a proper DEM file.
896 // Revision 1.6 1998/05/02 01:49:21 curt
897 // Fixed a bug where the wrong variable was being initialized.
899 // Revision 1.5 1998/04/25 15:00:32 curt
900 // Changed "r" to "rb" in gzopen() options. This fixes bad behavior in win32.
902 // Revision 1.4 1998/04/22 13:14:46 curt
903 // Fixed a bug in zlib usage.
905 // Revision 1.3 1998/04/18 03:53:05 curt
906 // Added zlib support.
908 // Revision 1.2 1998/04/14 02:43:27 curt
909 // Used "new" to auto-allocate large DEM parsing arrays in class constructor.
911 // Revision 1.1 1998/04/08 22:57:22 curt
912 // Adopted Gnu automake/autoconf system.
914 // Revision 1.3 1998/04/06 21:09:41 curt
915 // Additional win32 support.
916 // Fixed a bad bug in dem file parsing that was causing the output to be
917 // flipped about x = y.
919 // Revision 1.2 1998/03/23 20:35:41 curt
920 // Updated to use FG_EPSILON
922 // Revision 1.1 1998/03/19 02:54:47 curt
923 // Reorganized into a class lib called fgDEM.
925 // Revision 1.1 1998/03/19 01:46:28 curt