+static int get_cylinder_index(struct dive *dive, struct event *ev)
+{
+ int i;
+
+ /*
+ * Try to find a cylinder that matches the O2 percentage
+ * in the gas change event 'value' field.
+ *
+ * Crazy suunto gas change events. We really should do
+ * this in libdivecomputer or something.
+ */
+ for (i = 0; i < MAX_CYLINDERS; i++) {
+ cylinder_t *cyl = dive->cylinder+i;
+ int o2 = (cyl->gasmix.o2.permille + 5) / 10;
+ if (o2 == ev->value)
+ return i;
+ }
+
+ return 0;
+}
+
+static struct event *get_next_gaschange(struct event *event)
+{
+ while (event) {
+ if (!strcmp(event->name, "gaschange"))
+ return event;
+ event = event->next;
+ }
+ return event;
+}
+
+static int set_cylinder_index(struct plot_info *pi, int i, int cylinderindex, unsigned int end)
+{
+ while (i < pi->nr) {
+ struct plot_data *entry = pi->entry+i;
+ if (entry->sec > end)
+ break;
+ if (entry->cylinderindex != cylinderindex) {
+ entry->cylinderindex = cylinderindex;
+ entry->pressure[0] = 0;
+ }
+ i++;
+ }
+ return i;
+}
+
+static void check_gas_change_events(struct dive *dive, struct plot_info *pi)
+{
+ int i = 0, cylinderindex = 0;
+ struct event *ev = get_next_gaschange(dive->events);
+
+ if (!ev)
+ return;
+
+ do {
+ i = set_cylinder_index(pi, i, cylinderindex, ev->time.seconds);
+ cylinderindex = get_cylinder_index(dive, ev);
+ ev = get_next_gaschange(ev->next);
+ } while (ev);
+ set_cylinder_index(pi, i, cylinderindex, ~0u);
+}
+