//==============================================================================
Bool test(const Aabb& aabb, const LineSegment& ls)
{
F32 maxS = MIN_F32;
F32 minT = MAX_F32;
// do tests against three sets of planes
for(U i = 0; i < 3; ++i)
{
// segment is parallel to plane
if(isZero(ls.getDirection()[i]))
{
// segment passes by box
if(ls.getOrigin()[i] < aabb.getMin()[i]
|| ls.getOrigin()[i] > aabb.getMax()[i])
{
return false;
}
}
else
{
// compute intersection parameters and sort
F32 s =
(aabb.getMin()[i] - ls.getOrigin()[i]) / ls.getDirection()[i];
F32 t =
(aabb.getMax()[i] - ls.getOrigin()[i]) / ls.getDirection()[i];
if(s > t)
{
F32 temp = s;
s = t;
t = temp;
}
// adjust min and max values
if(s > maxS)
{
maxS = s;
}
if(t < minT)
{
minT = t;
}
// check for intersection failure
if(minT < 0.0 || maxS > 1.0 || maxS > minT)
{
return false;
}
}
}
// done, have intersection
return true;
}
bool intersects(const LineSegment<type>& l1, const LineSegment<type>& l2) {
if(l1.isDegenerate() || l2.isDegenerate()) {
return false;
}
type t = -(dot(l2.getNormal(), l1.getPoint1())+l2.getOffset())/dot(l2.getNormal(), l1.getDirection());
if(t < 0 || t > 1) {
return false;
}
t = -(dot(l1.getNormal(), l2.getPoint1())+l1.getOffset())/dot(l1.getNormal(), l2.getDirection());
if(t < 0 || t > 1) {
return false;
}
return true;
}
bool intersects(typename LineSegment<type>::Point& i, const LineSegment<type>& l1, const LineSegment<type>& l2) {
if(l1.m_degenerate || l2.m_degenerate) {
return false;
}
type t = -(dot(l2.getNormal(), l1.getPoint1)+l2.getOffset())/dot(l2.getNormal(), l1.getDirection());
if(t < 0 || t > 1) {
return false;
}
t = -(dot(l1.getNormal(), l2.getPoint1())+l1.getOffset())/dot(l1.getNormal(), l2.getDirection());
if(t < 0 || t > 1) {
return false;
}
i = lerp(l2.getPoint1(), l2.getPoint2(), t);
return true;
}
//==============================================================================
static Bool test(const LineSegment& ls, const Obb& obb)
{
F32 maxS = MIN_F32;
F32 minT = MAX_F32;
// compute difference vector
Vec4 diff = obb.getCenter() - ls.getOrigin();
// for each axis do
for(U i = 0; i < 3; ++i)
{
// get axis i
Vec4 axis = obb.getRotation().getColumn(i).xyz0();
// project relative vector onto axis
F32 e = axis.dot(diff);
F32 f = ls.getDirection().dot(axis);
// ray is parallel to plane
if(isZero(f))
{
// ray passes by box
if(-e - obb.getExtend()[i] > 0.0 || -e + obb.getExtend()[i] > 0.0)
{
return false;
}
continue;
}
F32 s = (e - obb.getExtend()[i]) / f;
F32 t = (e + obb.getExtend()[i]) / f;
// fix order
if(s > t)
{
F32 temp = s;
s = t;
t = temp;
}
// adjust min and max values
if(s > maxS)
{
maxS = s;
}
if(t < minT)
{
minT = t;
}
// check for intersection failure
if(minT < 0.0 || maxS > 1.0 || maxS > minT)
{
return false;
}
}
// done, have intersection
return true;
}
//==============================================================================
void CollisionDebugDrawer::visit(const LineSegment& ls)
{
m_dbg->setModelMatrix(Mat4::getIdentity());
m_dbg->begin(GL_LINES);
m_dbg->pushBackVertex(ls.getOrigin().xyz());
m_dbg->pushBackVertex((ls.getOrigin() + ls.getDirection()).xyz());
m_dbg->end();
}
//==============================================================================
Bool test(const LineSegment& ls, const Sphere& s)
{
const Vec4& v = ls.getDirection();
Vec4 w0 = s.getCenter() - ls.getOrigin();
F32 w0dv = w0.dot(v);
F32 rsq = s.getRadius() * s.getRadius();
if(w0dv < 0.0) // if the ang is >90
{
return w0.getLengthSquared() <= rsq;
}
Vec4 w1 = w0 - v; // aka center - P1, where P1 = seg.origin + seg.dir
F32 w1dv = w1.dot(v);
if(w1dv > 0.0) // if the ang is <90
{
return w1.getLengthSquared() <= rsq;
}
// the big parenthesis is the projection of w0 to v
Vec4 tmp = w0 - (v * (w0.dot(v) / v.getLengthSquared()));
return tmp.getLengthSquared() <= rsq;
}
