From: Dirk Hohndel <dirk@hohndel.org>
Date: Wed, 2 Nov 2011 04:12:21 +0000 (-0700)
Subject: Even more places with pressure and volume conversions
X-Git-Url: http://git.tdb.fi/?p=ext%2Fsubsurface.git;a=commitdiff_plain;h=485b02937d8ca1f9a9043c89e74a3d2f15d6426b

Even more places with pressure and volume conversions

Amazing at how many spots we are re-implementing the wheel.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
---

diff --git a/dive.h b/dive.h
index 783d640..b5a42d3 100644
--- a/dive.h
+++ b/dive.h
@@ -91,17 +91,12 @@ 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 / 28316.8466;
 }
 
-static inline double cuft_to_ml(double cuft)
+static inline double cuft_to_l(double cuft)
 {
 	return cuft * 28.3168466;
 }
@@ -156,6 +151,11 @@ static inline int to_PSI(pressure_t pressure)
 	return pressure.mbar * 0.0145037738 + 0.5;
 }
 
+static inline double bar_to_atm(double bar)
+{
+	return bar / 1.01325;
+}
+
 static inline double to_ATM(pressure_t pressure)
 {
 	return pressure.mbar / 1013.25;
diff --git a/divelist.c b/divelist.c
index acaf08d..2d04eb5 100644
--- a/divelist.c
+++ b/divelist.c
@@ -223,7 +223,6 @@ static void sac_data_func(GtkTreeViewColumn *col,
 			  gpointer data)
 {
 	int value;
-	const double liters_per_cuft = 28.317;
 	const char *fmt;
 	char buffer[16];
 	double sac;
@@ -242,7 +241,7 @@ static void sac_data_func(GtkTreeViewColumn *col,
 		break;
 	case CUFT:
 		fmt = "%4.2f";
-		sac /= liters_per_cuft;
+		sac = ml_to_cuft(sac * 1000);
 		break;
 	}
 	snprintf(buffer, sizeof(buffer), fmt, sac);
@@ -307,7 +306,7 @@ static double calculate_airuse(struct dive *dive)
 		if (!size)
 			continue;
 
-		kilo_atm = (cyl->start.mbar - cyl->end.mbar) / 1013250.0;
+		kilo_atm = (to_ATM(cyl->start) - to_ATM(cyl->end)) / 1000.0;
 
 		/* Liters of air at 1 atm == milliliters at 1k atm*/
 		airuse += kilo_atm * size;
diff --git a/equipment.c b/equipment.c
index 64a05d5..c7a683b 100644
--- a/equipment.c
+++ b/equipment.c
@@ -360,7 +360,7 @@ static void fill_cylinder_info(struct cylinder_widget *cylinder, cylinder_t *cyl
 	}
 
 	if (pressure && output_units.volume == CUFT) {
-		volume = cuft_to_ml(volume);
+		volume = cuft_to_l(volume);
 		volume /= bar_to_atm(pressure);
 	}
 
@@ -464,7 +464,7 @@ static void fill_tank_list(GtkListStore *store)
 		/* Is it in cuft and psi? */
 		if (psi) {
 			double bar = psi_to_bar(psi);
-			double airvolume = cuft_to_ml(size);
+			double airvolume = cuft_to_l(size) * 1000.0;
 			double atm = bar_to_atm(bar);
 
 			ml = airvolume / atm + 0.5;
diff --git a/parse-xml.c b/parse-xml.c
index c44b6f6..5eabc35 100644
--- a/parse-xml.c
+++ b/parse-xml.c
@@ -425,7 +425,7 @@ static void water_pressure(char *buffer, void *_depth)
 		if (!val.fp)
 			break;
 		/* cbar to atm */
-		atm = (val.fp / 100) / 1.01325;
+		atm = bar_to_atm(val.fp * 10);
 		/*
 		 * atm to cm. Why not mm? The precision just isn't
 		 * there.
@@ -1122,9 +1122,9 @@ static void match_standard_cylinder(cylinder_type_t *type)
 	if (type->description)
 		return;
 
-	cuft = type->size.mliter / 28317.0;
+	cuft = ml_to_cuft(type->size.mliter);
 	cuft *= to_ATM(type->workingpressure);
-	psi = type->workingpressure.mbar / 68.95;
+	psi = to_PSI(type->workingpressure);
 
 	switch (psi) {
 	case 2300 ... 2500:	/* 2400 psi: LP tank */
@@ -1177,7 +1177,8 @@ static void sanitize_cylinder_type(cylinder_type_t *type)
 		return;
 
 	if (input_units.volume == CUFT || import_source == SUUNTO) {
-		volume_of_air = type->size.mliter * 28.317;	/* milli-cu ft to milliliter */
+		/* confusing - we don't really start from ml but millicuft !*/
+		volume_of_air = cuft_to_l(type->size.mliter);
 		atm = to_ATM(type->workingpressure);		/* working pressure in atm */
 		volume = volume_of_air / atm;			/* milliliters at 1 atm: "true size" */
 		type->size.mliter = volume + 0.5;
diff --git a/uemis.c b/uemis.c
index f55407b..86b1860 100644
--- a/uemis.c
+++ b/uemis.c
@@ -86,7 +86,7 @@ static int pressure_to_depth(uint16_t value)
 {
 	double atm, cm;
 
-	atm = (value / 100.0) / 1.01325;
+	atm = bar_to_atm(value / 100.0);
 	cm = 100 * atm + 0.5;
 	return( (cm > 0) ? 10 * (long)cm : 0);
 }