VPM-B: add CVA to the deco planner.

Added keeping bottom dive state and every deco's time, so we can
run multiple deco simulations with different gradients until they
converge to some optimal value.

Some improvements on the deco time calculation may be needed.

Signed-off-by: Jan Darowski <jan.darowski@gmail.com>

1 files changed, 161 insertions, 121 deletions

diff --git a/planner.c b/planner.c
index 700985052..83e475758 100644
--- a/planner.c
+++ b/planner.c
@@ -869,6 +869,14 @@ bool enough_gas(int current_cylinder)
 
 bool plan(struct diveplan *diveplan, char **cached_datap, bool is_planner, bool show_disclaimer)
 {
+	int bottom_depth;
+	int bottom_gi;
+	int bottom_stopidx;
+
+	bool is_final_plan = true;
+	int deco_time;
+	int previous_deco_time;
+	char *bottom_cache = NULL;
 	struct sample *sample;
 	int po2;
 	int transitiontime, gi;
@@ -886,7 +894,7 @@ bool plan(struct diveplan *diveplan, char **cached_datap, bool is_planner, bool
 	int avg_depth, max_depth, bottom_time = 0;
 	int last_ascend_rate;
 	int best_first_ascend_cylinder;
-	struct gasmix gas;
+	struct gasmix gas, bottom_gas;
 	int o2time = 0;
 	int breaktime = -1;
 	int breakcylinder = 0;
@@ -1008,7 +1016,6 @@ bool plan(struct diveplan *diveplan, char **cached_datap, bool is_planner, bool
 
 		free(stoplevels);
 		free(gaschanges);
-
 		return(false);
 	}
 
@@ -1027,148 +1034,181 @@ bool plan(struct diveplan *diveplan, char **cached_datap, bool is_planner, bool
 	// VPM-B or Buehlmann Deco
 	nuclear_regeneration(clock);
 	vpmb_start_gradient();
+	previous_deco_time = 100000000;
+	deco_time = 10000000;
+	cache_deco_state(tissue_tolerance, &bottom_cache);  // Lets us make several iterations
+	bottom_depth = depth;
+	bottom_gi = gi;
+	bottom_gas = gas;
+	bottom_stopidx = stopidx;
+	//CVA
+	do {
+		is_final_plan = (prefs.deco_mode == BUEHLMANN) || (previous_deco_time - deco_time < 10);  // CVA time converges
+		previous_deco_time = deco_time;
+		restore_deco_state(bottom_cache);
+
+		depth = bottom_depth;
+		gi = bottom_gi;
+		clock = previous_point_time = bottom_time;
+		gas = bottom_gas;
+		stopping = false;
+		decodive = false;
+		stopidx = bottom_stopidx;
+		breaktime = -1;
+		breakcylinder = 0;
+		o2time = 0;
+		last_ascend_rate = ascent_velocity(depth, avg_depth, bottom_time);
+		if ((current_cylinder = get_gasidx(&displayed_dive, &gas)) == -1) {
+			report_error(translate("gettextFromC", "Can't find gas %s"), gasname(&gas));
+			current_cylinder = 0;
+		}
+		vpmb_next_gradient(deco_time);
 
-	while (1) {
-		/* We will break out when we hit the surface */
-		do {
-			/* Ascend to next stop depth */
-			int deltad = ascent_velocity(depth, avg_depth, bottom_time) * TIMESTEP;
-			if (ascent_velocity(depth, avg_depth, bottom_time) != last_ascend_rate) {
-				plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+		while (1) {
+			/* We will break out when we hit the surface */
+			do {
+				/* Ascend to next stop depth */
+				int deltad = ascent_velocity(depth, avg_depth, bottom_time) * TIMESTEP;
+				if (ascent_velocity(depth, avg_depth, bottom_time) != last_ascend_rate) {
+					if (is_final_plan)
+						plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+					previous_point_time = clock;
+					stopping = false;
+					last_ascend_rate = ascent_velocity(depth, avg_depth, bottom_time);
+				}
+				if (depth - deltad < stoplevels[stopidx])
+					deltad = depth - stoplevels[stopidx];
+
+				tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
+								&displayed_dive.cylinder[current_cylinder].gasmix,
+								TIMESTEP, po2, &displayed_dive, prefs.decosac);
+				clock += TIMESTEP;
+				depth -= deltad;
+			} while (depth > 0 && depth > stoplevels[stopidx]);
+
+			if (depth <= 0)
+				break; /* We are at the surface */
+
+			if (gi >= 0 && stoplevels[stopidx] <= gaschanges[gi].depth) {
+				/* We have reached a gas change.
+				 * Record this in the dive plan */
+				if (is_final_plan)
+					plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
 				previous_point_time = clock;
-				stopping = false;
-				last_ascend_rate = ascent_velocity(depth, avg_depth, bottom_time);
-			}
-			if (depth - deltad < stoplevels[stopidx])
-				deltad = depth - stoplevels[stopidx];
+				stopping = true;
 
-			tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
-						       &displayed_dive.cylinder[current_cylinder].gasmix,
-						       TIMESTEP, po2, &displayed_dive, prefs.decosac);
-			clock += TIMESTEP;
-			depth -= deltad;
-		} while (depth > 0 && depth > stoplevels[stopidx]);
-
-		if (depth <= 0)
-			break; /* We are at the surface */
-
-		if (gi >= 0 && stoplevels[stopidx] <= gaschanges[gi].depth) {
-			/* We have reached a gas change.
-			 * Record this in the dive plan */
-			plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
-			previous_point_time = clock;
-			stopping = true;
-
-			/* Check we need to change cylinder.
-			 * We might not if the cylinder was chosen by the user
-			 * or user has selected only to switch only at required stops.
-			 * If current gas is hypoxic, we want to switch asap */
-			if (current_cylinder != gaschanges[gi].gasidx) {
-				if (!prefs.switch_at_req_stop ||
-						!trial_ascent(depth, stoplevels[stopidx - 1], avg_depth, bottom_time, tissue_tolerance,
-						&displayed_dive.cylinder[current_cylinder].gasmix, po2, diveplan->surface_pressure / 1000.0) || get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) < 160) {
-					current_cylinder = gaschanges[gi].gasidx;
+				/* Check we need to change cylinder.
+				 * We might not if the cylinder was chosen by the user
+				 * or user has selected only to switch only at required stops.
+				 * If current gas is hypoxic, we want to switch asap */
+				if (current_cylinder != gaschanges[gi].gasidx) {
+					if (!prefs.switch_at_req_stop ||
+							!trial_ascent(depth, stoplevels[stopidx - 1], avg_depth, bottom_time, tissue_tolerance,
+							&displayed_dive.cylinder[current_cylinder].gasmix, po2, diveplan->surface_pressure / 1000.0) || get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) < 160) {
+						current_cylinder = gaschanges[gi].gasidx;
+						gas = displayed_dive.cylinder[current_cylinder].gasmix;
+#if DEBUG_PLAN & 16
+						printf("switch to gas %d (%d/%d) @ %5.2lfm\n", gaschanges[gi].gasidx,
+							(get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[gi].depth / 1000.0);
+#endif
+						/* Stop for the minimum duration to switch gas */
+						tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
+							&displayed_dive.cylinder[current_cylinder].gasmix,
+							prefs.min_switch_duration, po2, &displayed_dive, prefs.decosac);
+						clock += prefs.min_switch_duration;
+					} else {
+						pendinggaschange = true;
+					}
+				gi--;
+				}
+			}
+			--stopidx;
+
+			/* Save the current state and try to ascend to the next stopdepth */
+			while (1) {
+				/* Check if ascending to next stop is clear, go back and wait if we hit the ceiling on the way */
+				if (trial_ascent(depth, stoplevels[stopidx], avg_depth, bottom_time, tissue_tolerance,
+						&displayed_dive.cylinder[current_cylinder].gasmix, po2, diveplan->surface_pressure / 1000.0))
+					break; /* We did not hit the ceiling */
+
+				/* Add a minute of deco time and then try again */
+				decodive = true;
+				if (!stopping) {
+					/* The last segment was an ascend segment.
+					 * Add a waypoint for start of this deco stop */
+					if (is_final_plan)
+						plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+					previous_point_time = clock;
+					stopping = true;
+				}
+				if (pendinggaschange) {
+					current_cylinder = gaschanges[gi + 1].gasidx;
 					gas = displayed_dive.cylinder[current_cylinder].gasmix;
 #if DEBUG_PLAN & 16
-					printf("switch to gas %d (%d/%d) @ %5.2lfm\n", gaschanges[gi].gasidx,
-						(get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[gi].depth / 1000.0);
+					printf("switch to gas %d (%d/%d) @ %5.2lfm\n", gaschanges[gi + 1].gasidx,
+						(get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[gi + 1].depth / 1000.0);
 #endif
 					/* Stop for the minimum duration to switch gas */
 					tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
 						&displayed_dive.cylinder[current_cylinder].gasmix,
 						prefs.min_switch_duration, po2, &displayed_dive, prefs.decosac);
 					clock += prefs.min_switch_duration;
-				} else {
-					pendinggaschange = true;
+					pendinggaschange = false;
 				}
-			gi--;
-			}
-		}
 
-		--stopidx;
-
-		/* Save the current state and try to ascend to the next stopdepth */
-		while (1) {
-			/* Check if ascending to next stop is clear, go back and wait if we hit the ceiling on the way */
-			if (trial_ascent(depth, stoplevels[stopidx], avg_depth, bottom_time, tissue_tolerance,
-					 &displayed_dive.cylinder[current_cylinder].gasmix, po2, diveplan->surface_pressure / 1000.0))
-				break; /* We did not hit the ceiling */
-
-			/* Add a minute of deco time and then try again */
-			decodive = true;
-			if (!stopping) {
-				/* The last segment was an ascend segment.
-				 * Add a waypoint for start of this deco stop */
-				plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
-				previous_point_time = clock;
-				stopping = true;
-			}
+				/* Deco stop should end when runtime is at a whole minute */
+				int this_decotimestep;
+				this_decotimestep = DECOTIMESTEP - clock % DECOTIMESTEP;
 
-			if (pendinggaschange) {
-				current_cylinder = gaschanges[gi + 1].gasidx;
-				gas = displayed_dive.cylinder[current_cylinder].gasmix;
-#if DEBUG_PLAN & 16
-				printf("switch to gas %d (%d/%d) @ %5.2lfm\n", gaschanges[gi + 1].gasidx,
-					(get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[gi + 1].depth / 1000.0);
-#endif
-				/* Stop for the minimum duration to switch gas */
 				tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
-					&displayed_dive.cylinder[current_cylinder].gasmix,
-					prefs.min_switch_duration, po2, &displayed_dive, prefs.decosac);
-				clock += prefs.min_switch_duration;
-				pendinggaschange = false;
-			}
-
-			/* Deco stop should end when runtime is at a whole minute */
-			int this_decotimestep;
-			this_decotimestep = DECOTIMESTEP - clock % DECOTIMESTEP;
-
-			tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
-						       &displayed_dive.cylinder[current_cylinder].gasmix,
-						       this_decotimestep, po2, &displayed_dive, prefs.decosac);
-			clock += this_decotimestep;
-			/* Finish infinite deco */
-			if(clock >= 48 * 3600 && depth >= 6000) {
-				error = LONGDECO;
-				break;
-			}
-			if (prefs.doo2breaks) {
-				if (get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) == 1000) {
-					o2time += DECOTIMESTEP;
-					if (o2time >= 12 * 60) {
-						breaktime = 0;
-						breakcylinder = current_cylinder;
-						plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
-						previous_point_time = clock;
-						current_cylinder = 0;
-						gas = displayed_dive.cylinder[current_cylinder].gasmix;
-					}
-				} else {
-					if (breaktime >= 0) {
-						breaktime += DECOTIMESTEP;
-						if (breaktime >= 6 * 60) {
-							o2time = 0;
-							plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+								&displayed_dive.cylinder[current_cylinder].gasmix,
+								this_decotimestep, po2, &displayed_dive, prefs.decosac);
+				clock += this_decotimestep;
+				/* Finish infinite deco */
+				if(clock >= 48 * 3600 && depth >= 6000) {
+					error = LONGDECO;
+					break;
+				}
+				if (prefs.doo2breaks) {
+					if (get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) == 1000) {
+						o2time += DECOTIMESTEP;
+						if (o2time >= 12 * 60) {
+							breaktime = 0;
+							breakcylinder = current_cylinder;
+							if (is_final_plan)
+								plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
 							previous_point_time = clock;
-							current_cylinder = breakcylinder;
+							current_cylinder = 0;
 							gas = displayed_dive.cylinder[current_cylinder].gasmix;
-							breaktime = -1;
+						}
+					} else {
+						if (breaktime >= 0) {
+							breaktime += DECOTIMESTEP;
+							if (breaktime >= 6 * 60) {
+								o2time = 0;
+								if (is_final_plan)
+									plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+								previous_point_time = clock;
+								current_cylinder = breakcylinder;
+								gas = displayed_dive.cylinder[current_cylinder].gasmix;
+								breaktime = -1;
+							}
 						}
 					}
 				}
 			}
+			if (stopping) {
+				/* Next we will ascend again. Add a waypoint if we have spend deco time */
+				if (is_final_plan)
+					plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
+				previous_point_time = clock;
+				stopping = false;
+			}
 		}
-		if (stopping) {
-			/* Next we will ascend again. Add a waypoint if we have spend deco time */
-			plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
-			previous_point_time = clock;
-			stopping = false;
-		}
-	}
 
-	/* We made it to the surface
-	 * Create the final dive, add the plan to the notes and fixup some internal
-	 * data that we need to be there when plotting the dive */
+		deco_time = clock - bottom_time;
+	} while (!is_final_plan);
+
 	plan_add_segment(diveplan, clock - previous_point_time, 0, gas, po2, false);
 	create_dive_from_plan(diveplan, is_planner);
 	add_plan_to_notes(diveplan, &displayed_dive, show_disclaimer, error);