--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/model/DifferenceCurveFacet.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,68 @@
+package org.dive4elements.river.artifacts.model;
+
+import org.apache.log4j.Logger;
+
+import org.dive4elements.artifactdatabase.state.Facet;
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.river.artifacts.WINFOArtifact;
+import org.dive4elements.river.artifacts.states.DefaultState.ComputeType;
+
+
+/**
+ * Facet with the curve of a subtraction of two waterlevel-lines.
+ * TODO inherit directly from DataFacet? Check whether this Facet is obsolete.
+ */
+public class DifferenceCurveFacet extends WaterlevelFacet {
+
+    private static Logger logger = Logger.getLogger(DifferenceCurveFacet.class);
+
+
+    public DifferenceCurveFacet() {
+    }
+
+    public DifferenceCurveFacet(
+        int         index,
+        String      name,
+        String      description,
+        ComputeType type,
+        String      stateID,
+        String      hash
+
+    ) {
+        super(index, name, description, type, stateID, hash);
+    }
+
+    /**
+     * Get difference curve data.
+     * @return a WKms at given index.
+     */
+    @Override
+    public Object getData(Artifact artifact, CallContext context) {
+        WINFOArtifact winfo = (WINFOArtifact)artifact;
+
+        CalculationResult res = (CalculationResult)
+            winfo.compute(context, hash, stateId, type, false);
+
+        WKms [] wkms = (WKms [])res.getData();
+
+        WKms result = wkms[index];
+        logger.debug("Got difference curve data (" + result.getName()
+            + ") at index: " + index);
+
+        return result;
+    }
+
+
+    /** Copy deeply. */
+    @Override
+    public Facet deepCopy() {
+        WaterlevelFacet copy = new DifferenceCurveFacet();
+        copy.set(this);
+        copy.type    = type;
+        copy.stateId = stateId;
+        copy.hash    = hash;
+        return copy;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :