112 lines
4.2 KiB
C++

/** @file
* @author Daniel Chappuis
* @copyright 2010-2016 Daniel Chappuis
* @license BSD 3 clauses (see license file)
*/
#pragma once
#include <cfloat>
#include <ephysics/collision/shapes/ConvexShape.hpp>
#include <ephysics/body/CollisionBody.hpp>
#include <ephysics/mathematics/mathematics.hpp>
namespace ephysics {
/**
* @brief It represents a 3D box shape. Those axis are unit length.
* The three extents are half-widths of the box along the three
* axis x, y, z local axis. The "transform" of the corresponding
* rigid body will give an orientation and a position to the box. This
* collision shape uses an extra margin distance around it for collision
* detection purpose. The default margin is 4cm (if your units are meters,
* which is recommended). In case, you want to simulate small objects
* (smaller than the margin distance), you might want to reduce the margin by
* specifying your own margin distance using the "margin" parameter in the
* constructor of the box shape. Otherwise, it is recommended to use the
* default margin distance by not using the "margin" parameter in the constructor.
*/
class BoxShape : public ConvexShape {
protected :
vec3 m_extent; //!< Extent sizes of the box in the x, y and z direction
/// Private copy-constructor
BoxShape(const BoxShape& shape);
/// Private assignment operator
BoxShape& operator=(const BoxShape& shape);
/// Return a local support point in a given direction without the object margin
virtual vec3 getLocalSupportPointWithoutMargin(const vec3& direction,
void** cachedCollisionData) const;
/// Return true if a point is inside the collision shape
virtual bool testPointInside(const vec3& localPoint, ProxyShape* proxyShape) const;
/// Raycast method with feedback information
virtual bool raycast(const Ray& ray, RaycastInfo& raycastInfo, ProxyShape* proxyShape) const;
/// Return the number of bytes used by the collision shape
virtual size_t getSizeInBytes() const;
public :
/// Constructor
BoxShape(const vec3& extent, float margin = OBJECT_MARGIN);
/// Destructor
virtual ~BoxShape() = default;
/// Return the extents of the box
vec3 getExtent() const;
/// Set the scaling vector of the collision shape
virtual void setLocalScaling(const vec3& scaling);
/// Return the local bounds of the shape in x, y and z directions
virtual void getLocalBounds(vec3& _min, vec3& _max) const;
/// Return the local inertia tensor of the collision shape
virtual void computeLocalInertiaTensor(etk::Matrix3x3& tensor, float mass) const;
};
// Return the extents of the box
/**
* @return The vector with the three extents of the box shape (in meters)
*/
vec3 BoxShape::getExtent() const {
return m_extent + vec3(m_margin, m_margin, m_margin);
}
// Set the scaling vector of the collision shape
void BoxShape::setLocalScaling(const vec3& scaling) {
m_extent = (m_extent / m_scaling) * scaling;
CollisionShape::setLocalScaling(scaling);
}
// 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
*/
void BoxShape::getLocalBounds(vec3& _min, vec3& _max) const {
// Maximum bounds
_max = m_extent + vec3(m_margin, m_margin, m_margin);
// Minimum bounds
_min = -_max;
}
// Return the number of bytes used by the collision shape
size_t BoxShape::getSizeInBytes() const {
return sizeof(BoxShape);
}
// Return a local support point in a given direction without the objec margin
vec3 BoxShape::getLocalSupportPointWithoutMargin(const vec3& direction,
void** cachedCollisionData) const {
return vec3(direction.x() < 0.0 ? -m_extent.x() : m_extent.x(),
direction.y() < 0.0 ? -m_extent.y() : m_extent.y(),
direction.z() < 0.0 ? -m_extent.z() : m_extent.z());
}
// Return true if a point is inside the collision shape
bool BoxShape::testPointInside(const vec3& localPoint, ProxyShape* proxyShape) const {
return (localPoint.x() < m_extent[0] && localPoint.x() > -m_extent[0] &&
localPoint.y() < m_extent[1] && localPoint.y() > -m_extent[1] &&
localPoint.z() < m_extent[2] && localPoint.z() > -m_extent[2]);
}
}