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Diffstat (limited to 'utils/sofa-support.cpp')
| -rw-r--r-- | utils/sofa-support.cpp | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/utils/sofa-support.cpp b/utils/sofa-support.cpp new file mode 100644 index 00000000..e37789d5 --- /dev/null +++ b/utils/sofa-support.cpp @@ -0,0 +1,292 @@ +/* + * SOFA utility methods for inspecting SOFA file metrics and determining HRTF + * utility compatible layouts. + * + * Copyright (C) 2018-2019 Christopher Fitzgerald + * Copyright (C) 2019 Christopher Robinson + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Or visit: http://www.gnu.org/licenses/old-licenses/gpl-2.0.html + */ + +#include "sofa-support.h" + +#include <stdio.h> + +#include <algorithm> +#include <array> +#include <cmath> +#include <utility> +#include <vector> + +#include "mysofa.h" + + +namespace { + +using uint = unsigned int; +using double3 = std::array<double,3>; + + +/* Produces a sorted array of unique elements from a particular axis of the + * triplets array. The filters are used to focus on particular coordinates + * of other axes as necessary. The epsilons are used to constrain the + * equality of unique elements. + */ +std::vector<double> GetUniquelySortedElems(const std::vector<double3> &aers, const uint axis, + const double *const (&filters)[3], const double (&epsilons)[3]) +{ + std::vector<double> elems; + for(const double3 &aer : aers) + { + const double elem{aer[axis]}; + + uint j; + for(j = 0;j < 3;j++) + { + if(filters[j] && std::abs(aer[j] - *filters[j]) > epsilons[j]) + break; + } + if(j < 3) + continue; + + auto iter = elems.begin(); + for(;iter != elems.end();++iter) + { + const double delta{elem - *iter}; + if(delta > epsilons[axis]) continue; + if(delta >= -epsilons[axis]) break; + + iter = elems.emplace(iter, elem); + break; + } + if(iter == elems.end()) + elems.emplace_back(elem); + } + return elems; +} + +/* Given a list of azimuths, this will produce the smallest step size that can + * uniformly cover the list. Ideally this will be over half, but in degenerate + * cases this can fall to a minimum of 5 (the lower limit). + */ +double GetUniformAzimStep(const double epsilon, const std::vector<double> &elems) +{ + if(elems.size() < 5) return 0.0; + + /* Get the maximum count possible, given the first two elements. It would + * be impossible to have more than this since the first element must be + * included. + */ + uint count{static_cast<uint>(std::ceil(360.0 / (elems[1]-elems[0])))}; + count = std::min(count, 255u); + + for(;count >= 5;--count) + { + /* Given the stepping value for this number of elements, check each + * multiple to ensure there's a matching element. + */ + const double step{360.0 / count}; + bool good{true}; + size_t idx{1u}; + for(uint mult{1u};mult < count && good;++mult) + { + const double target{step*mult + elems[0]}; + while(idx < elems.size() && target-elems[idx] > epsilon) + ++idx; + good &= (idx < elems.size()) && !(std::abs(target-elems[idx++]) > epsilon); + } + if(good) + return step; + } + return 0.0; +} + +/* Given a list of elevations, this will produce the smallest step size that + * can uniformly cover the list. Ideally this will be over half, but in + * degenerate cases this can fall to a minimum of 5 (the lower limit). + */ +double GetUniformElevStep(const double epsilon, std::vector<double> &elems) +{ + if(elems.size() < 5) return 0.0; + + /* Reverse the elevations so it increments starting with -90 (flipped from + * +90). This makes it easier to work out a proper stepping value. + */ + std::reverse(elems.begin(), elems.end()); + for(auto &v : elems) v *= -1.0; + + uint count{static_cast<uint>(std::ceil(180.0 / (elems[1]-elems[0])))}; + count = std::min(count, 255u); + + double ret{0.0}; + for(;count >= 5;--count) + { + const double step{180.0 / count}; + bool good{true}; + size_t idx{1u}; + /* Elevations don't need to match all multiples if there's not enough + * elements to check. Missing elevations can be synthesized. + */ + for(uint mult{1u};mult <= count && idx < elems.size() && good;++mult) + { + const double target{step*mult + elems[0]}; + while(idx < elems.size() && target-elems[idx] > epsilon) + ++idx; + good &= !(idx < elems.size()) || !(std::abs(target-elems[idx++]) > epsilon); + } + if(good) + { + ret = step; + break; + } + } + /* Re-reverse the elevations to restore the correct order. */ + for(auto &v : elems) v *= -1.0; + std::reverse(elems.begin(), elems.end()); + + return ret; +} + +} // namespace + + +const char *SofaErrorStr(int err) +{ + switch(err) + { + case MYSOFA_OK: return "OK"; + case MYSOFA_INVALID_FORMAT: return "Invalid format"; + case MYSOFA_UNSUPPORTED_FORMAT: return "Unsupported format"; + case MYSOFA_INTERNAL_ERROR: return "Internal error"; + case MYSOFA_NO_MEMORY: return "Out of memory"; + case MYSOFA_READ_ERROR: return "Read error"; + } + return "Unknown"; +} + +std::vector<SofaField> GetCompatibleLayout(const size_t m, const float *xyzs) +{ + auto aers = std::vector<double3>(m, double3{}); + for(size_t i{0u};i < m;++i) + { + float vals[3]{xyzs[i*3], xyzs[i*3 + 1], xyzs[i*3 + 2]}; + mysofa_c2s(&vals[0]); + aers[i] = {vals[0], vals[1], vals[2]}; + } + + auto radii = GetUniquelySortedElems(aers, 2, {}, {0.1, 0.1, 0.001}); + std::vector<SofaField> fds; + fds.reserve(radii.size()); + + for(const double dist : radii) + { + auto elevs = GetUniquelySortedElems(aers, 1, {nullptr, nullptr, &dist}, {0.1, 0.1, 0.001}); + + /* Remove elevations that don't have a valid set of azimuths. */ + auto invalid_elev = [&dist,&aers](const double ev) -> bool + { + auto azims = GetUniquelySortedElems(aers, 0, {nullptr, &ev, &dist}, {0.1, 0.1, 0.001}); + + if(std::abs(ev) > 89.999) + return azims.size() != 1; + if(azims.empty() || !(std::abs(azims[0]) < 0.1)) + return true; + return GetUniformAzimStep(0.1, azims) <= 0.0; + }; + elevs.erase(std::remove_if(elevs.begin(), elevs.end(), invalid_elev), elevs.end()); + + double step{GetUniformElevStep(0.1, elevs)}; + if(step <= 0.0) + { + if(elevs.empty()) + fprintf(stdout, "No usable elevations on field distance %f.\n", dist); + else + { + fprintf(stdout, "Non-uniform elevations on field distance %.3f.\nGot: %+.2f", dist, + elevs[0]); + for(size_t ei{1u};ei < elevs.size();++ei) + fprintf(stdout, ", %+.2f", elevs[ei]); + fputc('\n', stdout); + } + continue; + } + + uint evStart{0u}; + for(uint ei{0u};ei < elevs.size();ei++) + { + if(!(elevs[ei] < 0.0)) + { + fprintf(stdout, "Too many missing elevations on field distance %f.\n", dist); + return fds; + } + + double eif{(90.0+elevs[ei]) / step}; + const double ev_start{std::round(eif)}; + + if(std::abs(eif - ev_start) < (0.1/step)) + { + evStart = static_cast<uint>(ev_start); + break; + } + } + + const auto evCount = static_cast<uint>(std::round(180.0 / step)) + 1; + if(evCount < 5) + { + fprintf(stdout, "Too few uniform elevations on field distance %f.\n", dist); + continue; + } + + SofaField field{}; + field.mDistance = dist; + field.mEvCount = evCount; + field.mEvStart = evStart; + field.mAzCounts.resize(evCount, 0u); + auto &azCounts = field.mAzCounts; + + for(uint ei{evStart};ei < evCount;ei++) + { + double ev{-90.0 + ei*180.0/(evCount - 1)}; + auto azims = GetUniquelySortedElems(aers, 0, {nullptr, &ev, &dist}, {0.1, 0.1, 0.001}); + + if(ei == 0 || ei == (evCount-1)) + { + if(azims.size() != 1) + { + fprintf(stdout, "Non-singular poles on field distance %f.\n", dist); + return fds; + } + azCounts[ei] = 1; + } + else + { + step = GetUniformAzimStep(0.1, azims); + if(step <= 0.0) + { + fprintf(stdout, "Non-uniform azimuths on elevation %f, field distance %f.\n", + ev, dist); + return fds; + } + azCounts[ei] = static_cast<uint>(std::round(360.0f / step)); + } + } + + fds.emplace_back(std::move(field)); + } + + return fds; +} |