/*

* Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package javax.microedition.m3g;

import java.util.Vector;

public class Group extends Node

{

    //------------------------------------------------------------------

    // Instance data

    //------------------------------------------------------------------

    // The child links are duplicated on the Java side for the same

    // reason as the other node->node references; see Node.java

    Vector children;

    //------------------------------------------------------------------

    // Constructors

    //------------------------------------------------------------------

    public Group()

    {

        super(_ctor(Interface.getHandle()));

    }

    Group(int handle)

    {

        super(handle);

        int n = _getChildCount(handle);

        while (n-- > 0)

        {

            linkChild((Node) getInstance(_getChild(handle, n)));

        }

    }

    //------------------------------------------------------------------

    // Public methods

    //------------------------------------------------------------------

    public void addChild(Node child)

    {

        _addChild(handle, child != null ? child.handle : 0);

        if (child != null)

        {

            linkChild(child);

        }

    }

    public void removeChild(Node child)

    {

        if (child != null)

        {

            _removeChild(handle, child.handle);

            detachChild(child);

        }

    }

    public int getChildCount()

    {

        return _getChildCount(handle);

    }

    public Node getChild(int index)

    {

        /* Instead of trying to match the indexing of children on the

         * native side, we just call the native getter. This may have

         * some performance penalty, but likely not enough to make it

         * worth the extra maintenance burden of duplicating the

         * native ordering here. */

        return (Node) getInstance(_getChild(handle, index));

    }

    public boolean pick(int mask,

                        float ox, float oy, float oz,

                        float dx, float dy, float dz,

                        RayIntersection ri)

    {

        float[] result = RayIntersection.createResult();

        float[] ray = {ox, oy, oz, dx, dy, dz};

        int hIntersected;

        hIntersected = _pick3D(handle, mask, ray, result);

        if (hIntersected != 0)

        {

            if (ri != null)

            {

                ri.fill(hIntersected, result);

            }

            return true;

        }

        else

        {

            return false;

        }

    }

    public boolean pick(int mask, float x, float y, Camera camera, RayIntersection ri)

    {

        float[] result = RayIntersection.createResult();

        int hIntersected;

        hIntersected = _pick2D(handle, mask, x, y, camera != null ? camera.handle : 0, result);

        if (hIntersected != 0)

        {

            if (ri != null)

            {

                ri.fill(hIntersected, result);

            }

            return true;

        }

        else

        {

            return false;

        }

    }

    //------------------------------------------------------------------

    // Private methods

    //------------------------------------------------------------------

    /**

     * Adds a Java-side child link in this Group.

     */

    private void linkChild(Node child)

    {

        if (child == null)

        {

            throw new Error(); // DEBUG

        }

        if (children == null)

        {

            children = new Vector();

        }

        children.addElement(child);

        child.setParent(this);

    }

    /**

     * Removes a Java-side child link from this Group.

     */

    private void detachChild(Node child)

    {

        if (children != null)

        {

            if (children.removeElement(child))

            {

                /* If no children remain, we delete the array to free some

                 * memory. If a Group is frequently cleared and

                 * re-populated, this should be covered by the free list

                 * used by most VM implementations without causing

                 * significant performance degradation. */

                if (children.isEmpty())

                {

                    children = null;

                }

                child.setParent(null);

            }

        }

    }

    // Native methods

    private static native int _ctor(int hInterface);

    private static native void _addChild(int handle, int hNode);

    private static native void _removeChild(int handle, int hNode);

    private static native int _getChildCount(int handle);

    private static native int _getChild(int handle, int index);

    private static native int _pick3D(int handle, int mask, float[] ray, float[] result);

    private static native int _pick2D(int handle, int mask, float x, float y, int hCamera, float[] result);

}