cleanup: fold core/divecomputer.cpp into core/device.c

core/device.h was declaring a number of functions that were related
to divecomputers (dcs): creating a fake dc for manually entered dives
and registering / accessing dc nicknames. On could argue whether
these should be lumped together, but it is what it is.

However, part of that was implemented in C++/Qt code in a separate
core/divecomputer.cpp file. Some function therein where only
accessible to C++ and declared in core/divecomputer.h.

All in all, a big mess. Let's simply combine the files and
conditionally compile the C++-only functions depending on
the __cplusplus define.

Yes, that means turning device.c into device.cpp. A brave soul
might turn the C++/Qt code into C code if they whish later on.

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

1 files changed, 377 insertions, 0 deletions

diff --git a/core/device.cpp b/core/device.cpp
new file mode 100644
index 000000000..d72f4d481
--- /dev/null
+++ b/core/device.cpp
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "ssrf.h"
+#include "dive.h"
+#include "subsurface-string.h"
+#include "device.h"
+#include "errorhelper.h" // for verbose flag
+#include "core/settings/qPrefDiveComputer.h"
+
+/*
+ * Good fake dive profiles are hard.
+ *
+ * "depthtime" is the integral of the dive depth over
+ * time ("area" of the dive profile). We want that
+ * area to match the average depth (avg_d*max_t).
+ *
+ * To do that, we generate a 6-point profile:
+ *
+ *  (0, 0)
+ *  (t1, max_d)
+ *  (t2, max_d)
+ *  (t3, d)
+ *  (t4, d)
+ *  (max_t, 0)
+ *
+ * with the same ascent/descent rates between the
+ * different depths.
+ *
+ * NOTE: avg_d, max_d and max_t are given constants.
+ * The rest we can/should play around with to get a
+ * good-looking profile.
+ *
+ * That six-point profile gives a total area of:
+ *
+ *   (max_d*max_t) - (max_d*t1) - (max_d-d)*(t4-t3)
+ *
+ * And the "same ascent/descent rates" requirement
+ * gives us (time per depth must be same):
+ *
+ *   t1 / max_d = (t3-t2) / (max_d-d)
+ *   t1 / max_d = (max_t-t4) / d
+ *
+ * We also obviously require:
+ *
+ *   0 <= t1 <= t2 <= t3 <= t4 <= max_t
+ *
+ * Let us call 'd_frac = d / max_d', and we get:
+ *
+ * Total area must match average depth-time:
+ *
+ *   (max_d*max_t) - (max_d*t1) - (max_d-d)*(t4-t3) = avg_d*max_t
+ *      max_d*(max_t-t1-(1-d_frac)*(t4-t3)) = avg_d*max_t
+ *             max_t-t1-(1-d_frac)*(t4-t3) = avg_d*max_t/max_d
+ *                   t1+(1-d_frac)*(t4-t3) = max_t*(1-avg_d/max_d)
+ *
+ * and descent slope must match ascent slopes:
+ *
+ *   t1 / max_d = (t3-t2) / (max_d*(1-d_frac))
+ *           t1 = (t3-t2)/(1-d_frac)
+ *
+ * and
+ *
+ *   t1 / max_d = (max_t-t4) / (max_d*d_frac)
+ *           t1 = (max_t-t4)/d_frac
+ *
+ * In general, we have more free variables than we have constraints,
+ * but we can aim for certain basics, like a good ascent slope.
+ */
+static int fill_samples(struct sample *s, int max_d, int avg_d, int max_t, double slope, double d_frac)
+{
+	double t_frac = max_t * (1 - avg_d / (double)max_d);
+	int t1 = lrint(max_d / slope);
+	int t4 = lrint(max_t - t1 * d_frac);
+	int t3 = lrint(t4 - (t_frac - t1) / (1 - d_frac));
+	int t2 = lrint(t3 - t1 * (1 - d_frac));
+
+	if (t1 < 0 || t1 > t2 || t2 > t3 || t3 > t4 || t4 > max_t)
+		return 0;
+
+	s[1].time.seconds = t1;
+	s[1].depth.mm = max_d;
+	s[2].time.seconds = t2;
+	s[2].depth.mm = max_d;
+	s[3].time.seconds = t3;
+	s[3].depth.mm = lrint(max_d * d_frac);
+	s[4].time.seconds = t4;
+	s[4].depth.mm = lrint(max_d * d_frac);
+
+	return 1;
+}
+
+/* we have no average depth; instead of making up a random average depth
+ * we should assume either a PADI rectangular profile (for short and/or
+ * shallow dives) or more reasonably a six point profile with a 3 minute
+ * safety stop at 5m */
+static void fill_samples_no_avg(struct sample *s, int max_d, int max_t, double slope)
+{
+	// shallow or short dives are just trapecoids based on the given slope
+	if (max_d < 10000 || max_t < 600) {
+		s[1].time.seconds = lrint(max_d / slope);
+		s[1].depth.mm = max_d;
+		s[2].time.seconds = max_t - lrint(max_d / slope);
+		s[2].depth.mm = max_d;
+	} else {
+		s[1].time.seconds = lrint(max_d / slope);
+		s[1].depth.mm = max_d;
+		s[2].time.seconds = max_t - lrint(max_d / slope) - 180;
+		s[2].depth.mm = max_d;
+		s[3].time.seconds = max_t - lrint(5000 / slope) - 180;
+		s[3].depth.mm = 5000;
+		s[4].time.seconds = max_t - lrint(5000 / slope);
+		s[4].depth.mm = 5000;
+	}
+}
+
+extern "C" void fake_dc(struct divecomputer *dc)
+{
+	alloc_samples(dc, 6);
+	struct sample *fake = dc->sample;
+	int i;
+
+	dc->samples = 6;
+
+	/* The dive has no samples, so create a few fake ones */
+	int max_t = dc->duration.seconds;
+	int max_d = dc->maxdepth.mm;
+	int avg_d = dc->meandepth.mm;
+
+	memset(fake, 0, 6 * sizeof(struct sample));
+	fake[5].time.seconds = max_t;
+	for (i = 0; i < 6; i++) {
+		fake[i].bearing.degrees = -1;
+		fake[i].ndl.seconds = -1;
+	}
+	if (!max_t || !max_d) {
+		dc->samples = 0;
+		return;
+	}
+
+	/* Set last manually entered time to the total dive length */
+	dc->last_manual_time = dc->duration;
+
+	/*
+	 * We want to fake the profile so that the average
+	 * depth ends up correct. However, in the absence of
+	 * a reasonable average, let's just make something
+	 * up. Note that 'avg_d == max_d' is _not_ a reasonable
+	 * average.
+	 * We explicitly treat avg_d == 0 differently */
+	if (avg_d == 0) {
+		/* we try for a sane slope, but bow to the insanity of
+		 * the user supplied data */
+		fill_samples_no_avg(fake, max_d, max_t, MAX(2.0 * max_d / max_t, (double)prefs.ascratelast6m));
+		if (fake[3].time.seconds == 0) { // just a 4 point profile
+			dc->samples = 4;
+			fake[3].time.seconds = max_t;
+		}
+		return;
+	}
+	if (avg_d < max_d / 10 || avg_d >= max_d) {
+		avg_d = (max_d + 10000) / 3;
+		if (avg_d > max_d)
+			avg_d = max_d * 2 / 3;
+	}
+	if (!avg_d)
+		avg_d = 1;
+
+	/*
+	 * Ok, first we try a basic profile with a specific ascent
+	 * rate (5 meters per minute) and d_frac (1/3).
+	 */
+	if (fill_samples(fake, max_d, avg_d, max_t, (double)prefs.ascratelast6m, 0.33))
+		return;
+
+	/*
+	 * Ok, assume that didn't work because we cannot make the
+	 * average come out right because it was a quick deep dive
+	 * followed by a much shallower region
+	 */
+	if (fill_samples(fake, max_d, avg_d, max_t, 10000.0 / 60, 0.10))
+		return;
+
+	/*
+	 * Uhhuh. That didn't work. We'd need to find a good combination that
+	 * satisfies our constraints. Currently, we don't, we just give insane
+	 * slopes.
+	 */
+	if (fill_samples(fake, max_d, avg_d, max_t, 10000.0, 0.01))
+		return;
+
+	/* Even that didn't work? Give up, there's something wrong */
+}
+
+static void match_id(void *_dc, const char *model, uint32_t deviceid,
+		     const char *, const char *serial, const char *firmware)
+{
+	struct divecomputer *dc = (divecomputer *)_dc;
+
+	if (dc->deviceid != deviceid)
+		return;
+	if (!model || !dc->model || strcmp(dc->model, model))
+		return;
+
+	if (serial && !dc->serial)
+		dc->serial = strdup(serial);
+	if (firmware && !dc->fw_version)
+		dc->fw_version = strdup(firmware);
+}
+
+/*
+ * When setting the device ID, we also fill in the
+ * serial number and firmware version data
+ */
+extern "C" void set_dc_deviceid(struct divecomputer *dc, unsigned int deviceid)
+{
+	if (deviceid) {
+		dc->deviceid = deviceid;
+		call_for_each_dc(dc, match_id, false);
+	}
+}
+
+DiveComputerList dcList;
+
+bool DiveComputerNode::operator==(const DiveComputerNode &a) const
+{
+	return model == a.model &&
+	       deviceId == a.deviceId &&
+	       firmware == a.firmware &&
+	       serialNumber == a.serialNumber &&
+	       nickName == a.nickName;
+}
+
+bool DiveComputerNode::operator!=(const DiveComputerNode &a) const
+{
+	return !(*this == a);
+}
+
+bool DiveComputerNode::operator<(const DiveComputerNode &a) const
+{
+	return std::tie(model, deviceId) < std::tie(a.model, a.deviceId);
+}
+
+const DiveComputerNode *DiveComputerList::getExact(const QString &m, uint32_t d)
+{
+	auto it = std::lower_bound(dcs.begin(), dcs.end(), DiveComputerNode{m, d, {}, {}, {}});
+	return it != dcs.end() && it->model == m && it->deviceId == d ? &*it : NULL;
+}
+
+const DiveComputerNode *DiveComputerList::get(const QString &m)
+{
+	auto it = std::lower_bound(dcs.begin(), dcs.end(), DiveComputerNode{m, 0, {}, {}, {}});
+	return it != dcs.end() && it->model == m ? &*it : NULL;
+}
+
+void DiveComputerNode::showchanges(const QString &n, const QString &s, const QString &f) const
+{
+	if (nickName != n && !n.isEmpty())
+		qDebug("new nickname %s for DC model %s deviceId 0x%x", qPrintable(n), qPrintable(model), deviceId);
+	if (serialNumber != s && !s.isEmpty())
+		qDebug("new serial number %s for DC model %s deviceId 0x%x", qPrintable(s), qPrintable(model), deviceId);
+	if (firmware != f && !f.isEmpty())
+		qDebug("new firmware version %s for DC model %s deviceId 0x%x", qPrintable(f), qPrintable(model), deviceId);
+}
+
+void DiveComputerList::addDC(QString m, uint32_t d, QString n, QString s, QString f)
+{
+	if (m.isEmpty() || d == 0)
+		return;
+	auto it = std::lower_bound(dcs.begin(), dcs.end(), DiveComputerNode{m, d, {}, {}, {}});
+	if (it != dcs.end() && it->model == m && it->deviceId == d) {
+		// debugging: show changes
+		if (verbose)
+			it->showchanges(n, s, f);
+		// Update any non-existent fields from the old entry
+		if (!n.isEmpty())
+			it->nickName = n;
+		if (!s.isEmpty())
+			it->serialNumber = s;
+		if (!f.isEmpty())
+			it->firmware = f;
+	} else {
+		dcs.insert(it, DiveComputerNode{m, d, s, f, n});
+	}
+}
+
+extern "C" void create_device_node(const char *model, uint32_t deviceid, const char *serial, const char *firmware, const char *nickname)
+{
+	dcList.addDC(model, deviceid, nickname, serial, firmware);
+}
+
+extern "C" void clear_device_nodes()
+{
+	dcList.dcs.clear();
+}
+
+static bool compareDCById(const DiveComputerNode &a, const DiveComputerNode &b)
+{
+	return a.deviceId < b.deviceId;
+}
+
+extern "C" void call_for_each_dc (void *f, void (*callback)(void *, const char *, uint32_t, const char *, const char *, const char *),
+				  bool select_only)
+{
+	QVector<DiveComputerNode> values = dcList.dcs;
+	std::sort(values.begin(), values.end(), compareDCById);
+	for (const DiveComputerNode &node : values) {
+		bool found = false;
+		if (select_only) {
+			int j;
+			struct dive *d;
+			for_each_dive (j, d) {
+				struct divecomputer *dc;
+				if (!d->selected)
+					continue;
+				for_each_dc (d, dc) {
+					if (dc->deviceid == node.deviceId) {
+						found = true;
+						break;
+					}
+				}
+				if (found)
+					break;
+			}
+		} else {
+			found = true;
+		}
+		if (found)
+			callback(f, qPrintable(node.model), node.deviceId, qPrintable(node.nickName),
+						 qPrintable(node.serialNumber), qPrintable(node.firmware));
+	}
+}
+
+extern "C" int is_default_dive_computer(const char *vendor, const char *product)
+{
+	return qPrefDiveComputer::vendor() == vendor && qPrefDiveComputer::product() == product;
+}
+
+extern "C" int is_default_dive_computer_device(const char *name)
+{
+	return qPrefDiveComputer::device() == name;
+}
+
+extern "C" void set_dc_nickname(struct dive *dive)
+{
+	if (!dive)
+		return;
+
+	struct divecomputer *dc;
+
+	for_each_dc (dive, dc) {
+		if (!empty_string(dc->model) && dc->deviceid &&
+		    !dcList.getExact(dc->model, dc->deviceid)) {
+			// we don't have this one, yet
+			const DiveComputerNode *existNode = dcList.get(dc->model);
+			if (existNode) {
+				// we already have this model but a different deviceid
+				QString simpleNick(dc->model);
+				if (dc->deviceid == 0)
+					simpleNick.append(" (unknown deviceid)");
+				else
+					simpleNick.append(" (").append(QString::number(dc->deviceid, 16)).append(")");
+				dcList.addDC(dc->model, dc->deviceid, simpleNick);
+			} else {
+				dcList.addDC(dc->model, dc->deviceid);
+			}
+		}
+	}
+}
+
+QString get_dc_nickname(const struct divecomputer *dc)
+{
+	const DiveComputerNode *existNode = dcList.getExact(dc->model, dc->deviceid);
+
+	if (existNode && !existNode->nickName.isEmpty())
+		return existNode->nickName;
+	else
+		return dc->model;
+}