diff --git a/glm/gtx/intersect.hpp b/glm/gtx/intersect.hpp index 56aabbc9..132fa7e1 100644 --- a/glm/gtx/intersect.hpp +++ b/glm/gtx/intersect.hpp @@ -90,8 +90,9 @@ namespace glm template bool intersectLineSphere( genType const & point0, genType const & point1, - genType const & center, typename genType::value_type radius, - genType & position, genType & normal); + genType const & sphereCenter, typename genType::value_type sphereRadius, + genType & intersectionPosition1, genType & intersectionNormal1, + genType & intersectionPosition2 = genType(), genType & intersectionNormal2 = genType()); /// @} }//namespace glm diff --git a/glm/gtx/intersect.inl b/glm/gtx/intersect.inl index 3c8527e7..9e361f16 100644 --- a/glm/gtx/intersect.inl +++ b/glm/gtx/intersect.inl @@ -170,33 +170,27 @@ namespace glm GLM_FUNC_QUALIFIER bool intersectLineSphere ( genType const & point0, genType const & point1, - genType const & center, typename genType::value_type radius, - genType & position, genType & normal + genType const & sphereCenter, typename genType::value_type sphereRadius, + genType & intersectionPoint1, genType & intersectionNormal1, + genType & intersectionPoint2, genType & intersectionNormal2 ) { typename genType::value_type Epsilon = std::numeric_limits::epsilon(); - - genType dir = point1 - point0; - typename genType::value_type a = dot(dir, dir); - typename genType::value_type b = typename genType::value_type(2) * dot(center, dir); - typename genType::value_type c = dot(center, center) - radius * radius; - typename genType::value_type d = b * b - typename genType::value_type(4) * a * c; - typename genType::value_type e = sqrt(d); - typename genType::value_type x1 = (-b - e) / (typename genType::value_type(2) * a); - typename genType::value_type x2 = (-b + e) / (typename genType::value_type(2) * a); - - if(x1 > Epsilon) + genType dir = normalize(point1 - point0); + genType diff = sphereCenter - point0; + typename genType::value_type t0 = dot(diff, dir); + typename genType::value_type dSquared = dot(diff, diff) - t0 * t0; + if( dSquared > sphereRadius * sphereRadius ) { - position = center + dir * radius; - normal = (position - center) / radius; - return true; + return false; } - else if(x2 > Epsilon) - { - position = center + dir * radius; - normal = (position - center) / radius; - return true; - } - return false; + typename genType::value_type t1 = sqrt( sphereRadius * sphereRadius - dSquared ); + if( t0 < t1 + Epsilon ) + t1 = -t1; + intersectionPoint1 = point0 + dir * (t0 - t1); + intersectionNormal1 = (intersectionPoint1 - sphereCenter) / sphereRadius; + intersectionPoint2 = point0 + dir * (t0 + t1); + intersectionNormal2 = (intersectionPoint2 - sphereCenter) / sphereRadius; + return true; } }//namespace glm