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flightgear/Scenery/obj.cxx
curt 7f1d04962e Beginning to add support for view frustum culling. 
Added some temporary code to calculate bouding radius, until the
  scenery generation tools and scenery can be updated.
1998-05-16 13:09:57 +00:00

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/*
* obj.cxx -- routines to handle "sorta" WaveFront .obj format files.
*
* 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)
**************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#include <stdio.h>
#include <string.h>
#include <GL/glut.h>
#include <XGL/xgl.h>
#include <Debug/fg_debug.h>
#include <Include/fg_constants.h>
#include <Include/fg_zlib.h>
#include <Main/options.hxx>
#include <Math/mat3.h>
#include <Math/fg_random.h>
#include <Math/polar3d.h>
#include "obj.hxx"
#include "scenery.hxx"
#define MAXNODES 100000
static double nodes[MAXNODES][3];
static double normals[MAXNODES][3];
/* given three points defining a triangle, calculate the normal */
static void calc_normal(double p1[3], double p2[3],
double p3[3], double normal[3])
{
double v1[3], v2[3];
double temp;
v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
MAT3cross_product(normal, v1, v2);
MAT3_NORMALIZE_VEC(normal,temp);
/* fgPrintf( FG_TERRAIN, FG_DEBUG, " Normal = %.2f %.2f %.2f\n",
normal[0], normal[1], normal[2]);*/
}
#define FG_TEX_CONSTANT 128.0
// Calculate texture coordinates for a given point.
fgPolarPoint3d calc_tex_coords(double *node, fgCartesianPoint3d *ref) {
fgCartesianPoint3d cp;
fgPolarPoint3d pp;
cp.x = node[0] + ref->x;
cp.y = node[1] + ref->y;
cp.z = node[2] + ref->z;
pp = fgCartToPolar3d(cp);
pp.lon = fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.lon, 25.0);
pp.lat = fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.lat, 25.0);
return(pp);
}
// Calculate distance between (0,0,0) and the specified point
static double calc_dist(double *p) {
return ( sqrt(p[0]*p[0] + p[1]*p[1] + p[2]*p[2]) );
}
/* Load a .obj file and generate the GL call list */
GLint fgObjLoad(char *path, fgCartesianPoint3d *ref, double *radius) {
fgOPTIONS *o;
fgCartesianPoint3d cp;
fgPolarPoint3d pp;
char fgpath[256], line[256], winding_str[256];
double approx_normal[3], normal[3], scale, dist;
// double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
// GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
GLint tile;
fgFile f;
int first, ncount, vncount, n1, n2, n3, n4;
int winding;
int last1, last2, odd;
o = &current_options;
// First try "path.obz" (compressed format)
strcpy(fgpath, path);
strcat(fgpath, ".obz");
if ( (f = fgopen(fgpath, "rb")) == NULL ) {
// Next try "path.obj" (uncompressed format)
strcpy(fgpath, path);
strcat(fgpath, ".obj");
if ( (f = fgopen(fgpath, "rb")) == NULL ) {
// Next try "path.obj.gz" (compressed format)
strcat(fgpath, ".gz");
if ( (f = fgopen(fgpath, "rb")) == NULL ) {
strcpy(fgpath, path);
strcat(fgpath, ".obj");
fgPrintf( FG_TERRAIN, FG_ALERT,
"Cannot open file: %s\n", fgpath );
return(-1);
}
}
}
tile = xglGenLists(1);
xglNewList(tile, GL_COMPILE);
/*
xglTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
xglTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
xglTexGenfv(GL_S, GL_OBJECT_PLANE, sgenparams);
xglTexGenfv(GL_T, GL_OBJECT_PLANE, sgenparams);
// xglTexGenfv(GL_S, GL_SPHERE_MAP, 0);
// xglTexGenfv(GL_T, GL_SPHERE_MAP, 0);
xglEnable(GL_TEXTURE_GEN_S);
xglEnable(GL_TEXTURE_GEN_T);
*/
first = 1;
ncount = 1;
vncount = 1;
*radius = 0.0;
while ( fggets(f, line, 250) != NULL ) {
if ( line[0] == '#' ) {
/* comment -- ignore */
} else if ( line[0] == '\n' ) {
/* empty line -- ignore */
} else if ( strncmp(line, "ref ", 4) == 0 ) {
/* reference point (center offset) */
sscanf(line, "ref %lf %lf %lf\n", &ref->x, &ref->y, &ref->z);
} else if ( strncmp(line, "v ", 2) == 0 ) {
/* node (vertex) */
if ( ncount < MAXNODES ) {
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex = %s", line); */
sscanf(line, "v %lf %lf %lf\n",
&nodes[ncount][0], &nodes[ncount][1],
&nodes[ncount][2]);
// temporary code to calculate bounding radius
dist = calc_dist(nodes[ncount]);
// printf("node = %.2f %.2f %.2f dist = %.2f\n",
// nodes[ncount][0], nodes[ncount][1], nodes[ncount][2],
// dist);
if ( (dist > *radius) && (dist < 100000.0) ) {
*radius = dist;
}
ncount++;
} else {
fgPrintf( FG_TERRAIN, FG_EXIT,
"Read too many nodes ... dying :-(\n");
}
} else if ( strncmp(line, "vn ", 3) == 0 ) {
/* vertex normal */
if ( vncount < MAXNODES ) {
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex normal = %s", line); */
sscanf(line, "vn %lf %lf %lf\n",
&normals[vncount][0], &normals[vncount][1],
&normals[vncount][2]);
vncount++;
} else {
fgPrintf( FG_TERRAIN, FG_EXIT,
"Read too many vertex normals ... dying :-(\n");
}
} else if ( strncmp(line, "winding ", 8) == 0 ) {
sscanf(line+8, "%s", winding_str);
fgPrintf( FG_TERRAIN, FG_DEBUG, " WINDING = %s\n", winding_str);
/* can't call xglFrontFace() between xglBegin() & xglEnd() */
xglEnd();
first = 1;
if ( strcmp(winding_str, "cw") == 0 ) {
xglFrontFace( GL_CW );
winding = 0;
} else {
glFrontFace ( GL_CCW );
winding = 1;
}
} else if ( line[0] == 't' ) {
/* start a new triangle strip */
n1 = n2 = n3 = n4 = 0;
if ( !first ) {
/* close out the previous structure and start the next */
xglEnd();
} else {
first = 0;
}
/* fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s",
line); */
sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = "); */
xglBegin(GL_TRIANGLE_STRIP);
if ( winding ) {
odd = 1;
scale = 1.0;
} else {
odd = 0;
scale = 1.0;
}
if ( o->shading ) {
// Shading model is "GL_SMOOTH" so use precalculated
// (averaged) normals
MAT3_SCALE_VEC(normal, normals[n1], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n1], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
MAT3_SCALE_VEC(normal, normals[n2], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n2], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
MAT3_SCALE_VEC(normal, normals[n3], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n3], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
} else {
// Shading model is "GL_FLAT" so calculate per face
// normals on the fly.
if ( odd ) {
calc_normal(nodes[n1], nodes[n2],
nodes[n3], approx_normal);
} else {
calc_normal(nodes[n2], nodes[n1],
nodes[n3], approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n1], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
pp = calc_tex_coords(nodes[n2], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
pp = calc_tex_coords(nodes[n3], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
}
odd = 1 - odd;
last1 = n2;
last2 = n3;
if ( n4 > 0 ) {
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n4], scale);
} else {
// Shading model is "GL_FLAT"
calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
MAT3_SCALE_VEC(normal, approx_normal, scale);
}
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n4], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n4][0], nodes[n4][1], nodes[n4][2]);
odd = 1 - odd;
last1 = n3;
last2 = n4;
}
} else if ( line[0] == 'f' ) {
/* unoptimized face */
if ( !first ) {
/* close out the previous structure and start the next */
xglEnd();
} else {
first = 0;
}
xglBegin(GL_TRIANGLES);
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
pp = calc_tex_coords(nodes[n1], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
pp = calc_tex_coords(nodes[n2], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
pp = calc_tex_coords(nodes[n3], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
} else if ( line[0] == 'q' ) {
/* continue a triangle strip */
n1 = n2 = 0;
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
line); */
sscanf(line, "q %d %d\n", &n1, &n2);
/* fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2); */
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n1], scale);
xglNormal3dv(normal);
} else {
// Shading model is "GL_FLAT"
if ( odd ) {
calc_normal(nodes[last1], nodes[last2], nodes[n1],
approx_normal);
} else {
calc_normal(nodes[last2], nodes[last1], nodes[n1],
approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
}
pp = calc_tex_coords(nodes[n1], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
odd = 1 - odd;
last1 = last2;
last2 = n1;
if ( n2 > 0 ) {
/* fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n"); */
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n2], scale);
xglNormal3dv(normal);
} else {
// Shading model is "GL_FLAT"
if ( odd ) {
calc_normal(nodes[last1], nodes[last2], nodes[n2],
approx_normal);
} else {
calc_normal(nodes[last2], nodes[last1], nodes[n2],
approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
}
pp = calc_tex_coords(nodes[n2], ref);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
odd = 1 -odd;
last1 = last2;
last2 = n2;
}
} else {
fgPrintf( FG_TERRAIN, FG_WARN, "Unknown line in %s = %s\n",
path, line);
}
}
xglEnd();
/* Draw normal vectors (for visually verifying normals)*/
/*
xglBegin(GL_LINES);
xglColor3f(0.0, 0.0, 0.0);
for ( i = 0; i < ncount; i++ ) {
xglVertex3d(nodes[i][0],
nodes[i][1] ,
nodes[i][2]);
xglVertex3d(nodes[i][0] + 500*normals[i][0],
nodes[i][1] + 500*normals[i][1],
nodes[i][2] + 500*normals[i][2]);
}
xglEnd();
*/
// xglDisable(GL_TEXTURE_GEN_S);
// xglDisable(GL_TEXTURE_GEN_T);
xglFrontFace ( GL_CCW );
xglEndList();
fgclose(f);
/* reference point is the "center" (now included in input file) */
/*
ref->x = (xmin + xmax) / 2.0;
ref->y = (ymin + ymax) / 2.0;
ref->z = (zmin + zmax) / 2.0;
*/
return(tile);
}
/* $Log$
/* Revision 1.4 1998/05/16 13:09:57 curt
/* Beginning to add support for view frustum culling.
/* Added some temporary code to calculate bouding radius, until the
/* scenery generation tools and scenery can be updated.
/*
* Revision 1.3 1998/05/03 00:48:01 curt
* Updated texture coordinate fmod() parameter.
*
* Revision 1.2 1998/05/02 01:52:14 curt
* Playing around with texture coordinates.
*
* Revision 1.1 1998/04/30 12:35:28 curt
* Added a command line rendering option specify smooth/flat shading.
*
* Revision 1.35 1998/04/28 21:43:26 curt
* Wrapped zlib calls up so we can conditionally comment out zlib support.
*
* Revision 1.34 1998/04/28 01:21:42 curt
* Tweaked texture parameter calculations to keep the number smaller. This
* avoids the "swimming" problem.
* Type-ified fgTIME and fgVIEW.
*
* Revision 1.33 1998/04/27 15:58:15 curt
* Screwing around with texture coordinate generation ... still needs work.
*
* Revision 1.32 1998/04/27 03:30:13 curt
* Minor transformation adjustments to try to keep scenery tiles closer to
* (0, 0, 0) GLfloats run out of precision at the distances we need to model
* the earth, but we can do a bunch of pre-transformations using double math
* and then cast to GLfloat once everything is close in where we have less
* precision problems.
*
* Revision 1.31 1998/04/25 15:09:57 curt
* Changed "r" to "rb" in gzopen() options. This fixes bad behavior in win32.
*
* Revision 1.30 1998/04/24 14:21:08 curt
* Added "file.obj.gz" support.
*
* Revision 1.29 1998/04/24 00:51:07 curt
* Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
* Tweaked the scenery file extentions to be "file.obj" (uncompressed)
* or "file.obz" (compressed.)
*
* Revision 1.28 1998/04/22 13:22:44 curt
* C++ - ifing the code a bit.
*
* Revision 1.27 1998/04/18 04:13:17 curt
* Added zlib on the fly decompression support for loading scenery objects.
*
* Revision 1.26 1998/04/03 22:11:36 curt
* Converting to Gnu autoconf system.
*
* Revision 1.25 1998/03/14 00:30:50 curt
* Beginning initial terrain texturing experiments.
*
* Revision 1.24 1998/02/09 21:30:18 curt
* Fixed a nagging problem with terrain tiles not "quite" matching up perfectly.
*
* Revision 1.23 1998/02/09 15:07:52 curt
* Minor tweaks.
*
* Revision 1.22 1998/02/01 03:39:54 curt
* Minor tweaks.
*
* Revision 1.21 1998/01/31 00:43:25 curt
* Added MetroWorks patches from Carmen Volpe.
*
* Revision 1.20 1998/01/29 00:51:39 curt
* First pass at tile cache, dynamic tile loading and tile unloading now works.
*
* Revision 1.19 1998/01/27 03:26:42 curt
* Playing with new fgPrintf command.
*
* Revision 1.18 1998/01/19 19:27:16 curt
* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
* This should simplify things tremendously.
*
* Revision 1.17 1998/01/13 00:23:10 curt
* Initial changes to support loading and management of scenery tiles. Note,
* there's still a fair amount of work left to be done.
*
* Revision 1.16 1997/12/30 23:09:40 curt
* Worked on winding problem without luck, so back to calling glFrontFace()
* 3 times for each scenery area.
*
* Revision 1.15 1997/12/30 20:47:51 curt
* Integrated new event manager with subsystem initializations.
*
* Revision 1.14 1997/12/30 01:38:46 curt
* Switched back to per vertex normals and smooth shading for terrain.
*
* Revision 1.13 1997/12/18 23:32:36 curt
* First stab at sky dome actually starting to look reasonable. :-)
*
* Revision 1.12 1997/12/17 23:13:47 curt
* Began working on rendering the sky.
*
* Revision 1.11 1997/12/15 23:55:01 curt
* Add xgl wrappers for debugging.
* Generate terrain normals on the fly.
*
* Revision 1.10 1997/12/12 21:41:28 curt
* More light/material property tweaking ... still a ways off.
*
* Revision 1.9 1997/12/12 19:52:57 curt
* Working on lightling and material properties.
*
* Revision 1.8 1997/12/10 01:19:51 curt
* Tweaks for verion 0.15 release.
*
* Revision 1.7 1997/12/08 22:51:17 curt
* Enhanced to handle ccw and cw tri-stripe winding. This is a temporary
* admission of defeat. I will eventually go back and get all the stripes
* wound the same way (ccw).
*
* Revision 1.6 1997/11/25 19:25:35 curt
* Changes to integrate Durk's moon/sun code updates + clean up.
*
* Revision 1.5 1997/11/15 18:16:39 curt
* minor tweaks.
*
* Revision 1.4 1997/11/14 00:26:49 curt
* Transform scenery coordinates earlier in pipeline when scenery is being
* created, not when it is being loaded. Precalculate normals for each node
* as average of the normals of each containing polygon so Garoude shading is
* now supportable.
*
* Revision 1.3 1997/10/31 04:49:12 curt
* Tweaking vertex orders.
*
* Revision 1.2 1997/10/30 12:38:45 curt
* Working on new scenery subsystem.
*
* Revision 1.1 1997/10/28 21:14:54 curt
* Initial revision.
*
*/
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