CCR patch: adapt code for diluent cylinder pressures (3)

This patch implements the cylinder pressure calculations for diluent
gas in CCR dive computers. This is the third patch for achieving this.
The following were performed:

1) Add two lines to try_to_fill_sample() in parse-xml so that
   diluent cylinder pressures are stored from XML dive log file
   into structures of sample.
2) Add one line to populate_plot_entries() in profile.c so that
   the diluent cylinder pressures are copied from structures of
   sample to structures of plot_info.
3) add three constant #defines in profile.h
4) change populate_pressure_information() in gaspressures.c in
   order to take into account pressure calculations for the
   diluent cylinder, calling subordinate functions in the
   appropriate way.
5) change create_plot_info_new() in profile.c in order to initiate
   the pressure calculations for the diluent cylinder.
6) Implement two debugging functions (one in profile.c, another
   in gaspressures.c). These debugging functions are activated
   by means of #defines.

Two function calls dealing with oxygen pressure are currently commented
out.  They will be activated in the following patch that attends to CCR
oxygen partial pressure calculation.

[Dirk Hohndel: rather massive whitespace cleanup]

Signed-off-by: willem ferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 50 insertions, 13 deletions

diff --git a/gaspressures.c b/gaspressures.c
index be63f8714..3155a90ad 100644
--- a/gaspressures.c
+++ b/gaspressures.c
@@ -316,19 +316,46 @@ static inline int calc_pressure_time(struct dive *dive, struct divecomputer *dc,
 	return depth_to_mbar(depth, dive) * time;
 }
 
-void populate_pressure_information(struct dive *dive, struct divecomputer *dc, struct plot_info *pi)
+#ifdef PRINT_PRESSURES_DEBUG
+// A CCR debugging tool that prints the gas pressures in cylinder 0 and in the diluent cylinder, used in populate_pressure_information():
+static void debug_print_pressures(struct plot_info *pi)
 {
-	int i, cylinderindex;
+	int i;
+	for (i = 0; i < pi->nr; i++) {
+		struct plot_data *entry = pi->entry + i;
+		printf("%5d |%9d | %9d || %9d | %9d |\n", i, SENSOR_PRESSURE(entry), INTERPOLATED_PRESSURE(entry), DILUENT_PRESSURE(entry), INTERPOLATED_DILUENT_PRESSURE(entry));
+	}
+}
+#endif
+
+/* This function goes through the list of tank pressures, either SENSOR_PRESSURE(entry) or DILUENT_PRESSURE(entry),
+ * of structure plot_info for the dive profile where each item in the list corresponds to one point (node) of the
+ * profile. It finds values for which there are no tank pressures (pressure==0). For each missing item (node) of
+ * tank pressure it creates a pr_track_alloc structure that represents a segment on the dive profile and that
+ * contains tank pressures. There is a linked list of pr_track_alloc structures for each cylinder. These pr_track_alloc
+ * structures ultimately allow for filling the missing tank pressure values on the dive profile using the depth_pressure
+ * of the dive. To do this, it calculates the summed pressure-time value for the duration of the dive and stores these
+ * in the pr_track_alloc structures. If diluent_flag = 1, then DILUENT_PRESSURE(entry) is used instead of SENSOR_PRESSURE.
+ * This function is called by create_plot_info_new() in profile.c
+ */
+void populate_pressure_information(struct dive *dive, struct divecomputer *dc, struct plot_info *pi, int diluent_flag)
+{
+	int i, cylinderid, cylinderindex = -1;
 	pr_track_t *track_pr[MAX_CYLINDERS] = { NULL, };
-	pr_track_t *current;
+	pr_track_t *current = NULL;
 	bool missing_pr = false;
 
-	cylinderindex = -1;
-	current = NULL;
 	for (i = 0; i < pi->nr; i++) {
 		struct plot_data *entry = pi->entry + i;
-		int pressure = SENSOR_PRESSURE(entry);
-
+		unsigned pressure;
+		if (diluent_flag) { // if this is a diluent cylinder:
+			pressure = DILUENT_PRESSURE(entry);
+			cylinderid = DILUENT_CYLINDER;
+		} else {
+			pressure = SENSOR_PRESSURE(entry);
+			cylinderid = entry->cylinderindex;
+		}
+		/* If track_pr structure already exists, then update it: */
 		/* discrete integration of pressure over time to get the SAC rate equivalent */
 		if (current) {
 			entry->pressure_time = calc_pressure_time(dive, dc, entry - 1, entry);
@@ -336,9 +363,13 @@ void populate_pressure_information(struct dive *dive, struct divecomputer *dc, s
 			current->t_end = entry->sec;
 		}
 
+		/* If 1st record or different cylinder: Create a new track_pr structure: */
 		/* track the segments per cylinder and their pressure/time integral */
-		if (entry->cylinderindex != cylinderindex) {
-			cylinderindex = entry->cylinderindex;
+		if (cylinderid != cylinderindex) {
+			if (diluent_flag)			  // For CCR dives:
+				cylinderindex = DILUENT_CYLINDER; // indicate diluent cylinder
+			else
+				cylinderindex = entry->cylinderindex;
 			current = pr_track_alloc(pressure, entry->sec);
 			track_pr[cylinderindex] = list_add(track_pr[cylinderindex], current);
 			continue;
@@ -348,21 +379,27 @@ void populate_pressure_information(struct dive *dive, struct divecomputer *dc, s
 			missing_pr = 1;
 			continue;
 		}
-
 		current->end = pressure;
 
 		/* Was it continuous? */
-		if (SENSOR_PRESSURE(entry - 1))
+		if ((diluent_flag) && (DILUENT_PRESSURE(entry - 1))) // in the case of CCR diluent pressure
+			continue;
+		else if (SENSOR_PRESSURE(entry - 1)) // for all other cylinders
 			continue;
 
-		/* transmitter changed its working status */
+		/* transmitter stopped transmitting cylinder pressure data */
 		current = pr_track_alloc(pressure, entry->sec);
 		track_pr[cylinderindex] = list_add(track_pr[cylinderindex], current);
 	}
 
 	if (missing_pr) {
-		fill_missing_tank_pressures(dive, pi, track_pr, 0);
+		fill_missing_tank_pressures(dive, pi, track_pr, diluent_flag);
 	}
+
+#ifdef PRINT_PRESSURES_DEBUG
+	debug_print_pressures(pi);
+#endif
+
 	for (i = 0; i < MAX_CYLINDERS; i++)
 		list_free(track_pr[i]);
 }