reactphysics3d/src/collision/shapes/SphereShape.h

273 lines
10 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_SPHERE_SHAPE_H
#define REACTPHYSICS3D_SPHERE_SHAPE_H
// Libraries
#include "CollisionShape.h"
#include "../../mathematics/mathematics.h"
// ReactPhysics3D namespace
namespace reactphysics3d {
// Class SphereShape
/**
* This class represents a sphere collision shape that is centered
* at the origin and defined by its radius. This collision shape does not
* have an explicit object margin distance. The margin is implicitly the
* radius of the sphere. Therefore, no need to specify an object margin
* for a sphere shape.
*/
class SphereShape : public CollisionShape {
private :
// -------------------- Attributes -------------------- //
/// Radius of the sphere
decimal mRadius;
// -------------------- Methods -------------------- //
/// Private copy-constructor
SphereShape(const SphereShape& shape);
/// Private assignment operator
SphereShape& operator=(const SphereShape& shape);
public :
// -------------------- Methods -------------------- //
/// Constructor
SphereShape(decimal radius);
/// Destructor
virtual ~SphereShape();
/// Allocate and return a copy of the object
virtual SphereShape* clone(void* allocatedMemory) const;
/// Return the radius of the sphere
decimal getRadius() const;
/// Return the number of bytes used by the collision shape
virtual size_t getSizeInBytes() const;
/// Return a local support point in a given direction with the object margin
virtual Vector3 getLocalSupportPointWithMargin(const Vector3& direction) const;
/// Return a local support point in a given direction without the object margin
virtual Vector3 getLocalSupportPointWithoutMargin(const Vector3& direction) const;
/// Return the local bounds of the shape in x, y and z directions.
virtual void getLocalBounds(Vector3& min, Vector3& max) const;
/// Return the local inertia tensor of the collision shape
virtual void computeLocalInertiaTensor(Matrix3x3& tensor, decimal mass) const;
/// Update the AABB of a body using its collision shape
virtual void computeAABB(AABB& aabb, const Transform& transform);
/// Test equality between two sphere shapes
virtual bool isEqualTo(const CollisionShape& otherCollisionShape) const;
/// Create a proxy collision shape for the collision shape
virtual ProxyShape* createProxyShape(MemoryAllocator& allocator, CollisionBody* body,
const Transform& transform, decimal mass);
};
// Class ProxySphereShape
/**
* The proxy collision shape for a sphere shape.
*/
class ProxySphereShape : public ProxyShape {
private:
// -------------------- Attributes -------------------- //
/// Pointer to the actual collision shape
SphereShape* mCollisionShape;
// -------------------- Methods -------------------- //
/// Private copy-constructor
ProxySphereShape(const ProxySphereShape& proxyShape);
/// Private assignment operator
ProxySphereShape& operator=(const ProxySphereShape& proxyShape);
/// Return the non-const collision shape
virtual CollisionShape* getInternalCollisionShape() const;
public:
// -------------------- Methods -------------------- //
/// Constructor
ProxySphereShape(SphereShape* shape, CollisionBody* body,
const Transform& transform, decimal mass);
/// Destructor
~ProxySphereShape();
/// Return the collision shape
virtual const CollisionShape* getCollisionShape() const;
/// Return the number of bytes used by the proxy collision shape
virtual size_t getSizeInBytes() const;
/// Return a local support point in a given direction with the object margin
virtual Vector3 getLocalSupportPointWithMargin(const Vector3& direction);
/// Return a local support point in a given direction without the object margin
virtual Vector3 getLocalSupportPointWithoutMargin(const Vector3& direction);
/// Return the current collision shape margin
virtual decimal getMargin() const;
};
/// Allocate and return a copy of the object
inline SphereShape* SphereShape::clone(void* allocatedMemory) const {
return new (allocatedMemory) SphereShape(*this);
}
// Get the radius of the sphere
inline decimal SphereShape::getRadius() const {
return mRadius;
}
// Return the number of bytes used by the collision shape
inline size_t SphereShape::getSizeInBytes() const {
return sizeof(SphereShape);
}
// Return a local support point in a given direction with the object margin
inline Vector3 SphereShape::getLocalSupportPointWithMargin(const Vector3& direction) const {
// If the direction vector is not the zero vector
if (direction.lengthSquare() >= MACHINE_EPSILON * MACHINE_EPSILON) {
// Return the support point of the sphere in the given direction
return mMargin * direction.getUnit();
}
// If the direction vector is the zero vector we return a point on the
// boundary of the sphere
return Vector3(0, mMargin, 0);
}
// Return a local support point in a given direction without the object margin
inline Vector3 SphereShape::getLocalSupportPointWithoutMargin(const Vector3& direction) const {
// Return the center of the sphere (the radius is taken into account in the object margin)
return Vector3(0.0, 0.0, 0.0);
}
// Return the local bounds of the shape in x, y and z directions.
// This method is used to compute the AABB of the box
inline void SphereShape::getLocalBounds(Vector3& min, Vector3& max) const {
// Maximum bounds
max.x = mRadius;
max.y = mRadius;
max.z = mRadius;
// Minimum bounds
min.x = -mRadius;
min.y = min.x;
min.z = min.x;
}
// Return the local inertia tensor of the sphere
inline void SphereShape::computeLocalInertiaTensor(Matrix3x3& tensor, decimal mass) const {
decimal diag = decimal(0.4) * mass * mRadius * mRadius;
tensor.setAllValues(diag, 0.0, 0.0,
0.0, diag, 0.0,
0.0, 0.0, diag);
}
// Update the AABB of a body using its collision shape
inline void SphereShape::computeAABB(AABB& aabb, const Transform& transform) {
// Get the local extents in x,y and z direction
Vector3 extents(mRadius, mRadius, mRadius);
// Update the AABB with the new minimum and maximum coordinates
aabb.setMin(transform.getPosition() - extents);
aabb.setMax(transform.getPosition() + extents);
}
// Test equality between two sphere shapes
inline bool SphereShape::isEqualTo(const CollisionShape& otherCollisionShape) const {
const SphereShape& otherShape = dynamic_cast<const SphereShape&>(otherCollisionShape);
return (mRadius == otherShape.mRadius);
}
// Create a proxy collision shape for the collision shape
inline ProxyShape* SphereShape::createProxyShape(MemoryAllocator& allocator, CollisionBody* body,
const Transform& transform, decimal mass) {
return new (allocator.allocate(sizeof(ProxySphereShape))) ProxySphereShape(this, body,
transform, mass);
}
// Return the non-const collision shape
inline CollisionShape* ProxySphereShape::getInternalCollisionShape() const {
return mCollisionShape;
}
// Return the collision shape
inline const CollisionShape* ProxySphereShape::getCollisionShape() const {
return mCollisionShape;
}
// Return the number of bytes used by the proxy collision shape
inline size_t ProxySphereShape::getSizeInBytes() const {
return sizeof(ProxySphereShape);
}
// Return a local support point in a given direction with the object margin
inline Vector3 ProxySphereShape::getLocalSupportPointWithMargin(const Vector3& direction) {
return mCollisionShape->getLocalSupportPointWithMargin(direction);
}
// Return a local support point in a given direction without the object margin
inline Vector3 ProxySphereShape::getLocalSupportPointWithoutMargin(const Vector3& direction) {
return mCollisionShape->getLocalSupportPointWithoutMargin(direction);
}
// Return the current object margin
inline decimal ProxySphereShape::getMargin() const {
return mCollisionShape->getMargin();
}
}
#endif