1 // util.hxx - general-purpose utility functions.
2 // Copyright (C) 2002 Curtis L. Olson - curt@me.umn.edu
4 // This program is free software; you can redistribute it and/or
5 // modify it under the terms of the GNU General Public License as
6 // published by the Free Software Foundation; either version 2 of the
7 // License, or (at your option) any later version.
9 // This program is distributed in the hope that it will be useful, but
10 // WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 // General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with this program; if not, write to the Free Software
16 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 # error This library requires C++
30 * Initialize a single value through all existing weather levels.
32 * This function is useful mainly from the command-line.
34 * @param propname The name of the subproperty to initialized.
35 * @param value The initial value.
37 extern void fgDefaultWeatherValue (const char * propname, double value);
41 * Clean up and exit FlightGear.
43 * This function makes sure that network connections and I/O streams
46 * @param status The exit status to pass to the operating system.
48 extern void fgExit (int status = 0);
52 * Move a value towards a target.
54 * This function was originally written by Alex Perry.
56 * @param current The current value.
57 * @param target The target value.
58 * @param timeratio The percentage of smoothing time that has passed
59 * (elapsed time/smoothing time)
60 * @return The new value.
62 extern double fgGetLowPass (double current, double target, double timeratio);