Georeferencing: Save realization CRS to file

Instead of saving _that_ the map was developed with a recent realization of WGS84 for its geographic CRS, save the _spec_ of the geographic CRS itself.
OpenOrienteering · Feb 17, 2024 · 68c70f5 · 68c70f5
1 parent addecfe
commit 68c70f5
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Showing 8 changed files with 44 additions and 21 deletions.
diff --git a/src/core/georeferencing.cpp b/src/core/georeferencing.cpp
@@ -73,7 +73,7 @@ namespace literal
 	static const QLatin1String ref_point_deg("ref_point_deg");
 	static const QLatin1String projected_crs("projected_crs");
 	static const QLatin1String geographic_crs("geographic_crs");
-	static const QLatin1String is_realization("is_realization");
+	static const QLatin1String realization_spec("realization_spec");
 	static const QLatin1String spec("spec");
 	static const QLatin1String parameter("parameter");
 
@@ -88,8 +88,6 @@ namespace literal
 
 	static const QLatin1String proj_4("PROJ.4");
 	static const QLatin1String geographic_coordinates("Geographic coordinates");
-	static const QLatin1String f("false");
-	static const QLatin1String t("true");
 }
 
 
@@ -521,7 +519,7 @@ Georeferencing::Georeferencing()
   convergence(0.0),
   map_ref_point(0, 0),
   projected_ref_point(0, 0),
-  is_realization(true),
+  realization_crs_spec(gnss_crs_spec),
   explicit_realization(false)
 {
 	static ProjSetup run_once;
@@ -547,7 +545,7 @@ Georeferencing::Georeferencing(const Georeferencing& other)
   projected_crs_id(other.projected_crs_id),
   projected_crs_spec(other.projected_crs_spec),
   projected_crs_parameters(other.projected_crs_parameters),
-  is_realization(other.is_realization),
+  realization_crs_spec(other.realization_crs_spec),
   explicit_realization(other.explicit_realization),
   proj_transform(projected_crs_spec, gnss_crs_spec),
   geographic_ref_point(other.geographic_ref_point)
@@ -579,7 +577,7 @@ Georeferencing& Georeferencing::operator=(const Georeferencing& other)
 	projected_crs_id         = other.projected_crs_id;
 	projected_crs_spec       = other.projected_crs_spec;
 	projected_crs_parameters = other.projected_crs_parameters;
-	is_realization           = other.is_realization;
+	realization_crs_spec     = other.realization_crs_spec;
 	explicit_realization     = other.explicit_realization;
 	proj_transform           = ProjTransform(other.projected_crs_spec, gnss_crs_spec);
 	geographic_ref_point     = other.geographic_ref_point;
@@ -688,8 +686,8 @@ void Georeferencing::load(QXmlStreamReader& xml, bool load_scale_only)
 			else if (xml.name() == literal::geographic_crs)
 			{
 				XmlElementReader crs_element(xml);
-				explicit_realization = crs_element.hasAttribute(literal::is_realization);
-				is_realization = explicit_realization && crs_element.attribute<bool>(literal::is_realization);
+				explicit_realization = false;
+				realization_crs_spec = QString();
 				while (xml.readNextStartElement())
 				{
 					XmlElementReader current_element(xml);
@@ -702,6 +700,16 @@ void Georeferencing::load(QXmlStreamReader& xml, bool load_scale_only)
 						if (Georeferencing::ballpark_geographic_crs_spec != geographic_crs_spec)
 							throw FileFormatException(tr("Unsupported geographic CRS specification: %1").arg(geographic_crs_spec));
 					}
+					else if (xml.name() == literal::realization_spec)
+					{
+						explicit_realization = true;
+						QString language{};
+						if (current_element.hasAttribute(literal::language))
+							language = current_element.attribute<QString>(literal::language);
+						realization_crs_spec = xml.readElementText();
+						if (!realization_crs_spec.isEmpty() && language != literal::proj_4)
+							throw FileFormatException(tr("Unknown realization CRS specification language: %1").arg(language));
+					}
 					else if (xml.name() == literal::ref_point)
 					{
 						// Legacy, latitude/longitude in radiant
@@ -806,13 +814,20 @@ void Georeferencing::save(QXmlStreamWriter& xml) const
 	{
 		XmlElementWriter crs_element(xml, literal::geographic_crs);
 		crs_element.writeAttribute(literal::id, literal::geographic_coordinates);
-		if (explicit_realization)
-			crs_element.writeAttribute(literal::is_realization, is_realization ? literal::t : literal::f);
 		{
 			XmlElementWriter spec_element(xml, literal::spec);
 			spec_element.writeAttribute(literal::language, literal::proj_4);
 			xml.writeCharacters(ballpark_geographic_crs_spec);
 		}
+		if (explicit_realization)
+		{
+			XmlElementWriter realization_element(xml, literal::realization_spec);
+			if (!realization_crs_spec.isEmpty())
+			{
+				realization_element.writeAttribute(literal::language, literal::proj_4);
+				xml.writeCharacters(realization_crs_spec);
+			}
+		}
 		if (XMLFileFormat::active_version < 6)
 		{
 			// Legacy compatibility
@@ -1192,9 +1207,9 @@ bool Georeferencing::setDatumBallpark(bool ballpark)
 	// Default return value if no change is necessary
 	bool ok = (getState() == Geospatial);
 
-	if (is_realization != !ballpark)
+	if (realization_crs_spec.isEmpty() != ballpark)
 	{
-		is_realization = !ballpark;
+		realization_crs_spec = ballpark ? QString() : gnss_crs_spec;
 		proj_transform = ProjTransform(projected_crs_spec, getGeographicCRSSpec());
 		ok = proj_transform.isValid();
 		if (ok)

diff --git a/src/core/georeferencing.h b/src/core/georeferencing.h
@@ -446,14 +446,16 @@ friend QDebug operator<<(QDebug dbg, const Georeferencing& georef);
 	 * and also the source CRS when applicable.
 	 * @return a PROJ specification of the geographic CRS
 	 */
-	const QString& getGeographicCRSSpec() const { return is_realization ? gnss_crs_spec : ballpark_geographic_crs_spec; }
+	const QString& getGeographicCRSSpec() const { return realization_crs_spec.isEmpty()
+	                                                     ? ballpark_geographic_crs_spec
+	                                                     : realization_crs_spec; }
 
 	/** 
 	 * Returns whether transformations use loose accuracy around the WGS84
 	 * datum for explicitly requested compatibility with older releases of Mapper.
 	 * @return true if transformations are set compatible, false otherwise
 	 */
-	bool isDatumBallpark() const { return explicit_realization && !is_realization; }
+	bool isDatumBallpark() const { return explicit_realization && realization_crs_spec.isEmpty(); }
 
 	/**
 	 * Sets the coordinate reference system (CRS) of the geographical coordinates,
@@ -721,7 +723,7 @@ friend QDebug operator<<(QDebug dbg, const Georeferencing& georef);
 	QString projected_crs_spec;
 	std::vector< QString > projected_crs_parameters;
 
-	bool is_realization;
+	QString realization_crs_spec;
 	bool explicit_realization;
 
 	ProjTransform proj_transform;

diff --git a/test/data/templates/geotiff.xmap b/test/data/templates/geotiff.xmap
@@ -7,8 +7,9 @@
             <parameter>2180</parameter>
             <ref_point x="649800" y="392500"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="true">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec language="PROJ.4">EPSG:9057</realization_spec>
             <ref_point_deg lat="51.3793253" lon="21.15318339"/>
         </geographic_crs>
     </georeferencing>

diff --git a/test/data/templates/ogr-template.xmap b/test/data/templates/ogr-template.xmap
@@ -7,8 +7,9 @@
             <parameter>2180</parameter>
             <ref_point x="649800" y="392500"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="true">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec language="PROJ.4">EPSG:9057</realization_spec>
             <ref_point_deg lat="51.3793253" lon="21.15318339"/>
         </geographic_crs>
     </georeferencing>

diff --git a/test/data/templates/template-track-NA-ballpark-GDAL.xmap b/test/data/templates/template-track-NA-ballpark-GDAL.xmap
@@ -7,8 +7,9 @@
             <parameter>6342</parameter>
             <ref_point x="500000" y="4430000"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="false">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec/>
             <ref_point_deg lat="40.02021349" lon="-105.00001013"/>
         </geographic_crs>
     </georeferencing>

diff --git a/test/data/templates/template-track-NA.xmap b/test/data/templates/template-track-NA.xmap
@@ -7,8 +7,9 @@
             <parameter>6342</parameter>
             <ref_point x="500000" y="4430000"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="true">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec language="PROJ.4">EPSG:9057</realization_spec>
             <ref_point_deg lat="40.02021349" lon="-105.00001013"/>
         </geographic_crs>
     </georeferencing>

diff --git a/test/data/templates/template-track.xmap b/test/data/templates/template-track.xmap
@@ -7,8 +7,9 @@
             <parameter>2180</parameter>
             <ref_point x="649800" y="392500"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="true">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec language="PROJ.4">EPSG:9057</realization_spec>
             <ref_point_deg lat="51.3793253" lon="21.15318339"/>
         </geographic_crs>
     </georeferencing>

diff --git a/test/data/templates/world-file.xmap b/test/data/templates/world-file.xmap
@@ -7,8 +7,9 @@
             <parameter>2180</parameter>
             <ref_point x="649800" y="392500"/>
         </projected_crs>
-        <geographic_crs id="Geographic coordinates" is_realization="true">
+        <geographic_crs id="Geographic coordinates">
             <spec language="PROJ.4">+proj=latlong +datum=WGS84</spec>
+            <realization_spec language="PROJ.4">EPSG:9057</realization_spec>
             <ref_point_deg lat="51.3793253" lon="21.15318339"/>
         </geographic_crs>
     </georeferencing>