1 files changed, 242 insertions, 0 deletions
diff --git a/core/dive.c b/core/dive.c
index c977183a3..da4b19346 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -4062,3 +4062,245 @@ fraction_t best_he(depth_t depth, struct dive *dive)
 		fhe.permille = 0;
 	return fhe;
 }
+
+bool gasmix_is_air(const struct gasmix *gasmix)
+{
+	int o2 = gasmix->o2.permille;
+	int he = gasmix->he.permille;
+	return (he == 0) && (o2 == 0 || ((o2 >= O2_IN_AIR - 1) && (o2 <= O2_IN_AIR + 1)));
+}
+
+void invalidate_dive_cache(struct dive *dive)
+{
+	memset(dive->git_id, 0, 20);
+}
+
+bool dive_cache_is_valid(const struct dive *dive)
+{
+	static const unsigned char null_id[20] = { 0, };
+	return !!memcmp(dive->git_id, null_id, 20);
+}
+
+int get_surface_pressure_in_mbar(const struct dive *dive, bool non_null)
+{
+	int mbar = dive->surface_pressure.mbar;
+	if (!mbar && non_null)
+		mbar = SURFACE_PRESSURE;
+	return mbar;
+}
+
+/* Pa = N/m^2 - so we determine the weight (in N) of the mass of 10m
+ * of water (and use standard salt water at 1.03kg per liter if we don't know salinity)
+ * and add that to the surface pressure (or to 1013 if that's unknown) */
+int calculate_depth_to_mbar(int depth, pressure_t surface_pressure, int salinity)
+{
+	double specific_weight;
+	int mbar = surface_pressure.mbar;
+
+	if (!mbar)
+		mbar = SURFACE_PRESSURE;
+	if (!salinity)
+		salinity = SEAWATER_SALINITY;
+	if (salinity < 500)
+		salinity += FRESHWATER_SALINITY;
+	specific_weight = salinity / 10000.0 * 0.981;
+	mbar += lrint(depth / 10.0 * specific_weight);
+	return mbar;
+}
+
+int depth_to_mbar(int depth, struct dive *dive)
+{
+	return calculate_depth_to_mbar(depth, dive->surface_pressure, dive->salinity);
+}
+
+double depth_to_bar(int depth, struct dive *dive)
+{
+	return depth_to_mbar(depth, dive) / 1000.0;
+}
+
+double depth_to_atm(int depth, struct dive *dive)
+{
+	return mbar_to_atm(depth_to_mbar(depth, dive));
+}
+
+/* for the inverse calculation we use just the relative pressure
+ * (that's the one that some dive computers like the Uemis Zurich
+ * provide - for the other models that do this libdivecomputer has to
+ * take care of this, but the Uemis we support natively */
+int rel_mbar_to_depth(int mbar, struct dive *dive)
+{
+	int cm;
+	double specific_weight = 1.03 * 0.981;
+	if (dive->dc.salinity)
+		specific_weight = dive->dc.salinity / 10000.0 * 0.981;
+	/* whole mbar gives us cm precision */
+	cm = (int)lrint(mbar / specific_weight);
+	return cm * 10;
+}
+
+int mbar_to_depth(int mbar, struct dive *dive)
+{
+	pressure_t surface_pressure;
+	if (dive->surface_pressure.mbar)
+		surface_pressure = dive->surface_pressure;
+	else
+		surface_pressure.mbar = SURFACE_PRESSURE;
+	return rel_mbar_to_depth(mbar - surface_pressure.mbar, dive);
+}
+
+/* MOD rounded to multiples of roundto mm */
+depth_t gas_mod(struct gasmix *mix, pressure_t po2_limit, struct dive *dive, int roundto)
+{
+	depth_t rounded_depth;
+
+	double depth = (double) mbar_to_depth(po2_limit.mbar * 1000 / get_o2(mix), dive);
+	rounded_depth.mm = (int)lrint(depth / roundto) * roundto;
+	return rounded_depth;
+}
+
+/* Maximum narcotic depth rounded to multiples of roundto mm */
+depth_t gas_mnd(struct gasmix *mix, depth_t end, struct dive *dive, int roundto)
+{
+	depth_t rounded_depth;
+	pressure_t ppo2n2;
+	ppo2n2.mbar = depth_to_mbar(end.mm, dive);
+
+	int maxambient = (int)lrint(ppo2n2.mbar / (1 - get_he(mix) / 1000.0));
+	rounded_depth.mm = (int)lrint(((double)mbar_to_depth(maxambient, dive)) / roundto) * roundto;
+	return rounded_depth;
+}
+
+struct dive *get_dive(int nr)
+{
+	if (nr >= dive_table.nr || nr < 0)
+		return NULL;
+	return dive_table.dives[nr];
+}
+
+struct dive *get_dive_from_table(int nr, struct dive_table *dt)
+{
+	if (nr >= dt->nr || nr < 0)
+		return NULL;
+	return dt->dives[nr];
+}
+
+struct dive_site *get_dive_site_for_dive(struct dive *dive)
+{
+	if (dive)
+		return get_dive_site_by_uuid(dive->dive_site_uuid);
+	return NULL;
+}
+
+const char *get_dive_country(struct dive *dive)
+{
+	struct dive_site *ds = get_dive_site_by_uuid(dive->dive_site_uuid);
+	if (ds) {
+		int idx = taxonomy_index_for_category(&ds->taxonomy, TC_COUNTRY);
+		if (idx >= 0)
+			return ds->taxonomy.category[idx].value;
+	}
+	return NULL;
+}
+
+char *get_dive_location(struct dive *dive)
+{
+	struct dive_site *ds = get_dive_site_by_uuid(dive->dive_site_uuid);
+	if (ds && ds->name)
+		return ds->name;
+	return NULL;
+}
+
+unsigned int number_of_computers(struct dive *dive)
+{
+	unsigned int total_number = 0;
+	struct divecomputer *dc = &dive->dc;
+
+	if (!dive)
+		return 1;
+
+	do {
+		total_number++;
+		dc = dc->next;
+	} while (dc);
+	return total_number;
+}
+
+struct divecomputer *get_dive_dc(struct dive *dive, int nr)
+{
+	struct divecomputer *dc;
+	if (!dive)
+		return NULL;
+	dc = &dive->dc;
+
+	while (nr-- > 0) {
+		dc = dc->next;
+		if (!dc)
+			return &dive->dc;
+	}
+	return dc;
+}
+
+struct dive *get_dive_by_uniq_id(int id)
+{
+	int i;
+	struct dive *dive = NULL;
+
+	for_each_dive (i, dive) {
+		if (dive->id == id)
+			break;
+	}
+#ifdef DEBUG
+	if (dive == NULL) {
+		fprintf(stderr, "Invalid id %x passed to get_dive_by_diveid, try to fix the code\n", id);
+		exit(1);
+	}
+#endif
+	return dive;
+}
+
+int get_idx_by_uniq_id(int id)
+{
+	int i;
+	struct dive *dive = NULL;
+
+	for_each_dive (i, dive) {
+		if (dive->id == id)
+			break;
+	}
+#ifdef DEBUG
+	if (dive == NULL) {
+		fprintf(stderr, "Invalid id %x passed to get_dive_by_diveid, try to fix the code\n", id);
+		exit(1);
+	}
+#endif
+	return i;
+}
+
+bool dive_site_has_gps_location(struct dive_site *ds)
+{
+	return ds && (ds->latitude.udeg || ds->longitude.udeg);
+}
+
+int dive_has_gps_location(struct dive *dive)
+{
+	if (!dive)
+		return false;
+	return dive_site_has_gps_location(get_dive_site_by_uuid(dive->dive_site_uuid));
+}
+
+struct gasmix *get_gasmix(struct dive *dive, struct divecomputer *dc, int time, struct event **evp, struct gasmix *gasmix)
+{
+	struct event *ev = *evp;
+
+	if (!gasmix) {
+		int cyl = explicit_first_cylinder(dive, dc);
+		gasmix = &dive->cylinder[cyl].gasmix;
+		ev = dc ? get_next_event(dc->events, "gaschange") : NULL;
+	}
+	while (ev && ev->time.seconds < time) {
+		gasmix = get_gasmix_from_event(dive, ev);
+		ev = get_next_event(ev->next, "gaschange");
+	}
+	*evp = ev;
+	return gasmix;
+}