int BasicPrimitiveTests::IntersectingSegmentAgainstOBB(const LineSegment & segment, const OBB & obb, float & rtn_t1, float & rtn_t2)
{
Eigen::Matrix3f obb_rotation;
obb.GetRotationMatrix(obb_rotation);
Eigen::Vector3f segment_A_obb = obb_rotation * (segment.GetPointA() - obb.GetCenter());
Eigen::Vector3f segment_B_obb = obb_rotation * (segment.GetPointB() - obb.GetCenter());
rtn_t1 = 0.0f;
rtn_t2 = FLT_MAX;
Eigen::Vector3f aabb_min = -obb.GetExtents();
Eigen::Vector3f aabb_max = obb.GetExtents();
Eigen::Vector3f segment_direction = segment_B_obb - segment_A_obb;
for (int i = 0; i < 3; ++i)
{
if (abs(segment_direction[i]) < EPSILON)
{
//Ray is parallel to slab. Not hit if origin not within slab.
if (segment_A_obb[i] < aabb_min[i] || segment_A_obb[i] > aabb_max[i])
{
return 0;
}
}
else
{
float one_over_direction = 1.0f / segment_direction[i];
float t1 = (aabb_min[i] - segment_A_obb[i]) * one_over_direction;
float t2 = (aabb_max[i] - segment_A_obb[i]) * one_over_direction;
if (t1 > 1.0f && t2 > 1.0f)
{
return 0;
}
if (t1 > t2) Swap(t1, t2);
if (t1 > rtn_t1) rtn_t1 = t1;
if (t2 > rtn_t2) rtn_t2 = t2;
if (rtn_t1 > rtn_t2) return 0;
}
}
if (rtn_t1 >= 0.0f && rtn_t1 <= 1.0f)
{
if (rtn_t2 >= 0.0f && rtn_t2 <= 1.0f)
{
return 2;
}
else
{
return 1;
}
}
else
{
Swap(rtn_t1, rtn_t2);
if (rtn_t1 >= 0.0f && rtn_t1 <= 1.0f)
{
return 1;
}
return 0;
}
}
bool BasicPrimitiveTests::IntersectingRayAgainstOBB(const Ray & ray, const OBB & obb, float & rtn_t)
{
Eigen::Matrix3f obb_rotation;
obb.GetRotationMatrix(obb_rotation);
Eigen::Vector3f ray_d_obb = obb_rotation * ray.GetDirection();
Eigen::Vector3f ray_o_obb = obb_rotation * (ray.GetOrigin() - obb.GetCenter());
rtn_t = 0.0f;
float tmax = FLT_MAX;
Eigen::Vector3f aabb_min = -obb.GetExtents();
Eigen::Vector3f aabb_max = obb.GetExtents();
for (int i = 0; i < 3; ++i)
{
if (abs(ray_d_obb[i]) < EPSILON)
{
//Ray is parallel to slab. Not hit if origin not within slab.
if (ray_o_obb[i] < aabb_min[i] || ray_o_obb[i] > aabb_max[i])
{
return false;
}
}
else
{
float one_over_direction = 1.0f / ray_d_obb[i];
float t1 = (aabb_min[i] - ray_o_obb[i]) * one_over_direction;
float t2 = (aabb_max[i] - ray_o_obb[i]) * one_over_direction;
if (t1 > t2) Swap(t1, t2);
if (t1 > rtn_t) rtn_t = t1;
if (t2 > tmax) tmax = t2;
if (rtn_t > tmax) return false;
}
}
return true;
}