+ pressure_t startp, endp;
+
+ if (get_cylinder_pressure_range(dive, gc, &startp, &endp)) {
+ int start, end;
+ const char *unit = "bar";
+
+ switch (output_units.pressure) {
+ case PASCAL:
+ start = startp.mbar * 100;
+ end = startp.mbar * 100;
+ unit = "pascal";
+ break;
+ case BAR:
+ start = (startp.mbar + 500) / 1000;
+ end = (endp.mbar + 500) / 1000;
+ unit = "bar";
+ break;
+ case PSI:
+ start = to_PSI(startp);
+ end = to_PSI(endp);
+ unit = "psi";
+ break;
+ }
+
+ text_render_options_t tro = {10, 0.2, 1.0, 0.2, LEFT, TOP};
+ plot_text(gc, &tro, 0, startp.mbar, "%d %s", start, unit);
+ plot_text(gc, &tro, dive->duration.seconds, endp.mbar,
+ "%d %s", end, unit);
+ }
+}
+
+static void analyze_plot_info_minmax_minute(struct plot_data *entry, struct plot_data *first, struct plot_data *last, int index)
+{
+ struct plot_data *p = entry;
+ int time = entry->sec;
+ int seconds = 90*(index+1);
+ struct plot_data *min, *max;
+ int avg, nr;
+
+ /* Go back 'seconds' in time */
+ while (p > first) {
+ if (p[-1].sec < time - seconds)
+ break;
+ p--;
+ }
+
+ /* Then go forward until we hit an entry past the time */
+ min = max = p;
+ avg = p->val;
+ nr = 1;
+ while (++p < last) {
+ int val = p->val;
+ if (p->sec > time + seconds)
+ break;
+ avg += val;
+ nr ++;
+ if (val < min->val)
+ min = p;
+ if (val > max->val)
+ max = p;
+ }
+ entry->min[index] = min;
+ entry->max[index] = max;
+ entry->avg[index] = (avg + nr/2) / nr;
+}
+
+static void analyze_plot_info_minmax(struct plot_data *entry, struct plot_data *first, struct plot_data *last)
+{
+ analyze_plot_info_minmax_minute(entry, first, last, 0);
+ analyze_plot_info_minmax_minute(entry, first, last, 1);
+ analyze_plot_info_minmax_minute(entry, first, last, 2);
+}
+
+static struct plot_info *analyze_plot_info(struct plot_info *pi)
+{
+ int i;
+ int nr = pi->nr;
+
+ /* Smoothing function: 5-point triangular smooth */
+ for (i = 2; i < nr-2; i++) {
+ struct plot_data *entry = pi->entry+i;
+ int val;
+
+ val = entry[-2].val + 2*entry[-1].val + 3*entry[0].val + 2*entry[1].val + entry[2].val;
+ entry->smoothed = (val+4) / 9;
+ }
+
+ /* One-, two- and three-minute minmax data */
+ for (i = 0; i < nr; i++) {
+ struct plot_data *entry = pi->entry +i;
+ analyze_plot_info_minmax(entry, pi->entry, pi->entry+nr);
+ }
+
+ return pi;
+}
+
+/*
+ * Create a plot-info with smoothing and ranged min/max
+ *
+ * This also makes sure that we have extra empty events on both
+ * sides, so that you can do end-points without having to worry
+ * about it.
+ */
+static struct plot_info *depth_plot_info(struct dive *dive)
+{
+ int i, nr = dive->samples + 4, sec;
+ size_t alloc_size = plot_info_size(nr);
+ struct plot_info *pi;
+
+ pi = malloc(alloc_size);
+ if (!pi)
+ return pi;
+ memset(pi, 0, alloc_size);
+ pi->nr = nr;
+ sec = 0;
+ for (i = 0; i < dive->samples; i++) {
+ struct sample *sample = dive->sample+i;
+ struct plot_data *entry = pi->entry + i + 2;
+
+ sec = entry->sec = sample->time.seconds;
+ entry->val = sample->depth.mm;
+ }
+ /* Fill in the last two entries with empty values but valid times */
+ i = dive->samples + 2;
+ pi->entry[i].sec = sec + 20;
+ pi->entry[i+1].sec = sec + 40;
+
+ return analyze_plot_info(pi);
+}
+
+static void plot(struct graphics_context *gc, int w, int h, struct dive *dive)
+{
+ double topx, topy;
+ struct plot_info *pi = depth_plot_info(dive);