modify igc writer for consistent rounding. (#146)

diff --git a/igc.cc b/igc.cc
index eb30dbde0a79861ca4de93e7d4441b78be06a3ab..9fdc16d494d138717b2847894c0a0e1ef48dd702 100644 (file)
--- a/igc.cc
+++ b/igc.cc
@@ -530,15 +530,23 @@ static void get_tracks(const route_head** pres_track, const route_head** gnss_tr
 static char* latlon2str(const Waypoint* wpt)
 {
   static char str[18] = "";
-  char lat_hemi = wpt->latitude < 0 ? 'S' : 'N';
-  char lon_hemi = wpt->longitude < 0 ? 'W' : 'E';
-  unsigned char lat_deg = fabs(wpt->latitude);
-  unsigned char lon_deg = fabs(wpt->longitude);
-  unsigned int lat_min = (fabs(wpt->latitude) - lat_deg) * 60000 + 0.500000000001;
-  unsigned int lon_min = (fabs(wpt->longitude) - lon_deg) * 60000 + 0.500000000001;
-
-  if (snprintf(str, 18, "%02u%05u%c%03u%05u%c",
-               lat_deg, lat_min, lat_hemi, lon_deg, lon_min, lon_hemi) != 17) {
+  // We use lround here because it:
+  // "Returns the integral value that is nearest to x, with halfway cases rounded away from zero."
+  // The halfway rounding cases of *printf are not precisely defined, and can vary with implmentation.
+  // We don't really care which way the halfway cases go, but we want them to go that way consistenly
+  // across implementations.
+  // We also try to use a minimum of floating point arithmetic to minimize accumulated fp math errors.
+  long lat_milliminutes = lround(wpt->latitude * 60000.0);
+  long lon_milliminutes = lround(wpt->longitude * 60000.0);
+  char lat_hemi = lat_milliminutes < 0 ? 'S' : 'N';
+  char lon_hemi = lon_milliminutes < 0 ? 'W' : 'E';
+  ldiv_t lat_digits;
+  ldiv_t lon_digits;
+  lat_digits = ldiv(labs(lat_milliminutes), 60000L);
+  lon_digits = ldiv(labs(lon_milliminutes), 60000L);
+
+  if (snprintf(str, 18, "%02ld%05ld%c%03ld%05ld%c",
+               lat_digits.quot, lat_digits.rem, lat_hemi, lon_digits.quot, lon_digits.rem, lon_hemi) != 17) {
     fatal(MYNAME ": Bad waypoint format '%s'\n", str);
   }
   return str;

diff --git a/reference/igc1_3d.out b/reference/igc1_3d.out
index 2ecdeb4e2f7e4a81be3e9759f51f7f9ad4b1c1b1..e50544ed0aa4b0da2f0d68b0bc8119bc0284e8d1 100644 (file)
--- a/reference/igc1_3d.out
+++ b/reference/igc1_3d.out
@@ -2,8 +2,8 @@ AXXXZZZGPSBabel
 HFDTE240404\r
 HFPLTPILOT:CHRIS JONES\r
 C010170000000000000000101\r
-C3040552S15036542EBORAH \r
-C3040552S15036542EBORAH \r
+C3040552S15036542EBORAH\r
+C3040552S15036542EBORAH\r
 C3043796S15038952EBALDWI\r
 C3045821S15043392EMANAIR\r
 C3045821S15043392EMANAIR\r
@@ -55,11 +55,11 @@ B0422453040722S15036423EA0096100000
 B0423153040717S15036457EA0098800000\r
 B0423453040700S15036444EA0101900000\r
 B0424163040689S15036457EA0104100000\r
-B0424473040753S15036486EA0101900000\r
+B0424473040754S15036486EA0101900000\r
 B0425183040750S15036329EA0099200000\r
 B0425483040794S15036240EA0101900000\r
 B0426193040688S15036353EA0108000000\r
-B0426493040679S15036400EA0111700000\r
+B0426493040679S15036401EA0111700000\r
 B0427203040754S15036332EA0113300000\r
 B0427513040693S15036316EA0113200000\r
 B0428213040918S15036288EA0108900000\r
@@ -96,7 +96,7 @@ B0443383043886S15038927EA0099500000
 B0444093043845S15038947EA0099400000\r
 B0444403043904S15038862EA0099000000\r
 B0445113043934S15038756EA0098000000\r
-B0445423044092S15038774EA0095300000\r
+B0445423044093S15038774EA0095300000\r
 B0446133044150S15039144EA0094600000\r
 B0446443044370S15039248EA0094100000\r
 B0447153044594S15039415EA0092800000\r
@@ -105,7 +105,7 @@ B0448163044963S15040024EA0086900000
 B0448473044982S15040431EA0083300000\r
 B0449183044991S15040573EA0083000000\r
 B0449483045154S15040808EA0081500000\r
-B0450193045342S15041095EA0078100000\r
+B0450193045342S15041096EA0078100000\r
 B0450493045484S15041383EA0075000000\r
 B0451193045595S15041771EA0065700000\r
 B0451503045744S15042205EA0055400000\r

diff --git a/reference/igc1_gpx.out b/reference/igc1_gpx.out
index f0c55882040fda33cf9155849fcef7bbbbf99357..afbb5f1812b41cabd36883f6d94de3c3b765fc14 100644 (file)
--- a/reference/igc1_gpx.out
+++ b/reference/igc1_gpx.out
@@ -7,13 +7,13 @@
     <desc>IGCDATE000000: </desc>
     <rtept lat="-30.675866667" lon="150.609033333">
       <name>TAKEOFF</name>
-      <cmt>BORAH </cmt>
-      <desc>BORAH </desc>
+      <cmt>BORAH</cmt>
+      <desc>BORAH</desc>
     </rtept>
     <rtept lat="-30.675866667" lon="150.609033333">
       <name>START</name>
-      <cmt>BORAH </cmt>
-      <desc>BORAH </desc>
+      <cmt>BORAH</cmt>
+      <desc>BORAH</desc>
     </rtept>
     <rtept lat="-30.729933333" lon="150.649200000">
       <name>TURN01</name>
@@ -179,7 +179,7 @@
       <trkpt lat="-30.678150000" lon="150.607616667">
         <time>2004-04-24T04:24:16Z</time>
       </trkpt>
-      <trkpt lat="-30.679216667" lon="150.608100000">
+      <trkpt lat="-30.679233333" lon="150.608100000">
         <time>2004-04-24T04:24:47Z</time>
       </trkpt>
       <trkpt lat="-30.679166667" lon="150.605483333">
@@ -191,7 +191,7 @@
       <trkpt lat="-30.678133333" lon="150.605883333">
         <time>2004-04-24T04:26:19Z</time>
       </trkpt>
-      <trkpt lat="-30.677983333" lon="150.606666667">
+      <trkpt lat="-30.677983333" lon="150.606683333">
         <time>2004-04-24T04:26:49Z</time>
       </trkpt>
       <trkpt lat="-30.679233333" lon="150.605533333">
@@ -302,7 +302,7 @@
       <trkpt lat="-30.732233333" lon="150.645933333">
         <time>2004-04-24T04:45:11Z</time>
       </trkpt>
-      <trkpt lat="-30.734866667" lon="150.646233333">
+      <trkpt lat="-30.734883333" lon="150.646233333">
         <time>2004-04-24T04:45:42Z</time>
       </trkpt>
       <trkpt lat="-30.735833333" lon="150.652400000">
@@ -329,7 +329,7 @@
       <trkpt lat="-30.752566667" lon="150.680133333">
         <time>2004-04-24T04:49:48Z</time>
       </trkpt>
-      <trkpt lat="-30.755700000" lon="150.684916667">
+      <trkpt lat="-30.755700000" lon="150.684933333">
         <time>2004-04-24T04:50:19Z</time>
       </trkpt>
       <trkpt lat="-30.758066667" lon="150.689716667">

diff --git a/reference/igc1_igc.out b/reference/igc1_igc.out
index 9d3c0071eab306f647bb946bf7bb2785a23b26db..edfbea4ba9735b32b5201e5bd76c85e1523064eb 100644 (file)
--- a/reference/igc1_igc.out
+++ b/reference/igc1_igc.out
@@ -2,8 +2,8 @@ AXXXZZZGPSBabel
 HFDTE240404\r
 HFPLTPILOT:CHRIS JONES\r
 C010170000000000000000101\r
-C3040552S15036542EBORAH \r
-C3040552S15036542EBORAH \r
+C3040552S15036542EBORAH\r
+C3040552S15036542EBORAH\r
 C3043796S15038952EBALDWI\r
 C3045821S15043392EMANAIR\r
 C3045821S15043392EMANAIR\r
@@ -55,11 +55,11 @@ B0422453040722S15036423EA0000000000
 B0423153040717S15036457EA0000000000\r
 B0423453040700S15036444EA0000000000\r
 B0424163040689S15036457EA0000000000\r
-B0424473040753S15036486EA0000000000\r
+B0424473040754S15036486EA0000000000\r
 B0425183040750S15036329EA0000000000\r
 B0425483040794S15036240EA0000000000\r
 B0426193040688S15036353EA0000000000\r
-B0426493040679S15036400EA0000000000\r
+B0426493040679S15036401EA0000000000\r
 B0427203040754S15036332EA0000000000\r
 B0427513040693S15036316EA0000000000\r
 B0428213040918S15036288EA0000000000\r
@@ -96,7 +96,7 @@ B0443383043886S15038927EA0000000000
 B0444093043845S15038947EA0000000000\r
 B0444403043904S15038862EA0000000000\r
 B0445113043934S15038756EA0000000000\r
-B0445423044092S15038774EA0000000000\r
+B0445423044093S15038774EA0000000000\r
 B0446133044150S15039144EA0000000000\r
 B0446443044370S15039248EA0000000000\r
 B0447153044594S15039415EA0000000000\r
@@ -105,7 +105,7 @@ B0448163044963S15040024EA0000000000
 B0448473044982S15040431EA0000000000\r
 B0449183044991S15040573EA0000000000\r
 B0449483045154S15040808EA0000000000\r
-B0450193045342S15041095EA0000000000\r
+B0450193045342S15041096EA0000000000\r
 B0450493045484S15041383EA0000000000\r
 B0451193045595S15041771EA0000000000\r
 B0451503045744S15042205EA0000000000\r

diff --git a/reference/track/skydrop~kml.igc b/reference/track/skydrop~kml.igc
index ce3f057ebdc4f361404bb502add809476cd97193..bdb8202b3905897424cd241fc9148b5437980694 100644 (file)
--- a/reference/track/skydrop~kml.igc
+++ b/reference/track/skydrop~kml.igc
@@ -27,7 +27,7 @@ B1700274816053N00831019EA0000000792
 B1700284816058N00831019EA0000000794\r
 B1700294816063N00831019EA0000000792\r
 B1700304816068N00831020EA0000000792\r
-B1700314816072N00831022EA0000000794\r
+B1700314816073N00831022EA0000000794\r
 B1700324816078N00831023EA0000000797\r
 B1700334816083N00831025EA0000000799\r
 B1700344816087N00831027EA0000000800\r
@@ -52,12 +52,12 @@ B1700524816150N00831114EA0000000825
 B1700534816153N00831119EA0000000827\r
 B1700544816156N00831125EA0000000829\r
 B1700554816159N00831131EA0000000831\r
-B1700564816162N00831136EA0000000833\r
-B1700574816165N00831142EA0000000833\r
+B1700564816163N00831136EA0000000833\r
+B1700574816166N00831142EA0000000833\r
 B1700584816168N00831148EA0000000834\r
 B1700594816171N00831153EA0000000836\r
 B1701004816175N00831158EA0000000838\r
-B1701014816177N00831164EA0000000839\r
+B1701014816178N00831164EA0000000839\r
 B1701024816181N00831169EA0000000840\r
 B1701034816184N00831175EA0000000842\r
 B1701044816187N00831180EA0000000843\r
@@ -130,7 +130,7 @@ B1702114816328N00831602EA0000000901
 B1702124816329N00831610EA0000000902\r
 B1702134816329N00831618EA0000000903\r
 B1702144816330N00831626EA0000000903\r
-B1702154816330N00831633EA0000000903\r
+B1702154816330N00831634EA0000000903\r
 B1702164816330N00831642EA0000000904\r
 B1702174816330N00831650EA0000000904\r
 B1702184816331N00831658EA0000000905\r
@@ -143,7 +143,7 @@ B1702244816333N00831705EA0000000904
 B1702254816333N00831721EA0000000906\r
 B1702264816333N00831729EA0000000906\r
 B1702274816333N00831737EA0000000905\r
-B1702284816333N00831745EA0000000904\r
+B1702284816334N00831745EA0000000904\r
 B1702294816334N00831753EA0000000904\r
 B1702304816335N00831761EA0000000904\r
 B1702314816335N00831770EA0000000905\r
@@ -169,10 +169,10 @@ B1702514816335N00831917EA0000000902
 B1702524816334N00831925EA0000000903\r
 B1702534816334N00831933EA0000000905\r
 B1702544816333N00831941EA0000000906\r
-B1702554816333N00831948EA0000000906\r
+B1702554816333N00831949EA0000000906\r
 B1702564816332N00831956EA0000000905\r
 B1702574816331N00831964EA0000000904\r
-B1702584816330N00831972EA0000000904\r
+B1702584816331N00831972EA0000000904\r
 B1702594816330N00831980EA0000000904\r
 B1703004816329N00831988EA0000000905\r
 B1703014816328N00831996EA0000000906\r
@@ -260,7 +260,7 @@ B1704234816428N00832640EA0000000921
 B1704244816430N00832648EA0000000921\r
 B1704254816432N00832656EA0000000920\r
 B1704264816433N00832663EA0000000917\r
-B1704274816435N00832671EA0000000914\r
+B1704274816436N00832671EA0000000914\r
 B1704284816437N00832677EA0000000911\r
 B1704294816440N00832684EA0000000911\r
 B1704304816443N00832691EA0000000912\r
@@ -439,7 +439,7 @@ B1707244816943N00833214EA0000001000
 B1707254816946N00833206EA0000000999\r
 B1707264816949N00833198EA0000000999\r
 B1707274816951N00833190EA0000000999\r
-B1707284816954N00833181EA0000000998\r
+B1707284816954N00833182EA0000000998\r
 B1707294816956N00833174EA0000000998\r
 B1707304816959N00833165EA0000000998\r
 B1707314816961N00833157EA0000000999\r
@@ -447,7 +447,7 @@ B1707324816964N00833148EA0000000999
 B1707334816967N00833139EA0000001000\r
 B1707344816970N00833131EA0000001000\r
 B1707354816972N00833123EA0000000999\r
-B1707364816975N00833116EA0000000999\r
+B1707364816976N00833116EA0000000999\r
 B1707374816979N00833108EA0000001000\r
 B1707384816982N00833100EA0000001000\r
 B1707394816986N00833092EA0000001001\r
@@ -490,7 +490,7 @@ B1708164817106N00832809EA0000001020
 B1708174817108N00832801EA0000001021\r
 B1708184817111N00832793EA0000001022\r
 B1708194817114N00832785EA0000001022\r
-B1708204817116N00832777EA0000001022\r
+B1708204817117N00832777EA0000001022\r
 B1708214817119N00832768EA0000001022\r
 B1708224817122N00832760EA0000001022\r
 B1708234817124N00832751EA0000001022\r
@@ -574,7 +574,7 @@ B1709414817190N00832086EA0000001053
 B1709424817188N00832077EA0000001053\r
 B1709434817185N00832067EA0000001053\r
 B1709444817182N00832058EA0000001052\r
-B1709454817179N00832049EA0000001052\r
+B1709454817180N00832049EA0000001052\r
 B1709464817177N00832040EA0000001050\r
 B1709474817174N00832031EA0000001050\r
 B1709484817171N00832022EA0000001050\r
@@ -600,7 +600,7 @@ B1710074817131N00831832EA0000001052
 B1710084817130N00831823EA0000001051\r
 B1710094817128N00831813EA0000001050\r
 B1710104817127N00831803EA0000001049\r
-B1710114817125N00831793EA0000001050\r
+B1710114817126N00831793EA0000001050\r
 B1710124817124N00831783EA0000001050\r
 B1710134817123N00831773EA0000001050\r
 B1710144817122N00831763EA0000001049\r
@@ -617,7 +617,7 @@ B1710244817110N00831665EA0000001045
 B1710254817109N00831655EA0000001045\r
 B1710264817107N00831646EA0000001045\r
 B1710274817106N00831636EA0000001045\r
-B1710294817104N00831626EA0000001044\r
+B1710294817105N00831626EA0000001044\r
 B1710304817103N00831616EA0000001044\r
 B1710314817102N00831607EA0000001044\r
 B1710324817101N00831597EA0000001044\r
@@ -649,7 +649,7 @@ B1710574817055N00831351EA0000001043
 B1710584817053N00831342EA0000001044\r
 B1710594817050N00831333EA0000001044\r
 B1711004817047N00831324EA0000001046\r
-B1711014817045N00831315EA0000001047\r
+B1711014817045N00831316EA0000001047\r
 B1711024817043N00831307EA0000001047\r
 B1711034817040N00831298EA0000001048\r
 B1711044817038N00831290EA0000001048\r
@@ -664,7 +664,7 @@ B1711124817021N00831222EA0000001057
 B1711134817019N00831213EA0000001058\r
 B1711144817018N00831204EA0000001059\r
 B1711154817016N00831195EA0000001060\r
-B1711164817014N00831186EA0000001061\r
+B1711164817015N00831186EA0000001061\r
 B1711174817013N00831177EA0000001061\r
 B1711184817011N00831168EA0000001062\r
 B1711194817009N00831159EA0000001062\r
@@ -687,7 +687,7 @@ B1711354816973N00831015EA0000001073
 B1711364816971N00831006EA0000001073\r
 B1711374816968N00830997EA0000001074\r
 B1711384816966N00830988EA0000001074\r
-B1711394816963N00830979EA0000001074\r
+B1711394816964N00830979EA0000001074\r
 B1711404816961N00830969EA0000001074\r
 B1711414816958N00830960EA0000001075\r
 B1711424816956N00830951EA0000001076\r
@@ -816,7 +816,7 @@ B1713464816682N00829864EA0000001072
 B1713474816681N00829855EA0000001071\r
 B1713484816680N00829846EA0000001069\r
 B1713494816679N00829838EA0000001067\r
-B1713504816678N00829829EA0000001066\r
+B1713504816679N00829829EA0000001066\r
 B1713514816677N00829821EA0000001066\r
 B1713524816676N00829811EA0000001065\r
 B1713534816675N00829802EA0000001064\r
@@ -908,7 +908,7 @@ B1715194816590N00829603EA0000001008
 B1715204816585N00829609EA0000001006\r
 B1715214816581N00829615EA0000001006\r
 B1715224816577N00829620EA0000001005\r
-B1715234816573N00829626EA0000001004\r
+B1715234816574N00829626EA0000001004\r
 B1715244816570N00829630EA0000001001\r
 B1715254816565N00829636EA0000000999\r
 B1715264816561N00829642EA0000000999\r
@@ -931,7 +931,7 @@ B1715434816501N00829746EA0000000986
 B1715444816498N00829753EA0000000986\r
 B1715454816494N00829759EA0000000985\r
 B1715464816491N00829765EA0000000983\r
-B1715474816486N00829770EA0000000982\r
+B1715474816487N00829770EA0000000982\r
 B1715484816482N00829776EA0000000982\r
 B1715494816473N00829786EA0000000982\r
 B1715504816469N00829792EA0000000981\r
@@ -1012,7 +1012,7 @@ B1717054816201N00830276EA0000000897
 B1717064816198N00830284EA0000000895\r
 B1717074816195N00830291EA0000000893\r
 B1717084816192N00830297EA0000000891\r
-B1717094816189N00830304EA0000000890\r
+B1717094816190N00830305EA0000000890\r
 B1717104816187N00830311EA0000000889\r
 B1717114816183N00830319EA0000000887\r
 B1717124816180N00830326EA0000000885\r
@@ -1052,7 +1052,7 @@ B1717454816101N00830561EA0000000830
 B1717464816098N00830567EA0000000828\r
 B1717474816096N00830574EA0000000826\r
 B1717484816093N00830581EA0000000825\r
-B1717494816090N00830588EA0000000824\r
+B1717494816091N00830588EA0000000824\r
 B1717504816088N00830595EA0000000823\r
 B1717514816086N00830601EA0000000821\r
 B1717524816084N00830608EA0000000819\r
@@ -1126,9 +1126,9 @@ B1719004816070N00830899EA0000000831
 B1719014816071N00830890EA0000000832\r
 B1719024816072N00830881EA0000000834\r
 B1719034816074N00830873EA0000000834\r
-B1719044816075N00830865EA0000000833\r
+B1719044816076N00830865EA0000000833\r
 B1719054816077N00830856EA0000000833\r
-B1719064816079N00830847EA0000000833\r
+B1719064816079N00830848EA0000000833\r
 B1719074816080N00830838EA0000000834\r
 B1719084816082N00830829EA0000000834\r
 B1719094816083N00830820EA0000000834\r
@@ -1164,7 +1164,7 @@ B1719394816154N00830578EA0000000843
 B1719404816158N00830570EA0000000844\r
 B1719414816161N00830563EA0000000846\r
 B1719424816165N00830556EA0000000846\r
-B1719434816168N00830550EA0000000846\r
+B1719434816169N00830550EA0000000846\r
 B1719444816172N00830543EA0000000846\r
 B1719454816175N00830537EA0000000847\r
 B1719464816179N00830531EA0000000849\r
@@ -1212,7 +1212,7 @@ B1720274816149N00830412EA0000000839
 B1720284816146N00830419EA0000000837\r
 B1720294816144N00830426EA0000000836\r
 B1720304816141N00830433EA0000000834\r
-B1720314816138N00830440EA0000000832\r
+B1720314816139N00830440EA0000000832\r
 B1720324816136N00830448EA0000000832\r
 B1720334816131N00830463EA0000000830\r
 B1720344816128N00830470EA0000000828\r
@@ -1230,7 +1230,7 @@ B1720454816100N00830543EA0000000812
 B1720464816098N00830550EA0000000811\r
 B1720474816096N00830556EA0000000809\r
 B1720484816093N00830563EA0000000808\r
-B1720494816090N00830570EA0000000806\r
+B1720494816091N00830570EA0000000806\r
 B1720504816088N00830576EA0000000804\r
 B1720524816086N00830583EA0000000802\r
 B1720534816084N00830590EA0000000802\r

diff --git a/testo.d/igc.test b/testo.d/igc.test
index e5e92ee34f9ebb7d1f5b34ad56c5ff11f418d95a..68a1f01ee46cdd5fb375ffd1b1929fd1a2d64d8f 100644 (file)
--- a/testo.d/igc.test
+++ b/testo.d/igc.test
@@ -10,12 +10,12 @@ gpsbabel -i igc -f ${TMPDIR}/igc.out -o gpx -F ${TMPDIR}/igc.gpx
 compare ${REFERENCE}/igc1_gpx.out ${TMPDIR}/igc.gpx
 
 gpsbabel -i gpx -f ${TMPDIR}/igc.gpx -o igc -F ${TMPDIR}/igc.out
-sed '/^LXXXGenerated by GPSBabel Version/d' ${TMPDIR}/igc.out > ${TMPDIR}/igc_sed.out
-compare ${REFERENCE}/igc1_igc.out ${TMPDIR}/igc_sed.out
+sed '/^LXXXGenerated by GPSBabel Version/d' ${TMPDIR}/igc.out > ${TMPDIR}/igc_sed2.out
+compare ${REFERENCE}/igc1_igc.out ${TMPDIR}/igc_sed2.out
 
 gpsbabel -i gpx -f ${REFERENCE}/igc1_baro.gpx -i igc -f ${REFERENCE}/igc1_igc.out -o igc,timeadj=auto -F ${TMPDIR}/igc.out
-sed '/^LXXXGenerated by GPSBabel Version/d' ${TMPDIR}/igc.out > ${TMPDIR}/igc_sed.out
-compare ${REFERENCE}/igc1_3d.out ${TMPDIR}/igc_sed.out
+sed '/^LXXXGenerated by GPSBabel Version/d' ${TMPDIR}/igc.out > ${TMPDIR}/igc_sed3.out
+compare ${REFERENCE}/igc1_3d.out ${TMPDIR}/igc_sed3.out
 
 
 gpsbabel -i igc -f ${REFERENCE}/igc2.igc -o gpx -F ${TMPDIR}/igc2~igc.gpx