Print icd data only when it is really needed

Reduce the impact and visibility of icd calculations by writing
the data to the planner output only in cases where gas switches
involve:

1) ascent
2) helium is used as part of breathing gas
3) gas switch results in an increase in partial pressure of nitrogen.

Coding change:

1) The code for writing the header of the icd table as well as
   the inclusion of the data in the planner output is made
   conditional on the above three requirements. This involves
   moving the code that writes the table header into the
   function that writes an icd data item to buffer.
2) Manipulation of a boolean variable that controls writing
   of the table header to buffer and that also determines
   whether any icd results should be inluded in the planner
   results.
3) Reorganise comments so that there are not multiple tabs between
   the code and the start of a comment.

Correct type and insert braces where important

Signed-off-by: Willem Ferguson <willemferguson@zoology.up.ac.za>

1 files changed, 44 insertions, 40 deletions

diff --git a/core/plannernotes.c b/core/plannernotes.c
index a678131e2..1eca69417 100644
--- a/core/plannernotes.c
+++ b/core/plannernotes.c
@@ -36,13 +36,28 @@ int diveplan_duration(struct diveplan *diveplan)
  * Parameters: 1) Pointer to the output buffer position at which writing should start.
  *             2) The size of the part of the unused output buffer that remains unused.
  *             3) The data structure containing icd calculation results: icdvalues.
- *             4) The names of the gasses in the gas change: gas-from and gas-to.
+ *             4) A boolean value indicating whether a table header should be written before the data. Only during 1st call.
+ *             5) Pointers to gas mixes in the gas change: gas-from and gas-to.
  * Returns:    The size of the output buffer that has been used after the new results have been added.
  */
-int add_icd_entry(char *icdbuffer, unsigned int maxsize, struct icd_data *icdvalues, int time_seconds, int ambientpressure_mbar, struct gasmix *gas_from, struct gasmix *gas_to)
+int add_icd_entry(char *icdbuffer, unsigned int maxsize, struct icd_data *icdvalues, bool printheader, int time_seconds, int ambientpressure_mbar, struct gasmix *gas_from, struct gasmix *gas_to)
 {
-	int len;
-	len = snprintf(icdbuffer, maxsize, 
+	int len = 0;
+	if (printheader) { // Create a table description and a table header if no icd data have been written yet.
+		len = snprintf(icdbuffer + len, maxsize - len, "<div>%s:",
+			translate("gettextFromC","Isobaric counterdiffusion information"));
+		len += snprintf(icdbuffer + len, maxsize - len, "<table><tr><td align='left'><b>%s</b></td>",
+			translate("gettextFromC", "runtime"));
+		len += snprintf(icdbuffer + len, maxsize - len, "<td align='center'><b>%s</b></td>",
+			translate("gettextFromC", "gaschange"));
+		len += snprintf(icdbuffer + len, maxsize - len, "<td style='padding-left: 15px;'><b>%s</b></td>",
+			translate("gettextFromC", "&#916;He"));
+		len += snprintf(icdbuffer + len, maxsize - len, "<td style='padding-left: 20px;'><b>%s</b></td>",
+			translate("gettextFromC", "&#916;N&#8322;"));
+		len += snprintf(icdbuffer + len, maxsize - len, "<td style='padding-left: 10px;'><b>%s</b></td></tr>",
+			translate("gettextFromC", "max &#916;N&#8322;"));
+	}		// Add one entry to the icd table:
+	len += snprintf(icdbuffer + len, maxsize - len, 
 		"<tr><td rowspan='2' style= 'vertical-align:top;'>%3d%s</td>"
 		"<td rowspan=2 style= 'vertical-align:top;'>%s&#10137;",
 		(time_seconds + 30) / 60, translate("gettextFromC", "min"), gasname(gas_from));
@@ -72,7 +87,7 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 	const char *deco, *segmentsymbol;
 	static char buf[1000];
 	int len, lastdepth = 0, lasttime = 0, lastsetpoint = -1, newdepth = 0, lastprintdepth = 0, lastprintsetpoint = -1;
-	int icyl, icdlen = 0;
+	int icdlen = 0;
 	struct gasmix lastprintgasmix = {{ -1 }, { -1 }};
 	struct divedatapoint *dp = diveplan->dp;
 	bool plan_verbatim = prefs.verbatim_plan;
@@ -82,8 +97,7 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 	bool gaschange_after = !plan_verbatim;
 	bool gaschange_before;
 	bool lastentered = true;
-	bool istrimix = false;
-	bool icdwarning = false;
+	bool icdwarning = false, icdtableheader = true;
 	struct divedatapoint *nextdp = NULL;
 	struct divedatapoint *lastbottomdp = NULL;
 	struct icd_data icdvalues;
@@ -163,25 +177,6 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 				"<th style='padding-left: 10px; float: left;'>%s</th></tr></thead><tbody style='float: left;'>",
 				translate("gettextFromC", "gas"));
 	}
-	for (icyl = 0; icyl < MAX_CYLINDERS; icyl++) {	// If dive plan has an OC cylinder with helium, then initialise ICD table:
-		if ((dive->cylinder[icyl].cylinder_use == OC_GAS) && (get_he(&dive->cylinder[icyl].gasmix) > 0)) {	
-			istrimix = true;
-			icdlen = 0;
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<div>%s:",
-				translate("gettextFromC","Isobaric counterdiffusion information"));
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<table><tr><td align='left'><b>%s</b></td>",
-				translate("gettextFromC", "runtime"));
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<td align='center'><b>%s</b></td>",
-				translate("gettextFromC", "gaschange"));
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<td style='padding-left: 15px;'><b>%s</b></td>",
-				translate("gettextFromC", "&#916;He"));
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<td style='padding-left: 20px;'><b>%s</b></td>",
-				translate("gettextFromC", "&#916;N&#8322;"));
-			icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen, "<td style='padding-left: 10px;'><b>%s</b></td></tr>",
-				translate("gettextFromC", "max &#916;N&#8322;"));
-			break;
-		}
-	}
 
 	do {
 		struct gasmix gasmix, newgasmix = {};
@@ -323,10 +318,13 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 					} else {
 						len += snprintf(buffer + len, sz_buffer - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s</b></td>",
 							gasname(&newgasmix));
-						if (isascent && (get_he(&lastprintgasmix) > 0)) {		// For a trimix gas change on ascent, save ICD info if previous cylinder had helium
-							if (isobaric_counterdiffusion(&lastprintgasmix, &newgasmix, &icdvalues)) 					// Do icd calulations
+						if (isascent && (get_he(&lastprintgasmix) > 0)) { // For a trimix gas change on ascent, save ICD info if previous cylinder had helium
+							if (isobaric_counterdiffusion(&lastprintgasmix, &newgasmix, &icdvalues)) // Do icd calulations
 								icdwarning = true;
-							icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, dp->time, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &newgasmix); // Print calculations to buffer.
+							if (icdvalues.dN2 > 0) { // If the gas change involved helium as well as an increase in nitrogen..
+								icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, icdtableheader, dp->time, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &newgasmix); // .. then print calculations to buffer.
+								icdtableheader = false;
+							}
 						}
 					}
 					lastprintsetpoint = nextdp->setpoint;
@@ -341,10 +339,13 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 					} else {
 						len += snprintf(buffer + len, sz_buffer - len, "<td style='padding-left: 10px; color: red; float: left;'><b>%s</b></td>",
 							gasname(&gasmix));
-						if (get_he(&lastprintgasmix) > 0) {						// For a trimix gas change, save ICD info if previous cylinder had helium
-							if (isobaric_counterdiffusion(&lastprintgasmix, &gasmix, &icdvalues))			// Do icd calculations
+						if (get_he(&lastprintgasmix) > 0) {  // For a trimix gas change, save ICD info if previous cylinder had helium
+							if (isobaric_counterdiffusion(&lastprintgasmix, &gasmix, &icdvalues))  // Do icd calculations
 								icdwarning = true;
-							icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, lasttime, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &gasmix); // and print them to buffer.
+							if (icdvalues.dN2 > 0) { // If the gas change involved helium as well as an increase in nitrogen..
+								icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, icdtableheader, lasttime, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &gasmix); // .. then print data to buffer.
+								icdtableheader = false;
+							}
 						} 
 					}
 					// Set variables so subsequent iterations can test against the last gas printed
@@ -367,10 +368,13 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 						snprintf(temp, sz_temp, translate("gettextFromC", "Switch gas to %s (SP = %.1fbar)"), gasname(&newgasmix), (double) nextdp->setpoint / 1000.0);
 					} else {
 						snprintf(temp, sz_temp, translate("gettextFromC", "Switch gas to %s"), gasname(&newgasmix));
-						if ((isascent) && (get_he(&lastprintgasmix) > 0)) {										//	For a trimix gas change on ascent:
-							if (isobaric_counterdiffusion(&lastprintgasmix, &newgasmix, &icdvalues))				// Do icd calculations
+						if ((isascent) && (get_he(&lastprintgasmix) > 0)) {          // For a trimix gas change on ascent:
+							if (isobaric_counterdiffusion(&lastprintgasmix, &newgasmix, &icdvalues)) // Do icd calculations
 								icdwarning = true;
-							icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, dp->time, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &newgasmix); // and print them to buffer.
+							if (icdvalues.dN2 > 0) { // If the gas change involved helium as well as an increase in nitrogen..
+								icdlen += add_icd_entry(icdbuffer+icdlen, sz_icdbuf-icdlen, &icdvalues, icdtableheader, dp->time, depth_to_mbar(dp->depth.mm, dive), &lastprintgasmix, &newgasmix); // ... then print data to buffer.
+								icdtableheader = false;
+							}
 						}
 					}
 					len += snprintf(buffer + len, sz_buffer - len, "%s<br>", temp);
@@ -535,11 +539,11 @@ void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool show_d
 		len += snprintf(buffer + len, sz_buffer - len, "%s%s%s<br></div>", temp, warning, mingas);
 	}
 
-	/* For trimix OC dives, add the ICD table here */
-	if (istrimix) {
-		icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen,"</tbody></table>");	// End the ICD table
-		len += snprintf(buffer + len, sz_buffer - len, "%s", icdbuffer);				// ..and add it to the html buffer
-		if (icdwarning) {																// If necessary, add a warning message to html buffer
+	/* For trimix OC dives, if an icd table header and icd data were printed to buffer, then add the ICD table here */
+	if (!icdtableheader) {
+		icdlen += snprintf(icdbuffer + icdlen, sz_icdbuf - icdlen,"</tbody></table>"); // End the ICD table
+		len += snprintf(buffer + len, sz_buffer - len, "%s", icdbuffer); // ..and add it to the html buffer
+		if (icdwarning) { // If necessary, add warning
 			len += snprintf(buffer + len, sz_buffer - len, "<span style='color: red;'>%s</span> %s",
 				translate("gettextFromC", "Warning:"),
 				translate("gettextFromC", "Isobaric counterdiffusion conditions exceeded"));