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flightgear/FixObj/obj.cxx
curt f7a80a9de3 Renamed *.[ch] to *.[ch]xx
1998-06-08 17:11:44 +00:00

619 lines
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// obj.cxx -- routines to handle WaveFront .obj format files.
//
// Written by Curtis Olson, started October 1997.
//
// Copyright (C) 1997 - 1998 Curtis L. Olson - curt@me.umn.edu
//
// 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 <string.h>
#include "obj.hxx"
#include <Math/mat3.h>
// what do ya' know, here's some global variables
static double nodes[MAXNODES][3];
static double normals[MAXNODES][3];
static int faces[MAXNODES][3];
int ncount, vncount, fcount;
static int ccw_list[MAXNODES];
int ccw_list_ptr;
static int cw_list[MAXNODES];
int cw_list_ptr;
FILE *in, *out;
double refx, refy, refz;
// some simple list routines
// reset the list
void list_init(int *list_ptr) {
*list_ptr = 0;
}
// add to list
void list_add(int *list, int *list_ptr, int node) {
if ( *list_ptr >= MAXNODES ) {
printf("ERROR: list overflow in list_add()\n");
exit(-1);
}
list[*list_ptr] = node;
*list_ptr += 1;
// printf("list pointer = %d adding %d\n", *list_ptr, node);
}
// fix the cw list and append to ccw_list
void fix_cw_list(int *list, int list_ptr) {
int i, j, len;
if ( list_ptr < 3 ) {
printf("List is empty ... skipping\n");
return;
}
printf("Fixing cw list, size = %d\n", list_ptr);
i = 0;
while ( i < list_ptr ) {
// do next strip
// find length
len = 0;
// scan rest of strip (until -1)
while ( ((i+len) < list_ptr) && (list[i+len] != -1) ) {
// printf("len = %d item = %d\n", len, list[i+len] );
len++;
}
// printf(" Final length = %d\n", len);
if ( (len % 2) != 0 ) {
// if length is odd, just reverse order of nodes to
// reverse winding
if ( ccw_list_ptr ) {
list_add(ccw_list, &ccw_list_ptr, -1);
}
for ( j = i + len - 1; j >= i; j-- ) {
// printf(" odd -> item = %d\n", list[j] );
list_add(ccw_list, &ccw_list_ptr, list[j]);
}
} else {
// if length is even, reverse order of (n-1) nodes to
// reverse winding, and create an orphan triangle for the
// last "nth" node
if ( ccw_list_ptr ) {
list_add(ccw_list, &ccw_list_ptr, -1);
}
for ( j = i + len - 2; j >= i; j-- ) {
// printf(" even -> item = %d\n", list[j] );
list_add(ccw_list, &ccw_list_ptr, list[j]);
}
// printf(" even bonus -> item = %d\n", list[i + len - 1] );
// printf(" even bonus -> item = %d\n", list[i + len - 2] );
// printf(" even bonus -> item = %d\n", list[i + len - 3] );
list_add(ccw_list, &ccw_list_ptr, -1);
list_add(ccw_list, &ccw_list_ptr, list[i + len - 3]);
list_add(ccw_list, &ccw_list_ptr, list[i + len - 2]);
list_add(ccw_list, &ccw_list_ptr, list[i + len - 1]);
}
i += len + 1;
}
}
// Calculate distance between (0,0,0) and the specified point
static double calc_dist(double x, double y, double z) {
return ( sqrt(x*x + y*y + z*z) );
}
void dump_global_bounds( void ) {
double dist, radius;
int i;
radius = 0.0;
fprintf(out, "\n");
for ( i = 1; i < ncount; i++ ) {
dist = calc_dist(nodes[i][0] - refx, nodes[i][1] - refy,
nodes[i][2] - refz);
// printf("node = %.2f %.2f %.2f dist = %.2f\n",
// nodes[i][0], nodes[i][1], nodes[i][2],
// dist);
if ( dist > radius ) {
radius = dist;
}
}
fprintf(out, "gbs %.5f %.5f %.5f %.2f\n", refx, refy, refz, radius);
}
// dump nodes
void dump_nodes( void ) {
int i;
fprintf(out, "\n");
for ( i = 1; i < ncount; i++ ) {
fprintf(out, "v %.5f %.5f %.5f\n",
nodes[i][0] - refx, nodes[i][1] - refy, nodes[i][2] - refz);
}
}
// dump normals
void dump_normals( void ) {
int i;
fprintf(out, "\n");
for ( i = 1; i < vncount; i++ ) {
fprintf(out, "vn %.5f %.5f %.5f\n",
normals[i][0], normals[i][1], normals[i][2]);
}
}
// dump faces
void dump_faces( void ) {
int i, n1, n2, n3;
double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin, dist, radius;
fprintf(out, "\n");
for ( i = 1; i < fcount; i++ ) {
n1 = faces[i][0];
n2 = faces[i][1];
n3 = faces[i][2];
// calc center of face
xmin = xmax = nodes[n1][0];
ymin = ymax = nodes[n1][1];
zmin = zmax = nodes[n1][2];
if ( nodes[n2][0] < xmin ) { xmin = nodes[n2][0]; }
if ( nodes[n2][0] > xmax ) { xmax = nodes[n2][0]; }
if ( nodes[n2][1] < ymin ) { ymin = nodes[n2][1]; }
if ( nodes[n2][1] > ymax ) { ymax = nodes[n2][1]; }
if ( nodes[n2][2] < zmin ) { zmin = nodes[n2][2]; }
if ( nodes[n2][2] > zmax ) { zmax = nodes[n2][2]; }
if ( nodes[n3][0] < xmin ) { xmin = nodes[n3][0]; }
if ( nodes[n3][0] > xmax ) { xmax = nodes[n3][0]; }
if ( nodes[n3][1] < ymin ) { ymin = nodes[n3][1]; }
if ( nodes[n3][1] > ymax ) { ymax = nodes[n3][1]; }
if ( nodes[n3][2] < zmin ) { zmin = nodes[n3][2]; }
if ( nodes[n3][2] > zmax ) { zmax = nodes[n3][2]; }
x = (xmin + xmax) / 2.0;
y = (ymin + ymax) / 2.0;
z = (zmin + zmax) / 2.0;
// calc bounding radius
radius = calc_dist(nodes[n1][0] - x, nodes[n1][1] - y,
nodes[n1][2] - z);
dist = calc_dist(nodes[n2][0] - x, nodes[n2][1] - y, nodes[n2][2] - z);
if ( dist > radius ) { radius = dist; }
dist = calc_dist(nodes[n3][0] - x, nodes[n3][1] - y, nodes[n3][2] - z);
if ( dist > radius ) { radius = dist; }
// output data
fprintf(out, "bs %.2f %.2f %.2f %.2f\n", x, y, z, radius);
fprintf(out, "f %d %d %d\n", n1, n2, n3);
}
}
// dump list
void dump_list(int *list, int list_ptr) {
double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin, dist, radius;
int i, j, len, n;
if ( list_ptr < 3 ) {
printf("List is empty ... skipping\n");
return;
}
printf("Dumping list, size = %d\n", list_ptr);
i = 0;
while ( i < list_ptr ) {
// do next strip
if ( (i % 2) == 0 ) {
fprintf(out, "\nusemtl desert1\n");
} else {
fprintf(out, "\nusemtl desert2\n");
}
// find length of next tri strip
len = 0;
// scan rest of strip (until -1)
while ( ((i+len) < list_ptr) && (list[i+len] != -1) ) {
// printf("len = %d item = %d\n", len, list[i+len] );
len++;
}
// printf("strip length = %d\n", len);
// calc center of face
n = list[i];
xmin = xmax = nodes[n][0];
ymin = ymax = nodes[n][1];
zmin = zmax = nodes[n][2];
// printf("%.2f %.2f %.2f\n", nodes[n][0], nodes[n][1], nodes[n][2]);
for ( j = i + 1; j < i + len; j++ ) {
// printf("j = %d\n", j);
n = list[j];
if ( nodes[n][0] < xmin ) { xmin = nodes[n][0]; }
if ( nodes[n][0] > xmax ) { xmax = nodes[n][0]; }
if ( nodes[n][1] < ymin ) { ymin = nodes[n][1]; }
if ( nodes[n][1] > ymax ) { ymax = nodes[n][1]; }
if ( nodes[n][2] < zmin ) { zmin = nodes[n][2]; }
if ( nodes[n][2] > zmax ) { zmax = nodes[n][2]; }
// printf("%.2f %.2f %.2f\n", nodes[n][0], nodes[n][1], nodes[n][2]);
}
x = (xmin + xmax) / 2.0;
y = (ymin + ymax) / 2.0;
z = (zmin + zmax) / 2.0;
// printf("center = %.2f %.2f %.2f\n", x, y, z);
// calc bounding radius
n = list[i];
radius = calc_dist(nodes[n][0] - x, nodes[n][1] - y, nodes[n][2] - z);
for ( j = i + 1; j < i + len; j++ ) {
n = list[j];
dist = calc_dist(nodes[n][0] - x, nodes[n][1] - y,
nodes[n][2] - z);
if ( dist > radius ) { radius = dist; }
}
// printf("radius = %.2f\n", radius);
// dump bounding sphere and header
fprintf(out, "bs %.2f %.2f %.2f %.2f\n", x, y, z, radius);
fprintf(out, "t %d %d %d\n", list[i], list[i+1], list[i+2]);
// printf("t %d %d %d\n", list[i], list[i+1], list[i+2]);
i += 3;
// dump rest of strip (until -1)
while ( (i < list_ptr) && (list[i] != -1) ) {
fprintf(out, "q %d", list[i]);
i++;
if ( (i < list_ptr) && (list[i] != -1) ) {
fprintf(out, " %d", list[i]);
i++;
}
fprintf(out, "\n");
}
i++;
}
}
// Check the direction the current triangle faces, compared to it's
// pregenerated normal. Returns the dot product between the target
// normal and actual normal. If the dot product is close to 1.0, they
// nearly match. If the are close to -1.0, the are nearly opposite.
double check_cur_face(int n1, int n2, int n3) {
double v1[3], v2[3], approx_normal[3], dot_prod, temp;
// check for the proper rotation by calculating an approximate
// normal and seeing if it is close to the precalculated normal
v1[0] = nodes[n2][0] - nodes[n1][0];
v1[1] = nodes[n2][1] - nodes[n1][1];
v1[2] = nodes[n2][2] - nodes[n1][2];
v2[0] = nodes[n3][0] - nodes[n1][0];
v2[1] = nodes[n3][1] - nodes[n1][1];
v2[2] = nodes[n3][2] - nodes[n1][2];
MAT3cross_product(approx_normal, v1, v2);
MAT3_NORMALIZE_VEC(approx_normal,temp);
dot_prod = MAT3_DOT_PRODUCT(normals[n1], approx_normal);
// not first triangle
// if ( ((dot_prod < -0.5) && !is_backwards) ||
// ((dot_prod > 0.5) && is_backwards) ) {
// printf(" Approx normal = %.2f %.2f %.2f\n", approx_normal[0],
// approx_normal[1], approx_normal[2]);
// printf(" Dot product = %.4f\n", dot_prod);
// }
// angle = acos(dot_prod);
// printf("Normal ANGLE = %.3f rads.\n", angle);
return(dot_prod);
}
// Load a .obj file
void obj_fix(char *infile, char *outfile) {
char line[256];
double dot_prod;
int first, n1, n2, n3, n4;
double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
int is_ccw;
if ( (in = fopen(infile, "r")) == NULL ) {
printf("Cannot open file: %s\n", infile);
exit(-1);
}
if ( (out = fopen(outfile, "w")) == NULL ) {
printf("Cannot open file: %s\n", outfile);
exit(-1);
}
list_init(&ccw_list_ptr);
list_init(&cw_list_ptr);
// I start counting at one because that is how the triangle
// program refers to nodes and normals
first = 1;
ncount = 1;
vncount = 1;
fcount = 1;
printf("Reading file: %s\n", infile);
while ( fgets(line, 250, in) != NULL ) {
if ( line[0] == '#' ) {
// pass along the comments verbatim
fprintf(out, "%s", line);
} else if ( strlen(line) <= 1 ) {
// don't pass along empty lines
// fprintf(out, "%s", line);
} else if ( strncmp(line, "v ", 2) == 0 ) {
// save vertex to memory and output to file
if ( ncount < MAXNODES ) {
// printf("vertex = %s", line);
sscanf(line, "v %lf %lf %lf\n", &x, &y, &z);
nodes[ncount][0] = x;
nodes[ncount][1] = y;
nodes[ncount][2] = z;
// first time through set min's and max'es
if ( ncount == 1 ) {
xmin = x;
xmax = x;
ymin = y;
ymax = y;
zmin = z;
zmax = z;
}
// keep track of min/max vertex values
if ( x < xmin ) xmin = x;
if ( x > xmax ) xmax = x;
if ( y < ymin ) ymin = y;
if ( y > ymax ) ymax = y;
if ( z < zmin ) zmin = z;
if ( z > zmax ) zmax = z;
// fprintf(out, "v %.2f %.2f %.2f\n",
// nodes[ncount][0], nodes[ncount][1], nodes[ncount][2]);
ncount++;
} else {
printf("Read too many nodes ... dying :-(\n");
exit(-1);
}
} else if ( strncmp(line, "vn ", 3) == 0 ) {
// save vertex normals to memory and output to file
if ( vncount < MAXNODES ) {
// printf("vertex normal = %s", line);
sscanf(line, "vn %lf %lf %lf\n",
&normals[vncount][0], &normals[vncount][1],
&normals[vncount][2]);
// fprintf(out, "vn %.4f %.4f %.4f\n", normals[vncount][0],
// normals[vncount][1], normals[vncount][2]);
vncount++;
} else {
printf("Read too many vertex normals ... dying :-(\n");
exit(-1);
}
} else if ( line[0] == 't' ) {
// starting a new triangle strip
printf("Starting a new triangle strip\n");
n1 = n2 = n3 = n4 = 0;
printf("new tri strip = %s", line);
sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
// special cases to handle bugs in our beloved tri striper
if ( (n1 == 4) && (n2 == 2) && (n3 == 2) && (n4 == 1) ) {
n2 = 3;
}
if ( (n1 == 3) && (n2 == 1) && (n3 == 1) && (n4 == 0) ) {
n3 = 4;
}
dot_prod = check_cur_face(n1, n2, n3);
if ( dot_prod < 0.0 ) {
// this stripe is backwards (CW)
is_ccw = 0;
printf(" -> Starting a backwards stripe\n");
} else {
// this stripe is normal (CCW)
is_ccw = 1;
}
if ( is_ccw ) {
if ( ccw_list_ptr ) {
list_add(ccw_list, &ccw_list_ptr, -1);
}
list_add(ccw_list, &ccw_list_ptr, n1);
list_add(ccw_list, &ccw_list_ptr, n2);
list_add(ccw_list, &ccw_list_ptr, n3);
} else {
if ( cw_list_ptr ) {
list_add(cw_list, &cw_list_ptr, -1);
}
list_add(cw_list, &cw_list_ptr, n1);
list_add(cw_list, &cw_list_ptr, n2);
list_add(cw_list, &cw_list_ptr, n3);
}
if ( n4 > 0 ) {
if ( is_ccw ) {
list_add(ccw_list, &ccw_list_ptr, n4);
} else {
list_add(cw_list, &cw_list_ptr, n4);
}
}
} else if ( line[0] == 'f' ) {
if ( fcount < MAXNODES ) {
// pass along the unoptimized faces verbatim
sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
faces[fcount][0] = n1;
faces[fcount][1] = n2;
faces[fcount][2] = n3;
fcount++;
} else {
printf("Read too many unoptimized faces ... dying :-(\n");
exit(-1);
}
// fprintf(out, "%s", line);
} else if ( line[0] == 'q' ) {
// continue a triangle strip
n1 = n2 = 0;
// printf("continued tri strip = %s ", line);
sscanf(line, "q %d %d\n", &n1, &n2);
if ( is_ccw ) {
list_add(ccw_list, &ccw_list_ptr, n1);
} else {
list_add(cw_list, &cw_list_ptr, n1);
}
if ( n2 > 0 ) {
if ( is_ccw ) {
list_add(ccw_list, &ccw_list_ptr, n2);
} else {
list_add(cw_list, &cw_list_ptr, n2);
}
}
} else {
printf("Unknown line in %s = %s\n", infile, line);
}
}
// reference point is the "center"
refx = (xmin + xmax) / 2.0;
refy = (ymin + ymax) / 2.0;
refz = (zmin + zmax) / 2.0;
// convert the cw_list to ccw add append to ccw_list
fix_cw_list(cw_list, cw_list_ptr);
dump_global_bounds();
dump_nodes();
dump_normals();
if ( fcount > 1 ) {
dump_faces();
}
dump_list(ccw_list, ccw_list_ptr);
fclose(in);
fclose(out);
}
// $Log$
// Revision 1.1 1998/06/08 17:11:46 curt
// Renamed *.[ch] to *.[ch]xx
//
// Revision 1.16 1998/05/27 02:27:22 curt
// Commented out a couple of debugging messages.
//
// Revision 1.15 1998/05/24 02:47:47 curt
// For each strip, specify a default material property and calculate a center
// and bounding sphere.
//
// Revision 1.14 1998/05/23 15:19:49 curt
// Output more digits after the decimal place.
//
// Revision 1.13 1998/05/20 20:55:19 curt
// Fixed arbitrary polygon winding problem here so all tristrips are passed
// to runtime simulator with a consistant counter clockwise winding.
//
// Revision 1.12 1998/05/16 13:11:26 curt
// Fixed an off by one error in node, normal, and face counters.
//
// Revision 1.11 1998/04/27 15:59:24 curt
// Fixed an off by one error.
//
// Revision 1.10 1998/04/27 03:33:11 curt
// Code now calculates a center reference points and outputs everything
// relative to that. This is useful in the rendering engine to keep everything
// close to (0, 0, 0) where we can avoid many GLfloat precision problems.
//
// Revision 1.9 1998/04/18 04:01:03 curt
// Now use libMath rather than having local copies of math routines.
//
// Revision 1.8 1998/04/08 23:19:37 curt
// Adopted Gnu automake/autoconf system.
//
// Revision 1.7 1998/03/19 02:51:41 curt
// Added special case handling to compensate for bugs in our beloved tri striper
//
// Revision 1.6 1998/03/03 15:36:12 curt
// Tweaks for compiling with g++
//
// Revision 1.5 1998/03/03 03:37:03 curt
// Cumulative tweaks.
//
// Revision 1.4 1998/01/31 00:41:25 curt
// Made a few changes converting floats to doubles.
//
// Revision 1.3 1998/01/19 19:51:07 curt
// A couple final pre-release tweaks.
//
// Revision 1.2 1998/01/09 23:03:12 curt
// Restructured to split 1deg x 1deg dem's into 64 subsections.
//
// Revision 1.1 1997/12/08 19:28:54 curt
// Initial revision.
//
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