示例#1
0
bool trial_ascent(int trial_depth, int stoplevel, int avg_depth, int bottom_time, double tissue_tolerance, struct gasmix *gasmix, int po2, double surface_pressure)
{

	bool clear_to_ascend = true;
	char *trial_cache = NULL;

	cache_deco_state(tissue_tolerance, &trial_cache);
	while (trial_depth > stoplevel) {
		int deltad = ascent_velocity(trial_depth, avg_depth, bottom_time) * TIMESTEP;
		if (deltad > trial_depth) /* don't test against depth above surface */
			deltad = trial_depth;
		tissue_tolerance = add_segment(depth_to_mbar(trial_depth, &displayed_dive) / 1000.0,
					       gasmix,
					       TIMESTEP, po2, &displayed_dive, prefs.decosac);
		if (deco_allowed_depth(tissue_tolerance, surface_pressure, &displayed_dive, 1) > trial_depth - deltad) {
			/* We should have stopped */
			clear_to_ascend = false;
			break;
		}
		trial_depth -= deltad;
	}
	restore_deco_state(trial_cache);
	free(trial_cache);
	return clear_to_ascend;
}
示例#2
0
/* 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;
	depth_t lastdepth = {};
	duration_t t0 = {}, t1 = {};
	double tissue_tolerance;
	struct gasmix gas;

	if (!dive)
		return 0.0;
	if (*cached_datap) {
		tissue_tolerance = restore_deco_state(*cached_datap);
	} else {
		tissue_tolerance = init_decompression(dive);
		cache_deco_state(tissue_tolerance, cached_datap);
	}
	dc = &dive->dc;
	if (!dc->samples)
		return tissue_tolerance;
	psample = sample = dc->sample;

	for (i = 0; i < dc->samples; i++, sample++) {
		t1 = sample->time;
		get_gas_at_time(dive, dc, t0, &gas);
		if (i > 0)
			lastdepth = psample->depth;
		tissue_tolerance = interpolate_transition(dive, t0, t1, lastdepth, sample->depth, &gas, sample->po2);
		psample = sample;
		t0 = t1;
	}
	return tissue_tolerance;
}
示例#3
0
// Determine whether ascending to the next stop will break the ceiling.  Return true if the ascent is ok, false if it isn't.
bool trial_ascent(int trial_depth, int stoplevel, int avg_depth, int bottom_time, double tissue_tolerance, struct gasmix *gasmix, int po2, double surface_pressure)
{

	bool clear_to_ascend = true;
	char *trial_cache = NULL;

	// For VPM-B it is not relevant if we would violate a ceiling during ascent to the next stop but
	// if the next stop is below the ceiling at the start of the ascent (thus the offgasing during
	// the ascent is ignored.
	if (prefs.deco_mode == VPMB)
		return (deco_allowed_depth(tissue_tolerance, surface_pressure, &displayed_dive, 1) <= stoplevel);

	cache_deco_state(tissue_tolerance, &trial_cache);
	while (trial_depth > stoplevel) {
		int deltad = ascent_velocity(trial_depth, avg_depth, bottom_time) * TIMESTEP;
		if (deltad > trial_depth) /* don't test against depth above surface */
			deltad = trial_depth;
		tissue_tolerance = add_segment(depth_to_mbar(trial_depth, &displayed_dive) / 1000.0,
					       gasmix,
					       TIMESTEP, po2, &displayed_dive, prefs.decosac);
		if (deco_allowed_depth(tissue_tolerance, surface_pressure, &displayed_dive, 1) > trial_depth - deltad) {
			/* We should have stopped */
			clear_to_ascend = false;
			break;
		}
		trial_depth -= deltad;
	}
	restore_deco_state(trial_cache);
	free(trial_cache);
	return clear_to_ascend;
}
示例#4
0
void DivePlannerPointsModel::computeVariations()
{
	bool oldRecalc = setRecalc(false);
	struct dive *dive = alloc_dive();
	copy_dive(&displayed_dive, dive);
	struct decostop original[60], deeper[60], shallower[60], shorter[60], longer[60];
	struct deco_state *cache = NULL, *save = NULL;
	struct diveplan plan_copy;
	struct divedatapoint *last_segment;

	if(in_planner() && prefs.display_variations) {
		cache_deco_state(&save);
		cloneDiveplan(&plan_copy);
		plan(&plan_copy, dive, 1, original, &cache, true, false);
		free_dps(&plan_copy);
		restore_deco_state(save, false);

		last_segment = cloneDiveplan(&plan_copy);
		last_segment->depth.mm += 1000;
		last_segment->next->depth.mm += 1000;
		plan(&plan_copy, dive, 1, deeper, &cache, true, false);
		free_dps(&plan_copy);
		restore_deco_state(save, false);

		last_segment = cloneDiveplan(&plan_copy);
		last_segment->depth.mm -= 1000;
		last_segment->next->depth.mm -= 1000;
		plan(&plan_copy, dive, 1, shallower, &cache, true, false);
		free_dps(&plan_copy);
		restore_deco_state(save, false);

		last_segment = cloneDiveplan(&plan_copy);
		last_segment->next->time += 60;
		plan(&plan_copy, dive, 1, longer, &cache, true, false);
		free_dps(&plan_copy);
		restore_deco_state(save, false);

		last_segment = cloneDiveplan(&plan_copy);
		last_segment->next->time -= 60;
		plan(&plan_copy, dive, 1, shorter, &cache, true, false);
		free_dps(&plan_copy);
		restore_deco_state(save, false);
#ifdef SHOWSTOPVARIATIONS
		printf("\n\n");
#endif

		QString notes(displayed_dive.notes);
		free(displayed_dive.notes);

		char buf[200];
		sprintf(buf, "+ %d:%02d /m + %d:%02d /min", FRACTION(analyzeVariations(shallower, original, deeper, "m"),60),
			FRACTION(analyzeVariations(shorter, original, longer, "min"), 60));

		displayed_dive.notes = strdup(notes.replace("VARIATIONS", QString(buf)).toUtf8().data());
	}
	setRecalc(oldRecalc);
}
示例#5
0
/* 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, t0, t1, gasidx, lastdepth;
	double tissue_tolerance;
	struct gasmix gas;

	if (!dive)
		return 0.0;
	if (*cached_datap) {
		tissue_tolerance = restore_deco_state(*cached_datap);
	} else {
		tissue_tolerance = init_decompression(dive);
		cache_deco_state(tissue_tolerance, cached_datap);
	}
	dc = &dive->dc;
	if (!dc->samples)
		return tissue_tolerance;
	psample = sample = dc->sample;
	lastdepth = t0 = 0;
	/* we always start with gas 0 (unless an event tells us otherwise) */
	gas = dive->cylinder[0].gasmix;
	for (i = 0; i < dc->samples; i++, sample++) {
		t1 = sample->time.seconds;
		get_gas_from_events(&dive->dc, t0, &gas);
		if ((gasidx = get_gasidx(dive, &gas)) == -1) {
			report_error(translate("gettextFromC", "Can't find gas %s"), gasname(&gas));
			gasidx = 0;
		}
		if (i > 0)
			lastdepth = psample->depth.mm;
		tissue_tolerance = interpolate_transition(dive, t0, t1, lastdepth, sample->depth.mm, &dive->cylinder[gasidx].gasmix, sample->po2.mbar);
		psample = sample;
		t0 = t1;
	}
	return tissue_tolerance;
}
示例#6
0
void plan(struct diveplan *diveplan, char **cached_datap, bool is_planner, bool show_disclaimer)
{
	struct sample *sample;
	int po2;
	int transitiontime, gi;
	int current_cylinder;
	unsigned int stopidx;
	int depth;
	double tissue_tolerance = 0.0;
	struct gaschanges *gaschanges = NULL;
	int gaschangenr;
	int *stoplevels = NULL;
	char *trial_cache = NULL;
	bool stopping = false;
	bool clear_to_ascend;
	int clock, previous_point_time;
	int avg_depth, bottom_time = 0;
	int last_ascend_rate;
	int best_first_ascend_cylinder;
	struct gasmix gas;
	int o2time = 0;
	int breaktime = -1;
	int breakcylinder;

	set_gf(diveplan->gflow, diveplan->gfhigh, prefs.gf_low_at_maxdepth);
	if (!diveplan->surface_pressure)
		diveplan->surface_pressure = SURFACE_PRESSURE;
	create_dive_from_plan(diveplan, is_planner);

	/* Let's start at the last 'sample', i.e. the last manually entered waypoint. */
	sample = &displayed_dive.dc.sample[displayed_dive.dc.samples - 1];

	get_gas_at_time(&displayed_dive, &displayed_dive.dc, sample->time, &gas);

	po2 = displayed_dive.dc.sample[displayed_dive.dc.samples - 1].po2.mbar;
	if ((current_cylinder = get_gasidx(&displayed_dive, &gas)) == -1) {
		report_error(translate("gettextFromC", "Can't find gas %s"), gasname(&gas));
		current_cylinder = 0;
	}
	depth = displayed_dive.dc.sample[displayed_dive.dc.samples - 1].depth.mm;
	avg_depth = average_depth(diveplan);
	last_ascend_rate = ascend_velocity(depth, avg_depth, bottom_time);

	/* if all we wanted was the dive just get us back to the surface */
	if (!is_planner) {
		transitiontime = depth / 75; /* this still needs to be made configurable */
		plan_add_segment(diveplan, transitiontime, 0, gas, po2, false);
		create_dive_from_plan(diveplan, is_planner);
		return;
	}

	tissue_tolerance = tissue_at_end(&displayed_dive, cached_datap);

#if DEBUG_PLAN & 4
	printf("gas %s\n", gasname(&gas));
	printf("depth %5.2lfm \n", depth / 1000.0);
#endif

	best_first_ascend_cylinder = current_cylinder;
	/* Find the gases available for deco */
	gaschanges = analyze_gaslist(diveplan, &gaschangenr, depth, &best_first_ascend_cylinder);
	/* Find the first potential decostopdepth above current depth */
	for (stopidx = 0; stopidx < sizeof(decostoplevels) / sizeof(int); stopidx++)
		if (decostoplevels[stopidx] >= depth)
			break;
	if (stopidx > 0)
		stopidx--;
	/* Stoplevels are either depths of gas changes or potential deco stop depths. */
	stoplevels = sort_stops(decostoplevels, stopidx + 1, gaschanges, gaschangenr);
	stopidx += gaschangenr;

	/* Keep time during the ascend */
	bottom_time = clock = previous_point_time = displayed_dive.dc.sample[displayed_dive.dc.samples - 1].time.seconds;
	gi = gaschangenr - 1;

	if (best_first_ascend_cylinder != current_cylinder) {
		stopping = true;

		current_cylinder = best_first_ascend_cylinder;
		gas = displayed_dive.cylinder[current_cylinder].gasmix;
#if DEBUG_PLAN & 16
		printf("switch to gas %d (%d/%d) @ %5.2lfm\n", best_first_ascend_cylinder,
		       (get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[best_first_ascend_cylinder].depth / 1000.0);
#endif
	}
	while (1) {
		/* We will break out when we hit the surface */
		do {
			/* Ascend to next stop depth */
			int deltad = ascend_velocity(depth, avg_depth, bottom_time) * TIMESTEP;
			if (ascend_velocity(depth, avg_depth, bottom_time) != last_ascend_rate) {
				plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, false);
				previous_point_time = clock;
				stopping = false;
				last_ascend_rate = ascend_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);
			clock += TIMESTEP;
			depth -= deltad;
		} while (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;

			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
			gi--;
		}

		--stopidx;

		/* Save the current state and try to ascend to the next stopdepth */
		int trial_depth = depth;
		cache_deco_state(tissue_tolerance, &trial_cache);
		while (1) {
			/* Check if ascending to next stop is clear, go back and wait if we hit the ceiling on the way */
			clear_to_ascend = true;
			while (trial_depth > stoplevels[stopidx]) {
				int deltad = ascend_velocity(trial_depth, avg_depth, bottom_time) * TIMESTEP;
				if (deltad > trial_depth) /* don't test against depth above surface */
					deltad = trial_depth;
				tissue_tolerance = add_segment(depth_to_mbar(trial_depth, &displayed_dive) / 1000.0,
							       &displayed_dive.cylinder[current_cylinder].gasmix,
							       TIMESTEP, po2, &displayed_dive);
				if (deco_allowed_depth(tissue_tolerance, diveplan->surface_pressure / 1000.0, &displayed_dive, 1) > trial_depth - deltad) {
					/* We should have stopped */
					clear_to_ascend = false;
					break;
				}
				trial_depth -= deltad;
			}
			restore_deco_state(trial_cache);

			if (clear_to_ascend)
				break; /* We did not hit the ceiling */

			/* Add a minute of deco time and then try again */
			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;
			}
			tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
						       &displayed_dive.cylinder[current_cylinder].gasmix,
						       DECOTIMESTEP, po2, &displayed_dive);
			cache_deco_state(tissue_tolerance, &trial_cache);
			clock += DECOTIMESTEP;
			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);
							previous_point_time = clock;
							current_cylinder = breakcylinder;
							gas = displayed_dive.cylinder[current_cylinder].gasmix;
							breaktime = -1;
						}
					}
				}
			}
			trial_depth = depth;
		}
		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 */
	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);

	free(stoplevels);
	free(gaschanges);
}
示例#7
0
/* Let's try to do some deco calculations.
 */
void calculate_deco_information(struct dive *dive, struct divecomputer *dc, struct plot_info *pi, bool print_mode)
{
	int i, count_iteration = 0;
	double surface_pressure = (dc->surface_pressure.mbar ? dc->surface_pressure.mbar : get_surface_pressure_in_mbar(dive, true)) / 1000.0;
	int last_ndl_tts_calc_time = 0;
	int first_ceiling = 0;
	bool first_iteration = true;
	int final_tts = 0 , time_clear_ceiling = 0, time_deep_ceiling = 0, deco_time = 0, prev_deco_time = 10000000;
	char *cache_data_initial = NULL;
	/* For VPM-B outside the planner, cache the initial deco state for CVA iterations */
	if (prefs.deco_mode == VPMB && !in_planner())
		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)) {
		for (i = 1; i < pi->nr; i++) {
			struct plot_data *entry = pi->entry + i;
			int j, t0 = (entry - 1)->sec, t1 = entry->sec;
			int time_stepsize = 20;

			entry->ambpressure = depth_to_bar(entry->depth, dive);
			entry->gfline = MAX((double)prefs.gflow, (entry->ambpressure - surface_pressure) / (gf_low_pressure_this_dive - surface_pressure) *
										(prefs.gflow - prefs.gfhigh) +
									prefs.gfhigh) *
						(100.0 - AMB_PERCENTAGE) / 100.0 + AMB_PERCENTAGE;
			if (t0 > t1) {
				fprintf(stderr, "non-monotonous dive stamps %d %d\n", t0, t1);
				int xchg = t1;
				t1 = t0;
				t0 = xchg;
			}
			if (t0 != t1 && t1 - t0 < time_stepsize)
				time_stepsize = t1 - t0;
			for (j = t0 + time_stepsize; j <= t1; j += time_stepsize) {
				int depth = interpolate(entry[-1].depth, entry[0].depth, j - t0, t1 - t0);
				add_segment(depth_to_bar(depth, dive),
					&dive->cylinder[entry->cylinderindex].gasmix, time_stepsize, entry->o2pressure.mbar, dive, entry->sac);
				if ((t1 - j < time_stepsize) && (j < t1))
					time_stepsize = t1 - j;
			}
			if (t0 == t1) {
				entry->ceiling = (entry - 1)->ceiling;
			} else {
				/* Keep updating the VPM-B gradients until the start of the ascent phase of the dive. */
				if (prefs.deco_mode == VPMB && !in_planner() && (entry - 1)->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);
				}
				entry->ceiling = deco_allowed_depth(tissue_tolerance_calc(dive, depth_to_bar(entry->depth, dive)), surface_pressure, dive, !prefs.calcceiling3m);
				/* If using VPM-B outside the planner, take first_ceiling_pressure as the deepest ceiling */
				if (prefs.deco_mode == VPMB && !in_planner()) {
					if  (entry->ceiling >= first_ceiling) {
								time_deep_ceiling = t1;
								first_ceiling = entry->ceiling;
								first_ceiling_pressure.mbar = depth_to_mbar(first_ceiling, dive);
								if (first_iteration) {
									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);
								}
					}
					// Use the point where the ceiling clears as the end of deco phase for CVA calculations
					if (entry->ceiling > 0)
						time_clear_ceiling = 0;
					else if (time_clear_ceiling == 0)
						time_clear_ceiling = t1;
				}
			}
			for (j = 0; j < 16; j++) {
				double m_value = buehlmann_inertgas_a[j] + entry->ambpressure / buehlmann_inertgas_b[j];
				entry->ceilings[j] = deco_allowed_depth(tolerated_by_tissue[j], surface_pressure, dive, 1);
				entry->percentages[j] = tissue_inertgas_saturation[j] < entry->ambpressure ?
								tissue_inertgas_saturation[j] / entry->ambpressure * AMB_PERCENTAGE :
								AMB_PERCENTAGE + (tissue_inertgas_saturation[j] - entry->ambpressure) / (m_value - entry->ambpressure) * (100.0 - AMB_PERCENTAGE);
			}

			/* should we do more calculations?
			* We don't for print-mode because this info doesn't show up there
			* If the ceiling hasn't cleared by the last data point, we need tts for VPM-B CVA calculation
			* It is not necessary to do these calculation on the first VPMB iteration, except for the last data point */
			if ((prefs.calcndltts && !print_mode && (prefs.deco_mode != VPMB || in_planner() || !first_iteration)) ||
			    (prefs.deco_mode == VPMB && !in_planner() && i == pi->nr - 1)) {
				/* only calculate ndl/tts on every 30 seconds */
				if ((entry->sec - last_ndl_tts_calc_time) < 30 && i != pi->nr - 1) {
					struct plot_data *prev_entry = (entry - 1);
					entry->stoptime_calc = prev_entry->stoptime_calc;
					entry->stopdepth_calc = prev_entry->stopdepth_calc;
					entry->tts_calc = prev_entry->tts_calc;
					entry->ndl_calc = prev_entry->ndl_calc;
					continue;
				}
				last_ndl_tts_calc_time = entry->sec;

				/* We are going to mess up deco state, so store it for later restore */
				char *cache_data = NULL;
				cache_deco_state(&cache_data);
				calculate_ndl_tts(entry, dive, surface_pressure);
				if (prefs.deco_mode == VPMB && !in_planner() && i == pi->nr - 1)
					final_tts = entry->tts_calc;
				/* Restore "real" deco state for next real time step */
				restore_deco_state(cache_data);
				free(cache_data);
			}
		}
		if (prefs.deco_mode == VPMB && !in_planner()) {
			prev_deco_time = deco_time;
			// Do we need to update deco_time?
			if (final_tts > 0)
				deco_time = pi->maxtime + final_tts - time_deep_ceiling;
			else if (time_clear_ceiling > 0)
				deco_time = time_clear_ceiling - time_deep_ceiling;
			vpmb_next_gradient(deco_time, surface_pressure / 1000.0);
			final_tts = 0;
			last_ndl_tts_calc_time = 0;
			first_ceiling = 0;
			first_iteration = false;
			count_iteration ++;
			restore_deco_state(cache_data_initial);
		} else {
			// With Buhlmann, or not in planner, iterating isn't needed.  This makes the while condition false.
			prev_deco_time = deco_time = 0;
		}
	}
	free(cache_data_initial);
#if DECO_CALC_DEBUG & 1
	dump_tissues();
#endif
}
示例#8
0
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;
	int current_cylinder;
	unsigned int stopidx;
	int depth;
	double tissue_tolerance = 0.0;
	struct gaschanges *gaschanges = NULL;
	int gaschangenr;
	int *decostoplevels;
	int decostoplevelcount;
	unsigned int *stoplevels = NULL;
	int vpmb_first_stop;
	bool stopping = false;
	bool pendinggaschange = false;
	bool clear_to_ascend;
	int clock, previous_point_time;
	int avg_depth, max_depth, bottom_time = 0;
	int last_ascend_rate;
	int best_first_ascend_cylinder;
	struct gasmix gas, bottom_gas;
	int o2time = 0;
	int breaktime = -1;
	int breakcylinder = 0;
	int error = 0;
	bool decodive = false;

	set_gf(diveplan->gflow, diveplan->gfhigh, prefs.gf_low_at_maxdepth);
	if (!diveplan->surface_pressure)
		diveplan->surface_pressure = SURFACE_PRESSURE;
	create_dive_from_plan(diveplan, is_planner);

	// Do we want deco stop array in metres or feet?
	if (prefs.units.length == METERS ) {
		decostoplevels = decostoplevels_metric;
		decostoplevelcount = sizeof(decostoplevels_metric) / sizeof(int);
	} else {
		decostoplevels = decostoplevels_imperial;
		decostoplevelcount = sizeof(decostoplevels_imperial) / sizeof(int);
	}

	/* If the user has selected last stop to be at 6m/20', we need to get rid of the 3m/10' stop.
	 * Otherwise reinstate the last stop 3m/10' stop.
	 */
	if (prefs.last_stop)
		*(decostoplevels + 1) = 0;
	else
		*(decostoplevels + 1) = M_OR_FT(3,10);

	/* Let's start at the last 'sample', i.e. the last manually entered waypoint. */
	sample = &displayed_dive.dc.sample[displayed_dive.dc.samples - 1];

	get_gas_at_time(&displayed_dive, &displayed_dive.dc, sample->time, &gas);

	po2 = sample->setpoint.mbar;
	if ((current_cylinder = get_gasidx(&displayed_dive, &gas)) == -1) {
		report_error(translate("gettextFromC", "Can't find gas %s"), gasname(&gas));
		current_cylinder = 0;
	}
	depth = displayed_dive.dc.sample[displayed_dive.dc.samples - 1].depth.mm;
	average_max_depth(diveplan, &avg_depth, &max_depth);
	last_ascend_rate = ascent_velocity(depth, avg_depth, bottom_time);

	/* if all we wanted was the dive just get us back to the surface */
	if (!is_planner) {
		transitiontime = depth / 75; /* this still needs to be made configurable */
		plan_add_segment(diveplan, transitiontime, 0, gas, po2, false);
		create_dive_from_plan(diveplan, is_planner);
		return(false);
	}
	calc_crushing_pressure(depth_to_mbar(depth, &displayed_dive) / 1000.0);
	nuclear_regeneration(clock);
	clear_deco(displayed_dive.surface_pressure.mbar / 1000.0);
	vpmb_start_gradient();
	previous_deco_time = 100000000;
	deco_time = 10000000;

	tissue_tolerance = tissue_at_end(&displayed_dive, cached_datap);
	displayed_dive.surface_pressure.mbar = diveplan->surface_pressure;

#if DEBUG_PLAN & 4
	printf("gas %s\n", gasname(&gas));
	printf("depth %5.2lfm \n", depth / 1000.0);
#endif

	best_first_ascend_cylinder = current_cylinder;
	/* Find the gases available for deco */

	if (po2) {	// Don't change gas in CCR mode
		gaschanges = NULL;
		gaschangenr = 0;
	} else {
		gaschanges = analyze_gaslist(diveplan, &gaschangenr, depth, &best_first_ascend_cylinder);
	}
	/* Find the first potential decostopdepth above current depth */
	for (stopidx = 0; stopidx < decostoplevelcount; stopidx++)
		if (*(decostoplevels + stopidx) >= depth)
			break;
	if (stopidx > 0)
		stopidx--;
	/* Stoplevels are either depths of gas changes or potential deco stop depths. */
	stoplevels = sort_stops(decostoplevels, stopidx + 1, gaschanges, gaschangenr);
	stopidx += gaschangenr;

	/* Keep time during the ascend */
	bottom_time = clock = previous_point_time = displayed_dive.dc.sample[displayed_dive.dc.samples - 1].time.seconds;
	gi = gaschangenr - 1;

	if(prefs.deco_mode == RECREATIONAL) {
		bool safety_stop = prefs.safetystop && max_depth >= 10000;
		track_ascent_gas(depth, &displayed_dive.cylinder[current_cylinder], avg_depth, bottom_time, safety_stop);
		// How long can we stay at the current depth and still directly ascent to the surface?
		while (trial_ascent(depth, 0, avg_depth, bottom_time, tissue_tolerance, &displayed_dive.cylinder[current_cylinder].gasmix,
				  po2, diveplan->surface_pressure / 1000.0) &&
		       enough_gas(current_cylinder)) {
			tissue_tolerance = add_segment(depth_to_mbar(depth, &displayed_dive) / 1000.0,
						       &displayed_dive.cylinder[current_cylinder].gasmix,
						       DECOTIMESTEP, po2, &displayed_dive, prefs.bottomsac);
			update_cylinder_pressure(&displayed_dive, depth, depth, DECOTIMESTEP, prefs.bottomsac, &displayed_dive.cylinder[current_cylinder], false);
			clock += DECOTIMESTEP;
		}
		clock -= DECOTIMESTEP;
		plan_add_segment(diveplan, clock - previous_point_time, depth, gas, po2, true);
		previous_point_time = clock;
		do {
			/* Ascend to surface */
			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);
				previous_point_time = clock;
				last_ascend_rate = ascent_velocity(depth, avg_depth, bottom_time);
			}
			if (depth - deltad < 0)
				deltad = depth;

			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;
			if (depth <= 5000 && depth >= (5000 - deltad) && safety_stop) {
				plan_add_segment(diveplan, clock - previous_point_time, 5000, gas, po2, false);
				previous_point_time = clock;
				clock += 180;
				plan_add_segment(diveplan, clock - previous_point_time, 5000, gas, po2, false);
				previous_point_time = clock;
				safety_stop = false;
			}
		} while (depth > 0);
		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);
		fixup_dc_duration(&displayed_dive.dc);

		free(stoplevels);
		free(gaschanges);
		return(false);
	}

	if (best_first_ascend_cylinder != current_cylinder) {
		stopping = true;

		current_cylinder = best_first_ascend_cylinder;
		gas = displayed_dive.cylinder[current_cylinder].gasmix;

#if DEBUG_PLAN & 16
		printf("switch to gas %d (%d/%d) @ %5.2lfm\n", best_first_ascend_cylinder,
		       (get_o2(&gas) + 5) / 10, (get_he(&gas) + 5) / 10, gaschanges[best_first_ascend_cylinder].depth / 1000.0);
#endif
	}

	// 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;

	// Find first stop used for VPM-B Boyle's law compensation
	if (prefs.deco_mode == VPMB) {
		vpmb_first_stop = deco_allowed_depth(tissue_tolerance, diveplan->surface_pressure / 1000, &displayed_dive, 1);
		if (vpmb_first_stop > 0) {
			while (stoplevels[stopidx] > vpmb_first_stop) {
				stopidx--;
			}
			stopidx++;
			vpmb_first_stop = stoplevels[stopidx];
		}
		first_stop_pressure.mbar = depth_to_mbar(vpmb_first_stop, &displayed_dive);
	} else {
		first_stop_pressure.mbar = 0;
	}

	//CVA
	do {
		is_final_plan = (prefs.deco_mode == BUEHLMANN) || (previous_deco_time - deco_time < 10);  // CVA time converges
		if (deco_time != 10000000)
			vpmb_next_gradient(deco_time, diveplan->surface_pressure / 1000.0);

		previous_deco_time = deco_time;
		tissue_tolerance = 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;
		}

		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 = true;

				// Boyles Law compensation
				boyles_law(depth_to_mbar(stoplevels[stopidx], &displayed_dive) / 1000.0);

				/* 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;
						if (prefs.doo2breaks && get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) == 1000)
							o2time += prefs.min_switch_duration;
					} else {
						/* The user has selected the option to switch gas only at required stops.
						 * Remember that we are waiting to switch gas
						 */
						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;

					// Boyles Law compensation
					boyles_law(depth_to_mbar(stoplevels[stopidx], &displayed_dive) / 1000.0);
				}

				/* Are we waiting to switch gas?
				 * Occurs when the user has selected the option to switch only at required stops
				 */
				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;
					if (prefs.doo2breaks && get_o2(&displayed_dive.cylinder[current_cylinder].gasmix) == 1000)
						o2time += 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) {
					/* The backgas breaks option limits time on oxygen to 12 minutes, followed by 6 minutes on
					 * backgas (first defined gas).  This could be customized if there were demand.
					 */
					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 = 0;
							gas = displayed_dive.cylinder[current_cylinder].gasmix;
						}
					} 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;
			}
		}

		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);
	fixup_dc_duration(&displayed_dive.dc);

	free(stoplevels);
	free(gaschanges);
	return decodive;
}