Display values in info box only if value is interesting

Type duration_t changed from uint to int.

Default value of '-1' introduced for some of the values in struct sample:
NDL used -1 as default.
Bearing uses -1 as default (no bearing set).

Display pXX, EAD, END, density, MOD only if values are larger than 0.

In profile don't display data from two first and two last plot_data
entries in info box.

Signed-off-by: Stefan Fuchs <sfuchs@gmx.de>

5 files changed, 61 insertions, 47 deletions

diff --git a/core/display.h b/core/display.h
index 6d74b5c87..b5b6a3938 100644
--- a/core/display.h
+++ b/core/display.h
@@ -25,7 +25,6 @@ struct plot_info {
 	enum {AIR, NITROX, TRIMIX, FREEDIVING} dive_type;
 	double endtempcoord;
 	double maxpp;
-	bool has_ndl;
 	struct plot_data *entry;
 };
 
diff --git a/core/dive.c b/core/dive.c
index fccfe4da9..9e3d42a44 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -753,6 +753,10 @@ struct sample *prepare_sample(struct divecomputer *dc)
 			sample->sensor[0] = sample[-1].sensor[0];
 			sample->sensor[1] = sample[-1].sensor[1];
 		}
+		// Init some values with -1
+		sample->bearing.degrees = -1;
+		sample->ndl.seconds = -1;
+		
 		return sample;
 	}
 	return NULL;
@@ -1261,12 +1265,12 @@ static void fixup_meandepth(struct dive *dive)
 static void fixup_duration(struct dive *dive)
 {
 	struct divecomputer *dc;
-	unsigned int duration = 0;
+	duration_t duration = { };
 
 	for_each_dc (dive, dc)
-		duration = MAX(duration, dc->duration.seconds);
+		duration.seconds = MAX(duration.seconds, dc->duration.seconds);
 
-	dive->duration.seconds = duration;
+	dive->duration.seconds = duration.seconds;
 }
 
 /*
diff --git a/core/dive.h b/core/dive.h
index 0563e0d4e..a862748d7 100644
--- a/core/dive.h
+++ b/core/dive.h
@@ -199,28 +199,28 @@ void get_gas_string(const struct gasmix *gasmix, char *text, int len);
 const char *gasname(const struct gasmix *gasmix);
 
 #define MAX_SENSORS 2
-struct sample                         // BASE TYPE BYTES  UNITS    RANGE      DESCRIPTION
-{                                     // --------- -----  -----    -----      -----------
-	duration_t time;               // uint32_t   4  seconds  (0-68 yrs)   elapsed dive time up to this sample
-	duration_t stoptime;           // uint32_t   4  seconds  (0-18 h)     time duration of next deco stop
-	duration_t ndl;                // uint32_t   4  seconds  (0-18 h)     time duration before no-deco limit
-	duration_t tts;                // uint32_t   4  seconds  (0-18 h)     time duration to reach the surface
-	duration_t rbt;                // uint32_t   4  seconds  (0-18 h)     remaining bottom time
-	depth_t depth;                 // int32_t    4    mm     (0-2000 km)  dive depth of this sample
-	depth_t stopdepth;             // int32_t    4    mm     (0-2000 km)  depth of next deco stop
-	temperature_t temperature;     // int32_t    4  mdegrK   (0-2 MdegK)  ambient temperature
-	pressure_t pressure[MAX_SENSORS]; // int32_t    4    mbar   (0-2 Mbar)   cylinder pressures (main and CCR o2)
-	o2pressure_t setpoint;         // uint16_t   2    mbar   (0-65 bar)   O2 partial pressure (will be setpoint)
-	o2pressure_t o2sensor[3];      // uint16_t   6    mbar   (0-65 bar)   Up to 3 PO2 sensor values (rebreather)
-	bearing_t bearing;             // int16_t    2  degrees  (-32k to 32k deg) compass bearing
-	uint8_t sensor[MAX_SENSORS];   // uint8_t    1  sensorID (0-255)      ID of cylinder pressure sensor
-	uint16_t cns;                  // uint16_t   1     %     (0-64k %)    cns% accumulated
-	uint8_t heartbeat;             // uint8_t    1  beats/m  (0-255)      heart rate measurement
-	volume_t sac;                  //            4  ml/min                predefined SAC
-	bool in_deco;                  // bool       1    y/n      y/n        this sample is part of deco
-	bool manually_entered;         // bool       1    y/n      y/n        this sample was entered by the user,
-				       //                                     not calculated when planning a dive
-};                      // Total size of structure: 57 bytes, excluding padding at end
+struct sample                         // BASE TYPE BYTES  UNITS    RANGE               DESCRIPTION
+{                                     // --------- -----  -----    -----               -----------
+	duration_t time;                  // int32_t    4  seconds  (0-34 yrs)             elapsed dive time up to this sample
+	duration_t stoptime;              // int32_t    4  seconds  (0-34 yrs)             time duration of next deco stop
+	duration_t ndl;                   // int32_t    4  seconds  (-1 no val, 0-34 yrs)  time duration before no-deco limit
+	duration_t tts;                   // int32_t    4  seconds  (0-34 yrs)             time duration to reach the surface
+	duration_t rbt;                   // int32_t    4  seconds  (0-34 yrs)             remaining bottom time
+	depth_t depth;                    // int32_t    4    mm     (0-2000 km)            dive depth of this sample
+	depth_t stopdepth;                // int32_t    4    mm     (0-2000 km)            depth of next deco stop
+	temperature_t temperature;        // int32_t    4  mdegrK   (0-2 MdegK)            ambient temperature
+	pressure_t pressure[MAX_SENSORS]; // int32_t    4    mbar   (0-2 Mbar)             cylinder pressures (main and CCR o2)
+	o2pressure_t setpoint;            // uint16_t   2    mbar   (0-65 bar)             O2 partial pressure (will be setpoint)
+	o2pressure_t o2sensor[3];         // uint16_t   6    mbar   (0-65 bar)             Up to 3 PO2 sensor values (rebreather)
+	bearing_t bearing;                // int16_t    2  degrees  (-1 no val, 0-360 deg) compass bearing
+	uint8_t sensor[MAX_SENSORS];      // uint8_t    1  sensorID (0-255)                ID of cylinder pressure sensor
+	uint16_t cns;                     // uint16_t   1     %     (0-64k %)              cns% accumulated
+	uint8_t heartbeat;                // uint8_t    1  beats/m  (0-255)                heart rate measurement
+	volume_t sac;                     //            4  ml/min                          predefined SAC
+	bool in_deco;                     // bool       1    y/n      y/n                  this sample is part of deco
+	bool manually_entered;            // bool       1    y/n      y/n                  this sample was entered by the user,
+	                                  //                                               not calculated when planning a dive
+};	                                  // Total size of structure: 57 bytes, excluding padding at end
 
 struct divetag {
 	/*
diff --git a/core/profile.c b/core/profile.c
index a1d0c45f0..50e906a09 100644
--- a/core/profile.c
+++ b/core/profile.c
@@ -495,6 +495,8 @@ struct plot_info calculate_max_limits_new(struct dive *dive, struct divecomputer
 	entry->running_sum = (entry - 1)->running_sum + (_time - (entry - 1)->sec) * (_depth + (entry - 1)->depth) / 2; \
 	memset(entry->pressure, 0, sizeof(entry->pressure)); \
 	entry->sac = _sac;          \
+	entry->ndl = -1;          \
+	entry->bearing = -1;          \
 	entry++;                    \
 	idx++
 
@@ -576,7 +578,6 @@ struct plot_data *populate_plot_entries(struct dive *dive, struct divecomputer *
 		entry->stoptime = sample->stoptime.seconds;
 		entry->ndl = sample->ndl.seconds;
 		entry->tts = sample->tts.seconds;
-		pi->has_ndl |= sample->ndl.seconds;
 		entry->in_deco = sample->in_deco;
 		entry->cns = sample->cns;
 		if (dc->divemode == CCR) {
@@ -1320,7 +1321,7 @@ struct divecomputer *select_dc(struct dive *dive)
 	return get_dive_dc(dive, i);
 }
 
-static void plot_string(struct plot_info *pi, struct plot_data *entry, struct membuffer *b, bool has_ndl)
+static void plot_string(struct plot_info *pi, struct plot_data *entry, struct membuffer *b)
 {
 	int pressurevalue, mod, ead, end, eadd;
 	const char *depth_unit, *pressure_unit, *temp_unit, *vertical_speed_unit;
@@ -1353,13 +1354,13 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
 		put_format(b, translate("gettextFromC", "SAC: %.*f%s/min\n"), decimals, sacvalue, unit);
 	if (entry->cns)
 		put_format(b, translate("gettextFromC", "CNS: %u%%\n"), entry->cns);
-	if (prefs.pp_graphs.po2)
+	if (prefs.pp_graphs.po2 && entry->pressures.o2 > 0)
 		put_format(b, translate("gettextFromC", "pO%s: %.2fbar\n"), UTF8_SUBSCRIPT_2, entry->pressures.o2);
-	if (prefs.pp_graphs.pn2)
+	if (prefs.pp_graphs.pn2 && entry->pressures.n2 > 0)
 		put_format(b, translate("gettextFromC", "pN%s: %.2fbar\n"), UTF8_SUBSCRIPT_2, entry->pressures.n2);
-	if (prefs.pp_graphs.phe)
+	if (prefs.pp_graphs.phe && entry->pressures.he > 0)
 		put_format(b, translate("gettextFromC", "pHe: %.2fbar\n"), entry->pressures.he);
-	if (prefs.mod) {
+	if (prefs.mod && entry->mod > 0) {
 		mod = lrint(get_depth_units(lrint(entry->mod), NULL, &depth_unit));
 		put_format(b, translate("gettextFromC", "MOD: %d%s\n"), mod, depth_unit);
 	}
@@ -1368,15 +1369,21 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
 	if (prefs.ead) {
 		switch (pi->dive_type) {
 		case NITROX:
-			ead = lrint(get_depth_units(lrint(entry->ead), NULL, &depth_unit));
-			put_format(b, translate("gettextFromC", "EAD: %d%s\nEADD: %d%s / %.1fg/ℓ\n"), ead, depth_unit, eadd, depth_unit, entry->density);
-			break;
+			if (entry->ead > 0) {
+				ead = lrint(get_depth_units(lrint(entry->ead), NULL, &depth_unit));
+				put_format(b, translate("gettextFromC", "EAD: %d%s\nEADD: %d%s / %.1fg/ℓ\n"), ead, depth_unit, eadd, depth_unit, entry->density);
+				break;
+			}
 		case TRIMIX:
-			end = lrint(get_depth_units(lrint(entry->end), NULL, &depth_unit));
-			put_format(b, translate("gettextFromC", "END: %d%s\nEADD: %d%s / %.1fg/ℓ\n"), end, depth_unit, eadd, depth_unit, entry->density);
-			break;
+			if (entry->end > 0) {
+				end = lrint(get_depth_units(lrint(entry->end), NULL, &depth_unit));
+				put_format(b, translate("gettextFromC", "END: %d%s\nEADD: %d%s / %.1fg/ℓ\n"), end, depth_unit, eadd, depth_unit, entry->density);
+				break;
+			}
 		case AIR:
-			put_format(b, translate("gettextFromC", "Density: %.1fg/ℓ\n"), entry->density);
+			if (entry->density > 0) {
+				put_format(b, translate("gettextFromC", "Density: %.1fg/ℓ\n"), entry->density);
+			}
 		case FREEDIVING:
 			/* nothing */
 			break;
@@ -1384,7 +1391,7 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
 	}
 	if (entry->stopdepth) {
 		depthvalue = get_depth_units(entry->stopdepth, NULL, &depth_unit);
-		if (entry->ndl) {
+		if (entry->ndl > 0) {
 			/* this is a safety stop as we still have ndl */
 			if (entry->stoptime)
 				put_format(b, translate("gettextFromC", "Safety stop: %umin @ %.0f%s\n"), DIV_UP(entry->stoptime, 60),
@@ -1403,7 +1410,7 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
 		}
 	} else if (entry->in_deco) {
 		put_string(b, translate("gettextFromC", "In deco\n"));
-	} else if (has_ndl) {
+	} else if (entry->ndl >= 0) {
 		put_format(b, translate("gettextFromC", "NDL: %umin\n"), DIV_UP(entry->ndl, 60));
 	}
 	if (entry->tts)
@@ -1448,7 +1455,7 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
 	}
 	if (entry->heartbeat && prefs.hrgraph)
 		put_format(b, translate("gettextFromC", "heart rate: %d\n"), entry->heartbeat);
-	if (entry->bearing)
+	if (entry->bearing >= 0)
 		put_format(b, translate("gettextFromC", "bearing: %d\n"), entry->bearing);
 	if (entry->running_sum) {
 		depthvalue = get_depth_units(entry->running_sum / entry->sec, NULL, &depth_unit);
@@ -1463,13 +1470,14 @@ struct plot_data *get_plot_details_new(struct plot_info *pi, int time, struct me
 	struct plot_data *entry = NULL;
 	int i;
 
-	for (i = 0; i < pi->nr; i++) {
+	/* The two first and the two last plot entries do not have useful data */
+	for (i = 2; i < pi->nr - 2; i++) {
 		entry = pi->entry + i;
 		if (entry->sec >= time)
 			break;
 	}
 	if (entry)
-		plot_string(pi, entry, mb, pi->has_ndl);
+		plot_string(pi, entry, mb);
 	return (entry);
 }
 
diff --git a/core/units.h b/core/units.h
index d44c50ab4..5e92a00ba 100644
--- a/core/units.h
+++ b/core/units.h
@@ -42,8 +42,11 @@ extern "C" {
  * We also strive to make '0' a meaningless number saying "not
  * initialized", since many values are things that may not have
  * been reported (eg cylinder pressure or temperature from dive
- * computers that don't support them). But sometimes -1 is an even
- * more explicit way of saying "not there".
+ * computers that don't support them). But for some of the values
+ * 0 doesn't works as a flag for not initialized. Examples are
+ * compass bearing (bearing_t) or NDL (duration_t).
+ * Therefore some types have a default value which is -1 and has to
+ * be set at certain points in the code.
  *
  * Thus "millibar" for pressure, for example, or "millikelvin" for
  * temperatures. Doing temperatures in celsius or fahrenheit would
@@ -70,7 +73,7 @@ typedef int64_t timestamp_t;
 
 typedef struct
 {
-	uint32_t seconds; // durations up to 68 yrs
+	int32_t seconds; // durations up to 34 yrs
 } duration_t;
 
 typedef struct