Added a configuration option to have gf_low apply at max depth instead of at deepest ceiling.

Signed-off-by: Patrick Valsecchi <patrick@thus.ch>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

9 files changed, 34 insertions, 21 deletions

diff --git a/deco.c b/deco.c
index baa727c89..32705dd92 100644
--- a/deco.c
+++ b/deco.c
@@ -27,8 +27,9 @@ struct buehlmann_config {
   double  gf_high;		//! gradient factor high (at surface).
   double  gf_low;		//! gradient factor low (at bottom/start of deco calculation).
   double  gf_low_position_min;	//! gf_low_position below surface_min_shallow.
+  bool    gf_low_at_maxdepth;	//! if TRUE, gf_low applies at max depth instead of at deepest ceiling.
 };
-struct buehlmann_config buehlmann_config = { 1.0, 1.01, 0, 0.75, 0.35, 2.0 };
+struct buehlmann_config buehlmann_config = { 1.0, 1.01, 0, 0.75, 0.35, 2.0, FALSE };
 
 const double buehlmann_N2_a[] = {1.1696, 1.0, 0.8618, 0.7562,
 				 0.62, 0.5043, 0.441, 0.4,
@@ -75,8 +76,6 @@ const double buehlmann_He_factor_expositon_one_second[] = {
 #define WV_PRESSURE 0.0627 // water vapor pressure in bar
 #define DECO_STOPS_MULTIPLIER_MM 3000.0
 
-#define GF_LOW_AT_MAXDEPTH 0
-
 double tissue_n2_sat[16];
 double tissue_he_sat[16];
 int ci_pointing_to_guiding_tissue;
@@ -94,7 +93,6 @@ static double tissue_tolerance_calc(const struct dive *dive)
 	double gf_high = buehlmann_config.gf_high;
 	double gf_low = buehlmann_config.gf_low;
 	double surface = get_surface_pressure_in_mbar(dive, TRUE) / 1000.0;
-	double lowest_ceiling;
 
 	for (ci = 0; ci < 16; ci++)
 	{
@@ -106,12 +104,12 @@ static double tissue_tolerance_calc(const struct dive *dive)
 
 		/* tolerated = (tissue_inertgas_saturation - buehlmann_inertgas_a) * buehlmann_inertgas_b; */
 
-#if !GF_LOW_AT_MAXDEPTH
-		lowest_ceiling = (buehlmann_inertgas_b * tissue_inertgas_saturation - gf_low * buehlmann_inertgas_a * buehlmann_inertgas_b) /
-			((1.0 - buehlmann_inertgas_b) * gf_low + buehlmann_inertgas_b);
-		if (lowest_ceiling > gf_low_pressure_this_dive)
-			gf_low_pressure_this_dive = lowest_ceiling;
-#endif
+		if (!buehlmann_config.gf_low_at_maxdepth) {
+			double lowest_ceiling = (buehlmann_inertgas_b * tissue_inertgas_saturation - gf_low * buehlmann_inertgas_a * buehlmann_inertgas_b) /
+				((1.0 - buehlmann_inertgas_b) * gf_low + buehlmann_inertgas_b);
+			if (lowest_ceiling > gf_low_pressure_this_dive)
+				gf_low_pressure_this_dive = lowest_ceiling;
+		}
 
 		tolerated = (-buehlmann_inertgas_a * buehlmann_inertgas_b * (gf_high * gf_low_pressure_this_dive - gf_low * surface) -
 				(1.0 - buehlmann_inertgas_b) * (gf_high - gf_low) * gf_low_pressure_this_dive * surface +
@@ -139,10 +137,8 @@ double add_segment(double pressure, const struct gasmix *gasmix, int period_in_s
 	double ppn2 = (pressure - WV_PRESSURE) * (1000 - fo2 - fhe) / 1000.0;
 	double pphe = (pressure - WV_PRESSURE) * fhe / 1000.0;
 
-#if GF_LOW_AT_MAXDEPTH
-	if (pressure > gf_low_pressure_this_dive)
+	if (buehlmann_config.gf_low_at_maxdepth && pressure > gf_low_pressure_this_dive)
 		gf_low_pressure_this_dive = pressure;
-#endif
 
 	if (ccpo2) { /* CC */
 		double rel_o2_amb, f_dilutent;
@@ -268,10 +264,11 @@ unsigned int deco_allowed_depth(double tissues_tolerance, double surface_pressur
 	return depth;
 }
 
-void set_gf(short gflow, short gfhigh)
+void set_gf(short gflow, short gfhigh, bool gf_low_at_maxdepth)
 {
 	if (gflow != -1)
 		buehlmann_config.gf_low = (double)gflow / 100.0;
 	if (gfhigh != -1)
 		buehlmann_config.gf_high = (double)gfhigh / 100.0;
+	buehlmann_config.gf_low_at_maxdepth = gf_low_at_maxdepth;
 }
diff --git a/dive.h b/dive.h
index c881d2450..800596dd3 100644
--- a/dive.h
+++ b/dive.h
@@ -715,7 +715,7 @@ extern double add_segment(double pressure, const struct gasmix *gasmix, int peri
 extern void clear_deco(double surface_pressure);
 extern void dump_tissues(void);
 extern unsigned int deco_allowed_depth(double tissues_tolerance, double surface_pressure, struct dive *dive, bool smooth);
-extern void set_gf(short gflow, short gfhigh);
+extern void set_gf(short gflow, short gfhigh, bool gf_low_at_maxdepth);
 extern void cache_deco_state(double, char **datap);
 extern double restore_deco_state(char *data);
 
diff --git a/planner.c b/planner.c
index cdc13a599..e1f8ba244 100644
--- a/planner.c
+++ b/planner.c
@@ -574,7 +574,7 @@ void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep, b
 	int gaschangenr;
 	unsigned int *stoplevels = NULL;
 
-	set_gf(diveplan->gflow, diveplan->gfhigh);
+	set_gf(diveplan->gflow, diveplan->gfhigh, default_prefs.gf_low_at_maxdepth);
 	if (!diveplan->surface_pressure)
 		diveplan->surface_pressure = SURFACE_PRESSURE;
 	if (*divep)
diff --git a/pref.h b/pref.h
index 9e0d32034..28e795cd0 100644
--- a/pref.h
+++ b/pref.h
@@ -31,9 +31,8 @@ struct preferences {
 	short calc_ndl_tts;
 	short gflow;
 	short gfhigh;
-	int map_provider;
+	bool gf_low_at_maxdepth;
 	short display_invalid_dives;
-	short show_invalid;
 	short unit_system;
 	struct units units;
 	short show_sac;
diff --git a/qt-ui/mainwindow.cpp b/qt-ui/mainwindow.cpp
index 23c972741..1f3d7def9 100644
--- a/qt-ui/mainwindow.cpp
+++ b/qt-ui/mainwindow.cpp
@@ -564,6 +564,13 @@ bool MainWindow::askSaveChanges()
 	else							\
 		prefs.field = default_prefs.field
 
+#define GET_TXT(name, field)					\
+	v = s.value(QString(name));				\
+	if (v.isValid())					\
+		prefs.field = strdup(v.toString().toUtf8().constData());			\
+	else							\
+		prefs.field = default_prefs.field
+
 
 void MainWindow::initialUiSetup()
 {
@@ -623,7 +630,8 @@ void MainWindow::readSettings()
 	GET_BOOL("calcalltissues", calc_all_tissues);
 	GET_INT("gflow", gflow);
 	GET_INT("gfhigh", gfhigh);
-	set_gf(prefs.gflow, prefs.gfhigh);
+	GET_BOOL("gf_low_at_maxdepth", gf_low_at_maxdepth);
+	set_gf(prefs.gflow, prefs.gfhigh, prefs.gf_low_at_maxdepth);
 	GET_BOOL("show_sac", show_sac);
 	s.endGroup();
 
diff --git a/qt-ui/preferences.cpp b/qt-ui/preferences.cpp
index f638d9d7d..0249c894f 100644
--- a/qt-ui/preferences.cpp
+++ b/qt-ui/preferences.cpp
@@ -55,6 +55,7 @@ void PreferencesDialog::setUiFromPrefs()
 
 	ui.gflow->setValue(prefs.gflow);
 	ui.gfhigh->setValue(prefs.gfhigh);
+	ui.gf_low_at_maxdepth->setChecked(prefs.gf_low_at_maxdepth);
 
 	// units
 	if (prefs.unit_system == METRIC)
@@ -111,7 +112,7 @@ void PreferencesDialog::syncSettings()
 	s.setValue("pn2threshold", ui.pn2Threshold->value());
 	SB("ead", ui.ead_end_eadd);
 	SB("mod", ui.mod);
-	s.setValue("modppo2", ui.maxppo2->value());
+	s.setValue("modppO2", ui.maxppo2->value());
 	SB("dcceiling", ui.dc_reported_ceiling);
 	SB("redceiling", ui.red_ceiling);
 	SB("calcceiling", ui.calculated_ceiling);
@@ -120,6 +121,7 @@ void PreferencesDialog::syncSettings()
 	SB("calcalltissues", ui.all_tissues);
 	s.setValue("gflow", ui.gflow->value());
 	s.setValue("gfhigh", ui.gfhigh->value());
+	SB("gf_low_at_maxdepth", ui.gf_low_at_maxdepth);
 	SB("show_sac", ui.show_sac);
 	s.endGroup();
 
diff --git a/qt-ui/preferences.h b/qt-ui/preferences.h
index 1cd3d9096..fb0fcbc94 100644
--- a/qt-ui/preferences.h
+++ b/qt-ui/preferences.h
@@ -26,7 +26,6 @@ public slots:
 private:
 	explicit PreferencesDialog(QWidget* parent = 0, Qt::WindowFlags f = 0);
 	void setUiFromPrefs();
-	void setUIFromSettings();
 	Ui::PreferencesDialog ui;
 	struct preferences oldPrefs;
 };
diff --git a/qt-ui/preferences.ui b/qt-ui/preferences.ui
index 7e071face..581670c91 100644
--- a/qt-ui/preferences.ui
+++ b/qt-ui/preferences.ui
@@ -763,6 +763,13 @@
             <item row="1" column="1">
              <widget class="QSpinBox" name="gfhigh"/>
             </item>
+            <item row="2" column="0" colspan="2">
+             <widget class="QCheckBox" name="gf_low_at_maxdepth">
+              <property name="text">
+               <string>GFLow at max depth</string>
+              </property>
+             </widget>
+            </item>
            </layout>
           </widget>
          </item>
diff --git a/subsurfacestartup.c b/subsurfacestartup.c
index 8d5e609a9..39da8e47c 100644
--- a/subsurfacestartup.c
+++ b/subsurfacestartup.c
@@ -25,6 +25,7 @@ struct preferences default_prefs = {
 	.calc_ndl_tts = FALSE,
 	.gflow = 30,
 	.gfhigh = 75,
+	.gf_low_at_maxdepth = FALSE,
 	.font_size = 14.0,
 	.display_invalid_dives = FALSE,
 	.show_sac = FALSE,