Trim the dive to exclude surface time at beginning and end

We don't change any of the samples, we just don't plot (or consider for
dive time / mean calculations) the samples at the beginning or end of the
dive that are less than a certain threshold under water. Right now that's
an arbitrary 75cm which seems to Do The Right Thing(tm) for the dives I
tried this with - but I'm happy to look at other values if this causes
problems for people with dive computers I do not have access to.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/dive.c b/dive.c
index 65cfc4d53..384b8dcad 100644
--- a/dive.c
+++ b/dive.c
@@ -449,10 +449,10 @@ struct dive *fixup_dive(struct dive *dive)
 		lastindex = index;
 		lastpressure = pressure;
 
-		if (lastdepth)
+		if (lastdepth > SURFACE_THRESHOLD)
 			end = time;
 
-		if (depth) {
+		if (depth > SURFACE_THRESHOLD) {
 			if (start < 0)
 				start = lasttime;
 			if (depth > maxdepth)
@@ -479,6 +479,8 @@ struct dive *fixup_dive(struct dive *dive)
 		lastdepth = depth;
 		lasttime = time;
 	}
+	dive->start = start;
+	dive->end = end;
 	/* if all the samples for a cylinder have pressure data that
 	 * is basically equidistant throw out the sample cylinder pressure
 	 * information but make sure we still have a valid start and end