Add support to planner to use additional gases during the ascent

This change ended up being quite a bit bigger than expected as it
uncovered a number of bugs in the existing code.

The planner now handles gas changes correctly by creating (and later
parsing) events in the simulated divecomputer. At the end of the dive
specified in the input form the algorithm starts with the deepest
interesting depth: either the first stop below our ceiling or the deepest
depth at which we can change gases. It then traverses all the stop and all
the gas change depth and at each stage ensures that we are allowed to
ascend further before going on.

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

1 files changed, 210 insertions, 43 deletions

diff --git a/planner.c b/planner.c
index fd6ba2442..b05980648 100644
--- a/planner.c
+++ b/planner.c
@@ -13,7 +13,7 @@
 #include "display-gtk.h"
 
 
-int stoplevels[] = { 0, 3000, 6000, 9000, 12000, 15000, 18000, 21000, 24000, 27000,
+int decostoplevels[] = { 0, 3000, 6000, 9000, 12000, 15000, 18000, 21000, 24000, 27000,
 		     30000, 33000, 36000, 39000, 42000, 45000, 48000, 51000, 54000, 57000,
 		     60000, 63000, 66000, 69000, 72000, 75000, 78000, 81000, 84000, 87000,
 		     90000};
@@ -43,12 +43,36 @@ void dump_plan(struct diveplan *diveplan)
 }
 #endif
 
+void get_gas_from_events(struct divecomputer *dc, int time, int *o2, int *he)
+{
+	struct event *event = dc->events;
+	while (event && event->time.seconds <= time) {
+		if (!strcmp(event->name, "gaschange")) {
+			*o2 = 10 * event->value & 0xffff;
+			*he = 10 * event->value >> 16;
+		}
+		event = event->next;
+	}
+}
+
+
+static int get_gasidx(struct dive *dive, int o2, int he)
+{
+	int gasidx = -1;
+
+	while (++gasidx < MAX_CYLINDERS)
+		if (dive->cylinder[gasidx].gasmix.o2.permille == o2 &&
+		    dive->cylinder[gasidx].gasmix.he.permille == he)
+			return gasidx;
+	return -1;
+}
+
 /* returns the tissue tolerance at the end of this (partial) dive */
 double tissue_at_end(struct dive *dive, char **cached_datap)
 {
 	struct divecomputer *dc;
 	struct sample *sample, *psample;
-	int i, j, t0, t1, lastdepth;
+	int i, j, t0, t1, gasidx, lastdepth;
 	double tissue_tolerance;
 
 	if (!dive)
@@ -65,13 +89,19 @@ double tissue_at_end(struct dive *dive, char **cached_datap)
 	psample = sample = dc->sample;
 	lastdepth = t0 = 0;
 	for (i = 0; i < dc->samples; i++, sample++) {
+		int o2 = 0, he = 0;
 		t1 = sample->time.seconds;
+		get_gas_from_events(&dive->dc, t0, &o2, &he);
+		if ((gasidx = get_gasidx(dive, o2, he)) == -1) {
+			printf("can't find gas %d/%d\n", o2/10, he/10);
+			gasidx = 0;
+		}
 		if (i > 0)
 			lastdepth = psample->depth.mm;
 		for (j = t0; j < t1; j++) {
 			int depth = lastdepth + (j - t0) * (sample->depth.mm - lastdepth) / (t1 - t0);
 			tissue_tolerance = add_segment(depth_to_mbar(depth, dive) / 1000.0,
-						       &dive->cylinder[sample->sensor].gasmix, 1, sample->po2, dive);
+						       &dive->cylinder[gasidx].gasmix, 1, sample->po2, dive);
 		}
 		psample = sample;
 		t0 = t1;
@@ -82,7 +112,7 @@ double tissue_at_end(struct dive *dive, char **cached_datap)
 /* how many seconds until we can ascend to the next stop? */
 int time_at_last_depth(struct dive *dive, int next_stop, char **cached_data_p)
 {
-	int depth;
+	int depth, gasidx, o2 = 0, he = 0;
 	double surface_pressure, tissue_tolerance;
 	int wait = 0;
 	struct sample *sample;
@@ -93,10 +123,12 @@ int time_at_last_depth(struct dive *dive, int next_stop, char **cached_data_p)
 	tissue_tolerance = tissue_at_end(dive, cached_data_p);
 	sample = &dive->dc.sample[dive->dc.samples - 1];
 	depth = sample->depth.mm;
+	get_gas_from_events(&dive->dc, sample->time.seconds, &o2, &he);
+	gasidx = get_gasidx(dive, o2, he);
 	while (deco_allowed_depth(tissue_tolerance, surface_pressure, dive, 1) > next_stop) {
 		wait++;
 		tissue_tolerance = add_segment(depth_to_mbar(depth, dive) / 1000.0,
-					       &dive->cylinder[sample->sensor].gasmix, 1, sample->po2, dive);
+					       &dive->cylinder[gasidx].gasmix, 1, sample->po2, dive);
 	}
 	return wait;
 }
@@ -131,10 +163,12 @@ struct dive *create_dive_from_plan(struct diveplan *diveplan)
 	struct divedatapoint *dp;
 	struct divecomputer *dc;
 	int oldo2 = AIR_PERMILLE, oldhe = 0;
+	int lasttime = 0;
 
 	if (!diveplan || !diveplan->dp)
 		return NULL;
 #if DEBUG_PLAN & 4
+	printf("in create_dive_from_plan\n");
 	dump_plan(diveplan);
 #endif
 	dive = alloc_dive();
@@ -172,7 +206,7 @@ struct dive *create_dive_from_plan(struct diveplan *diveplan)
 		if (o2 != oldo2 || he != oldhe) {
 			int value = (o2 / 10) | (he / 10 << 16);
 			add_gas(dive, o2, he);
-			add_event(dc, time, 11, 0, value, "gaschange");
+			add_event(dc, lasttime, 11, 0, value, "gaschange");
 			oldo2 = o2; oldhe = he;
 		}
 
@@ -181,7 +215,7 @@ struct dive *create_dive_from_plan(struct diveplan *diveplan)
 		sample->time.seconds = time;
 		sample->depth.mm = depth;
 		finish_sample(dc);
-
+		lasttime = time;
 		dp = dp->next;
 	}
 	if (dc->samples == 0) {
@@ -189,6 +223,10 @@ struct dive *create_dive_from_plan(struct diveplan *diveplan)
 		free(dive);
 		dive = NULL;
 	}
+#if DEBUG_PLAN & 32
+	if (dive)
+		save_dive(stdout, dive);
+#endif
 	return dive;
 }
 
@@ -276,16 +314,102 @@ void plan_add_segment(struct diveplan *diveplan, int duration, int depth, int o2
 	add_to_end_of_diveplan(diveplan, dp);
 }
 
-void get_gas_from_events(struct divecomputer *dc, int time, int *o2, int *he)
+struct gaschanges {
+	int depth;
+	int gasidx;
+};
+
+static struct gaschanges *analyze_gaslist(struct diveplan *diveplan, struct dive *dive, int *gaschangenr)
 {
-	struct event *event = dc->events;
-	while (event && event->time.seconds <= time) {
-		if (!strcmp(event->name, "gaschange")) {
-			*o2 = 10 * event->value & 0xffff;
-			*he = 10 * event->value >> 16;
+	int nr = 0;
+	struct gaschanges *gaschanges = NULL;
+	struct divedatapoint *dp = diveplan->dp;
+
+	while (dp) {
+		if (dp->time == 0) {
+			int i = 0, j = 0;
+			nr++;
+			gaschanges = realloc(gaschanges, nr * sizeof(struct gaschanges));
+			while (i < nr - 1) {
+				if (dp->depth < gaschanges[i].depth) {
+					memmove(gaschanges + i + 1, gaschanges + i, (nr - i - 1) * sizeof(struct gaschanges));
+					break;
+				}
+				i++;
+			}
+			gaschanges[i].depth = dp->depth;
+			do {
+				if (dive->cylinder[j].gasmix.o2.permille == dp->o2 &&
+				    dive->cylinder[j].gasmix.he.permille == dp->he) {
+					gaschanges[i].gasidx = j;
+					break;
+				}
+				j++;
+			} while (j < MAX_CYLINDERS);
 		}
-		event = event->next;
+		dp = dp->next;
+	}
+	*gaschangenr = nr;
+#if DEBUG_PLAN & 16
+	for (nr = 0; nr < *gaschangenr; nr++)
+		printf("gaschange nr %d: @ %5.2lfm gasidx %d (%d/%d)\n", nr, gaschanges[nr].depth / 1000.0,
+			gaschanges[nr].gasidx, dive->cylinder[gaschanges[nr].gasidx].gasmix.o2.permille / 10,
+			dive->cylinder[gaschanges[nr].gasidx].gasmix.he.permille / 10);
+#endif
+	return gaschanges;
+}
+
+/* sort all the stops into one ordered list */
+static int *sort_stops(int *dstops, int dnr, struct gaschanges *gstops, int gnr)
+{
+	int i, gi, di;
+	int total = dnr + gnr;
+	int *stoplevels = malloc(total * sizeof(int));
+
+	/* no gaschanges */
+	if (gnr == 0) {
+		memcpy(stoplevels, dstops, dnr * sizeof(int));
+		return stoplevels;
+	}
+	i = total - 1;
+	gi = gnr - 1;
+	di = dnr - 1;
+	while (i >= 0) {
+		if (dstops[di] > gstops[gi].depth) {
+			stoplevels[i] = dstops[di];
+			di--;
+		} else if (dstops[di] == gstops[gi].depth) {
+			stoplevels[i] = dstops[di];
+			di--;
+			gi--;
+		} else {
+			stoplevels[i] = gstops[gi].depth;
+			gi--;
+		}
+		i--;
+		if (di < 0) {
+			while (gi >= 0)
+				stoplevels[i--] = gstops[gi--].depth;
+			break;
+		}
+		if (gi < 0) {
+			while (di >= 0)
+				stoplevels[i--] = dstops[di--];
+			break;
+		}
+	}
+	while (i >= 0)
+		stoplevels[i--] = 0;
+
+#if DEBUG_PLAN & 16
+	int k;
+	for (k = gnr + dnr -1; k >= 0; k--) {
+		printf("stoplevel[%d]: %5.2lfm\n", k, stoplevels[k]/1000.0);
+		if (stoplevels[k] == 0)
+			break;
 	}
+#endif
+	return stoplevels;
 }
 
 void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep)
@@ -294,8 +418,11 @@ void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep)
 	struct sample *sample;
 	int wait_time, o2, he;
 	int ceiling, depth, transitiontime;
-	int stopidx;
+	int stopidx, gi;
 	double tissue_tolerance;
+	struct gaschanges *gaschanges;
+	int gaschangenr;
+	int *stoplevels;
 
 	if (!diveplan->surface_pressure)
 		diveplan->surface_pressure = 1013;
@@ -311,23 +438,31 @@ void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep)
 	o2 = dive->cylinder[0].gasmix.o2.permille;
 	he = dive->cylinder[0].gasmix.he.permille;
 	get_gas_from_events(&dive->dc, sample->time.seconds, &o2, &he);
-#if DEBUG_PLAN & 4
-	printf("gas %d/%d\n", o2, he);
-#endif
+	depth = dive->dc.sample[dive->dc.samples - 1].depth.mm;
 	tissue_tolerance = tissue_at_end(dive, cached_datap);
 	ceiling = deco_allowed_depth(tissue_tolerance, diveplan->surface_pressure / 1000.0, dive, 1);
 #if DEBUG_PLAN & 4
-	printf("ceiling %5.2lfm\n", ceiling / 1000.0);
+	printf("gas %d/%d\n", o2, he);
+	printf("depth %5.2lfm ceiling %5.2lfm\n", depth / 1000.0, ceiling / 1000.0);
 #endif
-	for (stopidx = 0; stopidx < sizeof(stoplevels) / sizeof(int); stopidx++)
-		if (stoplevels[stopidx] >= ceiling)
+	if (depth < ceiling) /* that's not good... */
+		depth = ceiling;
+	for (stopidx = 0; stopidx < sizeof(decostoplevels) / sizeof(int); stopidx++)
+		if (decostoplevels[stopidx] >= depth)
 			break;
-
-	/* now get us to the first stop - NOTE, this could be 0m! */
-#if DEBUG_PLAN & 2
-	printf("first stop at %5.2lfm\n", stoplevels[stopidx] / 1000.0);
-#endif
-	depth = dive->dc.sample[dive->dc.samples - 1].depth.mm;
+	stopidx--;
+
+	/* so now we now the first decostop level above us
+	 * NOTE, this could be the surface or a long list of potential stops
+	 * we do NOT start only at the ceiling, as the ceiling may come down
+	 * further during the ascent.
+	 * Next we need to figure out if there are better gases available
+	 * and at which depths we are supposed to switch to them */
+	gaschanges = analyze_gaslist(diveplan, dive, &gaschangenr);
+	stoplevels = sort_stops(decostoplevels, stopidx + 1, gaschanges, gaschangenr);
+
+	gi = gaschangenr - 1;
+	stopidx += gaschangenr;
 	if (depth > stoplevels[stopidx]) {
 		transitiontime = (depth - stoplevels[stopidx]) / 150;
 #if DEBUG_PLAN & 2
@@ -339,7 +474,16 @@ void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep)
 		*divep = dive = create_dive_from_plan(diveplan);
 		record_dive(dive);
 	}
-	while (stopidx > 0) { /* this indicates that we had a non-zero first ceiling */
+	while (stopidx > 0) { /* this indicates that we aren't surfacing directly */
+		if (gi >= 0 && stoplevels[stopidx] == gaschanges[gi].depth) {
+			o2 = dive->cylinder[gaschanges[gi].gasidx].gasmix.o2.permille;
+			he = dive->cylinder[gaschanges[gi].gasidx].gasmix.he.permille;
+#if DEBUG_PLAN & 16
+			printf("switch to gas %d (%d/%d) @ %5.2lfm\n", gaschanges[gi].gasidx,
+				o2 / 10, he / 10, gaschanges[gi].depth / 1000.0);
+#endif
+			gi--;
+		}
 		wait_time = time_at_last_depth(dive, stoplevels[stopidx - 1], cached_datap);
 		/* typically deco plans are done in one minute increments; we may want to
 		 * make this configurable at some point */
@@ -363,6 +507,8 @@ void plan(struct diveplan *diveplan, char **cached_datap, struct dive **divep)
 	/* now make the dive visible as last dive of the dive list */
 	report_dives(FALSE, FALSE);
 	select_last_dive();
+	free(stoplevels);
+	free(gaschanges);
 }
 
 
@@ -576,18 +722,14 @@ void show_planned_dive(void)
 	memcpy(&tempplan, &diveplan, sizeof(struct diveplan));
 	dpp = &tempplan.dp;
 	dp = diveplan.dp;
-	while(*dpp) {
+	while(dp && *dpp) {
 		*dpp = malloc(sizeof(struct divedatapoint));
 		memcpy(*dpp, dp, sizeof(struct divedatapoint));
 		dp = dp->next;
-		if (dp && !dp->time) {
-			/* we have an incomplete entry - stop before it */
-			(*dpp)->next = NULL;
-			break;
-		}
 		dpp = &(*dpp)->next;
 	}
 #if DEBUG_PLAN & 1
+	printf("in show_planned_dive:\n");
 	dump_plan(&tempplan);
 #endif
 	plan(&tempplan, &cache_data, &planned_dive);
@@ -658,13 +800,9 @@ static gboolean duration_focus_out_cb(GtkWidget *entry, GdkEvent * event, gpoint
 	int idx = data - NULL;
 
 	durationtext = gtk_entry_get_text(GTK_ENTRY(entry));
-	if (validate_time(durationtext, &duration, &is_rel)) {
+	if (validate_time(durationtext, &duration, &is_rel))
 		add_duration_to_nth_dp(&diveplan, idx, duration, is_rel);
-		show_planned_dive();
-	} else {
-		/* we need to instead change the color of the input field or something */
-		printf("invalid duration for row %d\n", idx);
-	}
+	show_planned_dive();
 	return FALSE;
 }
 
@@ -677,6 +815,7 @@ static gboolean starttime_focus_out_cb(GtkWidget *entry, GdkEvent * event, gpoin
 	if (validate_time(starttimetext, &starttime, &is_rel)) {
 		/* we alway make this relative for now */
 		diveplan.when = time(NULL) + starttime;
+		show_planned_dive();
 	} else {
 		/* we need to instead change the color of the input field or something */
 		printf("invalid starttime\n");
@@ -684,6 +823,16 @@ static gboolean starttime_focus_out_cb(GtkWidget *entry, GdkEvent * event, gpoin
 	return FALSE;
 }
 
+static gboolean surfpres_focus_out_cb(GtkWidget *entry, GdkEvent * event, gpointer data)
+{
+	const char *surfprestext;
+
+	surfprestext = gtk_entry_get_text(GTK_ENTRY(entry));
+	diveplan.surface_pressure = atoi(surfprestext);
+	show_planned_dive();
+	return FALSE;
+}
+
 static GtkWidget *add_gas_combobox_to_box(GtkWidget *box, const char *label, int idx)
 {
 	GtkWidget *frame, *combo;
@@ -758,8 +907,9 @@ static void add_waypoint_cb(GtkButton *button, gpointer _data)
 
 void input_plan()
 {
-	GtkWidget *planner, *content, *vbox, *outervbox, *add_row, *deltat;
+	GtkWidget *planner, *content, *vbox, *hbox, *outervbox, *add_row, *deltat, *label, *surfpres;
 	char starttimebuf[64] = "+60:00";
+	char pressurebuf[64] = "1013";
 
 	if (diveplan.dp)
 		free_dps(diveplan.dp);
@@ -771,17 +921,34 @@ void input_plan()
 					GTK_STOCK_OK, GTK_RESPONSE_ACCEPT,
 					GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
 					NULL);
-
 	content = gtk_dialog_get_content_area (GTK_DIALOG (planner));
 	outervbox = gtk_vbox_new(FALSE, 2);
 	gtk_container_add (GTK_CONTAINER (content), outervbox);
+	label = gtk_label_new(_("<small>Add segments below.\nEach line describes part of the planned dive.\n"
+						"An entry with depth, time and gas describes a segment that ends "
+						"at the given depth, takes the given time (if relative, e.g. '+3:30') "
+						"or ends at the given time (if absolute), and uses the given gas.\n"
+						"An empty gas means 'use previous gas' (or AIR if no gas was specified).\n"
+						"An entry that has a depth and a gas given but no time is special; it "
+						"informs the planner that the gas specified is available for the ascent "
+						"once the depth given has been reached.</small>"));
+	gtk_label_set_line_wrap(GTK_LABEL(label), TRUE);
+	gtk_label_set_use_markup(GTK_LABEL(label), TRUE);
+	gtk_box_pack_start(GTK_BOX(outervbox), label, TRUE, TRUE, 0);
 	vbox = gtk_vbox_new(FALSE, 0);
 	gtk_box_pack_start(GTK_BOX(outervbox), vbox, TRUE, TRUE, 0);
-	deltat = add_entry_to_box(vbox, _("Dive starts in how many minutes?"));
+	hbox = gtk_hbox_new(FALSE, 0);
+	gtk_box_pack_start(GTK_BOX(vbox), hbox, TRUE, TRUE, 0);
+	deltat = add_entry_to_box(hbox, _("Dive starts in how many minutes?"));
 	gtk_entry_set_max_length(GTK_ENTRY(deltat), 12);
 	gtk_entry_set_text(GTK_ENTRY(deltat), starttimebuf);
 	gtk_widget_add_events(deltat, GDK_FOCUS_CHANGE_MASK);
 	g_signal_connect(deltat, "focus-out-event", G_CALLBACK(starttime_focus_out_cb), NULL);
+	surfpres = add_entry_to_box(hbox, _("Surface Pressure (mbar)"));
+	gtk_entry_set_max_length(GTK_ENTRY(surfpres), 12);
+	gtk_entry_set_text(GTK_ENTRY(surfpres), pressurebuf);
+	gtk_widget_add_events(surfpres, GDK_FOCUS_CHANGE_MASK);
+	g_signal_connect(surfpres, "focus-out-event", G_CALLBACK(surfpres_focus_out_cb), NULL);
 	diveplan.when = time(NULL) + 3600;
 	diveplan.surface_pressure = 1013;
 	nr_waypoints = 4;