From: Aurelien Jacobs <redacted>
Date: Mon, 20 Jun 2016 20:58:12 +0000 (+0200)
Subject: analog: add support for negative number of digits
X-Git-Tag: libsigrok-0.5.0~297
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=28c95cc6c45ede9ec9d184d606bfc16505834429;p=libsigrok.git

analog: add support for negative number of digits

When a meter display 105.2 kΩ, libsigrok will return 105200 Ω
but it is really valuable to know that the last 2 digits are not
significant, so encoding.digits should be set to -2.
This would allow a sigrok client to display 105200 as 105.2 k
instead of 105.200 k.
---

diff --git a/include/libsigrok/libsigrok.h b/include/libsigrok/libsigrok.h
index 511ab28c..7d9260ed 100644
--- a/include/libsigrok/libsigrok.h
+++ b/include/libsigrok/libsigrok.h
@@ -508,7 +508,7 @@ struct sr_analog_encoding {
 	gboolean is_signed;
 	gboolean is_float;
 	gboolean is_bigendian;
-	uint8_t digits;
+	int8_t digits;
 	gboolean is_digits_decimal;
 	struct sr_rational scale;
 	struct sr_rational offset;
@@ -522,7 +522,7 @@ struct sr_analog_meaning {
 };
 
 struct sr_analog_spec {
-	uint8_t spec_digits;
+	int8_t spec_digits;
 };
 
 /** Generic option struct used by various subsystems. */
diff --git a/src/output/analog.c b/src/output/analog.c
index 99daf3ac..5f77a59c 100644
--- a/src/output/analog.c
+++ b/src/output/analog.c
@@ -118,7 +118,7 @@ static int receive(const struct sr_output *o, const struct sr_datafeed_packet *p
 			for (l = analog->meaning->channels, c = 0; l; l = l->next, c++) {
 				ch = l->data;
 				g_string_append_printf(*out, "%s: ", ch->name);
-				number = g_strdup_printf("%.*f", digits,
+				number = g_strdup_printf("%.*f", MAX(digits, 0),
 						fdata[i * num_channels + c]);
 				g_string_append(*out, number);
 				g_free(number);