VectorAnalysis.h 6.72 KB
 Kenneth Moreland committed Jul 07, 2015 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 ``````//============================================================================= // // Copyright (c) Kitware, Inc. // All rights reserved. // See LICENSE.txt for details. // // This software is distributed WITHOUT ANY WARRANTY; without even // the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR // PURPOSE. See the above copyright notice for more information. // // Copyright 2015 Sandia Corporation. // Copyright 2015 UT-Battelle, LLC. // Copyright 2015 Los Alamos National Security. // // Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, // the U.S. Government retains certain rights in this software. // Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National // Laboratory (LANL), the U.S. Government retains certain rights in // this software. // //============================================================================= #ifndef vtk_m_VectorAnalysis_h #define vtk_m_VectorAnalysis_h // This header file defines math functions that deal with linear albegra funcitons #include #include #include #include namespace vtkm { // ---------------------------------------------------------------------------- /// \brief Returns the linear interpolation of two values based on weight /// /// \c Lerp interpolates return the linerar interpolation of v0 and v1 based on w. v0 /// and v1 are scalars or vectors of same length. w can either be a scalar or a /// vector of the same length as x and y. If w is outside [0,1] then lerp /// extrapolates. If w=0 => v0 is returned if w=1 => v1 is returned. /// `````` Kenneth Moreland committed Aug 27, 2015 43 ``````template `````` Kenneth Moreland committed Jul 07, 2015 44 ``````VTKM_EXEC_CONT_EXPORT `````` Kenneth Moreland committed Aug 27, 2015 45 46 47 ``````ValueType Lerp(const ValueType &value0, const ValueType & value1, const WeightType &weight) `````` Kenneth Moreland committed Jul 07, 2015 48 ``````{ `````` Kenneth Moreland committed Aug 27, 2015 49 `````` return static_cast(value0 + weight * (value1-value0)); `````` Kenneth Moreland committed Jul 07, 2015 50 ``````} `````` Kenneth Moreland committed Aug 27, 2015 51 ``````template `````` Kenneth Moreland committed Jul 07, 2015 52 ``````VTKM_EXEC_CONT_EXPORT `````` Kenneth Moreland committed Aug 27, 2015 53 54 55 ``````vtkm::Vec Lerp(const vtkm::Vec &value0, const vtkm::Vec &value1, const WeightType &weight) `````` Kenneth Moreland committed Jul 07, 2015 56 ``````{ `````` Kenneth Moreland committed Aug 27, 2015 57 58 59 60 61 62 63 64 65 `````` return value0 + static_cast(weight) * (value1-value0); } template VTKM_EXEC_CONT_EXPORT vtkm::Vec Lerp(const vtkm::Vec &value0, const vtkm::Vec &value1, const vtkm::Vec &weight) { return value0 + weight * (value1-value0); `````` Kenneth Moreland committed Jul 07, 2015 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 ``````} // ---------------------------------------------------------------------------- /// \brief Returns the square of the magnitude of a vector. /// /// It is usually much faster to compute the square of the magnitude than the /// square, so you should use this function in place of Magnitude or RMagnitude /// when possible. /// template VTKM_EXEC_CONT_EXPORT typename vtkm::VecTraits::ComponentType MagnitudeSquared(const T &x) { return vtkm::dot(x,x); } // ---------------------------------------------------------------------------- namespace detail { template VTKM_EXEC_CONT_EXPORT T MagnitudeTemplate(T x, vtkm::TypeTraitsScalarTag) { return vtkm::Abs(x); } template VTKM_EXEC_CONT_EXPORT typename vtkm::VecTraits::ComponentType MagnitudeTemplate(const T &x, vtkm::TypeTraitsVectorTag) { return vtkm::Sqrt(vtkm::MagnitudeSquared(x)); } } // namespace detail /// \brief Returns the magnitude of a vector. /// /// It is usually much faster to compute MagnitudeSquared, so that should be /// substituted when possible (unless you are just going to take the square /// root, which would be besides the point). On some hardware it is also faster /// to find the reciprocal magnitude, so RMagnitude should be used if you /// actually plan to divide by the magnitude. /// template typename vtkm::VecTraits::ComponentType Magnitude(const T &x) { return detail::MagnitudeTemplate( x, typename vtkm::TypeTraits::DimensionalityTag()); } // ---------------------------------------------------------------------------- namespace detail { template VTKM_EXEC_CONT_EXPORT T RMagnitudeTemplate(T x, vtkm::TypeTraitsScalarTag) { return T(1)/vtkm::Abs(x); } template VTKM_EXEC_CONT_EXPORT typename vtkm::VecTraits::ComponentType RMagnitudeTemplate(const T &x, vtkm::TypeTraitsVectorTag) { return vtkm::RSqrt(vtkm::MagnitudeSquared(x)); } } // namespace detail /// \brief Returns the reciprocal magnitude of a vector. /// /// On some hardware RMagnitude is faster than Magnitude, but neither is /// as fast as MagnitudeSquared. /// template typename vtkm::VecTraits::ComponentType RMagnitude(const T &x) { return detail::RMagnitudeTemplate( x, typename vtkm::TypeTraits::DimensionalityTag()); } // ---------------------------------------------------------------------------- namespace detail { template VTKM_EXEC_CONT_EXPORT T NormalTemplate(T x, vtkm::TypeTraitsScalarTag) { return vtkm::CopySign(T(1), x); } template VTKM_EXEC_CONT_EXPORT T NormalTemplate(const T &x, vtkm::TypeTraitsVectorTag) { return vtkm::RMagnitude(x)*x; } } // namespace detail /// \brief Returns a normalized version of the given vector. /// /// The resulting vector points in the same direction but has unit length. /// template VTKM_EXEC_CONT_EXPORT T Normal(const T &x) { return detail::NormalTemplate( x, typename vtkm::TypeTraits::DimensionalityTag()); } // ---------------------------------------------------------------------------- /// \brief Changes a vector to be normal. /// /// The given vector is scaled to be unit length. /// template VTKM_EXEC_CONT_EXPORT void Normalize(T &x) { x = vtkm::Normal(x); } // ---------------------------------------------------------------------------- /// \brief Find the cross product of two vectors. /// template VTKM_EXEC_CONT_EXPORT vtkm::Vec Cross(const vtkm::Vec &x, const vtkm::Vec &y) { return vtkm::Vec(x[1]*y[2] - x[2]*y[1], x[2]*y[0] - x[0]*y[2], x[0]*y[1] - x[1]*y[0]); } //----------------------------------------------------------------------------- /// \brief Find the normal of a triangle. /// /// Given three coordinates in space, which, unless degenerate, uniquely define /// a triangle and the plane the triangle is on, returns a vector perpendicular /// to that triangle/plane. /// template VTKM_EXEC_CONT_EXPORT vtkm::Vec TriangleNormal(const vtkm::Vec &a, const vtkm::Vec &b, const vtkm::Vec &c) { return vtkm::Cross(b-a, c-a); } } // namespace vtkm #endif //vtk_m_VectorAnalysis_h``````