1
0
Fork 0
flightgear/src/Sound/morse.cxx
2012-10-04 21:14:48 +02:00

253 lines
7 KiB
C++

// morse.cxx -- Morse code generation class
//
// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
#include <simgear/constants.h>
#include "morse.hxx"
#include <simgear/sound/sample_openal.hxx>
#include <cstring>
#include <stdlib.h>
static const char DI = '1';
static const char DIT = '1';
static const char DA = '2';
static const char DAH = '2';
static const char END = '0';
static const char alphabet[26][4] = {
{ DI, DAH, END, END }, /* A */
{ DA, DI, DI, DIT }, /* B */
{ DA, DI, DA, DIT }, /* C */
{ DA, DI, DIT, END }, /* D */
{ DIT, END, END, END }, /* E */
{ DI, DI, DA, DIT }, /* F */
{ DA, DA, DIT, END }, /* G */
{ DI, DI, DI, DIT }, /* H */
{ DI, DIT, END, END }, /* I */
{ DI, DA, DA, DAH }, /* J */
{ DA, DI, DAH, END }, /* K */
{ DI, DA, DI, DIT }, /* L */
{ DA, DAH, END, END }, /* M */
{ DA, DIT, END, END }, /* N */
{ DA, DA, DAH, END }, /* O */
{ DI, DA, DA, DIT }, /* P */
{ DA, DA, DI, DAH }, /* Q */
{ DI, DA, DIT, END }, /* R */
{ DI, DI, DIT, END }, /* S */
{ DAH, END, END, END }, /* T */
{ DI, DI, DAH, END }, /* U */
{ DI, DI, DI, DAH }, /* V */
{ DI, DA, DAH, END }, /* W */
{ DA, DI, DI, DAH }, /* X */
{ DA, DI, DA, DAH }, /* Y */
{ DA, DA, DI, DIT } /* Z */
};
static const char numerals[10][5] = {
{ DA, DA, DA, DA, DAH }, // 0
{ DI, DA, DA, DA, DAH }, // 1
{ DI, DI, DA, DA, DAH }, // 2
{ DI, DI, DI, DA, DAH }, // 3
{ DI, DI, DI, DI, DAH }, // 4
{ DI, DI, DI, DI, DIT }, // 5
{ DA, DI, DI, DI, DIT }, // 6
{ DA, DA, DI, DI, DIT }, // 7
{ DA, DA, DA, DI, DIT }, // 8
{ DA, DA, DA, DA, DIT } // 9
};
// constructor
FGMorse::FGMorse() {
}
// destructor
FGMorse::~FGMorse() {
}
// allocate and initialize sound samples
bool FGMorse::init() {
// Make Low DIT
make_tone( lo_dit, LO_FREQUENCY, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
TRANSITION_BYTES );
// Make High DIT
make_tone( hi_dit, HI_FREQUENCY, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
TRANSITION_BYTES );
// Make Low DAH
make_tone( lo_dah, LO_FREQUENCY, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
TRANSITION_BYTES );
// Make High DAH
make_tone( hi_dah, HI_FREQUENCY, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
TRANSITION_BYTES );
// Make SPACE
int i;
for ( i = 0; i < SPACE_SIZE; ++i ) {
space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
}
return true;
}
// allocate and initialize sound samples
bool FGMorse::cust_init(const int freq ) {
int i;
// Make DIT
make_tone( cust_dit, freq, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
TRANSITION_BYTES );
// Make DAH
make_tone( cust_dah, freq, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
TRANSITION_BYTES );
// Make SPACE
for ( i = 0; i < SPACE_SIZE; ++i ) {
space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
}
return true;
}
// make a SGSoundSample morse code transmission for the specified string
SGSoundSample *FGMorse::make_ident( const std::string& id, const int freq ) {
char *idptr = (char *)id.c_str();
int length = 0;
int i, j;
// 0. Select the frequency. If custom frequency, generate the
// sound fragments we need on the fly.
unsigned char *dit_ptr, *dah_ptr;
if ( freq == LO_FREQUENCY ) {
dit_ptr = lo_dit;
dah_ptr = lo_dah;
} else if ( freq == HI_FREQUENCY ) {
dit_ptr = hi_dit;
dah_ptr = hi_dah;
} else {
cust_init( freq );
dit_ptr = cust_dit;
dah_ptr = cust_dah;
}
// 1. Determine byte length of message
for ( i = 0; i < (int)id.length(); ++i ) {
if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
int c = (int)(idptr[i] - 'A');
for ( j = 0; j < 4 && alphabet[c][j] != END; ++j ) {
if ( alphabet[c][j] == DIT ) {
length += DIT_SIZE;
} else if ( alphabet[c][j] == DAH ) {
length += DAH_SIZE;
}
}
length += SPACE_SIZE;
} else if ( idptr[i] >= '0' && idptr[i] <= '9' ) {
int c = (int)(idptr[i] - '0');
for ( j = 0; j < 5; ++j) {
if ( numerals[c][j] == DIT ) {
length += DIT_SIZE;
} else if ( numerals[c][j] == DAH ) {
length += DAH_SIZE;
}
}
length += SPACE_SIZE;
} else {
// skip unknown character
}
}
// add 2x more space to the end of the string
length += 2 * SPACE_SIZE;
// 2. Allocate space for the message
const unsigned char* buffer = (const unsigned char *)malloc(length);
// 3. Assemble the message;
unsigned char *buf_ptr = (unsigned char*)buffer;
for ( i = 0; i < (int)id.length(); ++i ) {
if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
int c = (int)(idptr[i] - 'A');
for ( j = 0; j < 4 && alphabet[c][j] != END; ++j ) {
if ( alphabet[c][j] == DIT ) {
memcpy( buf_ptr, dit_ptr, DIT_SIZE );
buf_ptr += DIT_SIZE;
} else if ( alphabet[c][j] == DAH ) {
memcpy( buf_ptr, dah_ptr, DAH_SIZE );
buf_ptr += DAH_SIZE;
}
}
memcpy( buf_ptr, space, SPACE_SIZE );
buf_ptr += SPACE_SIZE;
} else if ( idptr[i] >= '0' && idptr[i] <= '9' ) {
int c = (int)(idptr[i] - '0');
for ( j = 0; j < 5; ++j ) {
if ( numerals[c][j] == DIT ) {
memcpy( buf_ptr, dit_ptr, DIT_SIZE );
buf_ptr += DIT_SIZE;
} else if ( numerals[c][j] == DAH ) {
memcpy( buf_ptr, dah_ptr, DAH_SIZE );
buf_ptr += DAH_SIZE;
}
}
memcpy( buf_ptr, space, SPACE_SIZE );
buf_ptr += SPACE_SIZE;
} else {
// skip unknown character
}
}
memcpy( buf_ptr, space, SPACE_SIZE );
buf_ptr += SPACE_SIZE;
memcpy( buf_ptr, space, SPACE_SIZE );
buf_ptr += SPACE_SIZE;
// 4. create the simple sound and return
SGSoundSample *sample = new SGSoundSample( &buffer, length,
BYTES_PER_SECOND );
sample->set_reference_dist( 10.0 );
sample->set_max_dist( 20.0 );
return sample;
}
FGMorse * FGMorse::_instance = NULL;
FGMorse * FGMorse::instance()
{
if( _instance == NULL ) {
_instance = new FGMorse();
_instance->init();
}
return _instance;
}