Distinguish internally between min pressure and end pressure

And don't artificially end dives on min pressure

This may be a problem for dive computers like Linus' Suunto Vyper Air
where the failure mode seems to be _high_ pressure readings (that's scary,
btw). If the transmitter fails at the end of the dive the pressure plot
ends with incorrect high pressure. But that's simply a bug with the dive
computer and not something that subsurface should hack around. Maybe we
should offer a way to edit the incorrect data points instead.

Always ending on the minimum pressure is definitely wrong as it causes
bogus plots when you do a valve shutdown during the dive (which means that
valid data gets plotted incorrectly).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

diff --git a/profile.c b/profile.c
index 2edaf694cd5f429387d5e3cba08f32c7fd3aeda8..ca383a53dc865e024a27334ecdeff89a38603f6f 100644 (file)
--- a/profile.c
+++ b/profile.c
@@ -22,6 +22,7 @@ struct plot_info {
        int maxtime;
        int meandepth, maxdepth;
        int minpressure, maxpressure;
+       int endpressure; /* start pressure better be max pressure */
        int mintemp, maxtemp;
        struct plot_data {
                int sec;
@@ -471,6 +472,7 @@ static int get_cylinder_pressure_range(struct graphics_context *gc, struct plot_
 static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info *pi)
 {
        int i;
+       int have_pressure = FALSE;
 
        if (!get_cylinder_pressure_range(gc, pi))
                return;
@@ -485,9 +487,15 @@ static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info
                mbar = entry->pressure;
                if (!mbar)
                        continue;
+               have_pressure = TRUE;
                line_to(gc, entry->sec, mbar);
        }
-       line_to(gc, pi->maxtime, pi->minpressure);
+       /* if we have valid samples, we don't want to draw a line to the minpressure
+        * but just end wherever the dive ended (think valve shutdowns during dive)
+        * but that doesn't work so well if we have only max and min
+        */
+       if (! have_pressure)
+               line_to(gc, pi->maxtime, pi->minpressure);
        cairo_stroke(gc->cr);
 }
 
@@ -506,24 +514,24 @@ static void plot_cylinder_pressure_text(struct graphics_context *gc, struct plot
                switch (output_units.pressure) {
                case PASCAL:
                        start = pi->maxpressure * 100;
-                       end = pi->minpressure * 100;
+                       end = pi->endpressure * 100;
                        unit = "pascal";
                        break;
                case BAR:
                        start = (pi->maxpressure + 500) / 1000;
-                       end = (pi->minpressure + 500) / 1000;
+                       end = (pi->endpressure + 500) / 1000;
                        unit = "bar";
                        break;
                case PSI:
                        start = mbar_to_PSI(pi->maxpressure);
-                       end = mbar_to_PSI(pi->minpressure);
+                       end = mbar_to_PSI(pi->endpressure);
                        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,
+               plot_text(gc, &tro, pi->maxtime, pi->endpressure,
                          "%d %s", end, unit);
        }
 }
@@ -706,7 +714,7 @@ static struct plot_info *create_plot_info(struct dive *dive)
        pi->nr = lastindex+1;
        pi->maxtime = pi->entry[lastindex].sec;
 
-       pi->minpressure = dive->cylinder[0].end.mbar;
+       pi->endpressure = pi->minpressure = dive->cylinder[0].end.mbar;
        pi->maxpressure = dive->cylinder[0].start.mbar;
 
        pi->meandepth = dive->meandepth.mm;