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fb019a0e BV |
1 | /* |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2014 Bert Vermeulen <bert@biot.com> | |
5 | * | |
6 | * This program is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, either version 3 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
6ec6c43b | 20 | #include <config.h> |
c2a25ebb BV |
21 | #include <stdio.h> |
22 | #include <stdint.h> | |
fb019a0e | 23 | #include <string.h> |
c2a25ebb | 24 | #include <ctype.h> |
962172e4 | 25 | #include <math.h> |
c1aae900 | 26 | #include <libsigrok/libsigrok.h> |
fb019a0e BV |
27 | #include "libsigrok-internal.h" |
28 | ||
e00b3f58 | 29 | /** @cond PRIVATE */ |
fb019a0e | 30 | #define LOG_PREFIX "analog" |
e00b3f58 UH |
31 | /** @endcond */ |
32 | ||
33 | /** | |
34 | * @file | |
35 | * | |
36 | * Handling and converting analog data. | |
37 | */ | |
38 | ||
39 | /** | |
40 | * @defgroup grp_analog Analog data handling | |
41 | * | |
42 | * Handling and converting analog data. | |
43 | * | |
44 | * @{ | |
45 | */ | |
fb019a0e | 46 | |
a5892391 BV |
47 | struct unit_mq_string { |
48 | uint64_t value; | |
2c240774 | 49 | const char *str; |
a5892391 BV |
50 | }; |
51 | ||
ca7dbb56 | 52 | /* Please use the same order as in enum sr_unit (libsigrok.h). */ |
a5892391 BV |
53 | static struct unit_mq_string unit_strings[] = { |
54 | { SR_UNIT_VOLT, "V" }, | |
55 | { SR_UNIT_AMPERE, "A" }, | |
56 | { SR_UNIT_OHM, "\xe2\x84\xa6" }, | |
57 | { SR_UNIT_FARAD, "F" }, | |
a5892391 BV |
58 | { SR_UNIT_KELVIN, "K" }, |
59 | { SR_UNIT_CELSIUS, "\xc2\xb0""C" }, | |
60 | { SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" }, | |
61 | { SR_UNIT_HERTZ, "Hz" }, | |
62 | { SR_UNIT_PERCENTAGE, "%" }, | |
f7bcc686 | 63 | { SR_UNIT_BOOLEAN, "" }, |
a5892391 BV |
64 | { SR_UNIT_SECOND, "s" }, |
65 | { SR_UNIT_SIEMENS, "S" }, | |
cdc31195 AJ |
66 | { SR_UNIT_DECIBEL_MW, "dBm" }, |
67 | { SR_UNIT_DECIBEL_VOLT, "dBV" }, | |
f7bcc686 | 68 | { SR_UNIT_UNITLESS, "" }, |
a5892391 BV |
69 | { SR_UNIT_DECIBEL_SPL, "dB" }, |
70 | { SR_UNIT_CONCENTRATION, "ppm" }, | |
71 | { SR_UNIT_REVOLUTIONS_PER_MINUTE, "RPM" }, | |
72 | { SR_UNIT_VOLT_AMPERE, "VA" }, | |
73 | { SR_UNIT_WATT, "W" }, | |
74 | { SR_UNIT_WATT_HOUR, "Wh" }, | |
75 | { SR_UNIT_METER_SECOND, "m/s" }, | |
76 | { SR_UNIT_HECTOPASCAL, "hPa" }, | |
77 | { SR_UNIT_HUMIDITY_293K, "%rF" }, | |
78 | { SR_UNIT_DEGREE, "\xc2\xb0" }, | |
f7bcc686 UH |
79 | { SR_UNIT_HENRY, "H" }, |
80 | { SR_UNIT_GRAM, "g" }, | |
81 | { SR_UNIT_CARAT, "ct" }, | |
82 | { SR_UNIT_OUNCE, "oz" }, | |
83 | { SR_UNIT_TROY_OUNCE, "oz t" }, | |
84 | { SR_UNIT_POUND, "lb" }, | |
85 | { SR_UNIT_PENNYWEIGHT, "dwt" }, | |
86 | { SR_UNIT_GRAIN, "gr" }, | |
87 | { SR_UNIT_TAEL, "tael" }, | |
88 | { SR_UNIT_MOMME, "momme" }, | |
89 | { SR_UNIT_TOLA, "tola" }, | |
90 | { SR_UNIT_PIECE, "pcs" }, | |
fe8c5aef FS |
91 | { SR_UNIT_JOULE, "J" }, |
92 | { SR_UNIT_COULOMB, "C" }, | |
93 | { SR_UNIT_AMPERE_HOUR, "Ah" }, | |
a5892391 BV |
94 | ALL_ZERO |
95 | }; | |
96 | ||
ca7dbb56 | 97 | /* Please use the same order as in enum sr_mqflag (libsigrok.h). */ |
a5892391 | 98 | static struct unit_mq_string mq_strings[] = { |
a5892391 BV |
99 | { SR_MQFLAG_AC, " AC" }, |
100 | { SR_MQFLAG_DC, " DC" }, | |
101 | { SR_MQFLAG_RMS, " RMS" }, | |
102 | { SR_MQFLAG_DIODE, " DIODE" }, | |
103 | { SR_MQFLAG_HOLD, " HOLD" }, | |
104 | { SR_MQFLAG_MAX, " MAX" }, | |
105 | { SR_MQFLAG_MIN, " MIN" }, | |
106 | { SR_MQFLAG_AUTORANGE, " AUTO" }, | |
107 | { SR_MQFLAG_RELATIVE, " REL" }, | |
f7bcc686 UH |
108 | { SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" }, |
109 | { SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" }, | |
110 | { SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" }, | |
111 | { SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" }, | |
112 | { SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" }, | |
113 | { SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" }, | |
114 | { SR_MQFLAG_SPL_LAT, " LAT" }, | |
115 | /* Not a standard function for SLMs, so this is a made-up notation. */ | |
116 | { SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" }, | |
117 | { SR_MQFLAG_DURATION, " DURATION" }, | |
a5892391 BV |
118 | { SR_MQFLAG_AVG, " AVG" }, |
119 | { SR_MQFLAG_REFERENCE, " REF" }, | |
f7bcc686 | 120 | { SR_MQFLAG_UNSTABLE, " UNSTABLE" }, |
6d5cd3bd | 121 | { SR_MQFLAG_FOUR_WIRE, " 4-WIRE" }, |
a5892391 BV |
122 | ALL_ZERO |
123 | }; | |
124 | ||
f200d59e | 125 | /** @private */ |
edb691fc | 126 | SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog, |
41caa319 AJ |
127 | struct sr_analog_encoding *encoding, |
128 | struct sr_analog_meaning *meaning, | |
129 | struct sr_analog_spec *spec, | |
130 | int digits) | |
131 | { | |
132 | memset(analog, 0, sizeof(*analog)); | |
133 | memset(encoding, 0, sizeof(*encoding)); | |
134 | memset(meaning, 0, sizeof(*meaning)); | |
135 | memset(spec, 0, sizeof(*spec)); | |
136 | ||
137 | analog->encoding = encoding; | |
138 | analog->meaning = meaning; | |
139 | analog->spec = spec; | |
140 | ||
141 | encoding->unitsize = sizeof(float); | |
142 | encoding->is_float = TRUE; | |
143 | #ifdef WORDS_BIGENDIAN | |
144 | encoding->is_bigendian = TRUE; | |
145 | #else | |
146 | encoding->is_bigendian = FALSE; | |
147 | #endif | |
148 | encoding->digits = digits; | |
149 | encoding->is_digits_decimal = TRUE; | |
150 | encoding->scale.p = 1; | |
151 | encoding->scale.q = 1; | |
152 | encoding->offset.p = 0; | |
153 | encoding->offset.q = 1; | |
154 | ||
155 | spec->spec_digits = digits; | |
156 | ||
157 | return SR_OK; | |
158 | } | |
159 | ||
22fb1bff UH |
160 | /** |
161 | * Convert an analog datafeed payload to an array of floats. | |
162 | * | |
e62b284c GS |
163 | * The caller must provide the #outbuf space for the conversion result, |
164 | * and is expected to free allocated space after use. | |
8dc423b0 | 165 | * |
22fb1bff UH |
166 | * @param[in] analog The analog payload to convert. Must not be NULL. |
167 | * analog->data, analog->meaning, and analog->encoding | |
168 | * must not be NULL. | |
169 | * @param[out] outbuf Memory where to store the result. Must not be NULL. | |
170 | * | |
22fb1bff UH |
171 | * @retval SR_OK Success. |
172 | * @retval SR_ERR Unsupported encoding. | |
173 | * @retval SR_ERR_ARG Invalid argument. | |
174 | * | |
175 | * @since 0.4.0 | |
176 | */ | |
edb691fc | 177 | SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog, |
4b4fdeea | 178 | float *outbuf) |
fb019a0e | 179 | { |
e62b284c GS |
180 | size_t count; |
181 | gboolean host_bigendian; | |
182 | gboolean input_float, input_signed, input_bigendian; | |
183 | size_t input_unitsize; | |
184 | double scale, offset, value; | |
185 | const uint8_t *data8; | |
186 | gboolean input_is_native; | |
187 | char type_text[10]; | |
5cee3d08 | 188 | |
e62b284c GS |
189 | if (!analog || !analog->data || !analog->meaning || !analog->encoding) |
190 | return SR_ERR_ARG; | |
191 | if (!outbuf) | |
5cee3d08 UH |
192 | return SR_ERR_ARG; |
193 | ||
194 | count = analog->num_samples * g_slist_length(analog->meaning->channels); | |
fb019a0e | 195 | |
e62b284c GS |
196 | /* |
197 | * Determine properties of the input data's and the host's | |
198 | * native formats, to simplify test conditions below. | |
199 | * Error messages for unsupported input property combinations | |
200 | * will only be seen by developers and maintainers of input | |
201 | * formats or acquisition device drivers. Terse output is | |
202 | * acceptable there, users shall never see them. | |
203 | */ | |
fb019a0e | 204 | #ifdef WORDS_BIGENDIAN |
e62b284c | 205 | host_bigendian = TRUE; |
fb019a0e | 206 | #else |
e62b284c | 207 | host_bigendian = FALSE; |
fb019a0e | 208 | #endif |
e62b284c GS |
209 | input_float = analog->encoding->is_float; |
210 | input_signed = analog->encoding->is_signed; | |
211 | input_bigendian = analog->encoding->is_bigendian; | |
212 | input_unitsize = analog->encoding->unitsize; | |
8dc423b0 | 213 | |
e62b284c GS |
214 | /* |
215 | * Prepare the iteration over the sample data: Get the common | |
216 | * scale/offset factors which apply to all individual values. | |
217 | * Position the read pointer on the first byte of input data. | |
218 | */ | |
219 | offset = analog->encoding->offset.p; | |
220 | offset /= analog->encoding->offset.q; | |
221 | scale = analog->encoding->scale.p; | |
222 | scale /= analog->encoding->scale.q; | |
223 | data8 = analog->data; | |
4d376e08 | 224 | |
e62b284c GS |
225 | /* |
226 | * Immediately handle the special case where input data needs | |
227 | * no conversion because it already is in the application's | |
228 | * native format. Do apply scale/offset though when applicable | |
229 | * on our way out. | |
230 | */ | |
231 | input_is_native = input_float && | |
232 | input_unitsize == sizeof(outbuf[0]) && | |
233 | input_bigendian == host_bigendian; | |
234 | if (input_is_native) { | |
235 | memcpy(outbuf, data8, count * sizeof(outbuf[0])); | |
236 | if (scale != 1.0 || offset != 0.0) { | |
237 | while (count--) { | |
238 | *outbuf *= scale; | |
239 | *outbuf += offset; | |
240 | outbuf++; | |
4d376e08 | 241 | } |
4d376e08 SB |
242 | } |
243 | return SR_OK; | |
fb019a0e BV |
244 | } |
245 | ||
e62b284c GS |
246 | /* |
247 | * Accept sample values in different widths and data types and | |
248 | * endianess formats (floating point or signed or unsigned | |
249 | * integer, in either endianess, for a set of supported widths). | |
250 | * Common scale/offset factors apply to all sample values. | |
251 | * | |
252 | * Do most internal calculations on double precision values. | |
253 | * Only trim the result data to single precision, since that's | |
254 | * the routine's result data type in its public API which needs | |
255 | * to be kept for compatibility. It remains an option for later | |
256 | * to add another public routine which returns double precision | |
257 | * result data, call sites could migrate at their own pace. | |
258 | */ | |
259 | if (input_float && input_unitsize == sizeof(float)) { | |
260 | float (*reader)(const uint8_t **p); | |
261 | if (input_bigendian) | |
262 | reader = read_fltbe_inc; | |
263 | else | |
264 | reader = read_fltle_inc; | |
265 | while (count--) { | |
266 | value = reader(&data8); | |
267 | value *= scale; | |
268 | value += offset; | |
269 | *outbuf++ = value; | |
270 | } | |
271 | return SR_OK; | |
272 | } | |
273 | if (input_float && input_unitsize == sizeof(double)) { | |
274 | double (*reader)(const uint8_t **p); | |
275 | if (input_bigendian) | |
276 | reader = read_dblbe_inc; | |
277 | else | |
278 | reader = read_dblle_inc; | |
279 | while (count--) { | |
280 | value = reader(&data8); | |
281 | value *= scale; | |
282 | value += offset; | |
283 | *outbuf++ = value; | |
fb019a0e | 284 | } |
e62b284c GS |
285 | return SR_OK; |
286 | } | |
287 | if (input_float) { | |
288 | snprintf(type_text, sizeof(type_text), "%c%zu%s", | |
289 | 'f', input_unitsize * 8, input_bigendian ? "be" : "le"); | |
290 | sr_err("Unsupported type for analog-to-float conversion: %s.", | |
291 | type_text); | |
292 | return SR_ERR; | |
fb019a0e BV |
293 | } |
294 | ||
e62b284c GS |
295 | if (input_unitsize == sizeof(uint8_t) && input_signed) { |
296 | int8_t (*reader)(const uint8_t **p); | |
297 | reader = read_i8_inc; | |
298 | while (count--) { | |
299 | value = reader(&data8); | |
300 | value *= scale; | |
301 | value += offset; | |
302 | *outbuf++ = value; | |
303 | } | |
304 | return SR_OK; | |
305 | } | |
306 | if (input_unitsize == sizeof(uint8_t)) { | |
307 | uint8_t (*reader)(const uint8_t **p); | |
308 | reader = read_u8_inc; | |
309 | while (count--) { | |
310 | value = reader(&data8); | |
311 | value *= scale; | |
312 | value += offset; | |
313 | *outbuf++ = value; | |
314 | } | |
315 | return SR_OK; | |
316 | } | |
317 | if (input_unitsize == sizeof(uint16_t) && input_signed) { | |
318 | int16_t (*reader)(const uint8_t **p); | |
319 | if (input_bigendian) | |
320 | reader = read_i16be_inc; | |
321 | else | |
322 | reader = read_i16le_inc; | |
323 | while (count--) { | |
324 | value = reader(&data8); | |
325 | value *= scale; | |
326 | value += offset; | |
327 | *outbuf++ = value; | |
328 | } | |
329 | return SR_OK; | |
330 | } | |
331 | if (input_unitsize == sizeof(uint16_t)) { | |
332 | uint16_t (*reader)(const uint8_t **p); | |
333 | if (input_bigendian) | |
334 | reader = read_u16be_inc; | |
335 | else | |
336 | reader = read_u16le_inc; | |
337 | while (count--) { | |
338 | value = reader(&data8); | |
339 | value *= scale; | |
340 | value += offset; | |
341 | *outbuf++ = value; | |
342 | } | |
343 | return SR_OK; | |
344 | } | |
345 | if (input_unitsize == sizeof(uint32_t) && input_signed) { | |
346 | int32_t (*reader)(const uint8_t **p); | |
347 | if (input_bigendian) | |
348 | reader = read_i32be_inc; | |
349 | else | |
350 | reader = read_i32le_inc; | |
351 | while (count--) { | |
352 | value = reader(&data8); | |
353 | value *= scale; | |
354 | value += offset; | |
355 | *outbuf++ = value; | |
356 | } | |
357 | return SR_OK; | |
358 | } | |
359 | if (input_unitsize == sizeof(uint32_t)) { | |
360 | uint32_t (*reader)(const uint8_t **p); | |
361 | if (input_bigendian) | |
362 | reader = read_u32be_inc; | |
363 | else | |
364 | reader = read_u32le_inc; | |
365 | while (count--) { | |
366 | value = reader(&data8); | |
367 | value *= scale; | |
368 | value += offset; | |
369 | *outbuf++ = value; | |
370 | } | |
371 | return SR_OK; | |
372 | } | |
373 | snprintf(type_text, sizeof(type_text), "%c%zu%s", | |
374 | input_float ? 'f' : input_signed ? 'i' : 'u', | |
375 | input_unitsize * 8, input_bigendian ? "be" : "le"); | |
376 | sr_err("Unsupported type for analog-to-float conversion: %s.", | |
377 | type_text); | |
378 | return SR_ERR; | |
fb019a0e | 379 | } |
c2a25ebb | 380 | |
962172e4 AJ |
381 | /** |
382 | * Scale a float value to the appropriate SI prefix. | |
383 | * | |
384 | * @param[in,out] value The float value to convert to appropriate SI prefix. | |
385 | * @param[in,out] digits The number of significant decimal digits in value. | |
386 | * | |
387 | * @return The SI prefix to which value was scaled, as a printable string. | |
388 | * | |
389 | * @since 0.5.0 | |
390 | */ | |
391 | SR_API const char *sr_analog_si_prefix(float *value, int *digits) | |
392 | { | |
f200d59e | 393 | /** @cond PRIVATE */ |
405b9c10 | 394 | #define NEG_PREFIX_COUNT 5 /* number of prefixes below unity */ |
962172e4 | 395 | #define POS_PREFIX_COUNT (int)(ARRAY_SIZE(prefixes) - NEG_PREFIX_COUNT - 1) |
f200d59e | 396 | /** @endcond */ |
8dc423b0 | 397 | static const char *prefixes[] = { "f", "p", "n", "µ", "m", "", "k", "M", "G", "T" }; |
962172e4 | 398 | |
8dc423b0 | 399 | if (!value || !digits || isnan(*value)) |
962172e4 AJ |
400 | return prefixes[NEG_PREFIX_COUNT]; |
401 | ||
402 | float logval = log10f(fabsf(*value)); | |
403 | int prefix = (logval / 3) - (logval < 1); | |
404 | ||
8dc423b0 UH |
405 | if (prefix < -NEG_PREFIX_COUNT) |
406 | prefix = -NEG_PREFIX_COUNT; | |
407 | if (3 * prefix < -*digits) | |
408 | prefix = (-*digits + 2 * (*digits < 0)) / 3; | |
409 | if (prefix > POS_PREFIX_COUNT) | |
410 | prefix = POS_PREFIX_COUNT; | |
962172e4 AJ |
411 | |
412 | *value *= powf(10, -3 * prefix); | |
413 | *digits += 3 * prefix; | |
8dc423b0 | 414 | |
962172e4 AJ |
415 | return prefixes[prefix + NEG_PREFIX_COUNT]; |
416 | } | |
417 | ||
5728718b AJ |
418 | /** |
419 | * Check if a unit "accepts" an SI prefix. | |
420 | * | |
421 | * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or | |
422 | * SR_UNIT_PERCENTAGE are not. | |
423 | * | |
424 | * @param[in] unit The unit to check for SI prefix "friendliness". | |
425 | * | |
426 | * @return TRUE if the unit "accept" an SI prefix. | |
427 | * | |
428 | * @since 0.5.0 | |
429 | */ | |
430 | SR_API gboolean sr_analog_si_prefix_friendly(enum sr_unit unit) | |
431 | { | |
432 | static const enum sr_unit prefix_friendly_units[] = { | |
433 | SR_UNIT_VOLT, | |
434 | SR_UNIT_AMPERE, | |
435 | SR_UNIT_OHM, | |
436 | SR_UNIT_FARAD, | |
437 | SR_UNIT_KELVIN, | |
438 | SR_UNIT_HERTZ, | |
439 | SR_UNIT_SECOND, | |
440 | SR_UNIT_SIEMENS, | |
441 | SR_UNIT_VOLT_AMPERE, | |
442 | SR_UNIT_WATT, | |
443 | SR_UNIT_WATT_HOUR, | |
444 | SR_UNIT_METER_SECOND, | |
445 | SR_UNIT_HENRY, | |
446 | SR_UNIT_GRAM | |
447 | }; | |
448 | unsigned int i; | |
449 | ||
450 | for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++) | |
451 | if (unit == prefix_friendly_units[i]) | |
5e5fde6e | 452 | return TRUE; |
5728718b | 453 | |
5e5fde6e | 454 | return FALSE; |
5728718b AJ |
455 | } |
456 | ||
22fb1bff | 457 | /** |
a5892391 BV |
458 | * Convert the unit/MQ/MQ flags in the analog struct to a string. |
459 | * | |
8dc423b0 UH |
460 | * The string is allocated by the function and must be freed by the caller |
461 | * after use by calling g_free(). | |
462 | * | |
22fb1bff UH |
463 | * @param[in] analog Struct containing the unit, MQ and MQ flags. |
464 | * Must not be NULL. analog->meaning must not be NULL. | |
465 | * @param[out] result Pointer to store result. Must not be NULL. | |
a24da9a8 | 466 | * |
22fb1bff UH |
467 | * @retval SR_OK Success. |
468 | * @retval SR_ERR_ARG Invalid argument. | |
a5892391 BV |
469 | * |
470 | * @since 0.4.0 | |
471 | */ | |
edb691fc | 472 | SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog, |
a24da9a8 | 473 | char **result) |
a5892391 | 474 | { |
a24da9a8 | 475 | int i; |
5cee3d08 UH |
476 | GString *buf; |
477 | ||
478 | if (!analog || !(analog->meaning) || !result) | |
479 | return SR_ERR_ARG; | |
480 | ||
481 | buf = g_string_new(NULL); | |
a5892391 | 482 | |
a5892391 BV |
483 | for (i = 0; unit_strings[i].value; i++) { |
484 | if (analog->meaning->unit == unit_strings[i].value) { | |
a24da9a8 | 485 | g_string_assign(buf, unit_strings[i].str); |
a5892391 BV |
486 | break; |
487 | } | |
488 | } | |
489 | ||
490 | /* More than one MQ flag may apply. */ | |
a24da9a8 ML |
491 | for (i = 0; mq_strings[i].value; i++) |
492 | if (analog->meaning->mqflags & mq_strings[i].value) | |
493 | g_string_append(buf, mq_strings[i].str); | |
494 | ||
495 | *result = buf->str; | |
496 | g_string_free(buf, FALSE); | |
a5892391 BV |
497 | |
498 | return SR_OK; | |
499 | } | |
500 | ||
22fb1bff | 501 | /** |
90cefe0c BV |
502 | * Set sr_rational r to the given value. |
503 | * | |
22fb1bff UH |
504 | * @param[out] r Rational number struct to set. Must not be NULL. |
505 | * @param[in] p Numerator. | |
506 | * @param[in] q Denominator. | |
507 | * | |
508 | * @since 0.4.0 | |
90cefe0c | 509 | */ |
53e5d3d1 | 510 | SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q) |
90cefe0c | 511 | { |
5cee3d08 UH |
512 | if (!r) |
513 | return; | |
514 | ||
90cefe0c BV |
515 | r->p = p; |
516 | r->q = q; | |
517 | } | |
518 | ||
bdba3626 SB |
519 | #ifndef HAVE___INT128_T |
520 | struct sr_int128_t { | |
521 | int64_t high; | |
522 | uint64_t low; | |
523 | }; | |
524 | ||
525 | struct sr_uint128_t { | |
526 | uint64_t high; | |
527 | uint64_t low; | |
528 | }; | |
529 | ||
530 | static void mult_int64(struct sr_int128_t *res, const int64_t a, | |
531 | const int64_t b) | |
532 | { | |
533 | uint64_t t1, t2, t3, t4; | |
534 | ||
535 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
536 | t2 = (UINT32_MAX & a) * (b >> 32); | |
537 | t3 = (a >> 32) * (UINT32_MAX & b); | |
538 | t4 = (a >> 32) * (b >> 32); | |
539 | ||
540 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
541 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
542 | res->high >>= 32; | |
543 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
544 | } | |
545 | ||
546 | static void mult_uint64(struct sr_uint128_t *res, const uint64_t a, | |
547 | const uint64_t b) | |
548 | { | |
549 | uint64_t t1, t2, t3, t4; | |
550 | ||
551 | // (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2 | |
552 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
553 | t2 = (UINT32_MAX & a) * (b >> 32); | |
554 | t3 = (a >> 32) * (UINT32_MAX & b); | |
555 | t4 = (a >> 32) * (b >> 32); | |
556 | ||
557 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
558 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
559 | res->high >>= 32; | |
560 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
561 | } | |
562 | #endif | |
563 | ||
564 | /** | |
8dc423b0 | 565 | * Compare two sr_rational for equality. |
bdba3626 | 566 | * |
8dc423b0 | 567 | * The values are compared for numerical equality, i.e. 2/10 == 1/5. |
bdba3626 | 568 | * |
8dc423b0 UH |
569 | * @param[in] a First value. |
570 | * @param[in] b Second value. | |
bdba3626 | 571 | * |
8dc423b0 UH |
572 | * @retval 1 if both values are equal. |
573 | * @retval 0 Otherwise. | |
bdba3626 SB |
574 | * |
575 | * @since 0.5.0 | |
576 | */ | |
577 | SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b) | |
578 | { | |
579 | #ifdef HAVE___INT128_T | |
580 | __int128_t m1, m2; | |
581 | ||
582 | /* p1/q1 = p2/q2 <=> p1*q2 = p2*q1 */ | |
583 | m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q); | |
584 | m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q); | |
585 | ||
586 | return (m1 == m2); | |
587 | ||
588 | #else | |
589 | struct sr_int128_t m1, m2; | |
590 | ||
591 | mult_int64(&m1, a->q, b->p); | |
592 | mult_int64(&m2, a->p, b->q); | |
593 | ||
594 | return (m1.high == m2.high) && (m1.low == m2.low); | |
595 | #endif | |
596 | } | |
597 | ||
ee1b6054 | 598 | /** |
8dc423b0 | 599 | * Multiply two sr_rational. |
ee1b6054 SB |
600 | * |
601 | * The resulting nominator/denominator are reduced if the result would not fit | |
602 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
603 | * this may not be possible. | |
604 | * | |
8dc423b0 UH |
605 | * It is safe to use the same variable for result and input values. |
606 | * | |
607 | * @param[in] a First value. | |
608 | * @param[in] b Second value. | |
609 | * @param[out] res Result. | |
17d5a11c | 610 | * |
ee1b6054 | 611 | * @retval SR_OK Success. |
8dc423b0 | 612 | * @retval SR_ERR_ARG Resulting value too large. |
ee1b6054 SB |
613 | * |
614 | * @since 0.5.0 | |
615 | */ | |
616 | SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a, | |
617 | const struct sr_rational *b) | |
618 | { | |
619 | #ifdef HAVE___INT128_T | |
620 | __int128_t p; | |
621 | __uint128_t q; | |
622 | ||
623 | p = (__int128_t)(a->p) * (__int128_t)(b->p); | |
624 | q = (__uint128_t)(a->q) * (__uint128_t)(b->q); | |
625 | ||
626 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
627 | while (!((p & 1) || (q & 1))) { | |
628 | p /= 2; | |
629 | q /= 2; | |
630 | } | |
631 | } | |
632 | ||
633 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
634 | // TODO: determine gcd to do further reduction | |
635 | return SR_ERR_ARG; | |
636 | } | |
637 | ||
405b9c10 UH |
638 | res->p = (int64_t)p; |
639 | res->q = (uint64_t)q; | |
ee1b6054 SB |
640 | |
641 | return SR_OK; | |
642 | ||
643 | #else | |
644 | struct sr_int128_t p; | |
645 | struct sr_uint128_t q; | |
646 | ||
647 | mult_int64(&p, a->p, b->p); | |
648 | mult_uint64(&q, a->q, b->q); | |
649 | ||
650 | while (!(p.low & 1) && !(q.low & 1)) { | |
651 | p.low /= 2; | |
8dc423b0 UH |
652 | if (p.high & 1) |
653 | p.low |= (1ll << 63); | |
ee1b6054 SB |
654 | p.high >>= 1; |
655 | q.low /= 2; | |
8dc423b0 UH |
656 | if (q.high & 1) |
657 | q.low |= (1ll << 63); | |
ee1b6054 SB |
658 | q.high >>= 1; |
659 | } | |
660 | ||
661 | if (q.high) | |
662 | return SR_ERR_ARG; | |
663 | if ((p.high >= 0) && (p.low > INT64_MAX)) | |
664 | return SR_ERR_ARG; | |
665 | if (p.high < -1) | |
666 | return SR_ERR_ARG; | |
667 | ||
668 | res->p = (int64_t)p.low; | |
669 | res->q = q.low; | |
670 | ||
671 | return SR_OK; | |
672 | #endif | |
673 | } | |
674 | ||
17d5a11c | 675 | /** |
8dc423b0 | 676 | * Divide rational a by rational b. |
17d5a11c SB |
677 | * |
678 | * The resulting nominator/denominator are reduced if the result would not fit | |
679 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
680 | * this may not be possible. | |
681 | * | |
8dc423b0 UH |
682 | * It is safe to use the same variable for result and input values. |
683 | * | |
684 | * @param[in] num Numerator. | |
685 | * @param[in] div Divisor. | |
686 | * @param[out] res Result. | |
17d5a11c SB |
687 | * |
688 | * @retval SR_OK Success. | |
6762401d UH |
689 | * @retval SR_ERR_ARG Division by zero, denominator of divisor too large, |
690 | * or resulting value too large. | |
17d5a11c SB |
691 | * |
692 | * @since 0.5.0 | |
693 | */ | |
694 | SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num, | |
695 | const struct sr_rational *div) | |
696 | { | |
697 | struct sr_rational t; | |
698 | ||
699 | if (div->q > INT64_MAX) | |
700 | return SR_ERR_ARG; | |
701 | if (div->p == 0) | |
702 | return SR_ERR_ARG; | |
703 | ||
704 | if (div->p > 0) { | |
705 | t.p = div->q; | |
706 | t.q = div->p; | |
707 | } else { | |
708 | t.p = -div->q; | |
709 | t.q = -div->p; | |
710 | } | |
711 | ||
712 | return sr_rational_mult(res, num, &t); | |
713 | } | |
714 | ||
e00b3f58 | 715 | /** @} */ |