--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/jfree/JFreeUtil.java	Fri Sep 28 12:14:39 2012 +0200
@@ -0,0 +1,75 @@
+package de.intevation.flys.jfree;
+
+import de.intevation.flys.artifacts.math.Function;
+
+import java.awt.Shape;
+
+import java.awt.geom.Rectangle2D;
+
+import java.util.Iterator;
+
+import org.jfree.chart.entity.ChartEntity;
+import org.jfree.chart.entity.EntityCollection;
+
+import org.w3c.dom.Document;
+
+public class JFreeUtil {
+
+    /** Do not instantiate. */
+    private JFreeUtil() {
+    }
+
+
+    /**
+     * True if \param hotspot collides with a Entity in \param entities.
+     * @param hotspot Shape to compare against other shapes (bounds only).
+     * @param entities entities against which to compare shape.
+     * @param exclusiveEntityClass If not null, consider only entities of
+     *        given class.
+     * @return true if a collision (non-zero intersection) exists between
+     *        shapes.
+     */
+    public static boolean collides(Shape hotspot, EntityCollection entities,
+        Class exclusiveEntityClass) {
+        if (entities == null) return false;
+
+        Rectangle2D hotspotBox = hotspot.getBounds2D();
+
+        for (Iterator i = entities.iterator(); i.hasNext(); ) {
+            Object next = i.next();
+            ChartEntity entity = (ChartEntity) next;
+            if (exclusiveEntityClass == null
+                || exclusiveEntityClass.isInstance(entity))
+                {
+                if (entity.getArea().intersects(hotspotBox)) {
+                    // Found collision, early stop.
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+
+    public static StyledXYSeries sampleFunction2D(
+        Function func,
+        Document theme,
+        String   seriesKey,
+        int      samples,
+        double   start,
+        double   end
+    ) {
+        StyledXYSeries series = new StyledXYSeries(seriesKey, theme);
+
+        double step = (end - start) / (samples - 1);
+
+        for (int i = 0; i < samples; i++) {
+            double x = start + (step * i);
+            series.add(x, func.value(x));
+        }
+
+        return series;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :