VPMB profile: use bottom_time to calculate deco_time in planner

This corrects the issue where the displayed ceiling in the profile was
"broken" by the planner, especially for shorter and shallower dives.

Also fixes issue outside of planner where the deepest VPM-B ceiling was shown
too early, messing up the deco_time calculation.

VPM-B plans respond to change in O2% in gas as expected (in my testing)

Fixes: #630

Signed-off-by: Rick Walsh <rickmwalsh@gmail.com>

2 files changed, 24 insertions, 13 deletions

diff --git a/core/planner.c b/core/planner.c
index 18f3c8701..c0b07680d 100644
--- a/core/planner.c
+++ b/core/planner.c
@@ -34,6 +34,7 @@ int decostoplevels_imperial[] = { 0, 3048, 6096, 9144, 12192, 15240, 18288, 2133
 				325120, 345440, 365760, 386080 };
 
 double plangflow, plangfhigh;
+int bottom_time = 0;
 
 extern double regressiona();
 extern double regressionb();
@@ -669,7 +670,7 @@ bool plan(struct diveplan *diveplan, struct dive *dive, int timestep, struct dec
 	bool stopping = false;
 	bool pendinggaschange = false;
 	int clock, previous_point_time;
-	int avg_depth, max_depth, bottom_time = 0;
+	int avg_depth, max_depth;
 	int last_ascend_rate;
 	int best_first_ascend_cylinder;
 	struct gasmix gas, bottom_gas;
@@ -1066,6 +1067,7 @@ bool plan(struct diveplan *diveplan, struct dive *dive, int timestep, struct dec
 		diveplan->eff_gflow = lrint(100.0 * (regressiona() * first_stop_depth + regressionb()));
 	}
 
+
 	create_dive_from_plan(diveplan, dive, is_planner);
 	add_plan_to_notes(diveplan, dive, show_disclaimer, error);
 	fixup_dc_duration(&dive->dc);
diff --git a/core/profile.c b/core/profile.c
index 53eff57e6..e96febffb 100644
--- a/core/profile.c
+++ b/core/profile.c
@@ -31,6 +31,7 @@ static struct plot_data *last_pi_entry_new = NULL;
 void populate_pressure_information(struct dive *, struct divecomputer *, struct plot_info *, int);
 
 extern bool in_planner();
+extern int bottom_time;
 
 #ifdef DEBUG_PI
 /* debugging tool - not normally used */
@@ -954,19 +955,25 @@ static void calculate_ndl_tts(struct dive *dive, struct plot_data *entry, struct
  */
 void calculate_deco_information(struct dive *dive, struct divecomputer *dc, struct plot_info *pi, bool print_mode)
 {
-	int i, count_iteration = 0;
+	int i, count_iteration = 0, deco_time;
 	double surface_pressure = (dc->surface_pressure.mbar ? dc->surface_pressure.mbar : get_surface_pressure_in_mbar(dive, true)) / 1000.0;
 	bool first_iteration = true;
-	int deco_time = 0, prev_deco_time = 10000000;
+	int prev_deco_time = 10000000, time_deep_ceiling = 0;
+	if (in_planner())
+		deco_time = pi->maxtime - bottom_time;
+	else
+		deco_time = 0;
 	struct deco_state *cache_data_initial = NULL;
 	/* For VPM-B outside the planner, cache the initial deco state for CVA iterations */
-	if (decoMode() == VPMB && !in_planner())
+	if (decoMode() == VPMB) {
 		cache_deco_state(&cache_data_initial);
+	}
 	/* For VPM-B outside the planner, iterate until deco time converges (usually one or two iterations after the initial)
 	 * Set maximum number of iterations to 10 just in case */
 	while ((abs(prev_deco_time - deco_time) >= 30) && (count_iteration < 10)) {
-		int last_ndl_tts_calc_time = 0, first_ceiling = 0, current_ceiling, last_ceiling, final_tts = 0 , time_clear_ceiling = 0, time_deep_ceiling = 0;
-		deco_state->first_ceiling_pressure.mbar = depth_to_mbar(first_ceiling, dive);
+		int last_ndl_tts_calc_time = 0, first_ceiling = 0, current_ceiling, last_ceiling, final_tts = 0 , time_clear_ceiling = 0;
+		if (decoMode() == VPMB)
+			deco_state->first_ceiling_pressure.mbar = depth_to_mbar(first_ceiling, dive);
 		struct gasmix *gasmix = NULL;
 		struct event *ev = NULL;
 
@@ -1001,9 +1008,9 @@ void calculate_deco_information(struct dive *dive, struct divecomputer *dc, stru
 				if (decoMode() == VPMB && last_ceiling >= first_ceiling && first_iteration == true) {
 					nuclear_regeneration(t1);
 					vpmb_start_gradient();
-					/* For CVA calculations, start by guessing deco time = dive time remaining */
-					deco_time = pi->maxtime - t1;
-					vpmb_next_gradient(deco_time, surface_pressure / 1000.0);
+					/* For CVA iterations, calculate next gradient */
+					if (!first_iteration || in_planner())
+						vpmb_next_gradient(deco_time, surface_pressure / 1000.0);
 				}
 				entry->ceiling = deco_allowed_depth(tissue_tolerance_calc(dive, depth_to_bar(entry->depth, dive)), surface_pressure, dive, !prefs.calcceiling3m);
 				if (prefs.calcceiling3m)
@@ -1011,9 +1018,10 @@ void calculate_deco_information(struct dive *dive, struct divecomputer *dc, stru
 				else
 					current_ceiling = entry->ceiling;
 				last_ceiling = current_ceiling;
-				/* If using VPM-B outside the planner, take first_ceiling_pressure as the deepest ceiling */
+				/* If using VPM-B, take first_ceiling_pressure as the deepest ceiling */
 				if (decoMode() == VPMB) {
-					if  (current_ceiling > first_ceiling) {
+					if  (current_ceiling >= first_ceiling ||
+					     time_deep_ceiling == t0 && entry->depth == (entry - 1)->depth) {
 						time_deep_ceiling = t1;
 						first_ceiling = current_ceiling;
 						deco_state->first_ceiling_pressure.mbar = depth_to_mbar(first_ceiling, dive);
@@ -1021,7 +1029,8 @@ void calculate_deco_information(struct dive *dive, struct divecomputer *dc, stru
 							nuclear_regeneration(t1);
 							vpmb_start_gradient();
 							/* For CVA calculations, start by guessing deco time = dive time remaining */
-							deco_time = pi->maxtime - t1;
+							if (!in_planner())
+								deco_time = pi->maxtime - t1;
 							vpmb_next_gradient(deco_time, surface_pressure / 1000.0);
 						}
 					}
@@ -1083,7 +1092,7 @@ void calculate_deco_information(struct dive *dive, struct divecomputer *dc, stru
 			count_iteration ++;
 			restore_deco_state(cache_data_initial, true);
 		} else {
-			// With Buhlmann, or not in planner, iterating isn't needed.  This makes the while condition false.
+			// With Buhlmann iterating isn't needed.  This makes the while condition false.
 			prev_deco_time = deco_time = 0;
 		}
 	}