1 files changed, 108 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/geometry/euclidean/threed/SubPlane.java b/src/main/java/org/apache/commons/math3/geometry/euclidean/threed/SubPlane.java
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index 0000000..ce02a38
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+++ b/src/main/java/org/apache/commons/math3/geometry/euclidean/threed/SubPlane.java
@@ -0,0 +1,108 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.math3.geometry.euclidean.threed;
+
+import org.apache.commons.math3.geometry.Point;
+import org.apache.commons.math3.geometry.euclidean.oned.Euclidean1D;
+import org.apache.commons.math3.geometry.euclidean.oned.Vector1D;
+import org.apache.commons.math3.geometry.euclidean.twod.Euclidean2D;
+import org.apache.commons.math3.geometry.euclidean.twod.PolygonsSet;
+import org.apache.commons.math3.geometry.euclidean.twod.Vector2D;
+import org.apache.commons.math3.geometry.partitioning.AbstractSubHyperplane;
+import org.apache.commons.math3.geometry.partitioning.BSPTree;
+import org.apache.commons.math3.geometry.partitioning.Hyperplane;
+import org.apache.commons.math3.geometry.partitioning.Region;
+import org.apache.commons.math3.geometry.partitioning.SubHyperplane;
+
+/** This class represents a sub-hyperplane for {@link Plane}.
+ * @since 3.0
+ */
+public class SubPlane extends AbstractSubHyperplane<Euclidean3D, Euclidean2D> {
+
+    /** Simple constructor.
+     * @param hyperplane underlying hyperplane
+     * @param remainingRegion remaining region of the hyperplane
+     */
+    public SubPlane(final Hyperplane<Euclidean3D> hyperplane,
+                    final Region<Euclidean2D> remainingRegion) {
+        super(hyperplane, remainingRegion);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected AbstractSubHyperplane<Euclidean3D, Euclidean2D> buildNew(final Hyperplane<Euclidean3D> hyperplane,
+                                                                       final Region<Euclidean2D> remainingRegion) {
+        return new SubPlane(hyperplane, remainingRegion);
+    }
+
+    /** Split the instance in two parts by an hyperplane.
+     * @param hyperplane splitting hyperplane
+     * @return an object containing both the part of the instance
+     * on the plus side of the instance and the part of the
+     * instance on the minus side of the instance
+     */
+    @Override
+    public SplitSubHyperplane<Euclidean3D> split(Hyperplane<Euclidean3D> hyperplane) {
+
+        final Plane otherPlane = (Plane) hyperplane;
+        final Plane thisPlane  = (Plane) getHyperplane();
+        final Line  inter      = otherPlane.intersection(thisPlane);
+        final double tolerance = thisPlane.getTolerance();
+
+        if (inter == null) {
+            // the hyperplanes are parallel
+            final double global = otherPlane.getOffset(thisPlane);
+            if (global < -tolerance) {
+                return new SplitSubHyperplane<Euclidean3D>(null, this);
+            } else if (global > tolerance) {
+                return new SplitSubHyperplane<Euclidean3D>(this, null);
+            } else {
+                return new SplitSubHyperplane<Euclidean3D>(null, null);
+            }
+        }
+
+        // the hyperplanes do intersect
+        Vector2D p = thisPlane.toSubSpace((Point<Euclidean3D>) inter.toSpace((Point<Euclidean1D>) Vector1D.ZERO));
+        Vector2D q = thisPlane.toSubSpace((Point<Euclidean3D>) inter.toSpace((Point<Euclidean1D>) Vector1D.ONE));
+        Vector3D crossP = Vector3D.crossProduct(inter.getDirection(), thisPlane.getNormal());
+        if (crossP.dotProduct(otherPlane.getNormal()) < 0) {
+            final Vector2D tmp = p;
+            p           = q;
+            q           = tmp;
+        }
+        final SubHyperplane<Euclidean2D> l2DMinus =
+            new org.apache.commons.math3.geometry.euclidean.twod.Line(p, q, tolerance).wholeHyperplane();
+        final SubHyperplane<Euclidean2D> l2DPlus =
+            new org.apache.commons.math3.geometry.euclidean.twod.Line(q, p, tolerance).wholeHyperplane();
+
+        final BSPTree<Euclidean2D> splitTree = getRemainingRegion().getTree(false).split(l2DMinus);
+        final BSPTree<Euclidean2D> plusTree  = getRemainingRegion().isEmpty(splitTree.getPlus()) ?
+                                               new BSPTree<Euclidean2D>(Boolean.FALSE) :
+                                               new BSPTree<Euclidean2D>(l2DPlus, new BSPTree<Euclidean2D>(Boolean.FALSE),
+                                                                        splitTree.getPlus(), null);
+
+        final BSPTree<Euclidean2D> minusTree = getRemainingRegion().isEmpty(splitTree.getMinus()) ?
+                                               new BSPTree<Euclidean2D>(Boolean.FALSE) :
+                                                   new BSPTree<Euclidean2D>(l2DMinus, new BSPTree<Euclidean2D>(Boolean.FALSE),
+                                                                            splitTree.getMinus(), null);
+
+        return new SplitSubHyperplane<Euclidean3D>(new SubPlane(thisPlane.copySelf(), new PolygonsSet(plusTree, tolerance)),
+                                                   new SubPlane(thisPlane.copySelf(), new PolygonsSet(minusTree, tolerance)));
+
+    }
+
+}