public static void FastIntersectOrientedBoxPlane(
XMVector center,
XMVector extents,
XMVector axis0,
XMVector axis1,
XMVector axis2,
XMVector plane,
out XMVector outside,
out XMVector inside)
{
// Compute the distance to the center of the box.
XMVector dist = XMVector4.Dot(center, plane);
// Project the axes of the box onto the normal of the plane. Half the
// length of the projection (sometime called the "radius") is equal to
// h(u) * abs(n dot b(u))) + h(v) * abs(n dot b(v)) + h(w) * abs(n dot b(w))
// where h(i) are extents of the box, n is the plane normal, and b(i) are the
// axes of the box.
XMVector radius = XMVector3.Dot(plane, axis0);
radius.Y = XMVector3.Dot(plane, axis1).Y;
radius.Z = XMVector3.Dot(plane, axis2).Z;
radius = XMVector3.Dot(extents, radius.Abs());
// Outside the plane?
outside = XMVector.Greater(dist, radius);
// Fully inside the plane?
inside = XMVector.Less(dist, -radius);
}
public static void FastIntersectSpherePlane(XMVector center, XMVector radius, XMVector plane, out XMVector outside, out XMVector inside)
{
XMVector dist = XMVector4.Dot(center, plane);
// Outside the plane?
outside = XMVector.Greater(dist, radius);
// Fully inside the plane?
inside = XMVector.Less(dist, -radius);
}
public static void FastIntersectAxisAlignedBoxPlane(XMVector center, XMVector extents, XMVector plane, out XMVector outside, out XMVector inside)
{
// Compute the distance to the center of the box.
XMVector dist = XMVector4.Dot(center, plane);
// Project the axes of the box onto the normal of the plane. Half the
// length of the projection (sometime called the "radius") is equal to
// h(u) * abs(n dot b(u))) + h(v) * abs(n dot b(v)) + h(w) * abs(n dot b(w))
// where h(i) are extents of the box, n is the plane normal, and b(i) are the
// axes of the box. In this case b(i) = [(1,0,0), (0,1,0), (0,0,1)].
XMVector radius = XMVector3.Dot(extents, plane.Abs());
// Outside the plane?
outside = XMVector.Greater(dist, radius);
// Fully inside the plane?
inside = XMVector.Less(dist, -radius);
}
public static void FastIntersectTrianglePlane(XMVector v0, XMVector v1, XMVector v2, XMVector plane, out XMVector outside, out XMVector inside)
{
// Plane0
XMVector dist0 = XMVector4.Dot(v0, plane);
XMVector dist1 = XMVector4.Dot(v1, plane);
XMVector dist2 = XMVector4.Dot(v2, plane);
XMVector minDist = XMVector.Min(dist0, dist1);
minDist = XMVector.Min(minDist, dist2);
XMVector maxDist = XMVector.Max(dist0, dist1);
maxDist = XMVector.Max(maxDist, dist2);
XMVector zero = XMGlobalConstants.Zero;
// Outside the plane?
outside = XMVector.Greater(minDist, zero);
// Fully inside the plane?
inside = XMVector.Less(maxDist, zero);
}