reactphysics3d/src/collision/shapes/CapsuleShape.h
2018-03-28 22:55:02 +02:00

187 lines
7.6 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2016 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_CAPSULE_SHAPE_H
#define REACTPHYSICS3D_CAPSULE_SHAPE_H
// Libraries
#include "ConvexShape.h"
#include "body/CollisionBody.h"
#include "mathematics/mathematics.h"
// ReactPhysics3D namespace
namespace reactphysics3d {
// Class CapsuleShape
/**
* This class represents a capsule collision shape that is defined around the Y axis.
* A capsule shape can be seen as the convex hull of two spheres.
* The capsule shape is defined by its radius (radius of the two spheres of the capsule)
* and its height (distance between the centers of the two spheres). This collision shape
* does not have an explicit object margin distance. The margin is implicitly the radius
* and height of the shape. Therefore, no need to specify an object margin for a
* capsule shape.
*/
class CapsuleShape : public ConvexShape {
protected :
// -------------------- Attributes -------------------- //
/// Half height of the capsule (height = distance between the centers of the two spheres)
decimal mHalfHeight;
// -------------------- Methods -------------------- //
/// Return a local support point in a given direction without the object margin
virtual Vector3 getLocalSupportPointWithoutMargin(const Vector3& direction) const override;
/// Return true if a point is inside the collision shape
virtual bool testPointInside(const Vector3& localPoint, ProxyShape* proxyShape) const override;
/// Raycast method with feedback information
virtual bool raycast(const Ray& ray, RaycastInfo& raycastInfo, ProxyShape* proxyShape, MemoryAllocator& allocator) const override;
/// Raycasting method between a ray one of the two spheres end cap of the capsule
bool raycastWithSphereEndCap(const Vector3& point1, const Vector3& point2,
const Vector3& sphereCenter, decimal maxFraction,
Vector3& hitLocalPoint, decimal& hitFraction) const;
/// Return the number of bytes used by the collision shape
virtual size_t getSizeInBytes() const override;
public :
// -------------------- Methods -------------------- //
/// Constructor
CapsuleShape(decimal radius, decimal height);
/// Destructor
virtual ~CapsuleShape() override = default;
/// Deleted copy-constructor
CapsuleShape(const CapsuleShape& shape) = delete;
/// Deleted assignment operator
CapsuleShape& operator=(const CapsuleShape& shape) = delete;
/// Return the radius of the capsule
decimal getRadius() const;
/// Return the height of the capsule
decimal getHeight() const;
/// Return the local bounds of the shape in x, y and z directions
virtual void getLocalBounds(Vector3& min, Vector3& max) const override;
/// Return true if the collision shape is a polyhedron
virtual bool isPolyhedron() const override;
/// Return the local inertia tensor of the collision shape
virtual void computeLocalInertiaTensor(Matrix3x3& tensor, decimal mass) const override;
/// Return the string representation of the shape
virtual std::string to_string() const override;
};
// Get the radius of the capsule
/**
* @return The radius of the capsule shape (in meters)
*/
inline decimal CapsuleShape::getRadius() const {
return mMargin;
}
// Return the height of the capsule
/**
* @return The height of the capsule shape (in meters)
*/
inline decimal CapsuleShape::getHeight() const {
return mHalfHeight + mHalfHeight;
}
// Return the number of bytes used by the collision shape
inline size_t CapsuleShape::getSizeInBytes() const {
return sizeof(CapsuleShape);
}
// Return the local bounds of the shape in x, y and z directions
// This method is used to compute the AABB of the box
/**
* @param min The minimum bounds of the shape in local-space coordinates
* @param max The maximum bounds of the shape in local-space coordinates
*/
inline void CapsuleShape::getLocalBounds(Vector3& min, Vector3& max) const {
// Maximum bounds
max.x = mMargin;
max.y = mHalfHeight + mMargin;
max.z = mMargin;
// Minimum bounds
min.x = -mMargin;
min.y = -max.y;
min.z = min.x;
}
// Return true if the collision shape is a polyhedron
inline bool CapsuleShape::isPolyhedron() const {
return false;
}
// Return a local support point in a given direction without the object margin.
/// A capsule is the convex hull of two spheres S1 and S2. The support point in the direction "d"
/// of the convex hull of a set of convex objects is the support point "p" in the set of all
/// support points from all the convex objects with the maximum dot product with the direction "d".
/// Therefore, in this method, we compute the support points of both top and bottom spheres of
/// the capsule and return the point with the maximum dot product with the direction vector. Note
/// that the object margin is implicitly the radius and height of the capsule.
inline Vector3 CapsuleShape::getLocalSupportPointWithoutMargin(const Vector3& direction) const {
// Support point top sphere
decimal dotProductTop = mHalfHeight * direction.y;
// Support point bottom sphere
decimal dotProductBottom = -mHalfHeight * direction.y;
// Return the point with the maximum dot product
if (dotProductTop > dotProductBottom) {
return Vector3(0, mHalfHeight, 0);
}
else {
return Vector3(0, -mHalfHeight, 0);
}
}
// Return the string representation of the shape
inline std::string CapsuleShape::to_string() const {
return "CapsuleShape{halfHeight=" + std::to_string(mHalfHeight) + ", radius=" + std::to_string(getRadius()) + "}";
}
}
#endif