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flightgear/Main/GLUTmain.cxx
1998-06-08 17:57:04 +00:00

1218 lines
36 KiB
C++

//
// GLUTmain.cxx -- top level sim routines
//
// Written by Curtis Olson for OpenGL, started May 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>
# include <float.h>
#endif
#include <GL/glut.h>
#include <XGL/xgl.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif
#include <Include/fg_constants.h> // for VERSION
#include <Include/general.h>
#include <Aircraft/aircraft.h>
#include <Astro/moon.hxx>
#include <Astro/planets.hxx>
#include <Astro/sky.hxx>
#include <Astro/stars.hxx>
#include <Astro/sun.hxx>
#ifdef HAVE_OSS_AUDIO
# include <Audio/sl.h>
# include <Audio/sm.h>
#endif
#include <Cockpit/cockpit.hxx>
#include <Debug/fg_debug.h>
#include <Joystick/joystick.h>
#include <Math/fg_geodesy.h>
#include <Math/mat3.h>
#include <Math/polar3d.h>
#include <Scenery/scenery.hxx>
#include <Scenery/tilemgr.hxx>
#include <Time/event.hxx>
#include <Time/fg_time.hxx>
#include <Time/fg_timer.hxx>
#include <Time/sunpos.hxx>
#include <Weather/weather.h>
#include "GLUTkey.hxx"
#include "fg_init.hxx"
#include "options.hxx"
#include "views.hxx"
// This is a record containing global housekeeping information
fgGENERAL general;
// Another hack
int use_signals = 0;
// Yet another other hack. Used for my prototype instrument code. (Durk)
int displayInstruments;
// Global structures for the Audio library
#ifdef HAVE_OSS_AUDIO
slScheduler audio_sched ( 8000 ) ;
smMixer audio_mixer ;
slSample *s1;
slSample *s2;
#endif
// The following defines flight gear options. Because glutlib will also
// want to parse its own options, those options must not be included here
// or they will get parsed by the main program option parser. Hence case
// is significant for any option added that might be in conflict with
// glutlib's parser.
//
// glutlib parses for:
// -display
// -direct (invalid in Win32)
// -geometry
// -gldebug
// -iconized
// -indirect (invalid in Win32)
// -synce
//
// Note that glutlib depends upon strings while this program's
// option parser wants only initial characters followed by numbers
// or pathnames.
//
// fgInitVisuals() -- Initialize various GL/view parameters
static void fgInitVisuals( void ) {
fgLIGHT *l;
fgOPTIONS *o;
struct fgWEATHER *w;
l = &cur_light_params;
o = &current_options;
w = &current_weather;
// Go full screen if requested ...
if ( o->fullscreen ) {
glutFullScreen();
}
// If enabled, normal vectors specified with glNormal are scaled
// to unit length after transformation. See glNormal.
xglEnable( GL_NORMALIZE );
xglEnable( GL_LIGHTING );
xglEnable( GL_LIGHT0 );
xglLightfv( GL_LIGHT0, GL_POSITION, l->sun_vec );
xglFogi (GL_FOG_MODE, GL_LINEAR);
xglFogf (GL_FOG_START, w->visibility / 1000000.0 );
xglFogf (GL_FOG_END, w->visibility);
// xglFogf (GL_FOG_DENSITY, w->visibility);
if ( o->shading ) {
xglHint (GL_FOG_HINT, GL_NICEST );
} else {
xglHint (GL_FOG_HINT, GL_FASTEST );
}
if ( o->wireframe ) {
// draw wire frame
xglPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
}
// This is the default anyways, but it can't hurt
xglFrontFace ( GL_CCW );
}
// Update the view volume, position, and orientation
static void fgUpdateViewParams( void ) {
fgFLIGHT *f;
fgLIGHT *l;
fgOPTIONS *o;
fgVIEW *v;
f = current_aircraft.flight;
l = &cur_light_params;
o = &current_options;
v = &current_view;
v->Update(f);
v->UpdateWorldToEye(f);
if (displayInstruments) {
xglViewport( 0, (GLint)((v->winHeight) / 2 ) ,
(GLint)(v->winWidth), (GLint)(v->winHeight) / 2 );
// Tell GL we are about to modify the projection parameters
xglMatrixMode(GL_PROJECTION);
xglLoadIdentity();
gluPerspective(o->fov, v->win_ratio / 2.0, 1.0, 100000.0);
} else {
xglViewport(0, 0 , (GLint)(v->winWidth), (GLint)(v->winHeight) );
// Tell GL we are about to modify the projection parameters
xglMatrixMode(GL_PROJECTION);
xglLoadIdentity();
gluPerspective(o->fov, v->win_ratio, 10.0, 100000.0);
}
xglMatrixMode(GL_MODELVIEW);
xglLoadIdentity();
// set up our view volume (default)
gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
v->view_pos.x + v->view_forward[0],
v->view_pos.y + v->view_forward[1],
v->view_pos.z + v->view_forward[2],
v->view_up[0], v->view_up[1], v->view_up[2]);
// look almost straight up (testing and eclipse watching)
/* gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
v->view_pos.x + v->view_up[0] + .001,
v->view_pos.y + v->view_up[1] + .001,
v->view_pos.z + v->view_up[2] + .001,
v->view_up[0], v->view_up[1], v->view_up[2]); */
// lock view horizontally towards sun (testing)
/* gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
v->view_pos.x + v->surface_to_sun[0],
v->view_pos.y + v->surface_to_sun[1],
v->view_pos.z + v->surface_to_sun[2],
v->view_up[0], v->view_up[1], v->view_up[2]); */
// lock view horizontally towards south (testing)
/* gluLookAt(v->view_pos.x, v->view_pos.y, v->view_pos.z,
v->view_pos.x + v->surface_south[0],
v->view_pos.y + v->surface_south[1],
v->view_pos.z + v->surface_south[2],
v->view_up[0], v->view_up[1], v->view_up[2]); */
// set the sun position
xglLightfv( GL_LIGHT0, GL_POSITION, l->sun_vec );
}
// Draw a basic instrument panel
static void fgUpdateInstrViewParams( void ) {
fgVIEW *v;
v = &current_view;
xglViewport(0, 0 , (GLint)(v->winWidth), (GLint)(v->winHeight) / 2);
xglMatrixMode(GL_PROJECTION);
xglPushMatrix();
xglLoadIdentity();
gluOrtho2D(0, 640, 0, 480);
xglMatrixMode(GL_MODELVIEW);
xglPushMatrix();
xglLoadIdentity();
xglColor3f(1.0, 1.0, 1.0);
xglIndexi(7);
xglDisable(GL_DEPTH_TEST);
xglDisable(GL_LIGHTING);
xglLineWidth(1);
xglColor3f (0.5, 0.5, 0.5);
xglBegin(GL_QUADS);
xglVertex2f(0.0, 0.00);
xglVertex2f(0.0, 480.0);
xglVertex2f(640.0,480.0);
xglVertex2f(640.0, 0.0);
xglEnd();
xglRectf(0.0,0.0, 640, 480);
xglEnable(GL_DEPTH_TEST);
xglEnable(GL_LIGHTING);
xglMatrixMode(GL_PROJECTION);
xglPopMatrix();
xglMatrixMode(GL_MODELVIEW);
xglPopMatrix();
}
// Update all Visuals (redraws anything graphics related)
static void fgRenderFrame( void ) {
fgLIGHT *l;
fgOPTIONS *o;
fgTIME *t;
fgVIEW *v;
double angle;
GLfloat black[4] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat terrain_color[4] = { 0.54, 0.44, 0.29, 1.0 };
l = &cur_light_params;
o = &current_options;
t = &cur_time_params;
v = &current_view;
// update view volume parameters
fgUpdateViewParams();
if ( o->skyblend ) {
glClearColor(black[0], black[1], black[2], black[3]);
xglClear( GL_DEPTH_BUFFER_BIT );
} else {
glClearColor(l->sky_color[0], l->sky_color[1],
l->sky_color[2], l->sky_color[3]);
xglClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT );
}
// Tell GL we are switching to model view parameters
xglMatrixMode(GL_MODELVIEW);
// xglLoadIdentity();
// draw sky
xglDisable( GL_DEPTH_TEST );
xglDisable( GL_LIGHTING );
xglDisable( GL_CULL_FACE );
xglDisable( GL_FOG );
xglShadeModel( GL_SMOOTH );
if ( o->skyblend ) {
fgSkyRender();
}
// setup transformation for drawing astronomical objects
xglPushMatrix();
// Translate to view position
xglTranslatef( v->view_pos.x, v->view_pos.y, v->view_pos.z );
// Rotate based on gst (sidereal time)
angle = t->gst * 15.041085; /* should be 15.041085, Curt thought it was 15*/
// printf("Rotating astro objects by %.2f degrees\n",angle);
xglRotatef( angle, 0.0, 0.0, -1.0 );
// draw stars and planets
fgStarsRender();
fgPlanetsRender();
// draw the sun
fgSunRender();
// render the moon
xglEnable( GL_LIGHTING );
// set lighting parameters
xglLightfv(GL_LIGHT0, GL_AMBIENT, white );
xglLightfv(GL_LIGHT0, GL_DIFFUSE, white );
xglEnable( GL_CULL_FACE );
// Let's try some blending technique's (Durk)
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE);
fgMoonRender();
glDisable(GL_BLEND);
xglPopMatrix();
// draw scenery
if ( o->shading ) {
xglShadeModel( GL_SMOOTH );
} else {
xglShadeModel( GL_FLAT );
}
xglEnable( GL_DEPTH_TEST );
if ( o->fog ) {
xglEnable( GL_FOG );
xglFogfv (GL_FOG_COLOR, l->fog_color);
}
// set lighting parameters
xglLightfv(GL_LIGHT0, GL_AMBIENT, l->scene_ambient );
xglLightfv(GL_LIGHT0, GL_DIFFUSE, l->scene_diffuse );
if ( o->textures ) {
// texture parameters
xglEnable( GL_TEXTURE_2D );
xglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT ) ;
xglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT ) ;
xglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ) ;
xglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR /* GL_LINEAR_MIPMAP_LINEAR */ ) ;
xglTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ) ;
xglHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST ) ;
// set base color (I don't think this is doing anything here)
xglMaterialfv (GL_FRONT, GL_AMBIENT, white);
xglMaterialfv (GL_FRONT, GL_DIFFUSE, white);
} else {
xglDisable( GL_TEXTURE_2D );
xglMaterialfv (GL_FRONT, GL_AMBIENT, terrain_color);
xglMaterialfv (GL_FRONT, GL_DIFFUSE, terrain_color);
// xglMaterialfv (GL_FRONT, GL_AMBIENT, white);
// xglMaterialfv (GL_FRONT, GL_DIFFUSE, white);
}
fgTileMgrRender();
xglDisable( GL_TEXTURE_2D );
// display HUD
if( o->hud_status ) {
fgCockpitUpdate();
}
// display instruments
if (displayInstruments) {
fgUpdateInstrViewParams();
}
xglutSwapBuffers();
}
// Update internal time dependent calculations (i.e. flight model)
void fgUpdateTimeDepCalcs(int multi_loop) {
fgFLIGHT *f;
fgTIME *t;
fgVIEW *v;
int i;
f = current_aircraft.flight;
t = &cur_time_params;
v = &current_view;
// update the flight model
if ( multi_loop < 0 ) {
multi_loop = DEFAULT_MULTILOOP;
}
// printf("updating flight model x %d\n", multi_loop);
fgFlightModelUpdate(FG_LARCSIM, f, multi_loop);
// update the view angle
for ( i = 0; i < multi_loop; i++ ) {
if ( fabs(v->goal_view_offset - v->view_offset) < 0.05 ) {
v->view_offset = v->goal_view_offset;
break;
} else {
// move v->view_offset towards v->goal_view_offset
if ( v->goal_view_offset > v->view_offset ) {
if ( v->goal_view_offset - v->view_offset < FG_PI ) {
v->view_offset += 0.01;
} else {
v->view_offset -= 0.01;
}
} else {
if ( v->view_offset - v->goal_view_offset < FG_PI ) {
v->view_offset -= 0.01;
} else {
v->view_offset += 0.01;
}
}
if ( v->view_offset > FG_2PI ) {
v->view_offset -= FG_2PI;
} else if ( v->view_offset < 0 ) {
v->view_offset += FG_2PI;
}
}
}
}
void fgInitTimeDepCalcs( void ) {
// initialize timer
#ifdef HAVE_SETITIMER
fgTimerInit( 1.0 / DEFAULT_TIMER_HZ, fgUpdateTimeDepCalcs );
#endif HAVE_SETITIMER
}
// What should we do when we have nothing else to do? Let's get ready
// for the next move and update the display?
static void fgMainLoop( void ) {
fgAIRCRAFT *a;
fgFLIGHT *f;
fgGENERAL *g;
fgTIME *t;
static int remainder = 0;
int elapsed, multi_loop;
double cur_elev;
int i;
double accum;
// double joy_x, joy_y;
// int joy_b1, joy_b2;
a = &current_aircraft;
f = a->flight;
g = &general;
t = &cur_time_params;
fgPrintf( FG_ALL, FG_DEBUG, "Running Main Loop\n");
fgPrintf( FG_ALL, FG_DEBUG, "======= ==== ====\n");
// update "time"
fgTimeUpdate(f, t);
// Read joystick
/* fgJoystickRead( &joy_x, &joy_y, &joy_b1, &joy_b2 );
printf( "Joystick X %f Y %f B1 %d B2 %d\n",
joy_x, joy_y, joy_b1, joy_b2 );
fgElevSet( -joy_y );
fgAileronSet( joy_x ); */
// Get elapsed time for this past frame
elapsed = fgGetTimeInterval();
fgPrintf( FG_ALL, FG_BULK,
"Time interval is = %d, previous remainder is = %d\n",
elapsed, remainder);
// Calculate frame rate average
if ( elapsed > 0.0 ) {
accum = 0.0;
for ( i = FG_FRAME_RATE_HISTORY - 2; i >= 0; i-- ) {
accum += g->frames[i];
// printf("frame[%d] = %.2f\n", i, g->frames[i]);
g->frames[i+1] = g->frames[i];
}
g->frames[0] = 1000.0 / (float)elapsed;
// printf("frame[0] = %.2f\n", g->frames[0]);
accum += g->frames[0];
g->frame_rate = accum / (float)FG_FRAME_RATE_HISTORY;
// printf("ave = %.2f\n", g->frame_rate);
}
// Calculate model iterations needed for next frame
fgPrintf( FG_ALL, FG_DEBUG,
"--> Frame rate is = %.2f\n", g->frame_rate);
elapsed += remainder;
multi_loop = (int)(((float)elapsed * 0.001) * DEFAULT_MODEL_HZ);
remainder = elapsed - ((multi_loop*1000) / DEFAULT_MODEL_HZ);
fgPrintf( FG_ALL, FG_BULK,
"Model iterations needed = %d, new remainder = %d\n",
multi_loop, remainder);
// Run flight model
if ( ! use_signals ) {
// flight model
fgUpdateTimeDepCalcs(multi_loop);
}
// I'm just sticking this here for now, it should probably move
// eventually
/* cur_elev = mesh_altitude(FG_Longitude * RAD_TO_ARCSEC,
FG_Latitude * RAD_TO_ARCSEC); */
// there is no ground collision detection really, so for now I
// just hard code the ground elevation to be 0 */
cur_elev = 0;
// printf("Ground elevation is %.2f meters here.\n", cur_elev);
// FG_Runway_altitude = cur_elev * METER_TO_FEET;
if ( FG_Altitude * FEET_TO_METER < cur_elev + 3.758099) {
// set this here, otherwise if we set runway height above our
// current height we get a really nasty bounce.
FG_Runway_altitude = FG_Altitude - 3.758099;
// now set aircraft altitude above ground
FG_Altitude = cur_elev * METER_TO_FEET + 3.758099;
fgPrintf( FG_ALL, FG_BULK, "<*> resetting altitude to %.0f meters\n",
FG_Altitude * FEET_TO_METER);
}
fgAircraftOutputCurrent(a);
// see if we need to load any new scenery tiles
fgTileMgrUpdate();
// Process/manage pending events
global_events.Process();
// Run audio scheduler
#ifdef HAVE_OSS_AUDIO
audio_sched.update();
#endif
// redraw display
fgRenderFrame();
fgPrintf( FG_ALL, FG_DEBUG, "\n");
}
// Handle new window size or exposure
static void fgReshape( int width, int height ) {
fgVIEW *v;
v = &current_view;
// Do this so we can call fgReshape(0,0) ourselves without having
// to know what the values of width & height are.
if ( (height > 0) && (width > 0) ) {
v->win_ratio = (GLfloat) width / (GLfloat) height;
}
v->winWidth = width;
v->winHeight = height;
// Inform gl of our view window size (now handled elsewhere)
// xglViewport(0, 0, (GLint)width, (GLint)height);
fgUpdateViewParams();
// xglClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
}
// Initialize GLUT and define a main window
int fgGlutInit( int *argc, char **argv ) {
// GLUT will extract all glut specific options so later on we only
// need wory about our own.
xglutInit(argc, argv);
// Define Display Parameters
xglutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
// Define initial window size
xglutInitWindowSize(640, 480);
// Initialize windows
xglutCreateWindow("Flight Gear");
return(1);
}
// Initialize GLUT event handlers
int fgGlutInitEvents( void ) {
// call fgReshape() on window resizes
xglutReshapeFunc( fgReshape );
// call GLUTkey() on keyboard event
xglutKeyboardFunc( GLUTkey );
glutSpecialFunc( GLUTspecialkey );
// call fgMainLoop() whenever there is
// nothing else to do
xglutIdleFunc( fgMainLoop );
// draw the scene
xglutDisplayFunc( fgRenderFrame );
return(1);
}
// Main ...
int main( int argc, char **argv ) {
fgFLIGHT *f;
fgOPTIONS *o;
char config[256];
char path[256], slfile[256];
int result; // Used in command line argument.
f = current_aircraft.flight;
o = &current_options;
#ifdef HAVE_BC5PLUS
_control87(MCW_EM, MCW_EM); /* defined in float.h */
#endif
// Initialize the debugging output system
fgInitDebug();
fgPrintf(FG_GENERAL, FG_INFO, "Flight Gear: Version %s\n\n", VERSION);
// Initialize the Window/Graphics environment.
if( !fgGlutInit(&argc, argv) ) {
fgPrintf( FG_GENERAL, FG_EXIT, "GLUT initialization failed ...\n" );
}
// Attempt to locate and parse a config file
// First check fg_root
strcpy(config, o->fg_root);
strcat(config, "/system.fgfsrc");
result = o->parse_config_file(config);
// Next check home directory
if ( getenv("HOME") != NULL ) {
strcpy(config, getenv("HOME"));
strcat(config, "/.fgfsrc");
result = o->parse_config_file(config);
}
// Parse remaining command line options
// These will override anything specified in a config file
result = o->parse_command_line(argc, argv);
if ( result != FG_OPTIONS_OK ) {
// Something must have gone horribly wrong with the command
// line parsing or maybe the user just requested help ... :-)
o->usage();
fgPrintf( FG_GENERAL, FG_EXIT, "\nExiting ...\n");
}
// These are a few miscellaneous things that aren't really
// "subsystems" but still need to be initialized.
if( !fgInitGeneral()) {
fgPrintf( FG_GENERAL, FG_EXIT, "General initializations failed ...\n" );
}
// This is the top level init routine which calls all the other
// subsystem initialization routines. If you are adding a
// subsystem to flight gear, its initialization call should
// located in this routine.
if( !fgInitSubsystems()) {
fgPrintf( FG_GENERAL, FG_EXIT,
"Subsystem initializations failed ...\n" );
}
// setup OpenGL view parameters
fgInitVisuals();
if ( use_signals ) {
// init timer routines, signals, etc. Arrange for an alarm
// signal to be generated, etc.
fgInitTimeDepCalcs();
}
// Initialize the various GLUT Event Handlers.
if( !fgGlutInitEvents() ) {
fgPrintf( FG_GENERAL, FG_EXIT,
"GLUT event handler initialization failed ...\n" );
}
// Initialize audio support
#ifdef HAVE_OSS_AUDIO
audio_mixer . setMasterVolume ( 30 ) ; /* 50% of max volume. */
audio_sched . setSafetyMargin ( 1.0 ) ;
strcpy(path, o->fg_root);
strcat(path, "/Sounds/");
strcpy(slfile, path);
strcat(slfile, "prpidle.wav");
// s1 = new slSample ( slfile );
s1 = new slSample ( "/dos/X-System-HSR/sounds/xp_recip.wav", &audio_sched );
printf("Rate = %d Bps = %d Stereo = %d\n",
s1 -> getRate(), s1 -> getBps(), s1 -> getStereo());
audio_sched . loopSample ( s1 );
// strcpy(slfile, path);
// strcat(slfile, "thunder.wav");
// s2 -> loadFile ( slfile );
// s2 -> adjustVolume(0.5);
// audio_sched -> playSample ( s2 );
#endif
// pass control off to the master GLUT event handler
glutMainLoop();
// we never actually get here ... but just in case ... :-)
return(0);
}
// $Log$
// Revision 1.23 1998/06/08 17:57:04 curt
// Minor sound/startup position tweaks.
//
// Revision 1.22 1998/06/05 18:18:40 curt
// A bit of fiddling with audio ...
//
// Revision 1.21 1998/06/03 22:01:06 curt
// Tweaking sound library usage.
//
// Revision 1.20 1998/06/03 00:47:11 curt
// Updated to compile in audio support if OSS available.
// Updated for new version of Steve's audio library.
// STL includes don't use .h
// Small view optimizations.
//
// Revision 1.19 1998/06/01 17:54:40 curt
// Added Linux audio support.
// avoid glClear( COLOR_BUFFER_BIT ) when not using it to set the sky color.
// map stl tweaks.
//
// Revision 1.18 1998/05/29 20:37:19 curt
// Tweaked material properties & lighting a bit in GLUTmain.cxx.
// Read airport list into a "map" STL for dynamic list sizing and fast tree
// based lookups.
//
// Revision 1.17 1998/05/22 21:28:52 curt
// Modifications to use the new fgEVENT_MGR class.
//
// Revision 1.16 1998/05/20 20:51:33 curt
// Tweaked smooth shaded texture lighting properties.
// Converted fgLIGHT to a C++ class.
//
// Revision 1.15 1998/05/16 13:08:34 curt
// C++ - ified views.[ch]xx
// Shuffled some additional view parameters into the fgVIEW class.
// Changed tile-radius to tile-diameter because it is a much better
// name.
// Added a WORLD_TO_EYE transformation to views.cxx. This allows us
// to transform world space to eye space for view frustum culling.
//
// Revision 1.14 1998/05/13 18:29:57 curt
// Added a keyboard binding to dynamically adjust field of view.
// Added a command line option to specify fov.
// Adjusted terrain color.
// Root path info moved to fgOPTIONS.
// Added ability to parse options out of a config file.
//
// Revision 1.13 1998/05/11 18:18:15 curt
// For flat shading use "glHint (GL_FOG_HINT, GL_FASTEST )"
//
// Revision 1.12 1998/05/07 23:14:15 curt
// Added "D" key binding to set autopilot heading.
// Made frame rate calculation average out over last 10 frames.
// Borland C++ floating point exception workaround.
// Added a --tile-radius=n option.
//
// Revision 1.11 1998/05/06 03:16:23 curt
// Added an averaged global frame rate counter.
// Added an option to control tile radius.
//
// Revision 1.10 1998/05/03 00:47:31 curt
// Added an option to enable/disable full-screen mode.
//
// Revision 1.9 1998/04/30 12:34:17 curt
// Added command line rendering options:
// enable/disable fog/haze
// specify smooth/flat shading
// disable sky blending and just use a solid color
// enable wireframe drawing mode
//
// Revision 1.8 1998/04/28 01:20:21 curt
// Type-ified fgTIME and fgVIEW.
// Added a command line option to disable textures.
//
// Revision 1.7 1998/04/26 05:10:02 curt
// "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
//
// Revision 1.6 1998/04/25 22:06:30 curt
// Edited cvs log messages in source files ... bad bad bad!
//
// Revision 1.5 1998/04/25 20:24:01 curt
// Cleaned up initialization sequence to eliminate interdependencies
// between sun position, lighting, and view position. This creates a
// valid single pass initialization path.
//
// Revision 1.4 1998/04/24 14:19:30 curt
// Fog tweaks.
//
// Revision 1.3 1998/04/24 00:49:18 curt
// Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
// Trying out some different option parsing code.
// Some code reorganization.
//
// Revision 1.2 1998/04/22 13:25:41 curt
// C++ - ifing the code.
// Starting a bit of reorganization of lighting code.
//
// Revision 1.1 1998/04/21 17:02:39 curt
// Prepairing for C++ integration.
//
// Revision 1.71 1998/04/18 04:11:26 curt
// Moved fg_debug to it's own library, added zlib support.
//
// Revision 1.70 1998/04/14 02:21:02 curt
// Incorporated autopilot heading hold contributed by: Jeff Goeke-Smith
// <jgoeke@voyager.net>
//
// Revision 1.69 1998/04/08 23:35:34 curt
// Tweaks to Gnu automake/autoconf system.
//
// Revision 1.68 1998/04/03 22:09:03 curt
// Converting to Gnu autoconf system.
//
// Revision 1.67 1998/03/23 21:24:37 curt
// Source code formating tweaks.
//
// Revision 1.66 1998/03/14 00:31:20 curt
// Beginning initial terrain texturing experiments.
//
// Revision 1.65 1998/03/09 22:45:57 curt
// Minor tweaks for building on sparc platform.
//
// Revision 1.64 1998/02/20 00:16:23 curt
// Thursday's tweaks.
//
// Revision 1.63 1998/02/16 16:17:39 curt
// Minor tweaks.
//
// Revision 1.62 1998/02/16 13:39:42 curt
// Miscellaneous weekend tweaks. Fixed? a cache problem that caused whole
// tiles to occasionally be missing.
//
// Revision 1.61 1998/02/12 21:59:46 curt
// Incorporated code changes contributed by Charlie Hotchkiss
// <chotchkiss@namg.us.anritsu.com>
//
// Revision 1.60 1998/02/11 02:50:40 curt
// Minor changes.
//
// Revision 1.59 1998/02/09 22:56:54 curt
// Removed "depend" files from cvs control. Other minor make tweaks.
//
// Revision 1.58 1998/02/09 15:07:49 curt
// Minor tweaks.
//
// Revision 1.57 1998/02/07 15:29:40 curt
// Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
// <chotchkiss@namg.us.anritsu.com>
//
// Revision 1.56 1998/02/03 23:20:23 curt
// Lots of little tweaks to fix various consistency problems discovered by
// Solaris' CC. Fixed a bug in fg_debug.c with how the fgPrintf() wrapper
// passed arguments along to the real printf(). Also incorporated HUD changes
// by Michele America.
//
// Revision 1.55 1998/02/02 20:53:58 curt
// Incorporated Durk's changes.
//
// Revision 1.54 1998/01/31 00:43:10 curt
// Added MetroWorks patches from Carmen Volpe.
//
// Revision 1.53 1998/01/27 18:35:54 curt
// Minor tweaks.
//
// Revision 1.52 1998/01/27 00:47:56 curt
// Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
// system and commandline/config file processing code.
//
// Revision 1.51 1998/01/26 15:57:05 curt
// Tweaks for dynamic scenery development.
//
// Revision 1.50 1998/01/19 19:27:07 curt
// Merged in make system changes from Bob Kuehne <rpk@sgi.com>
// This should simplify things tremendously.
//
// Revision 1.49 1998/01/19 18:40:31 curt
// Tons of little changes to clean up the code and to remove fatal errors
// when building with the c++ compiler.
//
// Revision 1.48 1998/01/19 18:35:46 curt
// Minor tweaks and fixes for cygwin32.
//
// Revision 1.47 1998/01/13 00:23:08 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 1.46 1998/01/08 02:22:06 curt
// Beginning to integrate Tile management subsystem.
//
// Revision 1.45 1998/01/07 03:18:55 curt
// Moved astronomical stuff from .../Src/Scenery to .../Src/Astro/
//
// Revision 1.44 1997/12/30 22:22:31 curt
// Further integration of event manager.
//
// Revision 1.43 1997/12/30 20:47:43 curt
// Integrated new event manager with subsystem initializations.
//
// Revision 1.42 1997/12/30 16:36:47 curt
// Merged in Durk's changes ...
//
// Revision 1.41 1997/12/30 13:06:56 curt
// A couple lighting tweaks ...
//
// Revision 1.40 1997/12/30 01:38:37 curt
// Switched back to per vertex normals and smooth shading for terrain.
//
// Revision 1.39 1997/12/22 23:45:45 curt
// First stab at sunset/sunrise sky glow effects.
//
// Revision 1.38 1997/12/22 04:14:28 curt
// Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
//
// Revision 1.37 1997/12/19 23:34:03 curt
// Lot's of tweaking with sky rendering and lighting.
//
// Revision 1.36 1997/12/19 16:44:57 curt
// Working on scene rendering order and options.
//
// Revision 1.35 1997/12/18 23:32:32 curt
// First stab at sky dome actually starting to look reasonable. :-)
//
// Revision 1.34 1997/12/17 23:13:34 curt
// Began working on rendering a sky.
//
// Revision 1.33 1997/12/15 23:54:45 curt
// Add xgl wrappers for debugging.
// Generate terrain normals on the fly.
//
// Revision 1.32 1997/12/15 20:59:08 curt
// Misc. tweaks.
//
// Revision 1.31 1997/12/12 21:41:25 curt
// More light/material property tweaking ... still a ways off.
//
// Revision 1.30 1997/12/12 19:52:47 curt
// Working on lightling and material properties.
//
// Revision 1.29 1997/12/11 04:43:54 curt
// Fixed sun vector and lighting problems. I thing the moon is now lit
// correctly.
//
// Revision 1.28 1997/12/10 22:37:45 curt
// Prepended "fg" on the name of all global structures that didn't have it yet.
// i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
//
// Revision 1.27 1997/12/09 05:11:54 curt
// Working on tweaking lighting.
//
// Revision 1.26 1997/12/09 04:25:29 curt
// Working on adding a global lighting params structure.
//
// Revision 1.25 1997/12/08 22:54:09 curt
// Enabled GL_CULL_FACE.
//
// Revision 1.24 1997/11/25 19:25:32 curt
// Changes to integrate Durk's moon/sun code updates + clean up.
//
// Revision 1.23 1997/11/15 18:16:34 curt
// minor tweaks.
//
// Revision 1.22 1997/10/30 12:38:41 curt
// Working on new scenery subsystem.
//
// Revision 1.21 1997/09/23 00:29:38 curt
// Tweaks to get things to compile with gcc-win32.
//
// Revision 1.20 1997/09/22 14:44:19 curt
// Continuing to try to align stars correctly.
//
// Revision 1.19 1997/09/18 16:20:08 curt
// At dusk/dawn add/remove stars in stages.
//
// Revision 1.18 1997/09/16 22:14:51 curt
// Tweaked time of day lighting equations. Don't draw stars during the day.
//
// Revision 1.17 1997/09/16 15:50:29 curt
// Working on star alignment and time issues.
//
// Revision 1.16 1997/09/13 02:00:06 curt
// Mostly working on stars and generating sidereal time for accurate star
// placement.
//
// Revision 1.15 1997/09/05 14:17:27 curt
// More tweaking with stars.
//
// Revision 1.14 1997/09/05 01:35:53 curt
// Working on getting stars right.
//
// Revision 1.13 1997/09/04 02:17:34 curt
// Shufflin' stuff.
//
// Revision 1.12 1997/08/27 21:32:24 curt
// Restructured view calculation code. Added stars.
//
// Revision 1.11 1997/08/27 03:30:16 curt
// Changed naming scheme of basic shared structures.
//
// Revision 1.10 1997/08/25 20:27:22 curt
// Merged in initial HUD and Joystick code.
//
// Revision 1.9 1997/08/22 21:34:39 curt
// Doing a bit of reorganizing and house cleaning.
//
// Revision 1.8 1997/08/19 23:55:03 curt
// Worked on better simulating real lighting.
//
// Revision 1.7 1997/08/16 12:22:38 curt
// Working on improving the lighting/shading.
//
// Revision 1.6 1997/08/13 20:24:56 curt
// Changes due to changing sunpos interface.
//
// Revision 1.5 1997/08/06 21:08:32 curt
// Sun position now really* works (I think) ... I still have sun time warping
// code in place, probably should remove it soon.
//
// Revision 1.4 1997/08/06 15:41:26 curt
// Working on correct sun position.
//
// Revision 1.3 1997/08/06 00:24:22 curt
// Working on correct real time sun lighting.
//
// Revision 1.2 1997/08/04 20:25:15 curt
// Organizational tweaking.
//
// Revision 1.1 1997/08/02 18:45:00 curt
// Renamed GLmain.c GLUTmain.c
//
// Revision 1.43 1997/08/02 16:23:47 curt
// Misc. tweaks.
//
// Revision 1.42 1997/08/01 19:43:33 curt
// Making progress with coordinate system overhaul.
//
// Revision 1.41 1997/07/31 22:52:37 curt
// Working on redoing internal coordinate systems & scenery transformations.
//
// Revision 1.40 1997/07/30 16:12:42 curt
// Moved fg_random routines from Util/ to Math/
//
// Revision 1.39 1997/07/21 14:45:01 curt
// Minor tweaks.
//
// Revision 1.38 1997/07/19 23:04:47 curt
// Added an initial weather section.
//
// Revision 1.37 1997/07/19 22:34:02 curt
// Moved PI definitions to ../constants.h
// Moved random() stuff to ../Utils/ and renamed fg_random()
//
// Revision 1.36 1997/07/18 23:41:25 curt
// Tweaks for building with Cygnus Win32 compiler.
//
// Revision 1.35 1997/07/18 14:28:34 curt
// Hacked in some support for wind/turbulence.
//
// Revision 1.34 1997/07/16 20:04:48 curt
// Minor tweaks to aid Win32 port.
//
// Revision 1.33 1997/07/12 03:50:20 curt
// Added an #include <Windows32/Base.h> to help compiling for Win32
//
// Revision 1.32 1997/07/11 03:23:18 curt
// Solved some scenery display/orientation problems. Still have a positioning
// (or transformation?) problem.
//
// Revision 1.31 1997/07/11 01:29:58 curt
// More tweaking of terrian floor.
//
// Revision 1.30 1997/07/10 04:26:37 curt
// We now can interpolated ground elevation for any position in the grid. We
// can use this to enforce a "hard" ground. We still need to enforce some
// bounds checking so that we don't try to lookup data points outside the
// grid data set.
//
// Revision 1.29 1997/07/09 21:31:12 curt
// Working on making the ground "hard."
//
// Revision 1.28 1997/07/08 18:20:12 curt
// Working on establishing a hard ground.
//
// Revision 1.27 1997/07/07 20:59:49 curt
// Working on scenery transformations to enable us to fly fluidly over the
// poles with no discontinuity/distortion in scenery.
//
// Revision 1.26 1997/07/05 20:43:34 curt
// renamed mat3 directory to Math so we could add other math related routines.
//
// Revision 1.25 1997/06/29 21:19:17 curt
// Working on scenery management system.
//
// Revision 1.24 1997/06/26 22:14:53 curt
// Beginning work on a scenery management system.
//
// Revision 1.23 1997/06/26 19:08:33 curt
// Restructuring make, adding automatic "make dep" support.
//
// Revision 1.22 1997/06/25 15:39:47 curt
// Minor changes to compile with rsxnt/win32.
//
// Revision 1.21 1997/06/22 21:44:41 curt
// Working on intergrating the VRML (subset) parser.
//
// Revision 1.20 1997/06/21 17:12:53 curt
// Capitalized subdirectory names.
//
// Revision 1.19 1997/06/18 04:10:31 curt
// A couple more runway tweaks ...
//
// Revision 1.18 1997/06/18 02:21:24 curt
// Hacked in a runway
//
// Revision 1.17 1997/06/17 16:51:58 curt
// Timer interval stuff now uses gettimeofday() instead of ftime()
//
// Revision 1.16 1997/06/17 04:19:16 curt
// More timer related tweaks with respect to view direction changes.
//
// Revision 1.15 1997/06/17 03:41:10 curt
// Nonsignal based interval timing is now working.
// This would be a good time to look at cleaning up the code structure a bit.
//
// Revision 1.14 1997/06/16 19:32:51 curt
// Starting to add general timer support.
//
// Revision 1.13 1997/06/02 03:40:06 curt
// A tiny bit more view tweaking.
//
// Revision 1.12 1997/06/02 03:01:38 curt
// Working on views (side, front, back, transitions, etc.)
//
// Revision 1.11 1997/05/31 19:16:25 curt
// Elevator trim added.
//
// Revision 1.10 1997/05/31 04:13:52 curt
// WE CAN NOW FLY!!!
//
// Continuing work on the LaRCsim flight model integration.
// Added some MSFS-like keyboard input handling.
//
// Revision 1.9 1997/05/30 19:27:01 curt
// The LaRCsim flight model is starting to look like it is working.
//
// Revision 1.8 1997/05/30 03:54:10 curt
// Made a bit more progress towards integrating the LaRCsim flight model.
//
// Revision 1.7 1997/05/29 22:39:49 curt
// Working on incorporating the LaRCsim flight model.
//
// Revision 1.6 1997/05/29 12:31:39 curt
// Minor tweaks, moving towards general flight model integration.
//
// Revision 1.5 1997/05/29 02:33:23 curt
// Updated to reflect changing interfaces in other "modules."
//
// Revision 1.4 1997/05/27 17:44:31 curt
// Renamed & rearranged variables and routines. Added some initial simple
// timer/alarm routines so the flight model can be updated on a regular
// interval.
//
// Revision 1.3 1997/05/23 15:40:25 curt
// Added GNU copyright headers.
// Fog now works!
//
// Revision 1.2 1997/05/23 00:35:12 curt
// Trying to get fog to work ...
//
// Revision 1.1 1997/05/21 15:57:51 curt
// Renamed due to added GLUT support.
//
// Revision 1.3 1997/05/19 18:22:42 curt
// Parameter tweaking ... starting to stub in fog support.
//
// Revision 1.2 1997/05/17 00:17:34 curt
// Trying to stub in support for standard OpenGL.
//
// Revision 1.1 1997/05/16 16:05:52 curt
// Initial revision.
//