1 // morse.cxx -- Morse code generation class
3 // Written by Curtis Olson, started March 2001.
5 // Copyright (C) 2001 Curtis L. Olson - curt@flightgear.org
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., 675 Mass Ave, Cambridge, MA 02139, USA.
27 static const char alphabet[26][4] = {
28 { DI, DAH, end, end }, /* A */
29 { DA, DI, DI, DIT }, /* B */
30 { DA, DI, DA, DIT }, /* C */
31 { DA, DI, DIT, end }, /* D */
32 { DIT, end, end, end }, /* E */
33 { DI, DI, DA, DIT }, /* F */
34 { DA, DA, DIT, end }, /* G */
35 { DI, DI, DI, DIT }, /* H */
36 { DI, DIT, end, end }, /* I */
37 { DI, DA, DA, DAH }, /* J */
38 { DA, DI, DAH, end }, /* K */
39 { DI, DA, DI, DIT }, /* L */
40 { DA, DAH, end, end }, /* M */
41 { DA, DIT, end, end }, /* N */
42 { DA, DA, DAH, end }, /* O */
43 { DI, DA, DA, DIT }, /* P */
44 { DA, DA, DI, DAH }, /* Q */
45 { DI, DA, DIT, end }, /* R */
46 { DI, DI, DIT, end }, /* S */
47 { DAH, end, end, end }, /* T */
48 { DI, DI, DAH, end }, /* U */
49 { DI, DI, DI, DAH }, /* V */
50 { DI, DA, DAH, end }, /* W */
51 { DA, DI, DI, DAH }, /* X */
52 { DA, DI, DA, DAH }, /* Y */
53 { DA, DA, DI, DIT } /* Z */
66 // allocate and initialize sound samples
67 bool FGMorse::init() {
71 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
72 float level = ( sin( (double) i * 2.0 * M_PI
73 / (8000.0 / LO_FREQUENCY) ) )
74 * ((double)i / TRANSITION_BYTES)
77 /* Convert to unsigned byte */
78 lo_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
81 for ( i = TRANSITION_BYTES;
82 i < DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE; ++i ) {
83 float level = ( sin( (double) i * 2.0 * M_PI
84 / (8000.0 / LO_FREQUENCY) ) )
87 /* Convert to unsigned byte */
88 lo_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
91 for ( i = DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE;
92 i < DIT_SIZE - COUNT_SIZE;
94 float level = ( sin( (double) i * 2.0 * M_PI
95 / (8000.0 / LO_FREQUENCY) ) )
96 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
99 /* Convert to unsigned byte */
100 lo_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
102 for ( i = DIT_SIZE - COUNT_SIZE; i < DIT_SIZE; ++i ) {
103 lo_dit[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
107 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
108 float level = ( sin( (double) i * 2.0 * M_PI
109 / (8000.0 / HI_FREQUENCY)) )
110 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
112 /* Convert to unsigned byte */
113 hi_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
116 for ( i = TRANSITION_BYTES;
117 i < DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE; ++i ) {
118 float level = ( sin( (double) i * 2.0 * M_PI
119 / (8000.0 / HI_FREQUENCY) ) )
122 /* Convert to unsigned byte */
123 hi_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
125 j = TRANSITION_BYTES;
126 for ( i = DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE;
127 i < DIT_SIZE - COUNT_SIZE;
129 float level = ( sin( (double) i * 2.0 * M_PI
130 / (8000.0 / HI_FREQUENCY) ) )
131 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
134 /* Convert to unsigned byte */
135 hi_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
137 for ( i = DIT_SIZE - COUNT_SIZE; i < DIT_SIZE; ++i ) {
138 hi_dit[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
142 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
143 float level = ( sin( (double) i * 2.0 * M_PI
144 / (8000.0 / LO_FREQUENCY) ) )
145 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
147 /* Convert to unsigned byte */
148 lo_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
151 for ( i = TRANSITION_BYTES;
152 i < DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
154 float level = ( sin( (double) i * 2.0 * M_PI
155 / (8000.0 / LO_FREQUENCY) ) )
158 /* Convert to unsigned byte */
159 lo_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
161 j = TRANSITION_BYTES;
162 for ( int i = DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
163 i < DAH_SIZE - COUNT_SIZE;
165 float level = ( sin( (double) i * 2.0 * M_PI
166 / (8000.0 / LO_FREQUENCY) ) )
167 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
170 /* Convert to unsigned byte */
171 lo_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
173 for ( int i = DAH_SIZE - COUNT_SIZE; i < DAH_SIZE; ++i ) {
174 lo_dah[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
178 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
179 float level = ( sin( (double) i * 2.0 * M_PI
180 / (8000.0 / HI_FREQUENCY) ) )
181 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
183 /* Convert to unsigned byte */
184 hi_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
187 for ( i = TRANSITION_BYTES;
188 i < DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
190 float level = ( sin( (double) i * 2.0 * M_PI
191 / (8000.0 / HI_FREQUENCY) ) )
194 /* Convert to unsigned byte */
195 hi_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
197 j = TRANSITION_BYTES;
198 for ( int i = DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
199 i < DAH_SIZE - COUNT_SIZE;
201 float level = ( sin( (double) i * 2.0 * M_PI
202 / (8000.0 / HI_FREQUENCY) ) )
203 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
206 /* Convert to unsigned byte */
207 hi_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
209 for ( int i = DAH_SIZE - COUNT_SIZE; i < DAH_SIZE; ++i ) {
210 hi_dah[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
214 for ( int i = 0; i < SPACE_SIZE; ++i ) {
215 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
222 // allocate and initialize sound samples
223 bool FGMorse::cust_init(const int freq ) {
227 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
228 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq)) )
229 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
231 /* Convert to unsigned byte */
232 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
235 for ( i = TRANSITION_BYTES;
236 i < DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE; ++i ) {
237 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
240 /* Convert to unsigned byte */
241 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
243 j = TRANSITION_BYTES;
244 for ( i = DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE;
245 i < DIT_SIZE - COUNT_SIZE;
247 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
248 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
251 /* Convert to unsigned byte */
252 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
254 for ( i = DIT_SIZE - COUNT_SIZE; i < DIT_SIZE; ++i ) {
255 cust_dit[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
259 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
260 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
261 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
263 /* Convert to unsigned byte */
264 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
267 for ( i = TRANSITION_BYTES;
268 i < DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
270 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
273 /* Convert to unsigned byte */
274 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
276 j = TRANSITION_BYTES;
277 for ( int i = DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
278 i < DAH_SIZE - COUNT_SIZE;
280 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
281 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
284 /* Convert to unsigned byte */
285 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
287 for ( int i = DAH_SIZE - COUNT_SIZE; i < DAH_SIZE; ++i ) {
288 cust_dah[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
292 for ( int i = 0; i < SPACE_SIZE; ++i ) {
293 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
300 // make a FGSimpleSound morse code transmission for the specified string
301 FGSimpleSound *FGMorse::make_ident( const string& id, const int freq ) {
302 char *idptr = (char *)id.c_str();
307 // 0. Select the frequency. If custom frequency, generate the
308 // sound fragments we need on the fly.
309 unsigned char *dit_ptr, *dah_ptr;
311 if ( freq == LO_FREQUENCY ) {
314 } else if ( freq == HI_FREQUENCY ) {
323 // 1. Determine byte length of message
324 for ( i = 0; i < (int)id.length(); ++i ) {
325 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
326 char c = idptr[i] - 'A';
327 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
328 if ( alphabet[c][j] == DIT ) {
330 } else if ( alphabet[c][j] == DAH ) {
334 length += SPACE_SIZE;
336 // skip unknown character
339 // add 2x more space to the end of the string
340 length += 2 * SPACE_SIZE;
342 // 2. Allocate space for the message
343 unsigned char *buffer = new unsigned char[length];
345 // 3. Assemble the message;
346 unsigned char *buf_ptr = buffer;
348 for ( i = 0; i < (int)id.length(); ++i ) {
349 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
350 char c = idptr[i] - 'A';
351 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
352 if ( alphabet[c][j] == DIT ) {
353 memcpy( buf_ptr, dit_ptr, DIT_SIZE );
355 } else if ( alphabet[c][j] == DAH ) {
356 memcpy( buf_ptr, dah_ptr, DAH_SIZE );
360 memcpy( buf_ptr, space, SPACE_SIZE );
361 buf_ptr += SPACE_SIZE;
363 // skip unknown character
366 memcpy( buf_ptr, space, SPACE_SIZE );
367 buf_ptr += SPACE_SIZE;
368 memcpy( buf_ptr, space, SPACE_SIZE );
369 buf_ptr += SPACE_SIZE;
371 // 4. create the simple sound and return
372 FGSimpleSound *sample = new FGSimpleSound( buffer, length );