Centralising and redefining values as integers

This patch centralizes the definition for surface pressure, oxygen in
air, (re)defines all such values as plain integers and adapts calculations.

It eliminates 11 (!) occurrences of definitions for surface pressure and
also a few for oxygen in air.

It also rewrites the calculation for EAD, END and EADD using the new
definitons, harmonizing it for OC and CC and fixes a bug for EADD OC
calculation.

And finally it removes the unneeded variable entry_ead in gtk-gui.c.

Jan

Signed-off-by: Jan Schubert <Jan.Schubert@GMX.li>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 20 insertions, 18 deletions

diff --git a/profile.c b/profile.c
index 8fc99f2e4..d30f1d0f0 100644
--- a/profile.c
+++ b/profile.c
@@ -556,7 +556,7 @@ static void setup_pp_limits(struct graphics_context *gc, struct plot_info *pi)
 	 * we use 1.5 times the corresponding pressure as maximum partial
 	 * pressure the graph seems to look fine*/
 	maxdepth = get_maxdepth(pi);
-	gc->topy = 1.5 * (maxdepth + 10000) / 10000.0 * 1.01325;
+	gc->topy = 1.5 * (maxdepth + 10000) / 10000.0 * SURFACE_PRESSURE / 1000;
 	gc->bottomy = -gc->topy / 20;
 }
 
@@ -1815,7 +1815,7 @@ static void calculate_deco_information(struct dive *dive, struct divecomputer *d
 {
 	int i;
 	double amb_pressure;
-	double surface_pressure = (dive->surface_pressure.mbar ? dive->surface_pressure.mbar : 1013) / 1000.0;
+	double surface_pressure = (dive->surface_pressure.mbar ? dive->surface_pressure.mbar : SURFACE_PRESSURE) / 1000.0;
 
 	for (i = 1; i < pi->nr; i++) {
 		int fo2, fhe, j, t0, t1;
@@ -1824,36 +1824,37 @@ static void calculate_deco_information(struct dive *dive, struct divecomputer *d
 		int cylinderindex = entry->cylinderindex;
 
 		amb_pressure = depth_to_mbar(entry->depth, dive) / 1000.0;
-		fo2 = dive->cylinder[cylinderindex].gasmix.o2.permille ? : AIR_PERMILLE;
+		fo2 = dive->cylinder[cylinderindex].gasmix.o2.permille ? : O2_IN_AIR;
 		fhe = dive->cylinder[cylinderindex].gasmix.he.permille;
+		double ratio = (double)fhe / (1000.0 - fo2);
 
 		if (entry->po2) {
 			/* we have an O2 partial pressure in the sample - so this
 			 * is likely a CC dive... use that instead of the value
 			 * from the cylinder info */
 			double po2 = entry->po2 > amb_pressure ? amb_pressure : entry->po2;
-			double ratio = (double)fhe / (1000.0 - fo2);
+			entry->po2 = po2;
 			entry->phe = (amb_pressure - po2) * ratio;
 			entry->pn2 = amb_pressure - po2 - entry->phe;
-			entry->po2 = po2;
-                        entry->ead  = (entry->depth + 10000) *
-				(entry->po2+(amb_pressure-entry->po2)*(1-ratio))/amb_pressure - 10000;
-                        entry->end  = (entry->depth + 10000) *
-				(amb_pressure-entry->po2)*(1-ratio)/amb_pressure/N2_IN_AIR - 10000;
-                        entry->eadd = (entry->depth + 10000) *
-				(entry->po2/amb_pressure * O2_DENSITY + entry->pn2/amb_pressure * N2_DENSITY +
-					entry->phe/amb_pressure * HE_DENSITY) /
-				(O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) -10000;
 		} else {
 			entry->po2 = fo2 / 1000.0 * amb_pressure;
 			entry->phe = fhe / 1000.0 * amb_pressure;
 			entry->pn2 = (1000 - fo2 - fhe) / 1000.0 * amb_pressure;
-
-                        entry->ead = (entry->depth + 10000) * (1000 - fhe) / 1000.0 - 10000;
-                        entry->end = (entry->depth + 10000) * (1000 - fo2 - fhe) / 1000.0 / N2_IN_AIR - 10000;
-                        entry->eadd = (entry->depth + 10000) * (fo2 * O2_DENSITY + (1-fo2-fhe) * N2_DENSITY + fhe * HE_DENSITY) / (O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) -10000;
 		}
-		entry->mod = (prefs.mod_ppO2/fo2*1000 - 1) * 10000;
+
+                /* Calculate MOD, EAD, END and EADD based on partial pressures calculated before
+                 * so there is no difference in calculating between OC and CC
+                 * EAD takes O2 + N2 (air) into account
+                 * END just uses N2 */
+		entry->mod = (prefs.mod_ppO2 / fo2 * 1000 - 1) * 10000;
+		entry->ead = (entry->depth + 10000) *
+			(entry->po2 + (amb_pressure - entry->po2) * (1 - ratio)) / amb_pressure - 10000;
+		entry->end = (entry->depth + 10000) *
+			(amb_pressure - entry->po2) * (1 - ratio) / amb_pressure / N2_IN_AIR * 1000 - 10000;
+		entry->eadd = (entry->depth + 10000) *
+			(entry->po2 / amb_pressure * O2_DENSITY + entry->pn2 / amb_pressure *
+                                N2_DENSITY + entry->phe / amb_pressure * HE_DENSITY) /
+				(O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) * 1000 -10000;
 		if(entry->mod <0)
 			entry->mod=0;
 		if(entry->ead <0)
@@ -1862,6 +1863,7 @@ static void calculate_deco_information(struct dive *dive, struct divecomputer *d
 			entry->end=0;
 		if(entry->eadd <0)
 			entry->eadd=0;
+
 		if (entry->po2 > pi->maxpp && prefs.pp_graphs.po2)
 			pi->maxpp = entry->po2;
 		if (entry->phe > pi->maxpp && prefs.pp_graphs.phe)