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 ( int i = 0; i < SPACE_SIZE; ++i ) {
179 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
186 // allocate and initialize sound samples
187 bool FGMorse::cust_init(const int freq ) {
191 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
192 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq)) )
193 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
195 /* Convert to unsigned byte */
196 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
199 for ( i = TRANSITION_BYTES;
200 i < DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE; ++i ) {
201 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
204 /* Convert to unsigned byte */
205 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
207 j = TRANSITION_BYTES;
208 for ( i = DIT_SIZE - TRANSITION_BYTES - COUNT_SIZE;
209 i < DIT_SIZE - COUNT_SIZE;
211 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
212 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
215 /* Convert to unsigned byte */
216 cust_dit[ i ] = (unsigned char) ( level * 255.0 ) ;
218 for ( i = DIT_SIZE - COUNT_SIZE; i < DIT_SIZE; ++i ) {
219 cust_dit[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
223 for ( i = 0; i < TRANSITION_BYTES; ++i ) {
224 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
225 * ((double)i / TRANSITION_BYTES) / 2.0 + 0.5;
227 /* Convert to unsigned byte */
228 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
231 for ( i = TRANSITION_BYTES;
232 i < DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
234 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
237 /* Convert to unsigned byte */
238 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
240 j = TRANSITION_BYTES;
241 for ( int i = DAH_SIZE - TRANSITION_BYTES - COUNT_SIZE;
242 i < DAH_SIZE - COUNT_SIZE;
244 float level = ( sin( (double) i * 2.0 * M_PI / (8000.0 / freq) ) )
245 * ((double)j / TRANSITION_BYTES) / 2.0 + 0.5;
248 /* Convert to unsigned byte */
249 cust_dah[ i ] = (unsigned char) ( level * 255.0 ) ;
251 for ( int i = DAH_SIZE - COUNT_SIZE; i < DAH_SIZE; ++i ) {
252 cust_dah[ i ] = (unsigned char) ( 0.5 * 255.0 ) ;
256 for ( int i = 0; i < SPACE_SIZE; ++i ) {
257 space[ i ] = (unsigned char) ( 0.5 * 255 ) ;
264 // make a FGSimpleSound morse code transmission for the specified string
265 FGSimpleSound *FGMorse::make_ident( const string& id, const int freq ) {
266 char *idptr = (char *)id.c_str();
271 // 0. Select the frequency. If custom frequency, generate the
272 // sound fragments we need on the fly.
273 unsigned char *dit_ptr, *dah_ptr;
275 if ( freq == LO_FREQUENCY ) {
278 } else if ( freq == HI_FREQUENCY ) {
287 // 1. Determine byte length of message
288 for ( i = 0; i < (int)id.length(); ++i ) {
289 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
290 char c = idptr[i] - 'A';
291 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
292 if ( alphabet[c][j] == DIT ) {
294 } else if ( alphabet[c][j] == DAH ) {
298 length += SPACE_SIZE;
300 // skip unknown character
303 // add 2x more space to the end of the string
304 length += 2 * SPACE_SIZE;
306 // 2. Allocate space for the message
307 unsigned char *buffer = new unsigned char[length];
309 // 3. Assemble the message;
310 unsigned char *buf_ptr = buffer;
312 for ( i = 0; i < (int)id.length(); ++i ) {
313 if ( idptr[i] >= 'A' && idptr[i] <= 'Z' ) {
314 char c = idptr[i] - 'A';
315 for ( j = 0; j < 4 || alphabet[c][j] == end; ++j ) {
316 if ( alphabet[c][j] == DIT ) {
317 memcpy( buf_ptr, dit_ptr, DIT_SIZE );
319 } else if ( alphabet[c][j] == DAH ) {
320 memcpy( buf_ptr, dah_ptr, DAH_SIZE );
324 memcpy( buf_ptr, space, SPACE_SIZE );
325 buf_ptr += SPACE_SIZE;
327 // skip unknown character
330 memcpy( buf_ptr, space, SPACE_SIZE );
331 buf_ptr += SPACE_SIZE;
332 memcpy( buf_ptr, space, SPACE_SIZE );
333 buf_ptr += SPACE_SIZE;
335 // 4. create the simple sound and return
336 FGSimpleSound *sample = new FGSimpleSound( buffer, length );