Further cleanup of pressure and volume conversions

I'm amazed at how many spots we were doing conversions - some of them
subtly different than others.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This commit is contained in:
Dirk Hohndel 2011-11-01 21:00:46 -07:00
parent b26ca781b8
commit 5698057951
2 changed files with 38 additions and 22 deletions

16
dive.h
View file

@ -91,9 +91,19 @@ extern double get_depth_units(unsigned int mm, int *frac, const char **units);
extern double get_volume_units(unsigned int mm, int *frac, const char **units);
extern double get_temp_units(unsigned int mm, const char **units);
static inline double bar_to_atm(double bar)
{
return bar / 1.01325;
}
static inline double ml_to_cuft(int ml)
{
return ml / 28317.0;
return ml / 28316.8466;
}
static inline double cuft_to_ml(double cuft)
{
return cuft * 28.3168466;
}
static inline double mm_to_feet(int mm)
@ -137,6 +147,10 @@ static inline int to_K(temperature_t temp)
return (temp.mkelvin + 499)/1000;
}
static inline double psi_to_bar(double psi)
{
return psi / 14.5037738;
}
static inline int to_PSI(pressure_t pressure)
{
return pressure.mbar * 0.0145037738 + 0.5;

View file

@ -49,18 +49,19 @@ struct cylinder_widget {
GtkWidget *o2, *gasmix_button;
};
/* we want bar - so let's not use our unit functions */
static int convert_pressure(int mbar, double *p)
{
int decimals = 1;
double pressure;
pressure = mbar / 1000.0;
if (mbar) {
if (output_units.pressure == PSI) {
pressure *= 14.5037738; /* Bar to PSI */
pressure = mbar_to_PSI(mbar);
decimals = 0;
} else {
pressure = mbar / 1000.0;
}
}
*p = pressure;
return decimals;
}
@ -70,17 +71,18 @@ static int convert_volume_pressure(int ml, int mbar, double *v, double *p)
int decimals = 1;
double volume, pressure;
volume = ml / 1000.0;
pressure = mbar / 1000.0;
if (mbar) {
if (output_units.volume == CUFT) {
volume /= 28.3168466; /* Liters to cuft */
volume *= pressure / 1.01325;
}
volume = ml_to_cuft(ml);
volume *= bar_to_atm(mbar / 1000.0);
} else
volume = ml / 1000.0;
if (output_units.pressure == PSI) {
pressure *= 14.5037738; /* Bar to PSI */
pressure = mbar_to_PSI(mbar);
decimals = 0;
}
} else
pressure = mbar / 1000.0;
}
*v = volume;
*p = pressure;
@ -352,14 +354,14 @@ static void fill_cylinder_info(struct cylinder_widget *cylinder, cylinder_t *cyl
int mbar, ml;
if (output_units.pressure == PSI) {
pressure /= 14.5037738;
start /= 14.5037738;
end /= 14.5037738;
pressure = psi_to_bar(pressure);
start = psi_to_bar(start);
end = psi_to_bar(end);
}
if (pressure && output_units.volume == CUFT) {
volume *= 28.3168466; /* CUFT to liter */
volume /= pressure / 1.01325;
volume = cuft_to_ml(volume);
volume /= bar_to_atm(pressure);
}
ml = volume * 1000 + 0.5;
@ -461,9 +463,9 @@ static void fill_tank_list(GtkListStore *store)
/* Is it in cuft and psi? */
if (psi) {
double bar = 0.0689475729 * psi;
double airvolume = 28316.8466 * size;
double atm = bar / 1.01325;
double bar = psi_to_bar(psi);
double airvolume = cuft_to_ml(size);
double atm = bar_to_atm(bar);
ml = airvolume / atm + 0.5;
mbar = bar*1000 + 0.5;