profile: C++-ify plot_info

Use more C++ style memory management for plot_info: Use std::vector
for array data. Return the plot_info instead of filling an output
parameter. Add a constructor/destructor pair so that the caller
isn't bothered with memory management.

The bulk of the commit is replacement of pointers with references,
which is kind of gratuitous. But I started and then went on...

Default initializiation of gas_pressures made it necessary to convert
gas.c to c++, though with minimal changes to the code.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

profile-widget/diveeventitem.cpp

@@ -3,6 +3,7 @@
 #include "profile-widget/divecartesianaxis.h"
 #include "profile-widget/divepixmapcache.h"
 #include "profile-widget/animationfunctions.h"
+#include "core/dive.h"
 #include "core/event.h"
 #include "core/eventtype.h"
 #include "core/format.h"
@@ -177,9 +178,9 @@ void DiveEventItem::eventVisibilityChanged(const QString&, bool)
 static int depthAtTime(const plot_info &pi, duration_t time)
 {
 	// Do a binary search for the timestamp
-	auto it = std::lower_bound(pi.entry, pi.entry + pi.nr, time,
+	auto it = std::lower_bound(pi.entry.begin(), pi.entry.end(), time,
 				   [](const plot_data &d1, duration_t t) { return d1.sec < t.seconds; });
-	if (it == pi.entry + pi.nr || it->sec != time.seconds) {
+	if (it == pi.entry.end() || it->sec != time.seconds) {
 		qWarning("can't find a spot in the dataModel");
 		return DEPTH_NOT_FOUND;
 	}

profile-widget/diveprofileitem.cpp

@@ -49,7 +49,7 @@ void AbstractProfilePolygonItem::clipStop(double &x, double &y, double prev_x, d
 
 std::pair<double, double> AbstractProfilePolygonItem::getPoint(int i) const
 {
-	const struct plot_data *data = pInfo.entry;
+	const auto &data = pInfo.entry;
 	double x = data[i].sec;
 	double y = accessor(data[i]);
 
@@ -121,7 +121,7 @@ void DiveProfileItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *o
 	pen.setCosmetic(true);
 	pen.setWidth(2);
 	QPolygonF poly = polygon();
-	const struct plot_data *data = pInfo.entry;
+	const auto &data = pInfo.entry;
 	// This paints the colors of the velocities.
 	for (int i = from + 1; i < to; i++) {
 		QColor color = getColor((color_index_t)(VELOCITY_COLORS_START_IDX + data[i].velocity));
@@ -150,7 +150,7 @@ void DiveProfileItem::replot(const dive *d, int from, int to, bool in_planner)
 	/* Show any ceiling we may have encountered */
 	if (prefs.dcceiling && !prefs.redceiling) {
 		QPolygonF p = polygon();
-		plot_data *entry = pInfo.entry + to - 1;
+		auto entry = pInfo.entry.begin() + (to - 1);
 		for (int i = to - 1; i >= from; i--, entry--) {
 			if (!entry->in_deco) {
 				/* not in deco implies this is a safety stop, no ceiling */
@@ -176,7 +176,7 @@ void DiveProfileItem::replot(const dive *d, int from, int to, bool in_planner)
 	const int half_interval = vAxis.getMinLabelDistance(hAxis);
 	const int min_depth = 2000; // in mm
 	const int min_prominence = 2000; // in mm (should this adapt to depth range?)
-	const plot_data *data = pInfo.entry;
+	const auto &data = pInfo.entry;
 	const int max_peaks = (data[to - 1].sec - data[from].sec) / half_interval + 1;
 	struct Peak {
 		int range_from;
@@ -185,7 +185,7 @@ void DiveProfileItem::replot(const dive *d, int from, int to, bool in_planner)
 	};
 	std::vector<Peak> stack;
 	stack.reserve(max_peaks);
-	int highest_peak = std::max_element(data + from, data + to, comp_depth) - data;
+	int highest_peak = std::max_element(data.begin() + from, data.begin() + to, comp_depth) - data.begin();
 	if (data[highest_peak].depth < min_depth)
 		return;
 	stack.push_back(Peak{ from, to, highest_peak });
@@ -210,7 +210,7 @@ void DiveProfileItem::replot(const dive *d, int from, int to, bool in_planner)
 		// Continue search until peaks reach the minimum prominence (height from valley).
 		for ( ; new_from + 3 < act_peak.range_to; ++new_from) {
 			if (data[new_from].depth >= data[valley].depth + min_prominence) {
-				int new_peak = std::max_element(data + new_from, data + act_peak.range_to, comp_depth) - data;
+				int new_peak = std::max_element(data.begin() + new_from, data.begin() + act_peak.range_to, comp_depth) - data.begin();
 				if (data[new_peak].depth < min_depth)
 					break;
 				stack.push_back(Peak{ new_from, act_peak.range_to, new_peak });
@@ -236,7 +236,7 @@ void DiveProfileItem::replot(const dive *d, int from, int to, bool in_planner)
 		// Continue search until peaks reach the minimum prominence (height from valley).
 		for ( ; new_to >= act_peak.range_from + 3; --new_to) {
 			if (data[new_to].depth >= data[valley].depth + min_prominence) {
-				int new_peak = std::max_element(data + act_peak.range_from, data + new_to, comp_depth) - data;
+				int new_peak = std::max_element(data.begin() + act_peak.range_from, data.begin() + new_to, comp_depth) - data.begin();
 				if (data[new_peak].depth < min_depth)
 					break;
 				stack.push_back(Peak{ act_peak.range_from, new_to, new_peak });
@@ -533,17 +533,17 @@ void DiveGasPressureItem::replot(const dive *d, int fromIn, int toIn, bool in_pl
 	segments.clear();
 
 	for (int i = from; i < to; i++) {
-		const struct plot_data *entry = pInfo.entry + i;
+		auto entry = pInfo.entry.begin() + i;
 
 		for (int cyl = 0; cyl < pInfo.nr_cylinders; cyl++) {
-			double mbar = static_cast<double>(get_plot_pressure(&pInfo, i, cyl));
+			double mbar = static_cast<double>(get_plot_pressure(pInfo, i, cyl));
 			double time = static_cast<double>(entry->sec);
 
 			if (mbar < 1.0)
 				continue;
 
 			if (i == from && i < to - 1) {
-				double mbar2 = static_cast<double>(get_plot_pressure(&pInfo, i+1, cyl));
+				double mbar2 = static_cast<double>(get_plot_pressure(pInfo, i+1, cyl));
 				double time2 = static_cast<double>(entry[1].sec);
 				if (mbar2 < 1.0)
 					continue;
@@ -551,7 +551,7 @@ void DiveGasPressureItem::replot(const dive *d, int fromIn, int toIn, bool in_pl
 			}
 
 			if (i == to - 1 && i > from) {
-				double mbar2 = static_cast<double>(get_plot_pressure(&pInfo, i-1, cyl));
+				double mbar2 = static_cast<double>(get_plot_pressure(pInfo, i-1, cyl));
 				double time2 = static_cast<double>(entry[-1].sec);
 				if (mbar2 < 1.0)
 					continue;

profile-widget/divetooltipitem.cpp

@@ -212,7 +212,7 @@ void ToolTipItem::setPlotInfo(const plot_info &plot)
 
 void ToolTipItem::clearPlotInfo()
 {
-	memset(&pInfo, 0, sizeof(pInfo));
+	pInfo = plot_info();
 }
 
 void ToolTipItem::setTimeAxis(DiveCartesianAxis *axis)
@@ -231,7 +231,7 @@ void ToolTipItem::refresh(const dive *d, const QPointF &pos, bool inPlanner)
 	lastTime = time;
 	clear();
 
-	auto [idx, lines] = get_plot_details_new(d, &pInfo, time);
+	auto [idx, lines] = get_plot_details_new(d, pInfo, time);
 
 	tissues.fill();
 	painter.setPen(QColor(0, 0, 0, 0));

profile-widget/profilescene.cpp

@@ -7,6 +7,7 @@
 #include "diveprofileitem.h"
 #include "divetextitem.h"
 #include "tankitem.h"
+#include "core/dive.h"
 #include "core/device.h"
 #include "core/divecomputer.h"
 #include "core/event.h"
@@ -151,8 +152,6 @@ ProfileScene::ProfileScene(double dpr, bool printMode, bool isGrayscale) :
 	tankItem(new TankItem(*timeAxis, dpr)),
 	pixmaps(getDivePixmaps(dpr))
 {
-	init_plot_info(&plotInfo);
-
 	setSceneRect(0, 0, 100, 100);
 	setItemIndexMethod(QGraphicsScene::NoIndex);
 
@@ -188,7 +187,6 @@ ProfileScene::ProfileScene(double dpr, bool printMode, bool isGrayscale) :
 
 ProfileScene::~ProfileScene()
 {
-	free_plot_info_data(&plotInfo);
 }
 
 void ProfileScene::clear()
@@ -201,7 +199,7 @@ void ProfileScene::clear()
 	// the DiveEventItems
 	qDeleteAll(eventItems);
 	eventItems.clear();
-	free_plot_info_data(&plotInfo);
+	plotInfo = plot_info();
 	empty = true;
 }
 
@@ -454,7 +452,7 @@ void ProfileScene::plotDive(const struct dive *dIn, int dcIn, DivePlannerPointsM
 	 * create_plot_info_new() automatically frees old plot data.
 	 */
 	if (!keepPlotInfo)
-		create_plot_info_new(d, currentdc, &plotInfo, planner_ds);
+		plotInfo = create_plot_info_new(d, currentdc, planner_ds);
 
 	bool hasHeartBeat = plotInfo.maxhr;
 	// For mobile we might want to turn of some features that are normally shown.
@@ -466,7 +464,7 @@ void ProfileScene::plotDive(const struct dive *dIn, int dcIn, DivePlannerPointsM
 	updateVisibility(hasHeartBeat, simplified);
 	updateAxes(hasHeartBeat, simplified);
 
-	int newMaxtime = get_maxtime(&plotInfo);
+	int newMaxtime = get_maxtime(plotInfo);
 	if (calcMax || newMaxtime > maxtime)
 		maxtime = newMaxtime;
 
@@ -474,7 +472,7 @@ void ProfileScene::plotDive(const struct dive *dIn, int dcIn, DivePlannerPointsM
 	 * when we are dragging the handler to plan / add dive.
 	 * otherwhise, update normally.
 	 */
-	int newMaxDepth = get_maxdepth(&plotInfo);
+	int newMaxDepth = get_maxdepth(plotInfo);
 	if (!calcMax) {
 		if (maxdepth < newMaxDepth)
 			maxdepth = newMaxDepth;
@@ -509,18 +507,18 @@ void ProfileScene::plotDive(const struct dive *dIn, int dcIn, DivePlannerPointsM
 	// Find first and last plotInfo entry
 	int firstSecond = lrint(timeAxis->minimum());
 	int lastSecond = lrint(timeAxis->maximum());
-	auto it1 = std::lower_bound(plotInfo.entry, plotInfo.entry + plotInfo.nr, firstSecond,
+	auto it1 = std::lower_bound(plotInfo.entry.begin(), plotInfo.entry.end(), firstSecond,
 				   [](const plot_data &d, int s)
 				   { return d.sec < s; });
-	auto it2 = std::lower_bound(it1, plotInfo.entry + plotInfo.nr, lastSecond,
+	auto it2 = std::lower_bound(it1, plotInfo.entry.end(), lastSecond,
 				    [](const plot_data &d, int s)
 				    { return d.sec < s; });
-	if (it1 > plotInfo.entry && it1->sec > firstSecond)
+	if (it1 > plotInfo.entry.begin() && it1->sec > firstSecond)
 		--it1;
-	if (it2 < plotInfo.entry + plotInfo.nr)
+	if (it2 < plotInfo.entry.end())
 		++it2;
-	int from = it1 - plotInfo.entry;
-	int to = it2 - plotInfo.entry;
+	int from = it1 - plotInfo.entry.begin();
+	int to = it2 - plotInfo.entry.begin();
 
 	timeAxis->updateTicks(animSpeed);
 	animatedAxes.push_back(timeAxis);

profile-widget/ruleritem.cpp

@@ -113,7 +113,7 @@ void RulerItem2::recalculate()
 	setLine(line);
 
 	QString text;
-	for (const std::string &s: compare_samples(dive, pInfo, source->idx, dest->idx, 1)) {
+	for (const std::string &s: compare_samples(dive, *pInfo, source->idx, dest->idx, 1)) {
 		if (!text.isEmpty())
 			text += '\n';
 		text += QString::fromStdString(s);