/************************************************************************** * weather.c -- routines to model weather * * Written by Curtis Olson, started July 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 #endif #ifdef HAVE_WINDOWS_H # include #endif #include #include #include #include #include #include #include #include /* This is a record containing current weather info */ struct fgWEATHER current_weather; /* Initialize the weather modeling subsystem */ void fgWeatherInit( void ) { struct fgWEATHER *w; w = ¤t_weather; printf("Initializing weather subsystem\n"); /* Configure some wind */ /* FG_V_north_airmass = 15; */ /* ft/s =~ 10mph */ // fgWeatherSetVisibility(45000.0); /* in meters */ fgWeatherSetVisibility(32000.0); /* about 20 miles (in meters) */ } /* Update the weather parameters for the current position */ void fgWeatherUpdate( void ) { /* temporarily remove the code of this do-nothing routine */ #ifdef FG_WEATHER_UPDATE fgFLIGHT *f; struct fgWEATHER *w; f = current_aircraft.flight; w = ¤t_weather; /* Add some random turbulence */ /* FG_U_gust = fg_random() * 1.0 - 0.5; FG_V_gust = fg_random() * 1.0 - 0.5; FG_W_gust = fg_random() * 1.0 - 0.5; */ #endif FG_WEATHER_UPDATE } /* Get the current visibility */ float fgWeatherGetVisibility( void ) { struct fgWEATHER *w; w = ¤t_weather; return ( w->visibility ); } /* Set the visibility and update fog parameters */ void fgWeatherSetVisibility( float visibility ) { struct fgWEATHER *w; w = ¤t_weather; w->visibility = visibility; /* in meters */ // w->fog_density = -log(0.01 / w->visibility; /* for GL_FOG_EXP */ w->fog_density = sqrt( -log(0.01) ) / w->visibility; /* for GL_FOG_EXP2 */ xglFogf (GL_FOG_DENSITY, w->fog_density); fgPrintf( FG_INPUT, FG_DEBUG, "Fog density = %.4f\n", w->fog_density); } /* $Log$ /* Revision 1.17 1998/07/20 12:51:57 curt /* Default visibility to about 20 miles. /* * Revision 1.16 1998/06/12 01:00:59 curt * Build only static libraries. * Declare memmove/memset for Sloaris. * Added support for exponetial fog, which solves for the proper density to * achieve the desired visibility range. * * Revision 1.15 1998/04/25 22:06:34 curt * Edited cvs log messages in source files ... bad bad bad! * * Revision 1.14 1998/02/09 15:07:54 curt * Minor tweaks. * * Revision 1.13 1998/01/27 00:48:08 curt * Incorporated Paul Bleisch's new debug message * system and commandline/config file processing code. * * Revision 1.12 1998/01/19 19:27:22 curt * Merged in make system changes from Bob Kuehne * This should simplify things tremendously. * * Revision 1.11 1998/01/19 18:40:41 curt * Tons of little changes to clean up the code and to remove fatal errors * when building with the c++ compiler. * * Revision 1.10 1997/12/30 22:22:46 curt * Further integration of event manager. * * Revision 1.9 1997/12/30 20:48:03 curt * Integrated new event manager with subsystem initializations. * * Revision 1.8 1997/12/11 04:43:58 curt * Fixed sun vector and lighting problems. I thing the moon is now lit * correctly. * * Revision 1.7 1997/12/10 22:37:56 curt * Prepended "fg" on the name of all global structures that didn't have it yet. * i.e. "struct WEATHER {}" became "struct fgWEATHER {}" * * Revision 1.6 1997/08/27 03:30:38 curt * Changed naming scheme of basic shared structures. * * Revision 1.5 1997/08/22 21:34:42 curt * Doing a bit of reorganizing and house cleaning. * * Revision 1.4 1997/08/02 16:23:55 curt * Misc. tweaks. * * Revision 1.3 1997/07/31 22:52:41 curt * Working on redoing internal coordinate systems & scenery transformations. * * Revision 1.2 1997/07/30 16:12:44 curt * Moved fg_random routines from Util/ to Math/ * * Revision 1.1 1997/07/19 23:03:57 curt * Initial revision. * */