Merge pull request #2127 from rouault/projinfo_hide_ballpark

projinfo: add a --hide-ballpark option

6 files changed, 59 insertions, 22 deletions

diff --git a/docs/source/apps/projinfo.rst b/docs/source/apps/projinfo.rst
index 0e54c244..99adbd50 100644
--- a/docs/source/apps/projinfo.rst
+++ b/docs/source/apps/projinfo.rst
@@ -20,8 +20,9 @@ Synopsis
     |    [[--area name_or_code] | [--bbox west_long,south_lat,east_long,north_lat]]
     |    [--spatial-test contains|intersects]
     |    [--crs-extent-use none|both|intersection|smallest]
-    |    [--grid-check none|discard_missing|sort|known_available] [--show-superseded]
+    |    [--grid-check none|discard_missing|sort|known_available]
     |    [--pivot-crs always|if_no_direct_transformation|never|{auth:code[,auth:code]*}]
+    |    [--show-superseded] [--hide-ballpark]
     |    [--boundcrs-to-wgs84]
     |    [--main-db-path path] [--aux-db-path path]*
     |    [--identify] [--3d]
@@ -177,16 +178,6 @@ The following control parameters can appear in any order:
 
     .. note:: only used for coordinate operation computation
 
-.. option:: -show-superseded
-
-    When enabled, coordinate operations that are superseded by others will be
-    listed. Note that supersession is not equivalent to deprecation: superseded
-    operations are still considered valid although they have a better equivalent,
-    whereas deprecated operations have been determined to be erroneous and are
-    not considered at all.
-
-    .. note:: only used for coordinate operation computation
-
 .. option:: --pivot-crs always|if_no_direct_transformation|never|{auth:code[,auth:code]*}
 
     Determine if intermediate (pivot) CRS can be used when researching coordinate
@@ -201,6 +192,25 @@ The following control parameters can appear in any order:
 
     .. note:: only used for coordinate operation computation
 
+.. option:: --show-superseded
+
+    When enabled, coordinate operations that are superseded by others will be
+    listed. Note that supersession is not equivalent to deprecation: superseded
+    operations are still considered valid although they have a better equivalent,
+    whereas deprecated operations have been determined to be erroneous and are
+    not considered at all.
+
+    .. note:: only used for coordinate operation computation
+
+.. option:: --hide-ballpark
+
+    .. versionadded:: 7.1
+
+    Hides any coordinate operation that is, or contains, a
+    :term:`Ballpark transformation`
+
+    .. note:: only used for coordinate operation computation
+
 .. option:: --boundcrs-to-wgs84
 
     When specified, this option researches a coordinate operation from the
diff --git a/docs/source/glossary.rst b/docs/source/glossary.rst
index 21dd0f34..883460d4 100644
--- a/docs/source/glossary.rst
+++ b/docs/source/glossary.rst
@@ -6,6 +6,25 @@ Glossary
 
 .. glossary::
 
+    Ballpark transformation
+
+        For a transformation between two geographic CRS, a ballpark
+        transformation is a coordinate operation that only takes into account
+        potential difference of axis orders (long-lat vs lat-long),
+        units (degree vs grads) and  prime meridian (Greewich vs Paris/Rome/other
+        historic prime meridians). It does not attempt any datum shift, hence
+        the "ballpark" qualifier in its name. Its accuracy is unknown, and could
+        lead in some cases to errors of a few hundreds of metres.
+
+        For a transformation between two vertical CRS or a vertical CRS and
+        a geogrpahic CRS, a ballpark transformation only takes into account
+        potential different in units (e.g. metres vs feet). Its accuracy is
+        unknown, and could lead in some cases to errors of a few tens of metres.
+
+        .. note::
+
+            The term "Ballpark transformation" is specific to PROJ.
+
     Pseudocylindrical Projection
 
         Pseudocylindrical projections have the mathematical characteristics of
diff --git a/docs/source/operations/operations_computation.rst b/docs/source/operations/operations_computation.rst
index 1813a010..2836b75c 100644
--- a/docs/source/operations/operations_computation.rst
+++ b/docs/source/operations/operations_computation.rst
@@ -106,11 +106,8 @@ which can be used as an override).
 
 As those results all involve operations that does not have a perfect accuracy and that
 does not cover the area of use of the 2 CRSs, a
-'Ballpark geographic offset from NAD27 to NAD83' operation is synthetized by PROJ.
-This operation is a sort of dummy operation that only takes into account potential
-difference of axis orders (long-lat vs lat-long), units (degree vs grads) and
-prime meridian (Greewich vs Paris/Rome/other historic prime meridians). It does
-not attempt any datum shift, hence the "ballpark" qualifier in its name.
+'Ballpark geographic offset from NAD27 to NAD83' operation is synthetized by PROJ
+(see :term:`Ballpark transformation`)
 
 Filtering and sorting of coordinate operations
 ----------------------------------------------
diff --git a/src/apps/projinfo.cpp b/src/apps/projinfo.cpp
index 1e58cfb0..10ce346f 100644
--- a/src/apps/projinfo.cpp
+++ b/src/apps/projinfo.cpp
@@ -71,6 +71,7 @@ struct OutputOptions {
     bool c_ify = false;
     bool singleLine = false;
     bool strict = true;
+    bool ballparkAllowed = true;
 };
 } // anonymous namespace
 
@@ -89,10 +90,10 @@ static void usage() {
         << std::endl
         << "                [--grid-check "
            "none|discard_missing|sort|known_available] "
-           "[--show-superseded]"
         << std::endl
         << "                [--pivot-crs always|if_no_direct_transformation|"
         << "never|{auth:code[,auth:code]*}]" << std::endl
+        << "                [--show-superseded] [--hide-ballpark]" << std::endl
         << "                [--boundcrs-to-wgs84]" << std::endl
         << "                [--main-db-path path] [--aux-db-path path]*"
         << std::endl
@@ -725,6 +726,15 @@ static void outputOperations(
                   << std::endl;
         std::exit(1);
     }
+    if (!outputOpt.ballparkAllowed) {
+        std::vector<CoordinateOperationNNPtr> listNew;
+        for (const auto &op : list) {
+            if (!op->hasBallparkTransformation()) {
+                listNew.emplace_back(op);
+            }
+        }
+        list = std::move(listNew);
+    }
     if (outputOpt.quiet && !list.empty()) {
         outputObject(dbContext, list[0], allowUseIntermediateCRS, outputOpt);
         return;
@@ -1053,6 +1063,8 @@ int main(int argc, char **argv) {
             showSuperseded = true;
         } else if (arg == "--lax") {
             outputOpt.strict = false;
+        } else if (arg == "--hide-ballpark") {
+            outputOpt.ballparkAllowed = false;
         } else if (ci_equal(arg, "--3d")) {
             promoteTo3D = true;
         } else if (ci_equal(arg, "--searchpaths")) {
diff --git a/test/cli/testprojinfo b/test/cli/testprojinfo
index 4ec1bdbb..df8cac8c 100755
--- a/test/cli/testprojinfo
+++ b/test/cli/testprojinfo
@@ -58,8 +58,8 @@ echo "Testing projinfo -s NAD27 -t NAD83" >> ${OUT}
 $EXE -s NAD27 -t NAD83 >>${OUT}
 echo "" >>${OUT}
 
-echo "Testing projinfo -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary" >> ${OUT}
-$EXE -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary >>${OUT}
+echo "Testing projinfo -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary --hide-ballpark" >> ${OUT}
+$EXE -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary --hide-ballpark >>${OUT}
 echo "" >>${OUT}
 
 echo "Testing projinfo -s NAD27 -t NAD83 --grid-check none --spatial-test intersects" >> ${OUT}
diff --git a/test/cli/testprojinfo_out.dist b/test/cli/testprojinfo_out.dist
index 99fae293..17390534 100644
--- a/test/cli/testprojinfo_out.dist
+++ b/test/cli/testprojinfo_out.dist
@@ -266,8 +266,8 @@ COORDINATEOPERATION["Ballpark geographic offset from NAD27 to NAD83",
         AREA["World"],
         BBOX[-90,-180,90,180]]]
 
-Testing projinfo -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary
-Candidate operations found: 10
+Testing projinfo -s NAD27 -t NAD83 --grid-check none --spatial-test intersects --summary --hide-ballpark
+Candidate operations found: 9
 DERIVED_FROM(EPSG):1312, NAD27 to NAD83 (3), 2.0 m, Canada
 DERIVED_FROM(EPSG):1313, NAD27 to NAD83 (4), 1.5 m, Canada - NAD27
 DERIVED_FROM(EPSG):1241, NAD27 to NAD83 (1), 0.15 m, USA - CONUS including EEZ
@@ -275,7 +275,6 @@ DERIVED_FROM(EPSG):1243, NAD27 to NAD83 (2), 0.5 m, USA - Alaska including EEZ
 DERIVED_FROM(EPSG):1573, NAD27 to NAD83 (6), 1.5 m, Canada - Quebec
 EPSG:1462, NAD27 to NAD83 (5), 2.0 m, Canada - Quebec
 EPSG:9111, NAD27 to NAD83 (9), 1.5 m, Canada - Saskatchewan
-unknown id, Ballpark geographic offset from NAD27 to NAD83, unknown accuracy, World, has ballpark transformation
 EPSG:8555, NAD27 to NAD83 (7), 0.15 m, USA - CONUS and GoM
 EPSG:8549, NAD27 to NAD83 (8), 0.5 m, USA - Alaska