Rework sr_period_string

[libsigrok.git] / src / strutil.c

diff --git a/src/strutil.c b/src/strutil.c
index 11d614b3ccd5bfed0cc4c1b2c3d0b87609038545..3b0afadef530f42960dfda42a9c92d2eaa88437e 100644 (file)
--- a/src/strutil.c
+++ b/src/strutil.c
@@ -14,8 +14,7 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <config.h>
@@ -361,22 +360,37 @@ SR_API char *sr_samplerate_string(uint64_t samplerate)
  *
  * @since 0.1.0
  */
-SR_API char *sr_period_string(uint64_t frequency)
+SR_API char *sr_period_string(uint64_t v_p, uint64_t v_q)
 {
+       double freq, v;
        char *o;
-       int r;
+       int prec, r;
+
+       freq = 1 / ((double)v_p / v_q);
 
-       /* Allocate enough for a uint64_t as string + " ms". */
        o = g_malloc0(30 + 1);
 
-       if (frequency >= SR_GHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " ns", frequency / 1000000000);
-       else if (frequency >= SR_MHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " us", frequency / 1000000);
-       else if (frequency >= SR_KHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " ms", frequency / 1000);
-       else
-               r = snprintf(o, 30, "%" PRIu64 " s", frequency);
+       if (freq > SR_GHZ(1)) {
+               v = (double)v_p / v_q * 1000000000000.0;
+               prec = ((v - (uint64_t)v) < FLT_MIN) ? 0 : 3;
+               r = snprintf(o, 30, "%.*f ps", prec, v);
+       } else if (freq > SR_MHZ(1)) {
+               v = (double)v_p / v_q * 1000000000.0;
+               prec = ((v - (uint64_t)v) < FLT_MIN) ? 0 : 3;
+               r = snprintf(o, 30, "%.*f ns", prec, v);
+       } else if (freq > SR_KHZ(1)) {
+               v = (double)v_p / v_q * 1000000.0;
+               prec = ((v - (uint64_t)v) < FLT_MIN) ? 0 : 3;
+               r = snprintf(o, 30, "%.*f us", prec, v);
+       } else if (freq > 1) {
+               v = (double)v_p / v_q * 1000.0;
+               prec = ((v - (uint64_t)v) < FLT_MIN) ? 0 : 3;
+               r = snprintf(o, 30, "%.*f ms", prec, v);
+       } else {
+               v = (double)v_p / v_q;
+               prec = ((v - (uint64_t)v) < FLT_MIN) ? 0 : 3;
+               r = snprintf(o, 30, "%.*f s", prec, v);
+       }
 
        if (r < 0) {
                /* Something went wrong... */