--- a/flys-artifacts/ChangeLog	Fri May 25 09:27:01 2012 +0000
+++ b/flys-artifacts/ChangeLog	Fri May 25 13:31:40 2012 +0000
@@ -1,3 +1,11 @@
+2012-05-25	Felix Wolfsteller	<felix.wolfsteller@intevation.de>
+
+	Also draw lines to curve from q-mainvalues in dur. curve
+
+	* src/main/java/de/intevation/flys/artifacts/model/MainValuesQFacet.java:
+	  In analogy to the W-case, calculate where line from main value hits
+	  a wqday-curve from DurationCurve.
+
 2012-05-25	Felix Wolfsteller	<felix.wolfsteller@intevation.de>
 
 	Draw line of w-mainvalue to duration curve hit point to ground.

--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/MainValuesQFacet.java	Fri May 25 09:27:01 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/MainValuesQFacet.java	Fri May 25 13:31:40 2012 +0000
@@ -3,18 +3,24 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.log4j.Logger;
+
 import de.intevation.artifacts.Artifact;
 import de.intevation.artifacts.CallContext;
+import de.intevation.artifacts.DataProvider;
 
 import de.intevation.artifactdatabase.state.DefaultFacet;
 
 import de.intevation.flys.artifacts.MainValuesArtifact;
+import de.intevation.flys.artifacts.math.Linear;
 import de.intevation.flys.artifacts.model.FacetTypes;
+import de.intevation.flys.artifacts.model.WQDay;
 import de.intevation.flys.jfree.FLYSAnnotation;
 import de.intevation.flys.jfree.StickyAxisAnnotation;
 
 import de.intevation.flys.exports.DurationCurveGenerator;
 
+
 /**
  * Facet to show Main Q Values.
  * TODO Join with W implementation.
@@ -23,6 +29,9 @@
 extends      DefaultFacet
 implements   FacetTypes {
 
+    /** Own logger. */
+    private static Logger logger = Logger.getLogger(RelativePointFacet.class);
+
     /** Do we want MainValues at Gauge (not interpolated)? */
     protected boolean isAtGauge;
 
@@ -34,6 +43,39 @@
         this.isAtGauge   = atGauge;
     }
 
+    /**
+     * Set the hit-point in Q where a line drawn from the axis would hit the
+     * curve in WQDay (if hit).
+     * Employ linear interpolation.
+     */
+    protected static void setHitPoint(WQDay wqday, StickyAxisAnnotation annotation) {
+        int idx = 0;
+        float q = annotation.getPos();
+        boolean qIncreases = wqday.getQ(0) < wqday.getQ(wqday.size()-1);
+        if (qIncreases) {
+            while (idx < wqday.size() && wqday.getQ(idx) < q) {
+                idx++;
+            }
+        }
+        else {
+            idx = wqday.size() -1;
+            while (idx > 0 && wqday.getQ(idx) > q) {
+                idx--;
+            }
+        }
+
+        double day = 0d;
+        int mod = (qIncreases) ? -1 : +1;
+        if (idx != 0 && idx <= wqday.size()-1) {
+            day = Linear.linear(q, wqday.getQ(idx +mod), wqday.getQ(idx),
+                wqday.getDay(idx+mod), wqday.getDay(idx));
+            annotation.setHitPoint((float)day);
+        }
+        else {
+            logger.debug("StickyAnnotation does not hit wqday curve");
+        }
+    }
+
 
     /**
      * Returns the data this facet requires.
@@ -50,22 +92,46 @@
         List<NamedDouble>          qs = mvArtifact.getMainValuesQ(isAtGauge);
         List<StickyAxisAnnotation> xy = new ArrayList<StickyAxisAnnotation>();
 
+        WQDay wqdays = null;
+        List<DataProvider> providers = context.
+            getDataProvider(DurationCurveFacet.BB_DURATIONCURVE);
+        if (providers.size() < 1) {
+            logger.warn("Could not find durationcurve data provider.");
+        }
+        else {
+            wqdays = (WQDay) providers.get(0).provideData(
+                DurationCurveFacet.BB_DURATIONCURVE,
+                null,
+                context);
+        }
+
         // Rather specific case, Q-Annotations at a maybe second yaxis.
+        StickyAxisAnnotation annotation = null;
         if (this.name.equals(DURATION_MAINVALUES_Q)) {
             for (NamedDouble q: qs) {
-                xy.add(new StickyAxisAnnotation(
-                    q.getName(),
-                    (float) q.getValue(),
-                    StickyAxisAnnotation.SimpleAxis.Y_AXIS,
-                    DurationCurveGenerator.YAXIS.Q.idx));
+                annotation =
+                    new StickyAxisAnnotation(
+                        q.getName(),
+                        (float) q.getValue(),
+                        StickyAxisAnnotation.SimpleAxis.Y_AXIS,
+                        DurationCurveGenerator.YAXIS.Q.idx);
+                xy.add(annotation);
+                if (wqdays != null) {
+                    setHitPoint(wqdays, annotation);
+                }
             }
         }
         else {
             for (NamedDouble q: qs) {
-                xy.add(new StickyAxisAnnotation(
-                    q.getName(),
-                    (float) q.getValue(),
-                    StickyAxisAnnotation.SimpleAxis.X_AXIS));
+                annotation =
+                    new StickyAxisAnnotation(
+                        q.getName(),
+                        (float) q.getValue(),
+                        StickyAxisAnnotation.SimpleAxis.X_AXIS);
+                xy.add(annotation);
+                if (wqdays != null) {
+                    setHitPoint(wqdays, annotation);
+                }
             }
         }