1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "common/math/vec.h"
18 #include "common/math/macros.h"
19 
findOrthogonalVector(float inX,float inY,float inZ,float * outX,float * outY,float * outZ)20 void findOrthogonalVector(float inX, float inY, float inZ, float *outX,
21                           float *outY, float *outZ) {
22   ASSERT_NOT_NULL(outX);
23   ASSERT_NOT_NULL(outY);
24   ASSERT_NOT_NULL(outZ);
25   float x, y, z;
26 
27   // discard the one with the smallest absolute value
28   if (fabsf(inX) <= fabsf(inY) && fabsf(inX) <= fabsf(inZ)) {
29     x = 0.0f;
30     y = inZ;
31     z = -inY;
32   } else if (fabsf(inY) <= fabsf(inZ)) {
33     x = inZ;
34     y = 0.0f;
35     z = -inX;
36   } else {
37     x = inY;
38     y = -inX;
39     z = 0.0f;
40   }
41 
42   float magSquared = x * x + y * y + z * z;
43   ASSERT(magSquared > 0);
44   // Only set invMag if magSquared is non-zero.
45   float invMag = 1.0f;
46   if (magSquared > 0) {
47     invMag = 1.0f / sqrtf(magSquared);
48   }
49   *outX = x * invMag;
50   *outY = y * invMag;
51   *outZ = z * invMag;
52 }
53 
vecAdd(float * u,const float * v,const float * w,size_t dim)54 void vecAdd(float *u, const float *v, const float *w, size_t dim) {
55   ASSERT_NOT_NULL(u);
56   ASSERT_NOT_NULL(v);
57   ASSERT_NOT_NULL(w);
58   size_t i;
59   for (i = 0; i < dim; i++) {
60     u[i] = v[i] + w[i];
61   }
62 }
63 
vecAddInPlace(float * v,const float * w,size_t dim)64 void vecAddInPlace(float *v, const float *w, size_t dim) {
65   ASSERT_NOT_NULL(v);
66   ASSERT_NOT_NULL(w);
67   size_t i;
68   for (i = 0; i < dim; i++) {
69     v[i] += w[i];
70   }
71 }
72 
vecSub(float * u,const float * v,const float * w,size_t dim)73 void vecSub(float *u, const float *v, const float *w, size_t dim) {
74   ASSERT_NOT_NULL(u);
75   ASSERT_NOT_NULL(v);
76   ASSERT_NOT_NULL(w);
77   size_t i;
78   for (i = 0; i < dim; i++) {
79     u[i] = v[i] - w[i];
80   }
81 }
82 
vecScalarMul(float * u,const float * v,float c,size_t dim)83 void vecScalarMul(float *u, const float *v, float c, size_t dim) {
84   ASSERT_NOT_NULL(u);
85   ASSERT_NOT_NULL(v);
86   size_t i;
87   for (i = 0; i < dim; i++) {
88     u[i] = c * v[i];
89   }
90 }
91 
vecScalarMulInPlace(float * v,float c,size_t dim)92 void vecScalarMulInPlace(float *v, float c, size_t dim) {
93   ASSERT_NOT_NULL(v);
94   size_t i;
95   for (i = 0; i < dim; i++) {
96     v[i] *= c;
97   }
98 }
99 
vecNorm(const float * v,size_t dim)100 float vecNorm(const float *v, size_t dim) {
101   ASSERT_NOT_NULL(v);
102   float norm_sq = vecNormSquared(v, dim);
103   return sqrtf(norm_sq);
104 }
105 
vecNormSquared(const float * v,size_t dim)106 float vecNormSquared(const float *v, size_t dim) {
107   ASSERT_NOT_NULL(v);
108   return vecDot(v, v, dim);
109 }
110 
vecDot(const float * v,const float * w,size_t dim)111 float vecDot(const float *v, const float *w, size_t dim) {
112   ASSERT_NOT_NULL(v);
113   ASSERT_NOT_NULL(w);
114   size_t i;
115   float result = 0;
116   for (i = 0; i < dim; ++i) {
117     result += v[i] * w[i];
118   }
119   return result;
120 }
121 
vecMaxAbsoluteValue(const float * v,size_t dim)122 float vecMaxAbsoluteValue(const float *v, size_t dim) {
123   ASSERT_NOT_NULL(v);
124   float max = NANO_ABS(v[0]);
125   float tmp;
126   size_t i;
127   for (i = 1; i < dim; ++i) {
128     tmp = NANO_ABS(v[i]);
129     if(tmp > max) {
130       max = tmp;
131     }
132   }
133   return max;
134 }
135