246 lines
9.1 KiB
C++
246 lines
9.1 KiB
C++
/********************************************************************************
|
|
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/ *
|
|
* Copyright (c) 2010-2013 Daniel Chappuis *
|
|
*********************************************************************************
|
|
* *
|
|
* This software is provided 'as-is', without any express or implied warranty. *
|
|
* In no event will the authors be held liable for any damages arising from the *
|
|
* use of this software. *
|
|
* *
|
|
* Permission is granted to anyone to use this software for any purpose, *
|
|
* including commercial applications, and to alter it and redistribute it *
|
|
* freely, subject to the following restrictions: *
|
|
* *
|
|
* 1. The origin of this software must not be misrepresented; you must not claim *
|
|
* that you wrote the original software. If you use this software in a *
|
|
* product, an acknowledgment in the product documentation would be *
|
|
* appreciated but is not required. *
|
|
* *
|
|
* 2. Altered source versions must be plainly marked as such, and must not be *
|
|
* misrepresented as being the original software. *
|
|
* *
|
|
* 3. This notice may not be removed or altered from any source distribution. *
|
|
* *
|
|
********************************************************************************/
|
|
|
|
#ifndef REACTPHYSICS3D_SWEEP_AND_PRUNE_ALGORITHM_H
|
|
#define REACTPHYSICS3D_SWEEP_AND_PRUNE_ALGORITHM_H
|
|
|
|
// Libraries
|
|
#include "BroadPhaseAlgorithm.h"
|
|
#include "../../collision/shapes/AABB.h"
|
|
#include <map>
|
|
#include <vector>
|
|
#include <list>
|
|
|
|
|
|
/// Namespace ReactPhysics3D
|
|
namespace reactphysics3d {
|
|
|
|
// Structure EndPoint
|
|
/**
|
|
* EndPoint structure that represent an end-point of an AABB
|
|
* on one of the three x,y or z axis.
|
|
*/
|
|
struct EndPoint {
|
|
|
|
public:
|
|
|
|
/// ID of the AABB box corresponding to this end-point
|
|
bodyindex boxID;
|
|
|
|
/// True if the end-point is a minimum end-point of a box
|
|
bool isMin;
|
|
|
|
/// Value (one dimension coordinate) of the end-point
|
|
uint value;
|
|
|
|
/// Set the values of the endpoint
|
|
void setValues(bodyindex boxID, bool isMin, uint value) {
|
|
this->boxID = boxID;
|
|
this->isMin = isMin;
|
|
this->value = value;
|
|
}
|
|
};
|
|
|
|
// Structure BoxAABB
|
|
/**
|
|
* This structure represents an AABB in the Sweep-And-Prune algorithm
|
|
*/
|
|
struct BoxAABB {
|
|
|
|
public:
|
|
|
|
/// Index of the 3 minimum end-points of the AABB over the x,y,z axis
|
|
bodyindex min[3];
|
|
|
|
/// Index of the 3 maximum end-points of the AABB over the x,y,z axis
|
|
bodyindex max[3];
|
|
|
|
/// Body that corresponds to the owner of the AABB
|
|
CollisionBody* body;
|
|
};
|
|
|
|
// Structure AABBInt
|
|
/**
|
|
* Axis-Aligned Bounding box with integer coordinates.
|
|
*/
|
|
struct AABBInt {
|
|
|
|
public:
|
|
|
|
/// Minimum values on the three axis
|
|
uint min[3];
|
|
|
|
/// Maximum values on the three axis
|
|
uint max[3];
|
|
|
|
/// Constructor that takes an AABB as input
|
|
AABBInt(const AABB& aabb);
|
|
|
|
/// Constructor that set all the axis with an minimum and maximum value
|
|
AABBInt(uint minValue, uint maxValue);
|
|
};
|
|
|
|
// Class SweepAndPruneAlgorithm
|
|
/**
|
|
* This class implements the Sweep-And-Prune (SAP) broad-phase
|
|
* collision detection algorithm. This class implements an
|
|
* array-based implementation of the algorithm from Pierre Terdiman
|
|
* that is described here : www.codercorner.com/SAP.pdf.
|
|
*/
|
|
class SweepAndPruneAlgorithm : public BroadPhaseAlgorithm {
|
|
|
|
protected :
|
|
|
|
// -------------------- Constants -------------------- //
|
|
|
|
/// Invalid array index
|
|
const static bodyindex INVALID_INDEX;
|
|
|
|
/// Number of sentinel end-points in the array of a given axis
|
|
const static luint NB_SENTINELS;
|
|
|
|
// -------------------- Attributes -------------------- //
|
|
|
|
/// Array that contains all the AABB boxes of the broad-phase
|
|
BoxAABB* mBoxes;
|
|
|
|
/// Array of end-points on the three axis
|
|
EndPoint* mEndPoints[3];
|
|
|
|
/// Number of AABB boxes in the broad-phase
|
|
bodyindex mNbBoxes;
|
|
|
|
/// Max number of boxes in the boxes array
|
|
bodyindex mNbMaxBoxes;
|
|
|
|
/// Indices that are not used by any boxes
|
|
std::list<bodyindex> mFreeBoxIndices;
|
|
|
|
/// Map a body pointer to a box index
|
|
std::map<CollisionBody*,bodyindex> mMapBodyToBoxIndex;
|
|
|
|
// -------------------- Methods -------------------- //
|
|
|
|
/// Private copy-constructor
|
|
SweepAndPruneAlgorithm(const SweepAndPruneAlgorithm& algorithm);
|
|
|
|
/// Private assignment operator
|
|
SweepAndPruneAlgorithm& operator=(const SweepAndPruneAlgorithm& algorithm);
|
|
|
|
/// Resize the boxes and end-points arrays when it's full
|
|
void resizeArrays();
|
|
|
|
/// Shrink the boxes and end-points arrays when too much memory is allocated
|
|
void shrinkArrays();
|
|
|
|
/// Add an overlapping pair of AABBS
|
|
void addPair(CollisionBody* body1, CollisionBody* body2);
|
|
|
|
/// Check for 1D box intersection between two boxes that are sorted on the given axis.
|
|
bool testIntersect1DSortedAABBs(const BoxAABB& box1, const AABBInt& box2,
|
|
const EndPoint* const baseEndPoint, uint axis) const;
|
|
|
|
/// Check for 2D box intersection.
|
|
bool testIntersect2D(const BoxAABB& box1, const BoxAABB& box2,
|
|
luint axis1, uint axis2) const;
|
|
|
|
/// Notify the broad-phase that the AABB of an object has changed.
|
|
void updateObjectIntegerAABB(CollisionBody* body, const AABBInt& aabbInt);
|
|
|
|
public :
|
|
|
|
// -------------------- Methods -------------------- //
|
|
|
|
/// Constructor
|
|
SweepAndPruneAlgorithm(CollisionDetection& mCollisionDetection);
|
|
|
|
/// Destructor
|
|
virtual ~SweepAndPruneAlgorithm();
|
|
|
|
/// Notify the broad-phase about a new object in the world.
|
|
virtual void addProxyCollisionShape(CollisionBody* body, const AABB& aabb);
|
|
|
|
/// Notify the broad-phase about a object that has been removed from the world
|
|
virtual void removeProxyCollisionShape(CollisionBody* body);
|
|
|
|
/// Notify the broad-phase that the AABB of an object has changed
|
|
virtual void updateProxyCollisionShape(CollisionBody* body, const AABB& aabb);
|
|
};
|
|
|
|
/// Encode a floating value into a integer value in order to
|
|
/// work with integer comparison in the Sweep-And-Prune algorithm
|
|
/// because it is faster. The main issue when encoding floating
|
|
/// number into integer is to keep to sorting order. This is a
|
|
/// problem for negative float number. This article describes
|
|
/// how to solve this issue : http://www.stereopsis.com/radix.html
|
|
inline uint encodeFloatIntoInteger(float number) {
|
|
uint intNumber = (uint&) number;
|
|
|
|
// If it's a negative number
|
|
if(intNumber & 0x80000000)
|
|
intNumber = ~intNumber;
|
|
else { // If it is a positive number
|
|
intNumber |= 0x80000000;
|
|
}
|
|
|
|
return intNumber;
|
|
}
|
|
|
|
|
|
// Check for 1D box intersection between two boxes that are sorted on the given axis.
|
|
/// Therefore, only one test is necessary here. We know that the
|
|
/// minimum of box1 cannot be larger that the maximum of box2 on the axis.
|
|
inline bool SweepAndPruneAlgorithm::testIntersect1DSortedAABBs(const BoxAABB& box1,
|
|
const AABBInt& box2,
|
|
const EndPoint* const endPointsArray,
|
|
uint axis) const {
|
|
return !(endPointsArray[box1.max[axis]].value < box2.min[axis]);
|
|
}
|
|
|
|
// Check for 2D box intersection. This method is used when we know
|
|
/// that two boxes already overlap on one axis and when want to test
|
|
/// if they also overlap on the two others axis.
|
|
inline bool SweepAndPruneAlgorithm::testIntersect2D(const BoxAABB& box1, const BoxAABB& box2,
|
|
luint axis1, uint axis2) const {
|
|
return !(box2.max[axis1] < box1.min[axis1] || box1.max[axis1] < box2.min[axis1] ||
|
|
box2.max[axis2] < box1.min[axis2] || box1.max[axis2] < box2.min[axis2]);
|
|
}
|
|
|
|
// Notify the broad-phase that the AABB of an object has changed
|
|
inline void SweepAndPruneAlgorithm::updateProxyCollisionShape(CollisionBody* body, const AABB& aabb) {
|
|
|
|
// Compute the corresponding AABB with integer coordinates
|
|
AABBInt aabbInt(aabb);
|
|
|
|
// Call the update object method that uses an AABB with integer coordinates
|
|
updateObjectIntegerAABB(body, aabbInt);
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|