0895721e68
Incorporating the shared ptr code: - All scenegraph references from SimGear - SGMaterial which already had a reference counter uses now that common infrastructure. - SGMatModel is now counted. - SGSoundSample from SimGear - And the corresponding change for the sound samples in flightgear which fixes a latent crash if FGBeacon would evern be deleted.
120 lines
4 KiB
C++
120 lines
4 KiB
C++
/**
|
|
* \file beacon.hxx -- Provides marker beacon audio generation.
|
|
*/
|
|
|
|
// Written by Curtis Olson, started March 2001.
|
|
//
|
|
// Copyright (C) 2001 Curtis L. Olson - http://www.flightgear.org/~curt
|
|
//
|
|
// 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.
|
|
//
|
|
// $Id$
|
|
|
|
|
|
#ifndef _BEACON_HXX
|
|
#define _BEACON_HXX
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <simgear/compiler.h>
|
|
#include <simgear/sound/soundmgr_openal.hxx>
|
|
#include <simgear/structure/SGReferenced.hxx>
|
|
#include <simgear/structure/SGSharedPtr.hxx>
|
|
|
|
#include "morse.hxx"
|
|
|
|
|
|
// Quoting from http://www.smartregs.com/data/sa326.htm
|
|
// Smart REGS Glossary - marker beacon
|
|
//
|
|
// An electronic navigation facility transmitting a 75 MHz vertical fan
|
|
// or boneshaped radiation pattern. Marker beacons are identified by
|
|
// their modulation frequency and keying code, and when received by
|
|
// compatible airborne equipment, indicate to the pilot, both aurally
|
|
// and visually, that he is passing over the facility.
|
|
// (See outer marker middle marker inner marker.)
|
|
//
|
|
// Smart REGS Glossary - outer marker
|
|
//
|
|
// A marker beacon at or near the glideslope intercept altitude of an
|
|
// ILS approach. It is keyed to transmit two dashes per second on a
|
|
// 400 Hz tone, which is received aurally and visually by compatible
|
|
// airborne equipment. The OM is normally located four to seven miles from
|
|
// the runway threshold on the extended centerline of the runway.
|
|
//
|
|
// Smart REGS Glossary - middle marker
|
|
//
|
|
// A marker beacon that defines a point along the glideslope of an
|
|
// ILS normally located at or near the point of decision height
|
|
// (ILS Category I). It is keyed to transmit alternate dots and dashes,
|
|
// with the alternate dots and dashes keyed at the rate of 95 dot/dash
|
|
// combinations per minute on a 1300 Hz tone, which is received
|
|
// aurally and visually by compatible airborne equipment.
|
|
//
|
|
// Smart REGS Glossary - inner marker
|
|
//
|
|
// A marker beacon used with an ILS (CAT II) precision approach located
|
|
// between the middle marker and the end of the ILS runway,
|
|
// transmitting a radiation pattern keyed at six dots per second and
|
|
// indicating to the pilot, both aurally and visually, that he is at
|
|
// the designated decision height (DH), normally 100 feet above the
|
|
// touchdown zone elevation, on the ILS CAT II approach. It also marks
|
|
// progress during a CAT III approach.
|
|
// (See instrument landing system) (Refer to AIM.)
|
|
|
|
|
|
static const int INNER_FREQ = 3000;
|
|
static const int MIDDLE_FREQ = 1300;
|
|
static const int OUTER_FREQ = 400;
|
|
|
|
static const int INNER_SIZE = BYTES_PER_SECOND;
|
|
static const int MIDDLE_SIZE = (int)(BYTES_PER_SECOND * 60 / 95 );
|
|
static const int OUTER_SIZE = BYTES_PER_SECOND;
|
|
|
|
static const int INNER_DIT_LEN = (int)(BYTES_PER_SECOND / 6.0);
|
|
static const int MIDDLE_DIT_LEN = (int)(MIDDLE_SIZE / 3.0);
|
|
static const int MIDDLE_DAH_LEN = (int)(MIDDLE_SIZE * 2 / 3.0);
|
|
static const int OUTER_DAH_LEN = (int)(BYTES_PER_SECOND / 2.0);
|
|
|
|
// manages everything we need to know for an individual sound sample
|
|
class FGBeacon {
|
|
|
|
private:
|
|
|
|
SGSharedPtr<SGSoundSample> inner;
|
|
SGSharedPtr<SGSoundSample> middle;
|
|
SGSharedPtr<SGSoundSample> outer;
|
|
|
|
public:
|
|
|
|
FGBeacon();
|
|
~FGBeacon();
|
|
|
|
// allocate and initialize sound samples
|
|
bool init();
|
|
|
|
SGSoundSample *get_inner() { return inner; }
|
|
SGSoundSample *get_middle() { return middle; }
|
|
SGSoundSample *get_outer() { return outer; }
|
|
|
|
};
|
|
|
|
|
|
|
|
#endif // _BEACON_HXX
|
|
|
|
|