Calculate OTUs for every dive

[ext/subsurface.git] / divelist.c

diff --git a/divelist.c b/divelist.c
index 51646c460f7b05761134227d94e604c761ac1a15..c2194bbec06b52ddfe7d3888e65bc53ef19274fe 100644 (file)
--- a/divelist.c
+++ b/divelist.c
@@ -14,6 +14,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <math.h>
 
 #include "divelist.h"
 #include "dive.h"
@@ -222,6 +223,25 @@ static void sac_data_func(GtkTreeViewColumn *col,
        g_object_set(renderer, "text", buffer, NULL);
 }
 
+/* calculate OTU for a dive */
+static double calculate_otu(struct dive *dive)
+{
+       int i;
+       double otu = 0.0;
+
+       for (i = 1; i < dive->samples; i++) {
+               int t;
+               double po2;
+               struct sample *sample = dive->sample + i;
+               struct sample *psample = sample - 1;
+               t = sample->time.seconds - psample->time.seconds;
+               po2 = dive->cylinder[sample->cylinderindex].gasmix.o2.permille / 1000.0 *
+                       (sample->depth.mm + 10000) / 10000.0;
+               if (po2 >= 0.5)
+                       otu += pow(po2 - 0.5, 0.83) * t / 30.0;
+       }
+       return otu;
+}
 /*
  * Return air usage (in liters).
  */
@@ -389,6 +409,7 @@ static void fill_dive_list(void)
        for (i = 0; i < dive_table.nr; i++) {
                struct dive *dive = dive_table.dives[i];
 
+               dive->otu = calculate_otu(dive);
                gtk_list_store_append(store, &iter);
                gtk_list_store_set(store, &iter,
                        DIVE_INDEX, i,