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 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_ARRAY_UTIL_H_
12 #define WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_ARRAY_UTIL_H_
13
14 #include <cmath>
15 #include <vector>
16
17 #include "webrtc/base/optional.h"
18
19 namespace webrtc {
20
21 // Coordinates in meters. The convention used is:
22 // x: the horizontal dimension, with positive to the right from the camera's
23 // perspective.
24 // y: the depth dimension, with positive forward from the camera's
25 // perspective.
26 // z: the vertical dimension, with positive upwards.
27 template<typename T>
28 struct CartesianPoint {
CartesianPointCartesianPoint29 CartesianPoint() {
30 c[0] = 0;
31 c[1] = 0;
32 c[2] = 0;
33 }
CartesianPointCartesianPoint34 CartesianPoint(T x, T y, T z) {
35 c[0] = x;
36 c[1] = y;
37 c[2] = z;
38 }
xCartesianPoint39 T x() const { return c[0]; }
yCartesianPoint40 T y() const { return c[1]; }
zCartesianPoint41 T z() const { return c[2]; }
42 T c[3];
43 };
44
45 using Point = CartesianPoint<float>;
46
47 // Calculates the direction from a to b.
48 Point PairDirection(const Point& a, const Point& b);
49
50 float DotProduct(const Point& a, const Point& b);
51 Point CrossProduct(const Point& a, const Point& b);
52
53 bool AreParallel(const Point& a, const Point& b);
54 bool ArePerpendicular(const Point& a, const Point& b);
55
56 // Returns the minimum distance between any two Points in the given
57 // |array_geometry|.
58 float GetMinimumSpacing(const std::vector<Point>& array_geometry);
59
60 // If the given array geometry is linear it returns the direction without
61 // normalizing.
62 rtc::Optional<Point> GetDirectionIfLinear(
63 const std::vector<Point>& array_geometry);
64
65 // If the given array geometry is planar it returns the normal without
66 // normalizing.
67 rtc::Optional<Point> GetNormalIfPlanar(
68 const std::vector<Point>& array_geometry);
69
70 // Returns the normal of an array if it has one and it is in the xy-plane.
71 rtc::Optional<Point> GetArrayNormalIfExists(
72 const std::vector<Point>& array_geometry);
73
74 // The resulting Point will be in the xy-plane.
75 Point AzimuthToPoint(float azimuth);
76
77 template<typename T>
Distance(CartesianPoint<T> a,CartesianPoint<T> b)78 float Distance(CartesianPoint<T> a, CartesianPoint<T> b) {
79 return std::sqrt((a.x() - b.x()) * (a.x() - b.x()) +
80 (a.y() - b.y()) * (a.y() - b.y()) +
81 (a.z() - b.z()) * (a.z() - b.z()));
82 }
83
84 // The convention used:
85 // azimuth: zero is to the right from the camera's perspective, with positive
86 // angles in radians counter-clockwise.
87 // elevation: zero is horizontal, with positive angles in radians upwards.
88 // radius: distance from the camera in meters.
89 template <typename T>
90 struct SphericalPoint {
SphericalPointSphericalPoint91 SphericalPoint(T azimuth, T elevation, T radius) {
92 s[0] = azimuth;
93 s[1] = elevation;
94 s[2] = radius;
95 }
azimuthSphericalPoint96 T azimuth() const { return s[0]; }
elevationSphericalPoint97 T elevation() const { return s[1]; }
distanceSphericalPoint98 T distance() const { return s[2]; }
99 T s[3];
100 };
101
102 using SphericalPointf = SphericalPoint<float>;
103
104 // Helper functions to transform degrees to radians and the inverse.
105 template <typename T>
DegreesToRadians(T angle_degrees)106 T DegreesToRadians(T angle_degrees) {
107 return M_PI * angle_degrees / 180;
108 }
109
110 template <typename T>
RadiansToDegrees(T angle_radians)111 T RadiansToDegrees(T angle_radians) {
112 return 180 * angle_radians / M_PI;
113 }
114
115 } // namespace webrtc
116
117 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_ARRAY_UTIL_H_
118