Let SGCloudLayer handle coverage strings

This is currently handled in various places in FlightGear.

simgear/scene/sky/cloud.cxx

@@ -83,6 +83,13 @@ static bool bump_mapping = false;
 
 bool SGCloudLayer::enable_bump_mapping = false;
 
+const std::string SGCloudLayer::SG_CLOUD_OVERCAST_STRING = "overcast";
+const std::string SGCloudLayer::SG_CLOUD_BROKEN_STRING = "broken";
+const std::string SGCloudLayer::SG_CLOUD_SCATTERED_STRING = "scattered";
+const std::string SGCloudLayer::SG_CLOUD_FEW_STRING = "few";
+const std::string SGCloudLayer::SG_CLOUD_CIRRUS_STRING = "cirrus";
+const std::string SGCloudLayer::SG_CLOUD_CLEAR_STRING = "clear";
+
 // make an StateSet for a cloud layer given the named texture
 static osg::StateSet*
 SGMakeState(const SGPath &path, const char* colorTexture,
@@ -293,6 +300,56 @@ SGCloudLayer::setCoverage (Coverage coverage)
     }
 }
 
+const std::string &
+SGCloudLayer::getCoverageString( Coverage coverage )
+{
+	switch( coverage ) {
+		case SG_CLOUD_OVERCAST:
+			return SG_CLOUD_OVERCAST_STRING;
+		case SG_CLOUD_BROKEN:
+			return SG_CLOUD_BROKEN_STRING;
+		case SG_CLOUD_SCATTERED:
+			return SG_CLOUD_SCATTERED_STRING;
+		case SG_CLOUD_FEW:
+			return SG_CLOUD_FEW_STRING;
+		case SG_CLOUD_CIRRUS:
+			return SG_CLOUD_CIRRUS_STRING;
+		case SG_CLOUD_CLEAR:
+		default:
+			return SG_CLOUD_CLEAR_STRING;
+	}
+}
+
+SGCloudLayer::Coverage 
+SGCloudLayer::getCoverageType( const std::string & coverage )
+{
+	if( SG_CLOUD_OVERCAST_STRING == coverage ) {
+		return SG_CLOUD_OVERCAST;
+	} else if( SG_CLOUD_BROKEN_STRING == coverage ) {
+		return SG_CLOUD_BROKEN;
+	} else if( SG_CLOUD_SCATTERED_STRING == coverage ) {
+		return SG_CLOUD_SCATTERED;
+	} else if( SG_CLOUD_FEW_STRING == coverage ) {
+		return SG_CLOUD_FEW;
+	} else if( SG_CLOUD_CIRRUS_STRING == coverage ) {
+		return SG_CLOUD_CIRRUS;
+	} else {
+		return SG_CLOUD_CLEAR;
+	}
+}
+
+const std::string &
+SGCloudLayer::getCoverageString() const
+{
+	return getCoverageString(layer_coverage);
+}
+
+void
+SGCloudLayer::setCoverageString( const std::string & coverage )
+{
+	setCoverage( getCoverageType(coverage) );
+}
+
 void
 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 {

simgear/scene/sky/cloud.hxx

@@ -63,6 +63,13 @@ public:
 	SG_MAX_CLOUD_COVERAGES
     };
 
+    static const std::string SG_CLOUD_OVERCAST_STRING; // "overcast"
+    static const std::string SG_CLOUD_BROKEN_STRING; // "broken"
+    static const std::string SG_CLOUD_SCATTERED_STRING; // "scattered"
+    static const std::string SG_CLOUD_FEW_STRING; // "few"
+    static const std::string SG_CLOUD_CIRRUS_STRING; // "cirrus"
+    static const std::string SG_CLOUD_CLEAR_STRING; // "clear"
+
     /**
      * Constructor
      * @param tex_path the path to the set of cloud textures
@@ -123,6 +130,18 @@ public:
      */
     void setCoverage (Coverage coverage);
 
+    /** get coverage as string */
+    const string & getCoverageString() const;
+
+    /** get coverage as string */
+    static const string & getCoverageString( Coverage coverage );
+
+    /** get coverage type from string */
+    static Coverage getCoverageType( const std::string & coverage );
+
+    /** set coverage as string */
+    void setCoverageString( const string & coverage );
+
     /**
      * set the cloud movement direction
      * @param dir the cloud movement direction