diff options
Diffstat (limited to 'dive.h')
| -rw-r--r-- | dive.h | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -298,6 +298,21 @@ static inline int depth_to_mbar(int depth, struct dive *dive) return depth / 10.0 * specific_weight + surface_pressure + 0.5; } +/* 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 */ +static inline int rel_mbar_to_depth(int mbar, struct dive *dive) +{ + int cm; + double specific_weight = 1.03 * 0.981; + if (dive->salinity) + specific_weight = dive->salinity / 10000.0 * 0.981; + /* whole mbar gives us cm precision */ + cm = mbar / specific_weight + 0.5; + return cm * 10; +} + #define SURFACE_THRESHOLD 750 /* somewhat arbitrary: only below 75cm is it really diving */ /* this is a global spot for a temporary dive structure that we use to |