1 // morse.cxx -- Morse code generation class
3 // Written by Curtis Olson, started March 2001.
5 // Copyright (C) 2001 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 #include <simgear/constants.h>
29 static const char alphabet[26][4] = {
30 { DI, DAH, end, end }, /* A */
31 { DA, DI, DI, DIT }, /* B */
32 { DA, DI, DA, DIT }, /* C */
33 { DA, DI, DIT, end }, /* D */
34 { DIT, end, end, end }, /* E */
35 { DI, DI, DA, DIT }, /* F */
36 { DA, DA, DIT, end }, /* G */
37 { DI, DI, DI, DIT }, /* H */
38 { DI, DIT, end, end }, /* I */
39 { DI, DA, DA, DAH }, /* J */
40 { DA, DI, DAH, end }, /* K */
41 { DI, DA, DI, DIT }, /* L */
42 { DA, DAH, end, end }, /* M */
43 { DA, DIT, end, end }, /* N */
44 { DA, DA, DAH, end }, /* O */
45 { DI, DA, DA, DIT }, /* P */
46 { DA, DA, DI, DAH }, /* Q */
47 { DI, DA, DIT, end }, /* R */
48 { DI, DI, DIT, end }, /* S */
49 { DAH, end, end, end }, /* T */
50 { DI, DI, DAH, end }, /* U */
51 { DI, DI, DI, DAH }, /* V */
52 { DI, DA, DAH, end }, /* W */
53 { DA, DI, DI, DAH }, /* X */
54 { DA, DI, DA, DAH }, /* Y */
55 { DA, DA, DI, DIT } /* Z */
58 static const char numerals[10][5] = {
59 { DA, DA, DA, DA, DAH }, // 0
60 { DI, DA, DA, DA, DAH }, // 1
61 { DI, DI, DA, DA, DAH }, // 2
62 { DI, DI, DI, DA, DAH }, // 3
63 { DI, DI, DI, DI, DAH }, // 4
64 { DI, DI, DI, DI, DIT }, // 5
65 { DA, DI, DI, DI, DIT }, // 6
66 { DA, DA, DI, DI, DIT }, // 7
67 { DA, DA, DA, DI, DIT }, // 8
68 { DA, DA, DA, DA, DIT } // 9
81 // Make a tone of specified freq and total_len with trans_len ramp in
82 // and out and only the first len bytes with sound, the rest with
84 void make_tone( unsigned char *buf, int freq,
85 int len, int total_len, int trans_len )
89 for ( i = 0; i < trans_len; ++i ) {
90 float level = ( sin( (double) i * SGD_2PI / (BYTES_PER_SECOND / freq) ) )
91 * ((double)i / trans_len) / 2.0 + 0.5;
93 /* Convert to unsigned byte */
94 buf[ i ] = (unsigned char) ( level * 255.0 ) ;
97 for ( i = trans_len; i < len - trans_len; ++i ) {
98 float level = ( sin( (double) i * SGD_2PI / (BYTES_PER_SECOND / freq) ) )
101 /* Convert to unsigned byte */
102 buf[ i ] = (unsigned char) ( level * 255.0 ) ;
105 for ( i = len - trans_len; i < len; ++i ) {
106 float level = ( sin( (double) i * SGD_2PI / (BYTES_PER_SECOND / freq) ) )
107 * ((double)j / trans_len) / 2.0 + 0.5;
110 /* Convert to unsigned byte */
111 buf[ i ] = (unsigned char) ( level * 255.0 ) ;
113 for ( i = len; i < total_len; ++i ) {
114 buf[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
119 // allocate and initialize sound samples
120 bool FGMorse::init() {
122 make_tone( lo_dit, LO_FREQUENCY, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
126 make_tone( hi_dit, HI_FREQUENCY, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
130 make_tone( lo_dah, LO_FREQUENCY, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
134 make_tone( hi_dah, HI_FREQUENCY, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
139 for ( i = 0; i < SPACE_SIZE; ++i ) {
140 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
147 // allocate and initialize sound samples
148 bool FGMorse::cust_init(const int freq ) {
152 make_tone( cust_dit, freq, DIT_SIZE - COUNT_SIZE, DIT_SIZE,
156 make_tone( cust_dah, freq, DAH_SIZE - COUNT_SIZE, DAH_SIZE,
160 for ( i = 0; i < SPACE_SIZE; ++i ) {
161 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
168 // make a SGSoundSample morse code transmission for the specified string
169 SGSoundSample *FGMorse::make_ident( const string& id, const int freq ) {
171 char *idptr = (char *)id.c_str();
176 // 0. Select the frequency. If custom frequency, generate the
177 // sound fragments we need on the fly.
178 unsigned char *dit_ptr, *dah_ptr;
180 if ( freq == LO_FREQUENCY ) {
183 } else if ( freq == HI_FREQUENCY ) {
192 // 1. Determine byte length of message
193 for ( i = 0; i < (int)id.length(); ++i ) {
194 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
195 int c = (int)(idptr[i] - 'A');
196 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
197 if ( alphabet[c][j] == DIT ) {
199 } else if ( alphabet[c][j] == DAH ) {
203 length += SPACE_SIZE;
204 } else if ( idptr[i] >= '0' && idptr[i] <= '9' ) {
205 int c = (int)(idptr[i] - '0');
206 for ( j = 0; j < 5; ++j) {
207 if ( numerals[c][j] == DIT ) {
209 } else if ( numerals[c][j] == DAH ) {
213 length += SPACE_SIZE;
215 // skip unknown character
218 // add 2x more space to the end of the string
219 length += 2 * SPACE_SIZE;
221 // 2. Allocate space for the message
222 const unsigned char* buffer = (const unsigned char *)malloc(length);
224 // 3. Assemble the message;
225 unsigned char *buf_ptr = (unsigned char*)buffer;
227 for ( i = 0; i < (int)id.length(); ++i ) {
228 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
229 int c = (int)(idptr[i] - 'A');
230 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
231 if ( alphabet[c][j] == DIT ) {
232 memcpy( buf_ptr, dit_ptr, DIT_SIZE );
234 } else if ( alphabet[c][j] == DAH ) {
235 memcpy( buf_ptr, dah_ptr, DAH_SIZE );
239 memcpy( buf_ptr, space, SPACE_SIZE );
240 buf_ptr += SPACE_SIZE;
241 } else if ( idptr[i] >= '0' && idptr[i] <= '9' ) {
242 int c = (int)(idptr[i] - '0');
243 for ( j = 0; j < 5; ++j ) {
244 if ( numerals[c][j] == DIT ) {
245 memcpy( buf_ptr, dit_ptr, DIT_SIZE );
247 } else if ( numerals[c][j] == DAH ) {
248 memcpy( buf_ptr, dah_ptr, DAH_SIZE );
252 memcpy( buf_ptr, space, SPACE_SIZE );
253 buf_ptr += SPACE_SIZE;
255 // skip unknown character
258 memcpy( buf_ptr, space, SPACE_SIZE );
259 buf_ptr += SPACE_SIZE;
260 memcpy( buf_ptr, space, SPACE_SIZE );
261 buf_ptr += SPACE_SIZE;
263 // 4. create the simple sound and return
264 SGSoundSample *sample = new SGSoundSample( &buffer, length,
267 sample->set_reference_dist( 10.0 );
268 sample->set_max_dist( 20.0 );