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fix sphere-sphere collisions for moving spheres

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This commit is contained in:
David Rose 2008-06-18 22:08:35 +00:00
parent aa92d0c62e
commit 20197b6767
1 changed files with 35 additions and 36 deletions
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71
panda/src/collide/collisionSphere.cxx
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@ -312,11 +312,9 @@ test_intersection_from_sphere(const CollisionEntry &entry) const {
DCAST_INTO_R(sphere, entry.get_from(), 0);
CPT(TransformState) wrt_space = entry.get_wrt_space();
CPT(TransformState) wrt_prev_space = entry.get_wrt_prev_space();
const LMatrix4f &wrt_mat = wrt_space->get_mat();
LPoint3f from_a = sphere->get_center() * wrt_prev_space->get_mat();
LPoint3f from_b = sphere->get_center() * wrt_mat;
LPoint3f into_center(get_center());
@ -331,45 +329,46 @@ test_intersection_from_sphere(const CollisionEntry &entry) const {
LPoint3f contact_point(into_intersection_point);
float actual_t = 0.0f;
if (from_a != from_b) {
LVector3f from_direction = from_b - from_a;
if (!intersects_line(t1, t2, from_a, from_direction, from_radius)) {
// No intersection.
return NULL;
}
LVector3f vec = from_b - into_center;
float dist2 = dot(vec, vec);
if (dist2 > (into_radius + from_radius) * (into_radius + from_radius)) {
// No intersection with the current position. Check the delta
// from the previous frame.
CPT(TransformState) wrt_prev_space = entry.get_wrt_prev_space();
LPoint3f from_a = sphere->get_center() * wrt_prev_space->get_mat();
if (t2 < 0.0 || t1 > 1.0) {
// Both intersection points are before the start of the segment or
// after the end of the segment.
return NULL;
}
// doubles, not floats, to satisfy min and max templates.
actual_t = min(1.0, max(0.0, t1));
contact_point = from_a + actual_t * (from_b - from_a);
if (t1 < 0.0) {
// Point a is within the sphere. The first intersection point is
// point a itself.
into_intersection_point = from_a;
if (!from_a.almost_equal(from_b)) {
LVector3f from_direction = from_b - from_a;
if (!intersects_line(t1, t2, from_a, from_direction, from_radius)) {
// No intersection.
return NULL;
}
if (t2 < 0.0 || t1 > 1.0) {
// Both intersection points are before the start of the segment or
// after the end of the segment.
return NULL;
}
// doubles, not floats, to satisfy min and max templates.
actual_t = min(1.0, max(0.0, t1));
contact_point = from_a + actual_t * (from_b - from_a);
if (t1 < 0.0) {
// Point a is within the sphere. The first intersection point is
// point a itself.
into_intersection_point = from_a;
} else {
// Point a is outside the sphere, and point b is either inside the
// sphere or beyond it. The first intersection point is at t1.
into_intersection_point = from_a + t1 * from_direction;
}
} else {
// Point a is outside the sphere, and point b is either inside the
// sphere or beyond it. The first intersection point is at t1.
into_intersection_point = from_a + t1 * from_direction;
}
} else {
LVector3f vec = from_a - into_center;
float dist2 = dot(vec, vec);
if (dist2 > (into_radius + from_radius) * (into_radius + from_radius)) {
// No intersection.
// No delta, therefore no intersection.
return NULL;
}
into_intersection_point = from_a;
t1 = 0.0f;
}
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "intersection detected from " << entry.get_from_node_path()