Planner notes - revise logic for gasmix output

The logic for when to output a gasmix in the notes table is more
complicated than it seems at first.
- On a descent leg, the gas is the gas used for descent
- At a stop (calculated or user defined), the gas is the gas used for that
  stop
- But on an ascent leg (if displayed), the gas is the gas that is ABOUT TO
  BE USED
- The gas should not be repeated if it's the same gas as used on the last
  row of the table
- Ascent legs should only be displayed if the display transitions option
  is selected, OR if there is a gas change without a stop (the user can
  now set a minimum duration for a gaschange, but zero is still allowed).

The existing code tries to track what gas is being used/switched to at
each waypoint, and whether the gas should be printed or postponed to the
next leg.  It works sometimes but not always.

This patch replaces the postponed gas logic with:
- Is this an ascent leg? (determines whether the applicable gas is the
  preceding or following leg, and whether the leg should be displayed at
  all if the transitions option isn't selected)
- Is it an ascent with a gaschange without a stop?
- Has the gas actually changed from the last output?
- Will the next leg be at the same level and same gas (in which case merge
  them)?

Signed-off-by: Rick Walsh <rickmwalsh@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 27 insertions, 18 deletions

diff --git a/planner.c b/planner.c
index aee380b7e..6fc0ac29e 100644
--- a/planner.c
+++ b/planner.c
@@ -521,9 +521,10 @@ static unsigned int *sort_stops(int *dstops, int dnr, struct gaschanges *gstops,
 static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_disclaimer, int error)
 {
 	char buffer[2000000], temp[100000];
-	int len, lastdepth = 0, lasttime = 0, lastsetpoint = -1, newdepth = 0, lastprintdepth = 0;
+	int len, lastdepth = 0, lasttime = 0, lastsetpoint = -1, newdepth = 0, lastprintdepth = 0, lastprintsetpoint = -1;
+	struct gasmix lastprintgasmix = { -1, -1 };
 	struct divedatapoint *dp = diveplan->dp;
-	bool gaschange = !plan_verbatim, postponed = plan_verbatim;
+	bool gaschange = !plan_verbatim;
 	struct divedatapoint *nextdp = NULL;
 
 	disclaimer =  translate("gettextFromC", "DISCLAIMER / WARNING: THIS IS A NEW IMPLEMENTATION OF THE BUHLMANN "
@@ -567,6 +568,7 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 		const char *depth_unit;
 		double depthvalue;
 		int decimals;
+		bool isascent = (dp->depth < lastdepth);
 
 		nextdp = dp->next;
 		if (dp->time == 0)
@@ -639,6 +641,10 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 		} else {
 			if ((dp->depth == lastdepth && nextdp && dp->depth != nextdp->depth) ||
 			    plan_display_transitions || dp->entered || !dp->next || (gaschange && dp->next && dp->depth != nextdp->depth)) {
+			if (plan_display_transitions || dp->entered || !dp->next || dp->depth != nextdp->depth ||
+			    !isascent && (gasmix_distance(&lastprintgasmix, &gasmix) || lastprintsetpoint != dp->setpoint) &&
+			    ((nextdp && dp->depth != nextdp->depth) || gasmix_distance(&gasmix, &newgasmix) || (nextdp && dp->setpoint != nextdp->setpoint)) ||
+			    (isascent && gaschange && nextdp && dp->depth != nextdp->depth )) {
 				snprintf(temp, sizeof(temp), translate("gettextFromC", "%3.0f%s"), depthvalue, depth_unit);
 				len += snprintf(buffer + len, sizeof(buffer) - len, "<tr><td style='padding-left: 10px; float: right;'>%s</td>", temp);
 				if (plan_display_duration) {
@@ -650,20 +656,28 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 					len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; float: right;'>%s</td>", temp);
 				}
 
-				if (gaschange) {
-					if(dp->depth == lastdepth && !postponed) {
-						postponed = true;
-					} else {
-						if (dp->setpoint) {
-							snprintf(temp, sizeof(temp), translate("gettextFromC", "(SP = %.1fbar)"), (double) dp->setpoint / 1000.0);
-							len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s %s</b></td>", gasname(&newgasmix),
+				if (isascent && gaschange) {
+					if (dp->setpoint) {
+						snprintf(temp, sizeof(temp), translate("gettextFromC", "(SP = %.1fbar)"), (double) nextdp->setpoint / 1000.0);
+						len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s %s</b></td>", gasname(&newgasmix),
 									temp);
-						} else {
+					} else {
 							len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s</b></td>", gasname(&newgasmix));
-						}
-						gaschange = false;
-						postponed = false;
 					}
+					lastprintsetpoint = nextdp->setpoint;
+					lastprintgasmix = newgasmix;
+					gaschange = false;
+				} else if (gasmix_distance(&lastprintgasmix, &gasmix) != 0 || lastprintsetpoint != dp->setpoint) {
+					if (dp->setpoint) {
+						snprintf(temp, sizeof(temp), translate("gettextFromC", "(SP = %.1fbar)"), (double) dp->setpoint / 1000.0);
+						len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s %s</b></td>", gasname(&gasmix),
+									temp);
+					} else {
+							len += snprintf(buffer + len, sizeof(buffer) - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s</b></td>", gasname(&gasmix));
+					}
+					lastprintsetpoint = dp->setpoint;
+					lastprintgasmix = gasmix;
+					gaschange = false;
 				} else {
 					len += snprintf(buffer + len, sizeof(buffer) - len, "<td>&nbsp;</td>");
 				}
@@ -673,9 +687,6 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 			}
 		}
 		if (gaschange) {
-			if(dp->depth == lastdepth && !postponed) {
-				postponed = true;
-			} else {
 			// gas switch at this waypoint
 			if (plan_verbatim) {
 				if (lastsetpoint >= 0) {
@@ -687,8 +698,6 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 					len += snprintf(buffer + len, sizeof(buffer) - len, "%s<br>", temp);
 				}
 				gaschange = false;
-				postponed = true;
-			}
 			gasmix = newgasmix;
 			}
 		}