1 /* 2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "webrtc/modules/audio_processing/beamformer/array_util.h" 12 13 #include <algorithm> 14 #include <limits> 15 16 #include "webrtc/base/checks.h" 17 18 namespace webrtc { 19 namespace { 20 21 const float kMaxDotProduct = 1e-6f; 22 23 } // namespace 24 25 float GetMinimumSpacing(const std::vector<Point>& array_geometry) { 26 RTC_CHECK_GT(array_geometry.size(), 1u); 27 float mic_spacing = std::numeric_limits<float>::max(); 28 for (size_t i = 0; i < (array_geometry.size() - 1); ++i) { 29 for (size_t j = i + 1; j < array_geometry.size(); ++j) { 30 mic_spacing = 31 std::min(mic_spacing, Distance(array_geometry[i], array_geometry[j])); 32 } 33 } 34 return mic_spacing; 35 } 36 37 Point PairDirection(const Point& a, const Point& b) { 38 return {b.x() - a.x(), b.y() - a.y(), b.z() - a.z()}; 39 } 40 41 float DotProduct(const Point& a, const Point& b) { 42 return a.x() * b.x() + a.y() * b.y() + a.z() * b.z(); 43 } 44 45 Point CrossProduct(const Point& a, const Point& b) { 46 return {a.y() * b.z() - a.z() * b.y(), a.z() * b.x() - a.x() * b.z(), 47 a.x() * b.y() - a.y() * b.x()}; 48 } 49 50 bool AreParallel(const Point& a, const Point& b) { 51 Point cross_product = CrossProduct(a, b); 52 return DotProduct(cross_product, cross_product) < kMaxDotProduct; 53 } 54 55 bool ArePerpendicular(const Point& a, const Point& b) { 56 return std::abs(DotProduct(a, b)) < kMaxDotProduct; 57 } 58 59 rtc::Optional<Point> GetDirectionIfLinear( 60 const std::vector<Point>& array_geometry) { 61 RTC_DCHECK_GT(array_geometry.size(), 1u); 62 const Point first_pair_direction = 63 PairDirection(array_geometry[0], array_geometry[1]); 64 for (size_t i = 2u; i < array_geometry.size(); ++i) { 65 const Point pair_direction = 66 PairDirection(array_geometry[i - 1], array_geometry[i]); 67 if (!AreParallel(first_pair_direction, pair_direction)) { 68 return rtc::Optional<Point>(); 69 } 70 } 71 return rtc::Optional<Point>(first_pair_direction); 72 } 73 74 rtc::Optional<Point> GetNormalIfPlanar( 75 const std::vector<Point>& array_geometry) { 76 RTC_DCHECK_GT(array_geometry.size(), 1u); 77 const Point first_pair_direction = 78 PairDirection(array_geometry[0], array_geometry[1]); 79 Point pair_direction(0.f, 0.f, 0.f); 80 size_t i = 2u; 81 bool is_linear = true; 82 for (; i < array_geometry.size() && is_linear; ++i) { 83 pair_direction = PairDirection(array_geometry[i - 1], array_geometry[i]); 84 if (!AreParallel(first_pair_direction, pair_direction)) { 85 is_linear = false; 86 } 87 } 88 if (is_linear) { 89 return rtc::Optional<Point>(); 90 } 91 const Point normal_direction = 92 CrossProduct(first_pair_direction, pair_direction); 93 for (; i < array_geometry.size(); ++i) { 94 pair_direction = PairDirection(array_geometry[i - 1], array_geometry[i]); 95 if (!ArePerpendicular(normal_direction, pair_direction)) { 96 return rtc::Optional<Point>(); 97 } 98 } 99 return rtc::Optional<Point>(normal_direction); 100 } 101 102 rtc::Optional<Point> GetArrayNormalIfExists( 103 const std::vector<Point>& array_geometry) { 104 const rtc::Optional<Point> direction = GetDirectionIfLinear(array_geometry); 105 if (direction) { 106 return rtc::Optional<Point>(Point(direction->y(), -direction->x(), 0.f)); 107 } 108 const rtc::Optional<Point> normal = GetNormalIfPlanar(array_geometry); 109 if (normal && normal->z() < kMaxDotProduct) { 110 return normal; 111 } 112 return rtc::Optional<Point>(); 113 } 114 115 Point AzimuthToPoint(float azimuth) { 116 return Point(std::cos(azimuth), std::sin(azimuth), 0.f); 117 } 118 119 } // namespace webrtc 120
