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/*
* Copyright (C) 2005-2008 MaNGOS <http://www.mangosproject.org/>
*
* Copyright (C) 2008 Trinity <http://www.trinitycore.org/>
*
* 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
*/
#ifndef _TREENODE_H
#define _TREENODE_H
#include "ShortVector.h"
#include "ShortBox.h"
#include "NodeValueAccess.h"
#include "VMapTools.h"
#include <G3D/Vector3.h>
#include <G3D/AABox.h>
namespace VMAP
{
/**
This Class is mainly taken from G3D/AABSPTree.h and modified to match our data structure.
It is the node within our static BSP-Trees.
It does not use pointers but indexes to access the values and other nodes.
*/
//=====================================================
class TreeNode
{
private:
/** Location along the specified axis */
float iSplitLocation;
// Offest or the clients
int iChilds[2];
//Position within the TriangleBox array
unsigned int iStartPosition;
G3D::Vector3::Axis iSplitAxis;
G3D::AABox iBounds;
unsigned short iNumberOfValues;
public:
TreeNode() {}
TreeNode(unsigned short pNValues, unsigned int pStartPosition)
{
iChilds[0] = -1;
iChilds[1] = -1;
iStartPosition = pStartPosition;
iNumberOfValues = pNValues;
}
bool hasChilds() const { return(iChilds[0] >= 0 || iChilds[1] >= 0); }
TreeNode const* getChild(TreeNode const* pValueArray, int pNo) const;
// pChildNo = 0 or 1
inline void setChildPos(int pChildNo, int pChildPosInTreeNodeArray) { iChilds[pChildNo] = pChildPosInTreeNodeArray; }
inline G3D::Vector3::Axis getSplitAxis() const { return(iSplitAxis); }
inline void setSplitAxis(G3D::Vector3::Axis a) { iSplitAxis = a; }
inline void setSplitLocation(float l) { iSplitLocation = l; }
inline void setBounds(const G3D::AABox& pBox) { iBounds = pBox; }
inline void setBounds(const G3D::Vector3& lo, const G3D::Vector3& hi) { iBounds.set(lo,hi); }
inline void getBounds(G3D::AABox& pBox) const { pBox.set(iBounds.low(),iBounds.high()); }
inline float getSplitLocation() const { return(iSplitLocation); }
inline unsigned short getNValues() const { return (iNumberOfValues); }
inline unsigned int getStartPosition() const { return(iStartPosition); }
inline bool operator==(const TreeNode& n) const
{
return ((iSplitLocation == n.iSplitLocation) &&
(iChilds[0] == n.iChilds[0]) && (iChilds[1] == n.iChilds[1]) &&
(iStartPosition == n.iStartPosition) &&
(iSplitAxis == n.iSplitAxis) &&
(iBounds == n.iBounds) &&
(iNumberOfValues == n.iNumberOfValues));
}
inline bool operator!=(const TreeNode& n) const
{
return !((iSplitLocation == n.iSplitLocation) &&
(iChilds[0] == n.iChilds[0]) && (iChilds[1] == n.iChilds[1]) &&
(iStartPosition == n.iStartPosition) &&
(iSplitAxis == n.iSplitAxis) &&
(iBounds == n.iBounds) &&
(iNumberOfValues == n.iNumberOfValues));
}
/** Returns true if the ray intersects this node */
bool intersects(const G3D::Ray& ray, float distance) const {
// See if the ray will ever hit this node or its children
G3D::Vector3 location;
bool alreadyInsideBounds = false;
bool rayWillHitBounds =
MyCollisionDetection::collisionLocationForMovingPointFixedAABox(
ray.origin, ray.direction, iBounds, location, alreadyInsideBounds);
bool canHitThisNode = (alreadyInsideBounds ||
(rayWillHitBounds && ((location - ray.origin).squaredLength() < (distance*distance))));
return canHitThisNode;
}
template<typename RayCallback, typename TNode, typename TValue>
void intersectRay(
const G3D::Ray& ray,
RayCallback& intersectCallback,
float& distance,
const NodeValueAccess<TNode, TValue>& pNodeValueAccess,
bool pStopAtFirstHit,
bool intersectCallbackIsFast) const {
float enterDistance = distance;
if (! intersects(ray, distance)) {
// The ray doesn't hit this node, so it can't hit the children of the node.
return;
}
// Test for intersection against every object at this node.
for (unsigned int v = iStartPosition; v < (iNumberOfValues+iStartPosition); ++v) {
const TValue& nodeValue = pNodeValueAccess.getValue(v);
bool canHitThisObject = true;
if (! intersectCallbackIsFast) {
// See if
G3D::Vector3 location;
const G3D::AABox& bounds = nodeValue.getAABoxBounds();
bool alreadyInsideBounds = false;
bool rayWillHitBounds =
MyCollisionDetection::collisionLocationForMovingPointFixedAABox(
ray.origin, ray.direction, bounds, location, alreadyInsideBounds);
canHitThisObject = (alreadyInsideBounds ||
(rayWillHitBounds && ((location - ray.origin).squaredLength() < (distance*distance))));
}
if (canHitThisObject) {
// It is possible that this ray hits this object. Look for the intersection using the
// callback.
intersectCallback(ray, &nodeValue, pStopAtFirstHit, distance);
}
if(pStopAtFirstHit && distance < enterDistance)
return;
}
// There are three cases to consider next:
//
// 1. the ray can start on one side of the splitting plane and never enter the other,
// 2. the ray can start on one side and enter the other, and
// 3. the ray can travel exactly down the splitting plane
enum {NONE = -1};
int firstChild = NONE;
int secondChild = NONE;
if (ray.origin[iSplitAxis] < iSplitLocation) {
// The ray starts on the small side
firstChild = 0;
if (ray.direction[iSplitAxis] > 0) {
// The ray will eventually reach the other side
secondChild = 1;
}
} else if (ray.origin[iSplitAxis] > iSplitLocation) {
// The ray starts on the large side
firstChild = 1;
if (ray.direction[iSplitAxis] < 0) {
secondChild = 0;
}
} else {
// The ray starts on the splitting plane
if (ray.direction[iSplitAxis] < 0) {
// ...and goes to the small side
firstChild = 0;
} else if (ray.direction[iSplitAxis] > 0) {
// ...and goes to the large side
firstChild = 1;
}
}
// Test on the side closer to the ray origin.
if ((firstChild != NONE) && iChilds[firstChild]>0) {
getChild(pNodeValueAccess.getNodePtr() , firstChild)->intersectRay(ray, intersectCallback, distance, pNodeValueAccess, pStopAtFirstHit,intersectCallbackIsFast);
if(pStopAtFirstHit && distance < enterDistance)
return;
}
if (ray.direction[iSplitAxis] != 0) {
// See if there was an intersection before hitting the splitting plane.
// If so, there is no need to look on the far side and recursion terminates.
float distanceToSplittingPlane = (iSplitLocation - ray.origin[iSplitAxis]) / ray.direction[iSplitAxis];
if (distanceToSplittingPlane > distance) {
// We aren't going to hit anything else before hitting the splitting plane,
// so don't bother looking on the far side of the splitting plane at the other
// child.
return;
}
}
// Test on the side farther from the ray origin.
if ((secondChild != NONE) && iChilds[secondChild]>0) {
getChild(pNodeValueAccess.getNodePtr() , secondChild)->intersectRay(ray, intersectCallback, distance, pNodeValueAccess, pStopAtFirstHit,intersectCallbackIsFast);
}
}
};
}
#endif
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