Use the improved duration and average depth for everything

The code was written to get the SAC rate correct, but we probably do
want to have the duration and mean depth of the dive always be shown for
the non-surface-time.

So move the code from the sac-rate calculation to the generic dive fixup
part.  This makes the dive list and statistics all show the duration as
the under-water duration, which is not necessarily the same as
"difference between beginning and end of dive".

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

2 files changed, 42 insertions, 78 deletions

diff --git a/dive.c b/dive.c
index c07912ebd..798de357c 100644
--- a/dive.c
+++ b/dive.c
@@ -213,12 +213,6 @@ static void update_depth(depth_t *depth, int new)
 	}
 }
 
-static void update_duration(duration_t *duration, int new)
-{
-	if (new)
-		duration->seconds = new;
-}
-
 static void update_temperature(temperature_t *temperature, int new)
 {
 	if (new) {
@@ -229,6 +223,40 @@ static void update_temperature(temperature_t *temperature, int new)
 	}
 }
 
+/*
+ * Calculate how long we were actually under water, and the average
+ * depth while under water.
+ *
+ * This ignores any surface time in the middle of the dive.
+ */
+static void fixup_dc_duration(struct divecomputer *dc)
+{
+	int duration, i;
+	int lasttime, lastdepth, depthtime;
+
+	duration = 0;
+	lasttime = 0;
+	lastdepth = 0;
+	depthtime = 0;
+	for (i = 0; i < dc->samples; i++) {
+		struct sample *sample = dc->sample + i;
+		int time = sample->time.seconds;
+		int depth = sample->depth.mm;
+
+		/* We ignore segments at the surface */
+		if (depth > SURFACE_THRESHOLD || lastdepth > SURFACE_THRESHOLD) {
+			duration += time - lasttime;
+			depthtime += (time - lasttime)*(depth+lastdepth)/2;
+		}
+		lastdepth = depth;
+		lasttime = time;
+	}
+	if (duration) {
+		dc->duration.seconds = duration;
+		dc->meandepth.mm = (depthtime + duration/2) / duration;
+	}
+}
+
 static void fixup_pressure(struct dive *dive, struct sample *sample)
 {
 	unsigned int pressure, index;
@@ -566,12 +594,14 @@ static void fixup_dive_dc(struct dive *dive, struct divecomputer *dc)
 	double depthtime = 0;
 	int lasttime = 0;
 	int lastindex = -1;
-	int start = -1, end = -1;
 	int maxdepth = 0, mintemp = 0;
 	int lastdepth = 0;
 	int lasttemp = 0, lastpressure = 0;
 	int pressure_delta[MAX_CYLINDERS] = {INT_MAX, };
 
+	/* Fixup duration and mean depth */
+	fixup_dc_duration(dc);
+
 	update_min_max_temperatures(dive, dc->watertemp);
 	for (i = 0; i < dc->samples; i++) {
 		struct sample *sample = dc->sample + i;
@@ -603,13 +633,7 @@ static void fixup_dive_dc(struct dive *dive, struct divecomputer *dc)
 		lastindex = index;
 		lastpressure = pressure;
 
-		if (lastdepth > SURFACE_THRESHOLD)
-			end = time;
-
 		if (depth > SURFACE_THRESHOLD) {
-			end = time;
-			if (start < 0)
-				start = lasttime;
 			if (depth > maxdepth)
 				maxdepth = depth;
 		}
@@ -666,29 +690,7 @@ static void fixup_dive_dc(struct dive *dive, struct divecomputer *dc)
 			cyl->sample_end.mbar = 0;
 		}
 	}
-	if (end < 0) {
-		/* Assume an ascent/descent rate of 9 m/min */
-		int depth = dc->maxdepth.mm;
-		int asc_desc_time = depth*60/9000;
-		int duration = dc->duration.seconds;
-
-		/* Some sanity checks against insane dives */
-		if (duration < 2)
-			duration = 2;
-		if (asc_desc_time * 2 >= duration)
-			asc_desc_time = duration/2;
-
-		if (!dc->meandepth.mm)
-			dc->meandepth.mm = depth*(duration-asc_desc_time)/duration;
-		if (depth > maxdepth)
-			maxdepth = depth;
-	} else {
-		update_duration(&dc->duration, end - start);
-		if (start != end)
-			depthtime /= (end - start);
 
-		update_depth(&dc->meandepth, depthtime);
-	}
 	update_temperature(&dc->watertemp, mintemp);
 	update_depth(&dc->maxdepth, maxdepth);
 	if (maxdepth > dive->maxdepth.mm)
diff --git a/divelist.c b/divelist.c
index 501cf0487..952b03bb2 100644
--- a/divelist.c
+++ b/divelist.c
@@ -719,46 +719,6 @@ static double calculate_airuse(struct dive *dive)
 	return airuse;
 }
 
-/*
- * Calculate how long we were actually under water, and the average
- * depth while under water.
- *
- * This ignores any surface time in the middle of the dive.
- */
-static int calculate_duration(struct dive *dive, struct divecomputer *dc, int *meandepth)
-{
-	int duration, i;
-	int lasttime, lastdepth, depthtime;
-
-	duration = 0;
-	lasttime = 0;
-	lastdepth = 0;
-	depthtime = 0;
-	for (i = 0; i < dc->samples; i++) {
-		struct sample *sample = dc->sample + i;
-		int time = sample->time.seconds;
-		int depth = sample->depth.mm;
-
-		/* We ignore segments at the surface */
-		if (depth > SURFACE_THRESHOLD || lastdepth > SURFACE_THRESHOLD) {
-			duration += time - lasttime;
-			depthtime += (time - lasttime)*(depth+lastdepth)/2;
-		}
-		lastdepth = depth;
-		lasttime = time;
-	}
-	if (duration) {
-		if (meandepth)
-			*meandepth = depthtime / duration;
-		return duration;
-	}
-
-	/* No samples? */
-	if (meandepth)
-		*meandepth = dive->meandepth.mm;
-	return dive->duration.seconds;
-}
-
 /* this only uses the first divecomputer to calculate the SAC rate */
 static int calculate_sac(struct dive *dive)
 {
@@ -770,12 +730,14 @@ static int calculate_sac(struct dive *dive)
 	if (!airuse)
 		return 0;
 
-	duration = calculate_duration(dive, dc, &meandepth);
-
-	/* find and eliminate long surface intervals */
+	duration = dc->duration.seconds;
 	if (!duration)
 		return 0;
 
+	meandepth = dc->meandepth.mm;
+	if (!meandepth)
+		return 0;
+
 	/* Mean pressure in ATM (SAC calculations are in atm*l/min) */
 	pressure = (double) depth_to_mbar(meandepth, dive) / SURFACE_PRESSURE;
 	sac = airuse / pressure * 60 / duration;