/*
 GNU Maverik - a system for managing display and interaction in 
               Virtual Environment applications.
 Copyright (C) 1999-2001 Advanced Interfaces Group

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA


 The authors can be contacted via:
 www   - http://aig.cs.man.ac.uk
 email - maverik@aig.cs.man.ac.uk
 mail  - Advanced Interfaces Group, Room 2.94, Computer Science Building, 
         University of Manchester, Manchester, M13 9PL, UK
*/

/******************************************************************
*
*	VRML library for C++
*
*	Copyright (C) Satoshi Konno 1996-1997
*
*	File:	Node.cpp
*
******************************************************************/

#include "SceneGraph.h"

////////////////////////////////////////////////
//	LodNode::update
////////////////////////////////////////////////

void UpdateLod(LodNode *lod)
{
	int nNodes = lod->getNPrivateNodeElements();
	for (int n=0; n<nNodes; n++) {
		Node *node = lod->getPrivateNodeElementAt(n);
		node->remove();
	}

	SceneGraph *sg = lod->getSceneGraph();

	ViewpointNode *vpoint = sg->getViewpointNode();
	if (vpoint == NULL)
		vpoint = sg->getDefaultViewpointNode();

	if (vpoint) {
		SFMatrix	viewMatrix;
		float		viewPosition[3];
		vpoint->getTransformMatrix(&viewMatrix);
		vpoint->getPosition(viewPosition);
		viewMatrix.multi(viewPosition);

		SFMatrix	lodMatrix;
		float		lodCenter[3];
		lod->getTransformMatrix(&lodMatrix);
		lod->getCenter(lodCenter);
		lodMatrix.multi(lodCenter);

		float lx = lodCenter[0] - viewPosition[0];
		float ly = lodCenter[1] - viewPosition[1];
		float lz = lodCenter[2] - viewPosition[2];
		float distance = (float)sqrt(lx*lx + ly*ly + lz*lz);

		int nRange = lod->getNRanges();
		int n; // JMC
		for (n=0; n<nRange; n++) { //JMC
			if (distance < lod->getRange(n))
				break;
		}

		Node *node = lod->getPrivateNodeElementAt(n);
		if (!node)
			node = lod->getPrivateNodeElementAt(lod->getNPrivateNodeElements() - 1);
		assert(node);
		lod->addChildNode(node);
	}
}

void LodNode::update() 
{
	UpdateLod(this);
}

////////////////////////////////////////////////
//	LodNode::initialize
////////////////////////////////////////////////

void InitializeLod(LodNode *lod)
{
	lod->uninitialize();

	int nNode = lod->getNChildNodes();
	Node *node = lod->getChildNodes();
	while (node) {
		Node *nextNode = node->next();
//		node->remove();
		lod->addPrivateNodeElement(node);
		node = nextNode;
	}
/*
	Node *firstNode = lod->getPrivateNodeElementAt(0);
	if (firstNode)
		lod->addChildNode(firstNode);
*/
	int nNodes = lod->getNPrivateNodeElements();
}

void LodNode::initialize() 
{
	if (isInitialized() == false) {
		InitializeLod(this);
		setInitialized(true);
	}
}

////////////////////////////////////////////////
//	LodNode::uninitialize
////////////////////////////////////////////////

void UninitializeLod(LodNode *lod) 
{
	int nNodes = lod->getNPrivateNodeElements();
	for (int n=0; n<nNodes; n++) {
		Node *node = lod->getPrivateNodeElementAt(n);
		node->remove();
		lod->addChildNode(node);
	}
	lod->removeAllNodeElement();
	int nNode = lod->getNChildNodes();
}

void LodNode::uninitialize() 
{
	if (isInitialized() == true) {
		UninitializeLod(this);
		setInitialized(false);
	}
}

