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Diffstat (limited to 'external/include/glm/gtx/quaternion.inl')
| -rw-r--r-- | external/include/glm/gtx/quaternion.inl | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/external/include/glm/gtx/quaternion.inl b/external/include/glm/gtx/quaternion.inl new file mode 100644 index 0000000..c86ec18 --- /dev/null +++ b/external/include/glm/gtx/quaternion.inl @@ -0,0 +1,212 @@ +/// @ref gtx_quaternion +/// @file glm/gtx/quaternion.inl + +#include <limits> +#include "../gtc/constants.hpp" + +namespace glm +{ + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec3<T, P> cross(tvec3<T, P> const& v, tquat<T, P> const& q) + { + return inverse(q) * v; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec3<T, P> cross(tquat<T, P> const& q, tvec3<T, P> const& v) + { + return q * v; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> squad + ( + tquat<T, P> const & q1, + tquat<T, P> const & q2, + tquat<T, P> const & s1, + tquat<T, P> 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, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> intermediate + ( + tquat<T, P> const & prev, + tquat<T, P> const & curr, + tquat<T, P> const & next + ) + { + tquat<T, P> invQuat = inverse(curr); + return exp((log(next + invQuat) + log(prev + invQuat)) / static_cast<T>(-4)) * curr; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> exp(tquat<T, P> const& q) + { + tvec3<T, P> u(q.x, q.y, q.z); + T const Angle = glm::length(u); + if (Angle < epsilon<T>()) + return tquat<T, P>(); + + tvec3<T, P> const v(u / Angle); + return tquat<T, P>(cos(Angle), sin(Angle) * v); + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> log(tquat<T, P> const& q) + { + tvec3<T, P> u(q.x, q.y, q.z); + T Vec3Len = length(u); + + if (Vec3Len < epsilon<T>()) + { + if(q.w > static_cast<T>(0)) + return tquat<T, P>(log(q.w), static_cast<T>(0), static_cast<T>(0), static_cast<T>(0)); + else if(q.w < static_cast<T>(0)) + return tquat<T, P>(log(-q.w), pi<T>(), static_cast<T>(0), static_cast<T>(0)); + else + return tquat<T, P>(std::numeric_limits<T>::infinity(), std::numeric_limits<T>::infinity(), std::numeric_limits<T>::infinity(), std::numeric_limits<T>::infinity()); + } + else + { + T t = atan(Vec3Len, T(q.w)) / Vec3Len; + T QuatLen2 = Vec3Len * Vec3Len + q.w * q.w; + return tquat<T, P>(static_cast<T>(0.5) * log(QuatLen2), t * q.x, t * q.y, t * q.z); + } + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> pow(tquat<T, P> const & x, T const & y) + { + //Raising to the power of 0 should yield 1 + //Needed to prevent a division by 0 error later on + if(y > -epsilon<T>() && y < epsilon<T>()) + return tquat<T, P>(1,0,0,0); + + //To deal with non-unit quaternions + T magnitude = sqrt(x.x * x.x + x.y * x.y + x.z * x.z + x.w *x.w); + + //Equivalent to raising a real number to a power + //Needed to prevent a division by 0 error later on + if(abs(x.w / magnitude) > static_cast<T>(1) - epsilon<T>() && abs(x.w / magnitude) < static_cast<T>(1) + epsilon<T>()) + return tquat<T, P>(pow(x.w, y),0,0,0); + + T Angle = acos(x.w / magnitude); + T NewAngle = Angle * y; + T Div = sin(NewAngle) / sin(Angle); + T Mag = pow(magnitude, y - static_cast<T>(1)); + + return tquat<T, P>(cos(NewAngle) * magnitude * Mag, x.x * Div * Mag, x.y * Div * Mag, x.z * Div * Mag); + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec3<T, P> rotate(tquat<T, P> const& q, tvec3<T, P> const& v) + { + return q * v; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec4<T, P> rotate(tquat<T, P> const& q, tvec4<T, P> const& v) + { + return q * v; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER T extractRealComponent(tquat<T, P> 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, precision P> + GLM_FUNC_QUALIFIER T length2(tquat<T, P> const& q) + { + return q.x * q.x + q.y * q.y + q.z * q.z + q.w * q.w; + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> shortMix(tquat<T, P> const& x, tquat<T, P> 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); + tquat<T, P> y2(y); //BUG!!! tquat<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 tquat<T, P>( + 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, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> fastMix(tquat<T, P> const& x, tquat<T, P> const& y, T const & a) + { + return glm::normalize(x * (static_cast<T>(1) - a) + (y * a)); + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tquat<T, P> rotation(tvec3<T, P> const& orig, tvec3<T, P> const& dest) + { + T cosTheta = dot(orig, dest); + tvec3<T, P> rotationAxis; + + if(cosTheta >= static_cast<T>(1) - epsilon<T>()) + return quat(); + + 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(tvec3<T, P>(0, 0, 1), orig); + if(length2(rotationAxis) < epsilon<T>()) // bad luck, they were parallel, try again! + rotationAxis = cross(tvec3<T, P>(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 tquat<T, P>( + s * static_cast<T>(0.5f), + rotationAxis.x * invs, + rotationAxis.y * invs, + rotationAxis.z * invs); + } + +}//namespace glm |