flightgear/SplitTris/splittris.cxx

// splittris.cxx -- read in a .ele/.node file pair generated by the
//                  triangle program and output a simple Wavefront .obj
//                  file for the north, south, east, and west edge
//                  verticies ... including the normals.
//
// Written by Curtis Olson, started January 1998.
//
// Copyright (C) 1997  Curtis L. Olson  - curt@infoplane.com
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
// (Log is kept at end of this file)


#include <math.h>
#include <stdio.h>
#include <stdlib.h>   // for atoi()
#include <string.h>
#include <sys/stat.h> // for stat()
#include <unistd.h>   // for stat()

#include "splittris.hxx"

#include <Include/fg_constants.h>
#include <Bucket/bucketutils.h>
#include <Math/fg_geodesy.hxx>
#include <Math/mat3.h>
#include <Math/point3d.hxx>
#include <Math/polar3d.hxx>
#include <Misc/fgstream.hxx>

// int nodecount, tricount;
double xmin, xmax, ymin, ymax;

// static double nodes_orig[MAX_NODES][3];
// static Point3D nodes_cart[MAX_NODES];
// static int tris[MAX_TRIS][3];

container_3d nodes_orig;
container_3d nodes_cart;
container_tri tri_list;

fgBUCKET ne_index, nw_index, sw_index, se_index;
fgBUCKET north_index, south_index, east_index, west_index;


// given three points defining a triangle, calculate the normal
void calc_normal(const Point3D& p1, const Point3D& p2, 
		 const Point3D& p3, double normal[3])
{
    double v1[3], v2[3];
    double temp;

    v1[0] = p2.x() - p1.x(); v1[1] = p2.y() - p1.y(); v1[2] = p2.z() - p1.z();
    v2[0] = p3.x() - p1.x(); v2[1] = p3.y() - p1.y(); v2[2] = p3.z() - p1.z();

    MAT3cross_product(normal, v1, v2);
    MAT3_NORMALIZE_VEC(normal,temp);

    // printf("  Normal = %.2f %.2f %.2f\n", normal[0], normal[1], normal[2]);
}


// return the file base name ( foo/bar/file.ext = file.ext )
string extract_file(const string& input) {
    int pos;

    pos = input.rfind("/");
    ++pos;

    return input.substr(pos);
}


// return the file path name ( foo/bar/file.ext = foo/bar )
string extract_path(const string& input) {
    int pos;

    pos = input.rfind("/");

    return input.substr(0, pos);
}


// return the index of all triangles containing the specified node
void find_tris(int n, int *t1, int *t2, int *t3, int *t4, int *t5) {
    int i;

    *t1 = *t2 = *t3 = *t4 = *t5 = 0;

    i = 1;
    iterator_tri last = tri_list.end();
    iterator_tri current = tri_list.begin();

    // skip first null record
    ++current;

    for ( ; current != last; ++current )
    {
        if ( (n == (*current).n1) || (n == (*current).n2) || 
	     (n == (*current).n3) )
	{
            if ( *t1 == 0 ) {
		*t1 = i;
            } else if ( *t2 == 0 ) {
		*t2 = i;
            } else if ( *t3 == 0 ) {
		*t3 = i;
            } else if ( *t4 == 0 ) {
		*t4 = i;
	    } else {
		*t5 = i;
	    }
        }
        ++i;
    }
}


// Initialize a new mesh structure
void triload(const string& basename) {
    string nodename, elename;
    Point3D node1, node2, p;
    triangle tri;
    int nodecount, tricount, dim, junk1, junk2;
    int i;

    nodename = basename + ".node";
    elename  = basename + ".ele";

    cout << "Loading node file:  " + nodename + " ...\n";

    fg_gzifstream node_in( nodename );
    if ( !node_in ) {
	cout << "Cannot open file " + nodename + "\n";
	exit(-1);
    }

    // the triangle program starts counting at 1 by default which is
    // pretty obnoxious.  Let's just push null record zero's onto our
    // list to compensate
    nodes_orig.push_back(node1);
    nodes_cart.push_back(node1);
    tri_list.push_back(tri);

    node_in >> nodecount >> dim >> junk1 >> junk2;
    cout << "    Expecting " << nodecount << " nodes\n";

    for ( i = 1; i <= nodecount; i++ ) {
	node_in >> junk1 >> node1 >> junk2;
	nodes_orig.push_back(node1);
	// printf("%d %.2f %.2f %.2f\n", junk1, node1.x, node1.y, node1.z);
	
	// convert to radians (before we can convert to cartesian)
	p = Point3D( node1.x() * ARCSEC_TO_RAD,
	             node1.y() * ARCSEC_TO_RAD,
		     node1.z() );

	node2 = fgGeodToCart(p);
	nodes_cart.push_back(node2);
	// printf("%d %.2f %.2f %.2f\n", junk1, node2.x, node2.y, node2.z);

	if ( i == 1 ) {
	    xmin = xmax = node1.x();
	    ymin = ymax = node1.y();
	} else {
	    if ( node1.x() < xmin ) {
		xmin = node1.x();
	    }
	    if ( node1.x() > xmax ) {
		xmax = node1.x();
	    }
	    if ( node1.y() < ymin ) {
		ymin = node1.y();
	    }
	    if ( node1.y() > ymax ) {
		ymax = node1.y();
	    }
	}
    }

    cout << "Loading element file:  " + elename + " ...\n";
    fg_gzifstream ele_in( elename );
    if ( !ele_in ) {
	cout << "Cannot open file " + elename + "\n";
	exit(-1);
    }

    ele_in >> tricount >> junk1 >> junk2;
    cout << "    Expecting " << tricount << " elements\n";

    for ( i = 1; i <= tricount; i++ ) {
	// fscanf(ele_file, "%d %d %d %d\n", &junk1, 
	//        &(tri.n1), &(tri.n2), &(tri.n3));
	ele_in >> junk1 >> tri.n1 >> tri.n2 >> tri.n3;
	// printf("%d %d %d %d\n", junk1, tri.n1, tri.n2, tri.n3);
	tri_list.push_back(tri);
    }
}


// check if a file exists
int file_exists(char *file) {
    struct stat stat_buf;
    int result;

    cout << "checking " << file << " ... ";

    result = stat(file, &stat_buf);

    if ( result != 0 ) {
	// stat failed, no file
	cout << "not found.\n";
	return 0;
    } else {
	// stat succeeded, file exists
	cout << "exists.\n";
	return 1;
    }
}


// check to see if a shared object exists
int shared_object_exists(const char *basepath, const string& ext) {
    char file[256], scene_path[256];
    long int index;

    if ( ext == ".sw" ) {
	fgBucketGenBasePath(&west_index, scene_path);
	index = fgBucketGenIndex(&west_index);
	sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&sw_index, scene_path);
	index = fgBucketGenIndex(&sw_index);
	sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&south_index, scene_path);
	index = fgBucketGenIndex(&south_index);
	sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".se" ) {
	fgBucketGenBasePath(&east_index, scene_path);
	index = fgBucketGenIndex(&east_index);
	sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&se_index, scene_path);
	index = fgBucketGenIndex(&se_index);
	sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&south_index, scene_path);
	index = fgBucketGenIndex(&south_index);
	sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".ne" ) {
	fgBucketGenBasePath(&east_index, scene_path);
	index = fgBucketGenIndex(&east_index);
	sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&ne_index, scene_path);
	index = fgBucketGenIndex(&ne_index);
	sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&north_index, scene_path);
	index = fgBucketGenIndex(&north_index);
	sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".nw" ) {
	fgBucketGenBasePath(&west_index, scene_path);
	index = fgBucketGenIndex(&west_index);
	sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&nw_index, scene_path);
	index = fgBucketGenIndex(&nw_index);
	sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
	fgBucketGenBasePath(&north_index, scene_path);
	index = fgBucketGenIndex(&north_index);
	sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".south" ) {
	fgBucketGenBasePath(&south_index, scene_path);
	index = fgBucketGenIndex(&south_index);
	sprintf(file, "%s/%s/%ld.1.north", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".north" ) {
	fgBucketGenBasePath(&north_index, scene_path);
	index = fgBucketGenIndex(&north_index);
	sprintf(file, "%s/%s/%ld.1.south", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".west" ) {
	fgBucketGenBasePath(&west_index, scene_path);
	index = fgBucketGenIndex(&west_index);
	sprintf(file, "%s/%s/%ld.1.east", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    if ( ext == ".east" ) {
	fgBucketGenBasePath(&east_index, scene_path);
	index = fgBucketGenIndex(&east_index);
	sprintf(file, "%s/%s/%ld.1.west", basepath, scene_path, index);
	if ( file_exists(file) ) {
	    return(1);
	}
    }

    return(0);
}


// my custom file opening routine ... don't open if a shared edge or
// vertex alread exists
FILE *my_open(const string& basename, const string& basepath, 
	      const string& ext)
{
    FILE *fp;
    string filename;

    // create the output file name
    filename = basename + ext;

    // check if a shared object already exist from a different tile

    if ( shared_object_exists(basepath.c_str(), ext) ) {
	// not an actual file open error, but we've already got the
        // shared edge, so we don't want to create another one
	cout << "not opening\n";
	return(NULL);
    } else {
	// open the file
	fp = fopen(filename.c_str(), "w");
	cout << "Opening " + filename + "\n";
	return(fp);
    }
}


// dump in WaveFront .obj format
void dump_obj(const string& basename, const string& basepath) {
    Point3D node;
    double n1[3], n2[3], n3[3], n4[3], n5[3], norm[3], temp;
    FILE *fp, *sw, *se, *ne, *nw, *north, *south, *east, *west, *body;
    int i, t1, t2, t3, t4, t5, count, size;
    double x, y, z;

    sw = my_open(basename, basepath, ".sw");
    se = my_open(basename, basepath, ".se");
    ne = my_open(basename, basepath, ".ne");
    nw = my_open(basename, basepath, ".nw");

    north = my_open(basename, basepath, ".north");
    south = my_open(basename, basepath, ".south");
    east = my_open(basename, basepath, ".east");
    west = my_open(basename, basepath, ".west");

    body = my_open(basename, basepath, ".body");

    cout << "Dumping edges file basename:  " + basename + " ...\n";

    // dump vertices
    cout << "  writing vertices\n";

    iterator_3d last = nodes_orig.end();
    iterator_3d current = nodes_orig.begin();
    ++current;
    for ( ; current != last; ++current) {
	node = *current;

	if ( (fabs(node.y() - ymin) < FG_EPSILON) && 
	     (fabs(node.x() - xmin) < FG_EPSILON) ) {
	    fp = sw;
	} else if ( (fabs(node.y() - ymin) < FG_EPSILON) &&
		    (fabs(node.x() - xmax) < FG_EPSILON) ) {
	    fp = se;
	} else if ( (fabs(node.y() - ymax) < FG_EPSILON) &&
		    (fabs(node.x() - xmax) < FG_EPSILON)) {
	    fp = ne;
	} else if ( (fabs(node.y() - ymax) < FG_EPSILON) &&
		    (fabs(node.x() - xmin) < FG_EPSILON) ) {
	    fp = nw;
	} else if ( fabs(node.x() - xmin) < FG_EPSILON ) {
	    fp = west;
	} else if ( fabs(node.x() - xmax) < FG_EPSILON ) {
	    fp = east;
	} else if ( fabs(node.y() - ymin) < FG_EPSILON ) {
	    fp = south;
	} else if ( fabs(node.y() - ymax) < FG_EPSILON ) {
	    fp = north;
	} else {
	    fp = body;
	}

	x = node.x();
	y = node.y();
	z = node.z();

	if ( fp != NULL ) {
	    fprintf(fp, "gdn %.2f %.2f %.2f\n", x, y, z);
	}
    }

    cout << "  calculating and writing normals\n";

    // calculate and generate normals
    size = nodes_orig.size();
    for ( i = 1; i < size; i++ ) {
	// printf("Finding normal\n");

	find_tris(i, &t1, &t2, &t3, &t4, &t5);

	n1[0] = n1[1] = n1[2] = 0.0;
	n2[0] = n2[1] = n2[2] = 0.0;
	n3[0] = n3[1] = n3[2] = 0.0;
	n4[0] = n4[1] = n4[2] = 0.0;
	n5[0] = n5[1] = n5[2] = 0.0;

	count = 1;
	calc_normal(nodes_cart[tri_list[t1].n1],
		    nodes_cart[tri_list[t1].n2], 
		    nodes_cart[tri_list[t1].n3],
		    n1);

	if ( t2 > 0 ) {
	    calc_normal(nodes_cart[tri_list[t2].n1], 
			nodes_cart[tri_list[t2].n2], 
			nodes_cart[tri_list[t2].n3],
			n2);
	    count = 2;
	}

	if ( t3 > 0 ) {
	    calc_normal(nodes_cart[tri_list[t3].n1],
			nodes_cart[tri_list[t3].n2],
			nodes_cart[tri_list[t3].n3],
			n3);
	    count = 3;
	}

	if ( t4 > 0 ) {
	    calc_normal(nodes_cart[tri_list[t4].n1],
			nodes_cart[tri_list[t4].n2],
			nodes_cart[tri_list[t4].n3],
			n4);
	    count = 4;
	}

	if ( t5 > 0 ) {
	    calc_normal(nodes_cart[tri_list[t5].n1],
			nodes_cart[tri_list[t5].n2],
			nodes_cart[tri_list[t5].n3],
			n5);
	    count = 5;
	}

	// printf("  norm[2] = %.2f %.2f %.2f\n", n1[2], n2[2], n3[2]);

	norm[0] = ( n1[0] + n2[0] + n3[0] + n4[0] + n5[0] ) / (double)count;
	norm[1] = ( n1[1] + n2[1] + n3[1] + n4[1] + n5[1] ) / (double)count;
	norm[2] = ( n1[2] + n2[2] + n3[2] + n4[2] + n5[2] ) / (double)count;
	
	// printf("  count = %d\n", count);
	// printf("  Ave. normal = %.4f %.4f %.4f\n", norm[0], norm[1], 
	//        norm[2]);
	MAT3_NORMALIZE_VEC(norm, temp);
	// printf("  Normalized ave. normal = %.4f %.4f %.4f\n", 
	//        norm[0], norm[1], norm[2]);
	
	fp = NULL;

	if ( (fabs(nodes_orig[i].y() - ymin) < FG_EPSILON) && 
	     (fabs(nodes_orig[i].x() - xmin) < FG_EPSILON) ) {
	    fp = sw;
	} else if ( (fabs(nodes_orig[i].y() - ymin) < FG_EPSILON) &&
		    (fabs(nodes_orig[i].x() - xmax) < FG_EPSILON) ) {
	    fp = se;
	} else if ( (fabs(nodes_orig[i].y() - ymax) < FG_EPSILON) &&
		    (fabs(nodes_orig[i].x() - xmax) < FG_EPSILON)) {
	    fp = ne;
	} else if ( (fabs(nodes_orig[i].y() - ymax) < FG_EPSILON) &&
		    (fabs(nodes_orig[i].x() - xmin) < FG_EPSILON) ) {
	    fp = nw;
	} else if ( fabs(nodes_orig[i].x() - xmin) < FG_EPSILON ) {
	    fp = west;
	} else if ( fabs(nodes_orig[i].x() - xmax) < FG_EPSILON ) {
	    fp = east;
	} else if ( fabs(nodes_orig[i].y() - ymin) < FG_EPSILON ) {
	    fp = south;
	} else if ( fabs(nodes_orig[i].y() - ymax) < FG_EPSILON ) {
	    fp = north;
	}
	if ( fp != NULL ) {
	    fprintf(fp, "vn %.4f %.4f %.4f\n", norm[0], norm[1], norm[2]);
	}
    }

    if ( sw ) { fclose(sw); }
    if ( se ) { fclose(se); }
    if ( ne ) { fclose(ne); }
    if ( nw ) { fclose(nw); }

    if ( north ) { fclose(north); }
    if ( south ) { fclose(south); }
    if ( east ) { fclose(east); }
    if ( west ) { fclose(west); }

    if ( body ) { fclose(body); }
}


int main(int argc, char **argv) {
    string basename, basepath, temp;
    fgBUCKET p;
    long int index;
    int len;

    basename = argv[1];

    // find the base path of the file
    basepath = extract_path(basename);
    basepath = extract_path(basepath);
    basepath = extract_path(basepath);
    cout << "basepath = " + basepath + "\n";

    // find the index of the current file
    temp = extract_file(basename);
    len = temp.length();
    if ( len >= 2 ) {
	temp = temp.substr(0, len-2);
    }
    index = atoi( temp.c_str() );
    cout << "index = " << index << "\n";
    fgBucketParseIndex(index, &p);

    cout << "bucket = " << p.lon << " " << p.lat << " " << 
	p.x << " " << p.y << "\n";

    // generate the indexes of the neighbors
    fgBucketOffset(&p, &ne_index,  1,  1);
    fgBucketOffset(&p, &nw_index, -1,  1);
    fgBucketOffset(&p, &se_index,  1, -1);
    fgBucketOffset(&p, &sw_index, -1, -1);

    fgBucketOffset(&p, &north_index,  0,  1);
    fgBucketOffset(&p, &south_index,  0, -1);
    fgBucketOffset(&p, &east_index,  1,  0);
    fgBucketOffset(&p, &west_index, -1,  0);

    // printf("Corner indexes = %ld %ld %ld %ld\n", 
    //        ne_index, nw_index, sw_index, se_index);
    // printf("Edge indexes = %ld %ld %ld %ld\n",
    //        north_index, south_index, east_index, west_index);
	  

    // load the input data files
    triload(basename);

    // dump in WaveFront .obj format
    dump_obj(basename, basepath);

    return(0);
}


// $Log$
// Revision 1.7  1998/11/06 21:33:57  curt
// Updates to go along with changes in fgstream.
//
// Revision 1.6  1998/10/21 14:56:20  curt
// Fixed a units conversion bug.
//
// Revision 1.5  1998/10/20 15:50:33  curt
// whitespace tweak.
//
// Revision 1.4  1998/10/18 01:17:27  curt
// Point3D tweaks.
//
// Revision 1.3  1998/09/22 23:49:56  curt
// C++-ified, STL-ified, and string-ified.
//
// Revision 1.2  1998/09/21 23:16:23  curt
// Converted to c++ style comments.
//
// Revision 1.1  1998/07/08 14:59:13  curt
// *.[ch] renamed to *.[ch]xx
//
// Revision 1.11  1998/07/04 00:56:40  curt
// typedef'd struct fgBUCKET.
//
// Revision 1.10  1998/05/02 01:54:37  curt
// Converting to polar3d.h routines.
//
// Revision 1.9  1998/04/18 04:01:20  curt
// Now use libMath rather than having local copies of math routines.
//
// Revision 1.8  1998/04/14 02:26:08  curt
// Code reorganizations.  Added a Lib/ directory for more general libraries.
//
// Revision 1.7  1998/04/08 23:21:13  curt
// Adopted Gnu automake/autoconf system.
//
// Revision 1.6  1998/03/03 15:36:13  curt
// Tweaks for compiling with g++
//
// Revision 1.5  1998/03/03 03:37:04  curt
// Cumulative tweaks.
//
// Revision 1.4  1998/01/31 00:41:26  curt
// Made a few changes converting floats to doubles.
//
// Revision 1.3  1998/01/27 18:37:04  curt
// Lots of updates to get back in sync with changes made over in .../Src/
//
// Revision 1.2  1998/01/14 15:54:43  curt
// Initial revision completed.
//
// Revision 1.1  1998/01/14 02:11:31  curt
// Initial revision.
//