X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fanalog.c;h=da1560cd6702b91b66ae010b8263e84b30cebbcb;hb=88a0265ebcb265ba839c02cc5bcd39e359c9f60f;hp=e6efce2eb58e5132826487dd1002740f144d4da2;hpb=5cee3d08e4943f9b0c844ee85f8c3d4a043cb654;p=libsigrok.git

diff --git a/src/analog.c b/src/analog.c
index e6efce2e..da1560cd 100644
--- a/src/analog.c
+++ b/src/analog.c
@@ -45,7 +45,7 @@
 
 struct unit_mq_string {
 	uint64_t value;
-	char *str;
+	const char *str;
 };
 
 /* Please use the same order as in enum sr_unit (libsigrok.h). */
@@ -114,6 +114,7 @@ static struct unit_mq_string mq_strings[] = {
 	{ SR_MQFLAG_AVG, " AVG" },
 	{ SR_MQFLAG_REFERENCE, " REF" },
 	{ SR_MQFLAG_UNSTABLE, " UNSTABLE" },
+	{ SR_MQFLAG_FOUR_WIRE, " 4-WIRE" },
 	ALL_ZERO
 };
 
@@ -151,6 +152,23 @@ SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog,
 	return SR_OK;
 }
 
+/**
+ * Convert an analog datafeed payload to an array of floats.
+ *
+ * @param[in] analog The analog payload to convert. Must not be NULL.
+ *                   analog->data, analog->meaning, and analog->encoding
+ *                   must not be NULL.
+ * @param[out] outbuf Memory where to store the result. Must not be NULL.
+ *
+ * Sufficient memory for outbuf must have been pre-allocated by the caller,
+ * who is also responsible for freeing it when no longer needed.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR Unsupported encoding.
+ * @retval SR_ERR_ARG Invalid argument.
+ *
+ * @since 0.4.0
+ */
 SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
 		float *outbuf)
 {
@@ -170,9 +188,80 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
 	bigendian = FALSE;
 #endif
 	if (!analog->encoding->is_float) {
-		/* TODO */
-		sr_err("Only floating-point encoding supported so far.");
-		return SR_ERR;
+		float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q;
+		float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q;
+		gboolean is_signed = analog->encoding->is_signed;
+		gboolean is_bigendian = analog->encoding->is_bigendian;
+		int8_t *data8 = (int8_t *)(analog->data);
+		int16_t *data16 = (int16_t *)(analog->data);
+		int32_t *data32 = (int32_t *)(analog->data);
+
+		switch (analog->encoding->unitsize) {
+		case 1:
+			if (is_signed) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * data8[i];
+					outbuf[i] += offset;
+				}
+			} else {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * R8(data8 + i);
+					outbuf[i] += offset;
+				}
+			}
+			break;
+		case 2:
+			if (is_signed && is_bigendian) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RB16S(&data16[i]);
+					outbuf[i] += offset;
+				}
+			} else if (is_bigendian) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RB16(&data16[i]);
+					outbuf[i] += offset;
+				}
+			} else if (is_signed) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RL16S(&data16[i]);
+					outbuf[i] += offset;
+				}
+			} else {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RL16(&data16[i]);
+					outbuf[i] += offset;
+				}
+			}
+			break;
+		case 4:
+			if (is_signed && is_bigendian) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RB32S(&data32[i]);
+					outbuf[i] += offset;
+				}
+			} else if (is_bigendian) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RB32(&data32[i]);
+					outbuf[i] += offset;
+				}
+			} else if (is_signed) {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RL32S(&data32[i]);
+					outbuf[i] += offset;
+				}
+			} else {
+				for (unsigned int i = 0; i < count; i++) {
+					outbuf[i] = scale * RL32(&data32[i]);
+					outbuf[i] += offset;
+				}
+			}
+			break;
+		default:
+			sr_err("Unsupported unit size '%d' for analog-to-float conversion.",
+				analog->encoding->unitsize);
+			return SR_ERR;
+		}
+		return SR_OK;
 	}
 
 	if (analog->encoding->unitsize == sizeof(float)
@@ -203,52 +292,18 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
 	return SR_OK;
 }
 
-/*
- * Convert a floating point value to a string, limited to the given
- * number of decimal digits.
- *
- * @param value The value to convert.
- * @param digits Number of digits after the decimal point to print.
- * @param result Pointer to store result.
- *
- * The string is allocated by the function and must be freed by the caller
- * after use by calling g_free().
- *
- * @retval SR_OK
- *
- * @since 0.4.0
- */
-SR_API int sr_analog_float_to_string(float value, unsigned int digits, char **result)
-{
-	unsigned int cnt, i;
-
-	if (!result)
-		return SR_ERR_ARG;
-
-	/* This produces at least one too many digits */
-	*result = g_strdup_printf("%.*f", digits, value);
-	for (i = 0, cnt = 0; (*result)[i]; i++) {
-		if (isdigit((*result)[i++]))
-			cnt++;
-		if (cnt == digits) {
-			(*result)[i] = 0;
-			break;
-		}
-	}
-
-	return SR_OK;
-}
-
-/*
+/**
  * Convert the unit/MQ/MQ flags in the analog struct to a string.
  *
- * @param analog Struct containing the unit, MQ and MQ flags.
- * @param result Pointer to store result.
+ * @param[in] analog Struct containing the unit, MQ and MQ flags.
+ *                   Must not be NULL. analog->meaning must not be NULL.
+ * @param[out] result Pointer to store result. Must not be NULL.
  *
  * The string is allocated by the function and must be freed by the caller
  * after use by calling g_free().
  *
- * @retval SR_OK
+ * @retval SR_OK Success.
+ * @retval SR_ERR_ARG Invalid argument.
  *
  * @since 0.4.0
  */
@@ -281,11 +336,14 @@ SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog,
 	return SR_OK;
 }
 
-/*
+/**
  * Set sr_rational r to the given value.
  *
- * @param p Numerator
- * @param q Denominator
+ * @param[out] r Rational number struct to set. Must not be NULL.
+ * @param[in] p Numerator.
+ * @param[in] q Denominator.
+ *
+ * @since 0.4.0
  */
 SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
 {