+ cairo_stroke(cr);
+
+ /* Show mean depth */
+ cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.40);
+ move_to(gc, 0, dive->meandepth.mm);
+ line_to(gc, 1, dive->meandepth.mm);
+ cairo_stroke(cr);
+
+ gc->scalex = maxtime;
+
+ sample = dive->sample;
+ cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.80);
+ begins = sample->time.seconds;
+ move_to(gc, sample->time.seconds, sample->depth.mm);
+ for (i = 1; i < dive->samples; i++) {
+ sample++;
+ sec = sample->time.seconds;
+ if (sec <= maxtime) {
+ depth = sample->depth.mm;
+ line_to(gc, sec, depth);
+ }
+ }
+ gc->scaley = 1.0;
+ line_to(gc, MIN(sec,maxtime), 0);
+ line_to(gc, begins, 0);
+ cairo_close_path(cr);
+ cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.20);
+ cairo_fill_preserve(cr);
+ cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.80);
+ cairo_stroke(cr);
+}
+
+/* gets both the actual start and end pressure as well as the scaling factors */
+static int get_cylinder_pressure_range(struct dive *dive, struct graphics_context *gc,
+ pressure_t *startp, pressure_t *endp)
+{
+ int i;
+ int min, max;
+
+ gc->scalex = round_seconds_up(dive->duration.seconds);
+
+ max = 0;
+ min = 5000000;
+ if (startp)
+ startp->mbar = endp->mbar = 0;
+
+ for (i = 0; i < dive->samples; i++) {
+ int mbar;
+ struct sample *sample = dive->sample + i;
+
+ /* FIXME! We only track cylinder 0 right now */
+ if (sample->cylinderindex)
+ continue;
+ mbar = sample->cylinderpressure.mbar;
+ if (!mbar)
+ continue;
+ if (mbar < min)
+ min = mbar;
+ if (mbar > max)
+ max = mbar;
+ }
+ if (startp)
+ startp->mbar = max;
+ if (endp)
+ endp->mbar = min;
+ if (!max)
+ return 0;
+ gc->scaley = max * 1.5;
+ return 1;
+}
+
+static void plot_cylinder_pressure(struct dive *dive, struct graphics_context *gc)
+{
+ int i, sec = -1;
+
+ if (!get_cylinder_pressure_range(dive, gc, NULL, NULL))
+ return;
+
+ cairo_set_source_rgba(gc->cr, 0.2, 1.0, 0.2, 0.80);
+
+ move_to(gc, 0, dive->cylinder[0].start.mbar);
+ for (i = 1; i < dive->samples; i++) {
+ int mbar;
+ struct sample *sample = dive->sample + i;
+
+ mbar = sample->cylinderpressure.mbar;
+ if (!mbar)
+ continue;
+ sec = sample->time.seconds;
+ if (sec <= dive->duration.seconds)
+ line_to(gc, sec, mbar);
+ }
+ /*
+ * We may have "surface time" events, in which case we don't go
+ * back to dive duration
+ */
+ if (sec < dive->duration.seconds)
+ line_to(gc, dive->duration.seconds, dive->cylinder[0].end.mbar);
+ 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 = {0.2, 1.0, 0.2, LEFT};
+ const double liters_per_cuft = 28.317;
+ const char *unit;
+ double airuse;
+
+ airuse = calculate_airuse(dive);
+ if (!airuse)
+ return;
+
+ /* I really need to start addign some unit setting thing */
+ switch (output_units.volume) {
+ case LITER:
+ unit = "l";
+ break;
+ case CUFT:
+ unit = "cuft";
+ airuse /= liters_per_cuft;
+ break;
+ }
+ plot_text(gc, &tro, 0.8, 0.8, "vol: %4.2f %s", airuse, unit);
+ if (dive->duration.seconds) {
+ double pressure = 1 + (dive->meandepth.mm / 10000.0);
+ double sac = airuse / pressure * 60 / dive->duration.seconds;
+ plot_text(gc, &tro, 0.8, 0.85, "SAC: %4.2f %s/min", sac, unit);
+ }
+}
+
+static void plot_cylinder_pressure_text(struct dive *dive, struct graphics_context *gc)
+{
+ pressure_t startp, endp;
+
+ cairo_set_font_size(gc->cr, 10);
+
+ 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 = {0.2, 1.0, 0.2, LEFT};
+ 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 plot(struct graphics_context *gc, int w, int h, struct dive *dive)
+{
+ double topx, topy;
+
+ topx = w / 20.0;
+ topy = h / 20.0;
+ cairo_translate(gc->cr, topx, topy);
+
+ /*
+ * We can use "cairo_translate()" because that doesn't
+ * scale line width etc. But the actual scaling we need
+ * do set up ourselves..
+ *
+ * Snif. What a pity.
+ */
+ gc->maxx = (w - 2*topx);
+ gc->maxy = (h - 2*topy);
+
+ /* Cylinder pressure plot */
+ plot_cylinder_pressure(dive, gc);
+
+ /* Depth profile */
+ plot_depth_profile(dive, gc);
+
+ /* Text on top of all graphs.. */
+ plot_depth_text(dive, gc);
+ plot_cylinder_pressure_text(dive, gc);
+
+ /* And info box in the lower right corner.. */
+ gc->scalex = gc->scaley = 1.0;
+ plot_info(dive, gc);
+
+ /* Bounding box last */
+ cairo_set_source_rgb(gc->cr, 1, 1, 1);
+ move_to(gc, 0, 0);
+ line_to(gc, 0, 1);
+ line_to(gc, 1, 1);
+ line_to(gc, 1, 0);
+ cairo_close_path(gc->cr);
+ cairo_stroke(gc->cr);
+
+}
+
+static gboolean expose_event(GtkWidget *widget, GdkEventExpose *event, gpointer data)
+{
+ struct dive *dive = current_dive;
+ struct graphics_context gc;
+ int w,h;
+
+ w = widget->allocation.width;
+ h = widget->allocation.height;
+
+ gc.cr = gdk_cairo_create(widget->window);
+ cairo_set_source_rgb(gc.cr, 0, 0, 0);
+ cairo_paint(gc.cr);
+
+ if (dive)
+ plot(&gc, w, h, dive);