fly/flightgear
1
0
Fork 0
Code Activity
flightgear/Tri2obj/tri2obj.c
curt 6aaf9bebc7 Added support for shared normals.
1998-01-17 01:25:39 +00:00

668 lines
18 KiB
C
Raw Blame History

/* tri2obj.c -- read in a .ele/.node file pair generated by the triangle
* program and output a simple Wavefront .obj file.
*
* Written by Curtis Olson, started October 1997.
*
* 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 <stdio.h>
#include <stdlib.h> /* for atoi() */
#include <string.h>
#include <sys/stat.h> /* for stat() */
#include <unistd.h> /* for stat() */
#include "tri2obj.h"
#include "../../Src/Include/constants.h"
#include "../../Src/Include/types.h"
#include "../../Src/Math/fg_geodesy.h"
#include "../../Src/Math/mat3.h"
#include "../../Src/Math/polar.h"
#include "../../Src/Scenery/tileutils.h"
int nodecount, tricount;
int normalcount = 0;
struct fgCartesianPoint nodes[MAX_NODES];
int tris[MAX_TRIS][3];
int new_tris[MAX_TRIS][3];
float normals[MAX_NODES][3];
struct bucket my_index;
struct bucket ne_index, nw_index, sw_index, se_index;
struct bucket north_index, south_index, east_index, west_index;
/* convert a geodetic point lon(arcsec), lat(arcsec), elev(meter) to
* a cartesian point */
struct fgCartesianPoint geod_to_cart(double geod[3]) {
struct fgCartesianPoint p;
double gc_lon, gc_lat, sl_radius;
/* printf("A geodetic point is (%.2f, %.2f, %.2f)\n",
geod[0], geod[1], geod[2]); */
gc_lon = geod[0]*ARCSEC_TO_RAD;
fgGeodToGeoc(geod[1]*ARCSEC_TO_RAD, geod[2], &sl_radius, &gc_lat);
/* printf("A geocentric point is (%.2f, %.2f, %.2f)\n", gc_lon,
gc_lat, sl_radius+geod[2]); */
p = fgPolarToCart(gc_lon, gc_lat, sl_radius+geod[2]);
/* printf("A cart point is (%.8f, %.8f, %.8f)\n", p.x, p.y, p.z); */
return(p);
}
/* given three points defining a triangle, calculate the normal */
void calc_normal(struct fgCartesianPoint p1, struct fgCartesianPoint p2,
struct fgCartesianPoint p3, double normal[3])
{
double v1[3], v2[3];
float 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 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;
while ( i <= tricount ) {
if ( (n == tris[i][0]) || (n == tris[i][1]) || (n == tris[i][2]) ) {
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++;
}
}
/* return the file base name ( foo/bar/file.ext = file.ext ) */
void extract_file(char *in, char *base) {
int len, i;
len = strlen(in);
i = len - 1;
while ( (i >= 0) && (in[i] != '/') ) {
i--;
}
in += (i + 1);
strcpy(base, in);
}
/* return the file path name ( foo/bar/file.ext = foo/bar ) */
void extract_path(char *in, char *base) {
int len, i;
len = strlen(in);
strcpy(base, in);
i = len - 1;
while ( (i >= 0) && (in[i] != '/') ) {
i--;
}
base[i] = '\0';
}
/* check if a file exists */
int file_exists(char *file) {
struct stat stat_buf;
int result;
printf("checking %s ... ", file);
result = stat(file, &stat_buf);
if ( result != 0 ) {
/* stat failed, no file */
printf("not found.\n");
return(0);
} else {
/* stat succeeded, file exists */
printf("exists.\n");
return(1);
}
}
/* check to see if a shared object exists */
int shared_object_exists(char *basepath, char *ext, char *file) {
char scene_path[256];
long int index;
if ( strcmp(ext, ".sw") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&west_index, scene_path);
index = gen_index(&west_index);
sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&sw_index, scene_path);
index = gen_index(&sw_index);
sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&south_index, scene_path);
index = gen_index(&south_index);
sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".se") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&east_index, scene_path);
index = gen_index(&east_index);
sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&se_index, scene_path);
index = gen_index(&se_index);
sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&south_index, scene_path);
index = gen_index(&south_index);
sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".ne") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&east_index, scene_path);
index = gen_index(&east_index);
sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&ne_index, scene_path);
index = gen_index(&ne_index);
sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&north_index, scene_path);
index = gen_index(&north_index);
sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".nw") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.nw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&west_index, scene_path);
index = gen_index(&west_index);
sprintf(file, "%s/%s/%ld.1.ne", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&nw_index, scene_path);
index = gen_index(&nw_index);
sprintf(file, "%s/%s/%ld.1.se", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&north_index, scene_path);
index = gen_index(&north_index);
sprintf(file, "%s/%s/%ld.1.sw", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".south") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.south", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&south_index, scene_path);
index = gen_index(&south_index);
sprintf(file, "%s/%s/%ld.1.north", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".north") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.north", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&north_index, scene_path);
index = gen_index(&north_index);
sprintf(file, "%s/%s/%ld.1.south", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".west") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.west", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&west_index, scene_path);
index = gen_index(&west_index);
sprintf(file, "%s/%s/%ld.1.east", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".east") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.east", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
gen_base_path(&east_index, scene_path);
index = gen_index(&east_index);
sprintf(file, "%s/%s/%ld.1.west", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
if ( strcmp(ext, ".body") == 0 ) {
gen_base_path(&my_index, scene_path);
index = gen_index(&my_index);
sprintf(file, "%s/%s/%ld.1.body", basepath, scene_path, index);
if ( file_exists(file) ) {
return(1);
}
}
return(0);
}
/* given a file pointer, read all the vn (normals from it) */
void read_normals(FILE *fp) {
char line[256];
while ( fgets(line, 250, fp) != NULL ) {
if ( strncmp(line, "vn ", 3) == 0 ) {
sscanf(line, "vn %f %f %f\n", &normals[normalcount][0],
&normals[normalcount][1], &normals[normalcount][2]);
/*
printf("read_normals(%d) %.2f %.2f %.2f %s", normalcount,
normals[normalcount][0], normals[normalcount][1],
normals[normalcount][2], line);
*/
normalcount++;
}
}
}
/* my custom file opening routine ... don't open if a shared edge or
* vertex alread exists */
FILE *my_open(char *basename, char *basepath, char *ext) {
FILE *fp;
char filename[256];
/* check if a shared object already exists */
if ( shared_object_exists(basepath, ext, filename) ) {
/* not an actual file open error, but we've already got the
* shared edge, so we don't want to create another one */
fp = fopen(filename, "r");
printf("Opening %s\n", filename);
return(fp);
} else {
/* open the file */
printf("not opening\n");
return(NULL);
}
}
/* Initialize a new mesh structure */
void triload(char *basename, char *basepath) {
char nodename[256], elename[256];
double n[3];
FILE *ne, *nw, *se, *sw, *north, *south, *east, *west;
FILE *node, *ele;
int dim, junk1, junk2;
int i;
ne = my_open(basename, basepath, ".ne");
read_normals(ne);
fclose(ne);
nw = my_open(basename, basepath, ".nw");
read_normals(nw);
fclose(nw);
se = my_open(basename, basepath, ".se");
read_normals(se);
fclose(se);
sw = my_open(basename, basepath, ".sw");
read_normals(sw);
fclose(sw);
north = my_open(basename, basepath, ".north");
read_normals(north);
fclose(north);
south = my_open(basename, basepath, ".south");
read_normals(south);
fclose(south);
east = my_open(basename, basepath, ".east");
read_normals(east);
fclose(east);
west = my_open(basename, basepath, ".west");
read_normals(west);
fclose(west);
strcpy(nodename, basename);
strcat(nodename, ".node");
strcpy(elename, basename);
strcat(elename, ".ele");
printf("Loading node file: %s ...\n", nodename);
if ( (node = fopen(nodename, "r")) == NULL ) {
printf("Cannot open file '%s'\n", nodename);
exit(-1);
}
fscanf(node, "%d %d %d %d", &nodecount, &dim, &junk1, &junk2);
if ( nodecount > MAX_NODES - 1 ) {
printf("Error, too many nodes, need to increase array size\n");
exit(-1);
} else {
printf(" Expecting %d nodes\n", nodecount);
}
for ( i = 1; i <= nodecount; i++ ) {
fscanf(node, "%d %lf %lf %lf %d\n", &junk1,
&n[0], &n[1], &n[2], &junk2);
/* printf("%d %.2f %.2f %.2f\n", junk1, n[0], n[1], n[2]); */
nodes[i] = geod_to_cart(n);
/* printf("%d %.2f %.2f %.2f\n",
junk1, nodes[i].x, nodes[i].y, nodes[i].z); */
}
fclose(node);
printf("Loading element file: %s ...\n", elename);
if ( (ele = fopen(elename, "r")) == NULL ) {
printf("Cannot open file '%s'\n", elename);
exit(-1);
}
fscanf(ele, "%d %d %d", &tricount, &junk1, &junk2);
if ( tricount > MAX_TRIS - 1 ) {
printf("Error, too many elements, need to increase array size\n");
exit(-1);
} else {
printf(" Expecting %d elements\n", tricount);
}
for ( i = 1; i <= tricount; i++ ) {
fscanf(ele, "%d %d %d %d\n", &junk1,
&tris[i][0], &tris[i][1], &tris[i][2]);
/* printf("%d %d %d %d\n", junk1, tris[i][0], tris[i][1], tris[i][2]);*/
}
fclose(ele);
}
/* dump in WaveFront .obj format */
void dump_obj(char *basename) {
char objname[256];
double n1[3], n2[3], n3[3], n4[3], n5[3], norm[3], temp;
FILE *obj;
int i, t1, t2, t3, t4, t5, count;
strcpy(objname, basename);
strcat(objname, ".obj");
printf("Dumping to file: %s ...\n", objname);
obj = fopen(objname, "w");
/* dump vertices */
printf(" writing vertices\n");
for ( i = 1; i <= nodecount; i++ ) {
fprintf(obj, "v %.2f %.2f %.2f\n",
nodes[i].x, nodes[i].y, nodes[i].z);
}
printf(" calculating and writing normals\n");
printf(" First %d normals taken from shared files.\n", normalcount);
/* calculate and generate normals */
for ( i = 1; i <= nodecount; i++ ) {
if ( i <= normalcount ) {
/* use precalculated (shared) normal */
norm[0] = normals[i-1][0];
norm[1] = normals[i-1][1];
norm[2] = normals[i-1][2];
} else {
/* 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[tris[t1][0]], nodes[tris[t1][1]],
nodes[tris[t1][2]], n1);
if ( t2 > 0 ) {
calc_normal(nodes[tris[t2][0]], nodes[tris[t2][1]],
nodes[tris[t2][2]], n2);
count = 2;
}
if ( t3 > 0 ) {
calc_normal(nodes[tris[t3][0]], nodes[tris[t3][1]],
nodes[tris[t3][2]], n3);
count = 3;
}
if ( t4 > 0 ) {
calc_normal(nodes[tris[t4][0]], nodes[tris[t4][1]],
nodes[tris[t4][2]], n4);
count = 4;
}
if ( t5 > 0 ) {
calc_normal(nodes[tris[t5][0]], nodes[tris[t5][1]],
nodes[tris[t5][2]], 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]); */
}
/* printf("%d vn %.4f %.4f %.4f\n", i, norm[0], norm[1], norm[2]); */
fprintf(obj, "vn %.4f %.4f %.4f\n", norm[0], norm[1], norm[2]);
}
/* dump faces */
printf(" writing faces\n");
for ( i = 1; i <= tricount; i++ ) {
fprintf(obj, "f %d %d %d\n", tris[i][0], tris[i][1], tris[i][2]);
}
fclose(obj);
}
int main(int argc, char **argv) {
char basename[256], basepath[256], temp[256];
long int tmp_index;
int len;
strcpy(basename, argv[1]);
/* find the base path of the file */
extract_path(basename, basepath);
extract_path(basepath, basepath);
extract_path(basepath, basepath);
printf("%s\n", basepath);
/* find the index of the current file */
extract_file(basename, temp);
len = strlen(temp);
if ( len >= 2 ) {
temp[len-2] = '\0';
}
tmp_index = atoi(temp);
printf("%ld\n", tmp_index);
parse_index(tmp_index, &my_index);
printf("bucket = %d %d %d %d\n",
my_index.lon, my_index.lat, my_index.x, my_index.y);
/* generate the indexes of the neighbors */
offset_bucket(&my_index, &ne_index, 1, 1);
offset_bucket(&my_index, &nw_index, -1, 1);
offset_bucket(&my_index, &se_index, 1, -1);
offset_bucket(&my_index, &sw_index, -1, -1);
offset_bucket(&my_index, &north_index, 0, 1);
offset_bucket(&my_index, &south_index, 0, -1);
offset_bucket(&my_index, &east_index, 1, 0);
offset_bucket(&my_index, &west_index, -1, 0);
/* load the input data files */
triload(basename, basepath);
/* dump in WaveFront .obj format */
dump_obj(basename);
return(0);
}
/* $Log$
/* Revision 1.8 1998/01/17 01:25:39 curt
/* Added support for shared normals.
/*
* Revision 1.7 1998/01/12 02:42:00 curt
* Average up to five triangles per vertex instead of three.
*
* Revision 1.6 1998/01/09 23:03:15 curt
* Restructured to split 1deg x 1deg dem's into 64 subsections.
*
* Revision 1.5 1997/12/08 19:17:50 curt
* Fixed a type in the normal generation code.
*
* Revision 1.4 1997/12/02 13:13:32 curt
* Fixed problem with averaged vertex normals.
*
* Revision 1.3 1997/11/15 18:05:05 curt
* minor tweaks ...
*
* Revision 1.2 1997/11/14 00:29:13 curt
* Transform scenery coordinates at this point in pipeline when scenery is
* being translated to .obj format, not when it is being loaded into the end
* renderer. Precalculate normals for each node as average of the normals
* of each containing polygon so Garoude shading is now supportable.
*
* Revision 1.1 1997/10/29 23:05:15 curt
* Initial revision.
*
*/
View git blame Copy permalink