Add support for MOD, EAD, AND and EADD in the mouse over display

- MOD: Maximum Operation Depth based on a configurable limit
- EAD: Equivalent Air Depth considering N2 and (!) O2 narcotic
- END: Equivalent Nitrogen (Narcotic) Depth considering just N2 narcotic
       (ignoring O2)
- EADD: Equivalent Air Density Depth

Please note that some people and even diving organisations have opposite
definitions for EAD and END. Considering A stands for Air, lets choose the
above. And considering N for Nitrogen it also fits in this scheme.

This patch moves N2_IN_AIR from deco.c to dive.h as this is already used
in several places and might be useful for future use also. It also
respecifies N2_IN_AIR to a more correct value of 78,084%, the former one
also included all other gases than oxygen appearing in air. If someone
needs to use the former value it would be more correct to use 1-O2_IN_AIR
instead.

Signed-off-by: Jan Schubert / Jan.Schubert@GMX.li
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

7 files changed, 90 insertions, 5 deletions

diff --git a/deco.c b/deco.c
index 0005ba18c..1a2d13ac7 100644
--- a/deco.c
+++ b/deco.c
@@ -78,7 +78,6 @@ const double buehlmann_He_factor_expositon_one_second[] = {
 	1.00198406028040E-004, 7.83611475491108E-005, 6.13689891868496E-005, 4.81280465299827E-005};
 
 #define WV_PRESSURE 0.0627 /* water vapor pressure */
-#define N2_IN_AIR 0.7902
 #define DECO_STOPS_MULTIPLIER_MM 3000.0
 
 #define GF_LOW_AT_MAXDEPTH 0
diff --git a/dive.h b/dive.h
index 19a1768cb..c53e19404 100644
--- a/dive.h
+++ b/dive.h
@@ -11,6 +11,13 @@
 #include <libxml/tree.h>
 #include <openssl/sha.h>
 
+#define O2_IN_AIR 0.20942
+#define N2_IN_AIR 0.78084 // has been set to 0.7902 before to ignore other components of air
+#define O2_DENSITY 1.429  // Gramm/Liter
+#define N2_DENSITY 1.251
+#define HE_DENSITY 0.1786
+
+
 /*
  * Some silly typedefs to make our units very explicit.
  *
diff --git a/gtk-gui.c b/gtk-gui.c
index f72aac42e..ae9c3740d 100644
--- a/gtk-gui.c
+++ b/gtk-gui.c
@@ -439,6 +439,8 @@ OPTIONCALLBACK(cylinder_toggle, prefs.visible_cols.cylinder)
 OPTIONCALLBACK(po2_toggle, prefs.pp_graphs.po2)
 OPTIONCALLBACK(pn2_toggle, prefs.pp_graphs.pn2)
 OPTIONCALLBACK(phe_toggle, prefs.pp_graphs.phe)
+OPTIONCALLBACK(mod_toggle, prefs.mod)
+OPTIONCALLBACK(ead_toggle, prefs.ead)
 OPTIONCALLBACK(red_ceiling_toggle, prefs.profile_red_ceiling)
 OPTIONCALLBACK(calc_ceiling_toggle, prefs.profile_calc_ceiling)
 OPTIONCALLBACK(calc_ceiling_3m_toggle, prefs.calc_ceiling_3m_incr)
@@ -529,9 +531,9 @@ static void preferences_dialog(GtkWidget *w, gpointer data)
 {
 	int result;
 	GtkWidget *dialog, *notebook, *font, *frame, *box, *vbox, *button, *xmlfile_button;
-	GtkWidget *entry_po2, *entry_pn2, *entry_phe, *entry_gflow, *entry_gfhigh;
+	GtkWidget *entry_po2, *entry_pn2, *entry_phe, *entry_mod, *entry_ead, *entry_gflow, *entry_gfhigh;
 	const char *current_default, *new_default;
-	char threshold_text[10], utf8_buf[128];
+	char threshold_text[10], mod_text[10], utf8_buf[128];
 	struct preferences oldprefs = prefs;
 
 	dialog = gtk_dialog_new_with_buttons(_("Preferences"),
@@ -722,6 +724,31 @@ static void preferences_dialog(GtkWidget *w, gpointer data)
 	box = gtk_hbox_new(FALSE, 6);
 	gtk_container_add(GTK_CONTAINER(vbox), box);
 
+	button = gtk_check_button_new_with_label(_("Show MOD"));
+	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(button), prefs.mod);
+	gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 6);
+	g_signal_connect(G_OBJECT(button), "toggled", G_CALLBACK(mod_toggle), &entry_mod);
+
+	frame = gtk_frame_new(_("max ppO2"));
+	gtk_box_pack_start(GTK_BOX(box), frame, FALSE, FALSE, 6);
+	entry_mod = gtk_entry_new();
+	gtk_entry_set_max_length(GTK_ENTRY(entry_mod), 4);
+	snprintf(mod_text, sizeof(mod_text), "%.1f", prefs.mod_ppO2);
+	gtk_entry_set_text(GTK_ENTRY(entry_mod), mod_text);
+	gtk_widget_set_sensitive(entry_mod, prefs.mod);
+	gtk_container_add(GTK_CONTAINER(frame), entry_mod);
+
+	box = gtk_hbox_new(FALSE, 6);
+	gtk_container_add(GTK_CONTAINER(vbox), box);
+
+	button = gtk_check_button_new_with_label(_("Show EAD, END, EADD"));
+	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(button), prefs.ead);
+	gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 6);
+	g_signal_connect(G_OBJECT(button), "toggled", G_CALLBACK(ead_toggle), NULL);
+
+	box = gtk_hbox_new(FALSE, 6);
+	gtk_container_add(GTK_CONTAINER(vbox), box);
+
 	button = gtk_check_button_new_with_label(_("Show dc reported ceiling in red"));
 	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(button), prefs.profile_red_ceiling);
 	gtk_box_pack_start(GTK_BOX(box), button, FALSE, FALSE, 6);
@@ -766,7 +793,7 @@ static void preferences_dialog(GtkWidget *w, gpointer data)
 	gtk_widget_show_all(dialog);
 	result = gtk_dialog_run(GTK_DIALOG(dialog));
 	if (result == GTK_RESPONSE_ACCEPT) {
-		const char *po2_threshold_text, *pn2_threshold_text, *phe_threshold_text, *gflow_text, *gfhigh_text;
+		const char *po2_threshold_text, *pn2_threshold_text, *phe_threshold_text, *mod_text, *gflow_text, *gfhigh_text;
 		/* Make sure to flush any modified old dive data with old units */
 		update_dive(NULL);
 
@@ -778,6 +805,8 @@ static void preferences_dialog(GtkWidget *w, gpointer data)
 		sscanf(pn2_threshold_text, "%lf", &prefs.pp_graphs.pn2_threshold);
 		phe_threshold_text = gtk_entry_get_text(GTK_ENTRY(entry_phe));
 		sscanf(phe_threshold_text, "%lf", &prefs.pp_graphs.phe_threshold);
+		mod_text = gtk_entry_get_text(GTK_ENTRY(entry_mod));
+		sscanf(mod_text, "%lf", &prefs.mod_ppO2);
 		gflow_text = gtk_entry_get_text(GTK_ENTRY(entry_gflow));
 		sscanf(gflow_text, "%lf", &prefs.gflow);
 		gfhigh_text = gtk_entry_get_text(GTK_ENTRY(entry_gfhigh));
diff --git a/main.c b/main.c
index a0cd313d0..b96c39fd3 100644
--- a/main.c
+++ b/main.c
@@ -27,6 +27,9 @@ struct preferences default_prefs = {
 		.pn2_threshold =  4.0,
 		.phe_threshold = 13.0,
 	},
+	.mod  = FALSE,
+	.mod_ppO2  = 1.6,
+	.ead  = FALSE,
 	.profile_red_ceiling  = FALSE,
 	.profile_calc_ceiling = FALSE,
 	.calc_ceiling_3m_incr = FALSE,
diff --git a/pref.h b/pref.h
index 342c9f6a9..7dd0e5af4 100644
--- a/pref.h
+++ b/pref.h
@@ -25,6 +25,9 @@ struct preferences {
 	struct units units;
 	visible_cols_t visible_cols;
 	partial_pressure_graphs_t pp_graphs;
+	gboolean mod;
+	double mod_ppO2;
+	gboolean ead;
 	gboolean profile_red_ceiling;
 	gboolean profile_calc_ceiling;
 	gboolean calc_ceiling_3m_incr;
diff --git a/prefs.c b/prefs.c
index b6ae4ee6a..04db63044 100644
--- a/prefs.c
+++ b/prefs.c
@@ -85,6 +85,9 @@ void save_preferences(void)
 	SAVE_DOUBLE("pn2threshold", pp_graphs.pn2_threshold);
 	SAVE_DOUBLE("phethreshold", pp_graphs.phe_threshold);
 
+	SAVE_BOOL("mod", mod);
+	SAVE_DOUBLE("modppO2", mod_ppO2);
+	SAVE_BOOL("ead", ead);
 	SAVE_BOOL("redceiling", profile_red_ceiling);
 	SAVE_BOOL("calcceiling", profile_calc_ceiling);
 	SAVE_BOOL("calcceiling3m", calc_ceiling_3m_incr);
@@ -149,6 +152,13 @@ void load_preferences(void)
 		sscanf(conf_value, "%lf", &prefs.pp_graphs.phe_threshold);
 		free((void *)conf_value);
 	}
+	GET_BOOL("mod", mod);
+	conf_value = subsurface_get_conf("modppO2");
+	if (conf_value) {
+		sscanf(conf_value, "%lf", &prefs.mod_ppO2);
+		free((void *)conf_value);
+	}
+	GET_BOOL("ead", ead);
 	GET_BOOL("redceiling", profile_red_ceiling);
 	GET_BOOL("calcceiling", profile_calc_ceiling);
 	GET_BOOL("calcceiling3m", calc_ceiling_3m_incr);
diff --git a/profile.c b/profile.c
index be6d37261..7839f84ff 100644
--- a/profile.c
+++ b/profile.c
@@ -46,6 +46,7 @@ struct plot_data {
 	int cns;
 	int smoothed;
 	double po2, pn2, phe;
+	double mod, ead, end, eadd;
 	velocity_t velocity;
 	struct plot_data *min[3];
 	struct plot_data *max[3];
@@ -1835,11 +1836,32 @@ static void calculate_deco_information(struct dive *dive, struct divecomputer *d
 			entry->phe = (amb_pressure - po2) * ratio;
 			entry->pn2 = amb_pressure - po2 - entry->phe;
 			entry->po2 = po2;
+                        entry->ead  = (entry->depth + 10000) *
+				(entry->po2+(amb_pressure-entry->po2)*(1-ratio))/amb_pressure - 10000;
+                        entry->end  = (entry->depth + 10000) *
+				(amb_pressure-entry->po2)*(1-ratio)/amb_pressure/N2_IN_AIR - 10000;
+                        entry->eadd = (entry->depth + 10000) *
+				(entry->po2/amb_pressure * O2_DENSITY + entry->pn2/amb_pressure * N2_DENSITY +
+					entry->phe/amb_pressure * HE_DENSITY) /
+				(O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) -10000;
 		} else {
 			entry->po2 = fo2 / 1000.0 * amb_pressure;
 			entry->phe = fhe / 1000.0 * amb_pressure;
 			entry->pn2 = (1000 - fo2 - fhe) / 1000.0 * amb_pressure;
+
+                        entry->ead = (entry->depth + 10000) * (1000 - fhe) / 1000.0 - 10000;
+                        entry->end = (entry->depth + 10000) * (1000 - fo2 - fhe) / 1000.0 / N2_IN_AIR - 10000;
+                        entry->eadd = (entry->depth + 10000) * (fo2 * O2_DENSITY + (1-fo2-fhe) * N2_DENSITY + fhe * HE_DENSITY) / (O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) -10000;
 		}
+		entry->mod = (prefs.mod_ppO2/fo2*1000 - 1) * 10000;
+		if(entry->mod <0)
+			entry->mod=0;
+		if(entry->ead <0)
+			entry->ead=0;
+		if(entry->end <0)
+			entry->end=0;
+		if(entry->eadd <0)
+			entry->eadd=0;
 		if (entry->po2 > pi->maxpp && prefs.pp_graphs.po2)
 			pi->maxpp = entry->po2;
 		if (entry->phe > pi->maxpp && prefs.pp_graphs.phe)
@@ -2070,7 +2092,7 @@ void plot(struct graphics_context *gc, struct dive *dive, scale_mode_t scale)
 static void plot_string(struct plot_data *entry, char *buf, size_t bufsize,
 			int depth, int pressure, int temp, gboolean has_ndl)
 {
-	int pressurevalue;
+	int pressurevalue, mod, ead, end, eadd;
 	const char *depth_unit, *pressure_unit, *temp_unit;
 	char *buf2 = malloc(bufsize);
 	double depthvalue, tempvalue;
@@ -2136,6 +2158,18 @@ static void plot_string(struct plot_data *entry, char *buf, size_t bufsize,
 		memcpy(buf2, buf, bufsize);
 		snprintf(buf, bufsize, "%s\npHe:%.2f", buf2, entry->phe);
 	}
+	if (prefs.mod) {
+		mod = (int)get_depth_units(entry->mod, NULL, &depth_unit);
+		memcpy(buf2, buf, bufsize);
+		snprintf(buf, bufsize, "%s\nMOD:%d%s", buf2, mod, depth_unit);
+	}
+	if (prefs.ead) {
+		ead = (int)get_depth_units(entry->ead, NULL, &depth_unit);
+		end = (int)get_depth_units(entry->end, NULL, &depth_unit);
+		eadd = (int)get_depth_units(entry->eadd, NULL, &depth_unit);
+		memcpy(buf2, buf, bufsize);
+		snprintf(buf, bufsize, "%s\nEAD:%d%s\nEND:%d%s\nEADD:%d%s", buf2, ead, depth_unit, end, depth_unit, eadd, depth_unit);
+	}
 	free(buf2);
 }