// Ceres Solver - A fast non-linear least squares minimizer // Copyright 2023 Google Inc. All rights reserved. // http://ceres-solver.org/ // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // * Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation // and/or other materials provided with the distribution. // * Neither the name of Google Inc. nor the names of its contributors may be // used to endorse or promote products derived from this software without // specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. // // Author: jodebo_beck@gmx.de (Johannes Beck) #ifndef CERES_PUBLIC_INTERNAL_PARAMETER_DIMS_H_ #define CERES_PUBLIC_INTERNAL_PARAMETER_DIMS_H_ #include <array> #include <utility> #include "ceres/internal/integer_sequence_algorithm.h" namespace ceres::internal { // Helper class that represents the parameter dimensions. The parameter // dimensions are either dynamic or the sizes are known at compile time. It is // used to pass parameter block dimensions around (e.g. between functions or // classes). // // As an example if one have three parameter blocks with dimensions (2, 4, 1), // one would use 'StaticParameterDims<2, 4, 1>' which is a synonym for // 'ParameterDims<false, 2, 4, 1>'. // For dynamic parameter dims, one would just use 'DynamicParameterDims', which // is a synonym for 'ParameterDims<true>'. template <bool IsDynamic, int... Ns> class ParameterDims { public: using Parameters = std::integer_sequence<int, Ns...>; // The parameter dimensions are only valid if all parameter block dimensions // are greater than zero. static constexpr bool kIsValid = ((Ns > 0) && ...); static_assert(kIsValid, "Invalid parameter block dimension detected. Each parameter " "block dimension must be bigger than zero."); static constexpr bool kIsDynamic = IsDynamic; static constexpr int kNumParameterBlocks = sizeof...(Ns); static_assert(kIsDynamic || kNumParameterBlocks > 0, "At least one parameter block must be specified."); static constexpr int kNumParameters = (Ns + ... + 0); static constexpr int GetDim(int dim) { return params_[dim]; } // If one has all parameters packed into a single array this function unpacks // the parameters. template <typename T> static inline std::array<T*, kNumParameterBlocks> GetUnpackedParameters( T* ptr) { using Offsets = ExclusiveScan<Parameters>; return GetUnpackedParameters(ptr, Offsets()); } private: template <typename T, int... Indices> static inline std::array<T*, kNumParameterBlocks> GetUnpackedParameters( T* ptr, std::integer_sequence<int, Indices...>) { return std::array<T*, kNumParameterBlocks>{{ptr + Indices...}}; } static constexpr std::array<int, kNumParameterBlocks> params_{Ns...}; }; // Even static constexpr member variables needs to be defined (not only // declared). As the ParameterDims class is tempalted this definition must // be in the header file. template <bool IsDynamic, int... Ns> constexpr std::array<int, ParameterDims<IsDynamic, Ns...>::kNumParameterBlocks> ParameterDims<IsDynamic, Ns...>::params_; // Using declarations for static and dynamic parameter dims. This makes client // code easier to read. template <int... Ns> using StaticParameterDims = ParameterDims<false, Ns...>; using DynamicParameterDims = ParameterDims<true>; } // namespace ceres::internal #endif // CERES_PUBLIC_INTERNAL_PARAMETER_DIMS_H_