Show a bit of surface degassing in the planner

to display the deco parameters at the surface,
in particular tissue saturation and heat map.

Suggeted-by: Matthias Heinrichs <info@heinrichsweikamp.com>
Signed-off-by: Robert C. Helling <helling@atdotde.de>

core/planner.c

@@ -1080,6 +1080,14 @@ bool plan(struct deco_state *ds, struct diveplan *diveplan, struct dive *dive, i
 		diveplan->eff_gflow = lrint(100.0 * (regressiona() * first_stop_depth + regressionb()));
 	}
 
+	for (int i = 0; i < MAX_CYLINDERS; i++)
+		if (cylinder_nodata(&dive->cylinder[i])) {
+			// Switch to an empty air cylinder for breathing air at the surface
+			// If no empty cylinder is found, keep using last deco gas
+			current_cylinder = i;
+			break;
+		}
+	plan_add_segment(diveplan, 600, 0, current_cylinder, 0, false, OC);
 	create_dive_from_plan(diveplan, dive, is_planner);
 	add_plan_to_notes(diveplan, dive, show_disclaimer, error);
 	fixup_dc_duration(&dive->dc);

core/plannernotes.c

@@ -24,9 +24,12 @@ static int diveplan_duration(struct diveplan *diveplan)
 {
 	struct divedatapoint *dp = diveplan->dp;
 	int duration = 0;
+	int lastdepth = 0;
 	while(dp) {
-		if (dp->time > duration)
+		if (dp->time > duration && (dp->depth.mm > SURFACE_THRESHOLD || lastdepth > SURFACE_THRESHOLD)) {
 			duration = dp->time;
+			lastdepth = dp->depth.mm;
+		}
 		dp = dp->next;
 	}
 	return (duration + 30) / 60;
@@ -193,6 +196,9 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 		    !rebreatherchange_before &&
 		    !rebreatherchange_after)
 			continue;
+		// Ignore final surface segment for notes
+		if (lastdepth == 0 && dp->depth.mm == 0 && !dp->next)
+			continue;
 		if ((dp->time - lasttime < 10 && lastdepth == dp->depth.mm) && !(gaschange_after && dp->next && dp->depth.mm != dp->next->depth.mm))
 			continue;
 

core/profile.c

@@ -453,7 +453,7 @@ struct plot_info calculate_max_limits_new(struct dive *dive, struct divecomputer
 
 			if (depth > maxdepth)
 				maxdepth = s->depth.mm;
-			if ((depth > SURFACE_THRESHOLD || lastdepth > SURFACE_THRESHOLD) &&
+			if ((depth > SURFACE_THRESHOLD || lastdepth > SURFACE_THRESHOLD || in_planner()) &&
 			    s->time.seconds > maxtime)
 				maxtime = s->time.seconds;
 			lastdepth = depth;

profile-widget/diveeventitem.cpp

@@ -10,6 +10,8 @@
 #include "core/membuffer.h"
 #include "core/subsurface-string.h"
 
+#define DEPTH_NOT_FOUND (-2342)
+
 extern struct ev_select *ev_namelist;
 extern int evn_used;
 
@@ -234,7 +236,8 @@ bool DiveEventItem::shouldBeHidden()
 	struct sample *first_sample = &dc->sample[0];
 	if (!strcmp(event->name, "gaschange") &&
 	    (event->time.seconds == 0 ||
-	     (first_sample && event->time.seconds == first_sample->time.seconds)))
+	     (first_sample && event->time.seconds == first_sample->time.seconds) ||
+	     depthAtTime(event->time.seconds) < SURFACE_THRESHOLD))
 		return true;
 
 	/*
@@ -254,6 +257,17 @@ bool DiveEventItem::shouldBeHidden()
 	return false;
 }
 
+int DiveEventItem::depthAtTime(int time)
+{
+	QModelIndexList result = dataModel->match(dataModel->index(0, DivePlotDataModel::TIME), Qt::DisplayRole, time);
+	if (result.isEmpty()) {
+		Q_ASSERT("can't find a spot in the dataModel");
+		hide();
+		return DEPTH_NOT_FOUND;
+	}
+	return dataModel->data(dataModel->index(result.first().row(), DivePlotDataModel::DEPTH)).toInt();
+}
+
 void DiveEventItem::recalculatePos(bool instant)
 {
 	if (!vAxis || !hAxis || !internalEvent || !dataModel)
@@ -265,9 +279,11 @@ void DiveEventItem::recalculatePos(bool instant)
 		hide();
 		return;
 	}
+	int depth = depthAtTime(internalEvent->time.seconds);
+	if (depth == DEPTH_NOT_FOUND)
+		return;
 	if (!isVisible() && !shouldBeHidden())
 		show();
-	int depth = dataModel->data(dataModel->index(result.first().row(), DivePlotDataModel::DEPTH)).toInt();
 	qreal x = hAxis->posAtValue(internalEvent->time.seconds);
 	qreal y = vAxis->posAtValue(depth);
 	if (!instant)

profile-widget/diveeventitem.h

@@ -27,6 +27,7 @@ slots:
 private:
 	void setupToolTipString(struct gasmix lastgasmix);
 	void setupPixmap(struct gasmix lastgasmix);
+	int depthAtTime(int time);
 	DiveCartesianAxis *vAxis;
 	DiveCartesianAxis *hAxis;
 	DivePlotDataModel *dataModel;