util: Added format_si_value

[pulseview.git] / pv / util.cpp

diff --git a/pv/util.cpp b/pv/util.cpp
index 62f0ee1f67002b33ef2816bef15ccd3679dc4a00..2a04aaec7d99e68fb7ef9295c6ec4e40f5476425 100644 (file)
--- a/pv/util.cpp
+++ b/pv/util.cpp
@@ -36,9 +36,21 @@ static const QString SIPrefixes[9] =
        {"f", "p", "n", QChar(0x03BC), "m", "", "k", "M", "G"};
 const int FirstSIPrefixPower = -15;
 
-QString format_time(double t, unsigned int prefix,
+QString format_si_value(double v, QString unit, int prefix,
        unsigned int precision, bool sign)
 {
+       if (prefix < 0) {
+               int exp = -FirstSIPrefixPower;
+
+               prefix = 0;
+               while ((fabs(v) * pow(10.0, exp)) > 999.0 &&
+                       prefix < (int)(countof(SIPrefixes) - 1)) {
+                       prefix++;
+                       exp -= 3;
+               }
+       }
+
+       assert(prefix >= 0);
        assert(prefix < countof(SIPrefixes));
 
        const double multiplier = pow(10.0,
@@ -46,26 +58,23 @@ QString format_time(double t, unsigned int prefix,
 
        QString s;
        QTextStream ts(&s);
-       if (sign) {
+       if (sign)
                ts << forcesign;
-       }
        ts << fixed << qSetRealNumberPrecision(precision)
-               << (t  * multiplier) << SIPrefixes[prefix] << "s";
+               << (v  * multiplier) << SIPrefixes[prefix] << unit;
 
        return s;
 }
 
-QString format_second(double second)
+QString format_time(double t, int prefix,
+       unsigned int precision, bool sign)
 {
-       unsigned int i = 0;
-       int exp = - FirstSIPrefixPower;
-
-       while ((second * pow(10.0, exp)) > 999.0 && i < countof(SIPrefixes) - 1) {
-               i++;
-               exp -= 3;
-       }
+       return format_si_value(t, "s", prefix, precision, sign);
+}
 
-       return format_time(second, i, 0, false);
+QString format_second(double second)
+{
+       return format_si_value(second, "s", -1, 0, false);
 }
 
 } // namespace util