public static bool IntersectMovingSphereAABB(Sphere s, LVector3 d, AABB b, out LFloat t)
{
// Compute the AABB resulting from expanding b by sphere radius r
AABB e = b;
int _val = s.r._val;
e.min._x -= _val;
e.min._y -= _val;
e.min._z -= _val;
e.max._x += _val;
e.max._y += _val;
e.max._z += _val;
// Intersect ray against expanded AABB e. Exit with no intersection if ray
// misses e, else get intersection point p and time t as result
LVector3 p;
if (!IntersectRayAABB(s.c, d, e, out t, out p) || t > LFloat.one)
{
return(false);
}
// Compute which min and max faces of b the intersection point p lies
// outside of. Note, u and v cannot have the same bits set and
// they must have at least one bit set amongst them
int u = 0, v = 0;
if (p.x < b.min.x)
{
u |= 1;
}
if (p.x > b.max.x)
{
v |= 1;
}
if (p.y < b.min.y)
{
u |= 2;
}
if (p.y > b.max.y)
{
v |= 2;
}
if (p.z < b.min.z)
{
u |= 4;
}
if (p.z > b.max.z)
{
v |= 4;
}
// ‘Or’ all set bits together into a bit mask (note: here u + v == u | v)
int m = u + v;
// Define line segment [c, c+d] specified by the sphere movement
Segment seg = new Segment(s.c, s.c + d);
// If all 3 bits set (m == 7) then p is in a vertex region
if (m == 7)
{
// Must now intersect segment [c, c+d] against the capsules of the three
// edges meeting at the vertex and return the best time, if one or more hit
LFloat tmin = LFloat.FLT_MAX;
if (IntersectSegmentCapsule(seg, Corner(b, v), Corner(b, v ^ 1), s.r, out t))
{
tmin = Min(t, tmin);
}
if (IntersectSegmentCapsule(seg, Corner(b, v), Corner(b, v ^ 2), s.r, out t))
{
tmin = Min(t, tmin);
}
if (IntersectSegmentCapsule(seg, Corner(b, v), Corner(b, v ^ 4), s.r, out t))
{
tmin = Min(t, tmin);
}
if (tmin == LFloat.FLT_MAX)
{
return(false); // No intersection
}
t = tmin;
return(true); // Intersection at time t == tmin
}
// If only one bit set in m, then p is in a face region
if ((m & (m - 1)) == 0)
{
// Do nothing. Time t from intersection with
// expanded box is correct intersection time
return(true);
}
// p is in an edge region. Intersect against the capsule at the edge
return(IntersectSegmentCapsule(seg, Corner(b, u ^ 7), Corner(b, v), s.r, out t));
}
// Intersect sphere s0 moving in direction d over time interval t0 <= t <= t1, against
// a stationary sphere s1. If found intersecting, return time t of collision
public static bool TestMovingSphereSphere(Sphere s0, LVector3 d, LFloat t0, LFloat t1, Sphere s1, out LFloat t)
{
// Compute sphere bounding motion of s0 during time interval from t0 to t1
Sphere b = new Sphere();//TODO 移除掉new
LFloat mid = (t0 + t1) * LFloat.half;
b.c = s0.c + d * mid;
b.r = (mid - t0) * d.magnitude + s0.r;
t = LFloat.zero;
// If bounding sphere not overlapping s1, then no collision in this interval
if (!TestSphereSphere(b, s1))
{
return(false);
}
// Cannot rule collision out: recurse for more accurate testing. To terminate the
// recursion, collision is assumed when time interval becomes sufficiently small
if (t1 - t0 < LFloat.INTERVAL_EPSI_LON)
{
t = t0;
return(true);
}
// Recursively test first half of interval; return collision if detected
if (TestMovingSphereSphere(s0, d, t0, mid, s1, out t))
{
return(true);
}
// Recursively test second half of interval
return(TestMovingSphereSphere(s0, d, mid, t1, s1, out t));
}
