static inline Scalar penetrationOnAxis(const ShapeBox &boxA, const Transform &boxATransform,
const ShapeBox &boxB, const Transform &boxBTransform, const Vec3 &axis, const Vec3 &separation)
{
Scalar projectionA = transformToAxis(boxA, boxATransform, axis);
Scalar projectionB = transformToAxis(boxB, boxBTransform, axis);
Scalar distance = abs( separation.dot(axis) );
return projectionA + projectionB - distance;
}
/**
* This function checks if the two boxes overlap
* along the given axis. The final parameter toCentre
* is used to pass in the vector between the boxes centre
* points, to avoid having to recalculate it each time.
*/
static inline bool overlapOnAxis(
const CollisionBox &one,
const CollisionBox &two,
const Vector3 &axis,
const Vector3 &toCentre
)
{
// Project the half-size of one onto axis
real oneProject = transformToAxis(one, axis);
real twoProject = transformToAxis(two, axis);
// Project this onto the axis
real distance = real_abs(toCentre * axis);
// Check for overlap
return (distance < oneProject + twoProject);
}
/*
* This function checks if the two boxes overlap
* along the given axis, returning the ammount of overlap.
* The final parameter toCentre
* is used to pass in the vector between the boxes centre
* points, to avoid having to recalculate it each time.
*/
static inline real penetrationOnAxis(
const CollisionBox &one,
const CollisionBox &two,
const Vector3 &axis,
const Vector3 &toCentre
)
{
// Project the half-size of one onto axis
real oneProject = transformToAxis(one, axis);
real twoProject = transformToAxis(two, axis);
// Project this onto the axis
real distance = real_abs(toCentre * axis);
// Return the overlap (i.e. positive indicates
// overlap, negative indicates separation).
return oneProject + twoProject - distance;
}
bool IntersectionTests::boxAndHalfSpace(
const CollisionBox &box,
const CollisionPlane &plane
)
{
// Work out the projected radius of the box onto the plane direction
real projectedRadius = transformToAxis(box, plane.direction);
// Work out how far the box is from the origin
real boxDistance =
plane.direction *
box.getAxis(3) -
projectedRadius;
// Check for the intersection
return boxDistance <= plane.offset;
}
