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flightgear/Scenery/obj.c
curt ed0acbad5b 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.
1998-04-27 03:30:13 +00:00

526 lines
16 KiB
C

/* -*- Mode: C++ -*-
*
* obj.c -- routines to handle 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 <Math/mat3.h>
#include <Math/fg_random.h>
#include <Scenery/obj.h>
#include <Scenery/scenery.h>
#include <zlib/zlib.h>
#define MAXNODES 100000
static double nodes[MAXNODES][3];
static double normals[MAXNODES][3];
/* given three points defining a triangle, calculate the normal */
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
float calc_lon(double x, double y, double z) {
float tmp;
tmp = (RAD_TO_DEG*atan2(y, x)) * FG_TEX_CONSTANT;
// printf("lon = %.2f\n", (float)tmp);
return (float)tmp;
}
float calc_lat(double x, double y, double z) {
float tmp;
tmp = (90.0 - RAD_TO_DEG*atan2( sqrt(x*x + y*y), z )) * FG_TEX_CONSTANT;
// printf("lat = %.2f\n", (float)tmp);
return (float)tmp;
}
/* Load a .obj file and generate the GL call list */
GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
char gzpath[256], line[256], winding_str[256];
double approx_normal[3], normal[3], scale;
// double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
GLint tile;
gzFile f;
int first, ncount, vncount, n1, n2, n3, n4;
static int use_per_vertex_norms = 1;
int winding;
int last1, last2, odd;
// First try "path.obz" (compressed format)
strcpy(gzpath, path);
strcat(gzpath, ".obz");
if ( (f = gzopen(gzpath, "rb")) == NULL ) {
// Next try "path.obj" (uncompressed format)
strcat(path, ".obj");
if ( (f = gzopen(path, "rb")) == NULL ) {
// Next try "path.obj.gz" (compressed format)
strcat(path, ".gz");
if ( (f = gzopen(path, "rb")) == NULL ) {
fgPrintf(FG_TERRAIN, FG_ALERT, "Cannot open file: %s\n", path);
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;
while ( gzgets(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]);
/* 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;
*/
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 ( use_per_vertex_norms ) {
MAT3_SCALE_VEC(normal, normals[n1], scale);
xglNormal3dv(normal);
xglTexCoord2f(calc_lon(nodes[n1][0], nodes[n1][1], nodes[n1][2]), calc_lat(nodes[n1][0], nodes[n1][1], nodes[n1][2]));
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
MAT3_SCALE_VEC(normal, normals[n2], scale);
xglNormal3dv(normal);
xglTexCoord2f(calc_lon(nodes[n2][0], nodes[n2][1], nodes[n2][2]), calc_lat(nodes[n2][0], nodes[n2][1], nodes[n2][2]));
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
MAT3_SCALE_VEC(normal, normals[n3], scale);
xglNormal3dv(normal);
xglTexCoord2f(calc_lon(nodes[n3][0], nodes[n3][1], nodes[n3][2]), calc_lat(nodes[n3][0], nodes[n3][1], nodes[n3][2]));
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
} else {
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);
xglTexCoord2f(calc_lon(nodes[n1][0], nodes[n1][1], nodes[n1][2]), calc_lat(nodes[n1][0], nodes[n1][1], nodes[n1][2]));
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglTexCoord2f(calc_lon(nodes[n2][0], nodes[n2][1], nodes[n2][2]), calc_lat(nodes[n2][0], nodes[n2][1], nodes[n2][2]));
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglTexCoord2f(calc_lon(nodes[n3][0], nodes[n3][1], nodes[n3][2]), calc_lat(nodes[n3][0], nodes[n3][1], nodes[n3][2]));
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
}
odd = 1 - odd;
last1 = n2;
last2 = n3;
if ( n4 > 0 ) {
if ( use_per_vertex_norms ) {
MAT3_SCALE_VEC(normal, normals[n4], scale);
} else {
calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
MAT3_SCALE_VEC(normal, approx_normal, scale);
}
xglNormal3dv(normal);
xglTexCoord2f(calc_lon(nodes[n4][0], nodes[n4][1], nodes[n4][2]), calc_lat(nodes[n4][0], nodes[n4][1], nodes[n4][2]));
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]);
xglTexCoord2f(calc_lon(nodes[n1][0], nodes[n1][1], nodes[n1][2]), calc_lat(nodes[n1][0], nodes[n1][1], nodes[n1][2]));
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
xglTexCoord2f(calc_lon(nodes[n2][0], nodes[n2][1], nodes[n2][2]), calc_lat(nodes[n2][0], nodes[n2][1], nodes[n2][2]));
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
xglTexCoord2f(calc_lon(nodes[n3][0], nodes[n3][1], nodes[n3][2]), calc_lat(nodes[n3][0], nodes[n3][1], nodes[n3][2]));
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 ( use_per_vertex_norms ) {
MAT3_SCALE_VEC(normal, normals[n1], scale);
xglNormal3dv(normal);
} else {
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);
}
xglTexCoord2f(calc_lon(nodes[n1][0], nodes[n1][1], nodes[n1][2]), calc_lat(nodes[n1][0], nodes[n1][1], nodes[n1][2]));
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 ( use_per_vertex_norms ) {
MAT3_SCALE_VEC(normal, normals[n2], scale);
xglNormal3dv(normal);
} else {
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);
}
xglTexCoord2f(calc_lon(nodes[n2][0], nodes[n2][1], nodes[n2][2]), calc_lat(nodes[n2][0], nodes[n2][1], nodes[n2][2]));
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();
gzclose(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 1.32 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.
*
*/