+ line_to(gc, entry->sec, mbar);
+ }
+ line_to(gc, pi->maxtime, pi->minpressure);
+ cairo_stroke(gc->cr);
+}
+
+/*
+ * Return air usage (in liters).
+ */
+static double calculate_airuse(struct dive *dive)
+{
+ double airuse = 0;
+ int i;
+
+ for (i = 0; i < MAX_CYLINDERS; i++) {
+ cylinder_t *cyl = dive->cylinder + i;
+ int size = cyl->type.size.mliter;
+ double kilo_atm;
+
+ if (!size)
+ continue;
+
+ kilo_atm = (cyl->start.mbar - cyl->end.mbar) / 1013250.0;
+
+ /* Liters of air at 1 atm == milliliters at 1k atm*/
+ airuse += kilo_atm * size;
+ }
+ return airuse;
+}
+
+static void plot_info(struct dive *dive, struct graphics_context *gc)
+{
+ text_render_options_t tro = {10, 0.2, 1.0, 0.2, RIGHT, BOTTOM};
+ const double liters_per_cuft = 28.317;
+ const char *unit, *format, *desc;
+ double airuse;
+ char buffer1[80];
+ char buffer2[80];
+ int len;
+
+ airuse = calculate_airuse(dive);
+ if (!airuse) {
+ update_air_info("");
+ return;
+ }
+ switch (output_units.volume) {
+ case LITER:
+ unit = "l";
+ format = "vol: %4.0f %s";
+ break;
+ case CUFT:
+ unit = "cuft";
+ format = "vol: %4.2f %s";
+ airuse /= liters_per_cuft;
+ break;
+ }
+ tro.vpos = -1.0;
+ plot_text(gc, &tro, 0.98, 0.98, format, airuse, unit);
+ len = snprintf(buffer1, sizeof(buffer1), format, airuse, unit);
+ tro.vpos = -2.2;
+ if (dive->duration.seconds) {
+ double pressure = 1 + (dive->meandepth.mm / 10000.0);
+ double sac = airuse / pressure * 60 / dive->duration.seconds;
+ plot_text(gc, &tro, 0.98, 0.98, "SAC: %4.2f %s/min", sac, unit);
+ snprintf(buffer1+len, sizeof(buffer1)-len,
+ "\nSAC: %4.2f %s/min", sac, unit);
+ }
+ len = 0;
+ tro.vpos = -3.4;
+ desc = dive->cylinder[0].type.description;
+ if (desc || dive->cylinder[0].gasmix.o2.permille) {
+ int o2 = dive->cylinder[0].gasmix.o2.permille / 10;
+ if (!desc)
+ desc = "";
+ if (!o2)
+ o2 = 21;
+ plot_text(gc, &tro, 0.98, 0.98, "%s (%d%%)", desc, o2);
+ len = snprintf(buffer2, sizeof(buffer2), "%s (%d%%): used ", desc, o2);
+ }
+ snprintf(buffer2+len, sizeof(buffer2)-len, buffer1);
+ update_air_info(buffer2);
+}
+
+static int mbar_to_PSI(int mbar)
+{
+ pressure_t p = {mbar};
+ return to_PSI(p);
+}
+
+static void plot_cylinder_pressure_text(struct graphics_context *gc, struct plot_info *pi)
+{
+ if (get_cylinder_pressure_range(gc, pi)) {
+ int start, end;
+ const char *unit = "bar";
+
+ switch (output_units.pressure) {
+ case PASCAL:
+ start = pi->maxpressure * 100;
+ end = pi->minpressure * 100;
+ unit = "pascal";
+ break;
+ case BAR:
+ start = (pi->maxpressure + 500) / 1000;
+ end = (pi->minpressure + 500) / 1000;
+ unit = "bar";
+ break;
+ case PSI:
+ start = mbar_to_PSI(pi->maxpressure);
+ end = mbar_to_PSI(pi->minpressure);
+ unit = "psi";
+ break;
+ }
+
+ text_render_options_t tro = {10, 0.2, 1.0, 0.2, LEFT, TOP};
+ plot_text(gc, &tro, 0, pi->maxpressure, "%d %s", start, unit);
+ plot_text(gc, &tro, pi->maxtime, pi->minpressure,
+ "%d %s", end, unit);