Helper function for partial pressure calculation

This patch introduces a new structure holding partial pressures (doubles in bar) for
all three gases and a helper function to compute them from gasmix (which holds fractions)
and ambient pressure. Currentlty this works for OC and CCR, to be extended later to PSCR.

Currently the dive_comp_type argument is unused.

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/dive.h b/dive.h
index 3c32ee8b2..eb8909118 100644
--- a/dive.h
+++ b/dive.h
@@ -115,6 +115,11 @@ static inline int get_he(const struct gasmix *mix)
 	return mix->he.permille;
 }
 
+struct gas_pressures {
+	double o2, n2, he;
+};
+
+extern void fill_pressures(struct gas_pressures *pressures, const double amb_pressure, const struct gasmix *mix, double po2, const enum dive_comp_type type);
 extern void sanitize_gasmix(struct gasmix *mix);
 extern int gasmix_distance(const struct gasmix *a, const struct gasmix *b);
 extern struct gasmix *get_gasmix_from_event(struct event *ev);