diff options
Diffstat (limited to 'profile.c')
| -rw-r--r-- | profile.c | 19 |
1 files changed, 17 insertions, 2 deletions
@@ -1685,6 +1685,20 @@ static void setup_gas_sensor_pressure(struct dive *dive, struct divecomputer *dc } while ((secondary = secondary->next) != NULL); } +/* + * What's the pressure-time between two plot data entries? + * We're calculating the integral of pressure over time by + * adding these up. + */ +static inline double pressure_time(struct dive *dive, struct plot_data *a, struct plot_data *b) +{ + int time = b->sec - a->sec; + int depth = (a->depth + b->depth)/2; + int mbar = depth_to_mbar(depth, dive); + + return bar_to_atm(mbar / 1000.0) * time; +} + static void populate_pressure_information(struct dive *dive, struct divecomputer *dc, struct plot_info *pi) { int i, cylinderindex; @@ -1709,6 +1723,9 @@ static void populate_pressure_information(struct dive *dive, struct divecomputer entry->same_cylinder = entry->cylinderindex == cylinderindex; cylinderindex = entry->cylinderindex; + /* discrete integration of pressure over time to get the SAC rate equivalent */ + current->pressure_time += pressure_time(dive, entry-1, entry); + /* track the segments per cylinder and their pressure/time integral */ if (!entry->same_cylinder) { current = pr_track_alloc(SENSOR_PRESSURE(entry), entry->sec); @@ -1724,8 +1741,6 @@ static void populate_pressure_information(struct dive *dive, struct divecomputer } } /* finally, do the discrete integration to get the SAC rate equivalent */ - current->pressure_time += (entry->sec - (entry-1)->sec) * - depth_to_mbar((entry->depth + (entry-1)->depth) / 2, dive) / 1000.0; if (SENSOR_PRESSURE(entry)) { current->end = SENSOR_PRESSURE(entry); current->t_end = entry->sec; |