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Fixed the line-sphere intersection
The original implementation had the same mistakes than the ray-sphere intersection. Added two new 'out' parameters to return both intersection ponits. Changed the implementation to the geomethric method.
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@ -90,8 +90,9 @@ namespace glm
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template <typename genType>
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bool intersectLineSphere(
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genType const & point0, genType const & point1,
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genType const & center, typename genType::value_type radius,
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genType & position, genType & normal);
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genType const & sphereCenter, typename genType::value_type sphereRadius,
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genType & intersectionPosition1, genType & intersectionNormal1,
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genType & intersectionPosition2 = genType(), genType & intersectionNormal2 = genType());
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/// @}
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}//namespace glm
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@ -170,33 +170,27 @@ namespace glm
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GLM_FUNC_QUALIFIER bool intersectLineSphere
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(
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genType const & point0, genType const & point1,
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genType const & center, typename genType::value_type radius,
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genType & position, genType & normal
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genType const & sphereCenter, typename genType::value_type sphereRadius,
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genType & intersectionPoint1, genType & intersectionNormal1,
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genType & intersectionPoint2, genType & intersectionNormal2
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)
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{
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typename genType::value_type Epsilon = std::numeric_limits<typename genType::value_type>::epsilon();
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genType dir = point1 - point0;
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typename genType::value_type a = dot(dir, dir);
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typename genType::value_type b = typename genType::value_type(2) * dot(center, dir);
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typename genType::value_type c = dot(center, center) - radius * radius;
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typename genType::value_type d = b * b - typename genType::value_type(4) * a * c;
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typename genType::value_type e = sqrt(d);
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typename genType::value_type x1 = (-b - e) / (typename genType::value_type(2) * a);
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typename genType::value_type x2 = (-b + e) / (typename genType::value_type(2) * a);
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if(x1 > Epsilon)
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genType dir = normalize(point1 - point0);
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genType diff = sphereCenter - point0;
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typename genType::value_type t0 = dot(diff, dir);
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typename genType::value_type dSquared = dot(diff, diff) - t0 * t0;
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if( dSquared > sphereRadius * sphereRadius )
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{
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position = center + dir * radius;
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normal = (position - center) / radius;
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return true;
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return false;
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}
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else if(x2 > Epsilon)
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{
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position = center + dir * radius;
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normal = (position - center) / radius;
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return true;
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}
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return false;
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typename genType::value_type t1 = sqrt( sphereRadius * sphereRadius - dSquared );
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if( t0 < t1 + Epsilon )
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t1 = -t1;
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intersectionPoint1 = point0 + dir * (t0 - t1);
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intersectionNormal1 = (intersectionPoint1 - sphereCenter) / sphereRadius;
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intersectionPoint2 = point0 + dir * (t0 + t1);
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intersectionNormal2 = (intersectionPoint2 - sphereCenter) / sphereRadius;
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return true;
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}
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}//namespace glm
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