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Diffstat (limited to 'Project/glm/gtx/quaternion.inl')
| -rw-r--r-- | Project/glm/gtx/quaternion.inl | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/Project/glm/gtx/quaternion.inl b/Project/glm/gtx/quaternion.inl new file mode 100644 index 0000000..d125bcc --- /dev/null +++ b/Project/glm/gtx/quaternion.inl @@ -0,0 +1,159 @@ +/// @ref gtx_quaternion + +#include <limits> +#include "../gtc/constants.hpp" + +namespace glm +{ + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q> quat_identity() + { + return qua<T, Q>(static_cast<T>(1), static_cast<T>(0), static_cast<T>(0), static_cast<T>(0)); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<3, T, Q> cross(vec<3, T, Q> const& v, qua<T, Q> const& q) + { + return inverse(q) * v; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<3, T, Q> cross(qua<T, Q> const& q, vec<3, T, Q> const& v) + { + return q * v; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER qua<T, Q> squad + ( + qua<T, Q> const& q1, + qua<T, Q> const& q2, + qua<T, Q> const& s1, + qua<T, Q> const& s2, + T const& h) + { + return mix(mix(q1, q2, h), mix(s1, s2, h), static_cast<T>(2) * (static_cast<T>(1) - h) * h); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER qua<T, Q> intermediate + ( + qua<T, Q> const& prev, + qua<T, Q> const& curr, + qua<T, Q> const& next + ) + { + qua<T, Q> invQuat = inverse(curr); + return exp((log(next * invQuat) + log(prev * invQuat)) / static_cast<T>(-4)) * curr; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<3, T, Q> rotate(qua<T, Q> const& q, vec<3, T, Q> const& v) + { + return q * v; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<4, T, Q> rotate(qua<T, Q> const& q, vec<4, T, Q> const& v) + { + return q * v; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER T extractRealComponent(qua<T, Q> const& q) + { + T w = static_cast<T>(1) - q.x * q.x - q.y * q.y - q.z * q.z; + if(w < T(0)) + return T(0); + else + return -sqrt(w); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER GLM_CONSTEXPR T length2(qua<T, Q> const& q) + { + return q.x * q.x + q.y * q.y + q.z * q.z + q.w * q.w; + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER qua<T, Q> shortMix(qua<T, Q> const& x, qua<T, Q> const& y, T const& a) + { + if(a <= static_cast<T>(0)) return x; + if(a >= static_cast<T>(1)) return y; + + T fCos = dot(x, y); + qua<T, Q> y2(y); //BUG!!! qua<T> y2; + if(fCos < static_cast<T>(0)) + { + y2 = -y; + fCos = -fCos; + } + + //if(fCos > 1.0f) // problem + T k0, k1; + if(fCos > (static_cast<T>(1) - epsilon<T>())) + { + k0 = static_cast<T>(1) - a; + k1 = static_cast<T>(0) + a; //BUG!!! 1.0f + a; + } + else + { + T fSin = sqrt(T(1) - fCos * fCos); + T fAngle = atan(fSin, fCos); + T fOneOverSin = static_cast<T>(1) / fSin; + k0 = sin((static_cast<T>(1) - a) * fAngle) * fOneOverSin; + k1 = sin((static_cast<T>(0) + a) * fAngle) * fOneOverSin; + } + + return qua<T, Q>( + k0 * x.w + k1 * y2.w, + k0 * x.x + k1 * y2.x, + k0 * x.y + k1 * y2.y, + k0 * x.z + k1 * y2.z); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER qua<T, Q> fastMix(qua<T, Q> const& x, qua<T, Q> const& y, T const& a) + { + return glm::normalize(x * (static_cast<T>(1) - a) + (y * a)); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER qua<T, Q> rotation(vec<3, T, Q> const& orig, vec<3, T, Q> const& dest) + { + T cosTheta = dot(orig, dest); + vec<3, T, Q> rotationAxis; + + if(cosTheta >= static_cast<T>(1) - epsilon<T>()) { + // orig and dest point in the same direction + return quat_identity<T,Q>(); + } + + if(cosTheta < static_cast<T>(-1) + epsilon<T>()) + { + // special case when vectors in opposite directions : + // there is no "ideal" rotation axis + // So guess one; any will do as long as it's perpendicular to start + // This implementation favors a rotation around the Up axis (Y), + // since it's often what you want to do. + rotationAxis = cross(vec<3, T, Q>(0, 0, 1), orig); + if(length2(rotationAxis) < epsilon<T>()) // bad luck, they were parallel, try again! + rotationAxis = cross(vec<3, T, Q>(1, 0, 0), orig); + + rotationAxis = normalize(rotationAxis); + return angleAxis(pi<T>(), rotationAxis); + } + + // Implementation from Stan Melax's Game Programming Gems 1 article + rotationAxis = cross(orig, dest); + + T s = sqrt((T(1) + cosTheta) * static_cast<T>(2)); + T invs = static_cast<T>(1) / s; + + return qua<T, Q>( + s * static_cast<T>(0.5f), + rotationAxis.x * invs, + rotationAxis.y * invs, + rotationAxis.z * invs); + } +}//namespace glm |