Fix profile and average depth for freedives

[ext/subsurface.git] / dive.c

diff --git a/dive.c b/dive.c
index f4bf497a7da0edeafb91b5a26b1de067f87d64b7..54784cdbabfb01fbb5c5a8db539cdc481f20c613 100644 (file)
--- a/dive.c
+++ b/dive.c
@@ -472,11 +472,19 @@ struct dive *fixup_dive(struct dive *dive)
                        cyl->sample_end.mbar = 0;
                }
        }
-       if (end < 0)
-       {
+       if (end < 0) {
                /* Assume an ascent/descent rate of 9 m/min */
-               int asc_desc_time = dive->maxdepth.mm*60/9000;
-               dive->meandepth.mm = dive->maxdepth.mm*(dive->duration.seconds-asc_desc_time)/dive->duration.seconds;
+               int depth = dive->maxdepth.mm;
+               int asc_desc_time = depth*60/9000;
+               int duration = dive->duration.seconds;
+
+               /* Some sanity checks against insane dives */
+               if (duration < 2)
+                       duration = 2;
+               if (asc_desc_time * 2 >= duration)
+                       asc_desc_time = duration/2;
+
+               dive->meandepth.mm = depth*(duration-asc_desc_time)/duration;
                return dive;
        }