src/main/common/vector.h

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * some functions are taken from https://github.com/iNavFlight/inav/
  23  */
  24
  25 #pragma once
  26
  27 #include "common/maths.h"
  28
  29 typedef union {
  30     float v[2];
  31     struct {
  32        float x,y;
  33     };
  34 } fpVector2_t;
  35
  36
  37 typedef union {
  38     float v[3];
  39     struct {
  40        float x, y, z;
  41     };
  42 } fpVector3_t;
  43
  44 typedef struct {
  45     float m[3][3];
  46 } fpMat33_t;
  47
  48 static inline fpVector3_t * vectorZero(fpVector3_t *v)
  49 {
  50     v->x = 0.0f;
  51     v->y = 0.0f;
  52     v->z = 0.0f;
  53     return v;
  54 }
  55
  56 static inline float vectorNormSquared(const fpVector3_t * v)
  57 {
  58     return sq(v->x) + sq(v->y) + sq(v->z);
  59 }
  60
  61 static inline float vectorNorm(const fpVector3_t * v)
  62 {
  63     return sqrtf(vectorNormSquared(v));
  64 }
  65
  66 static inline fpVector3_t * vectorCrossProduct(fpVector3_t *result, const fpVector3_t *a, const fpVector3_t *b)
  67 {
  68     fpVector3_t ab;
  69
  70     ab.x = a->y * b->z - a->z * b->y;
  71     ab.y = a->z * b->x - a->x * b->z;
  72     ab.z = a->x * b->y - a->y * b->x;
  73
  74     *result = ab;
  75     return result;
  76 }
  77
  78 static inline fpVector3_t * vectorAdd(fpVector3_t *result, const fpVector3_t *a, const fpVector3_t *b)
  79 {
  80     fpVector3_t ab;
  81
  82     ab.x = a->x + b->x;
  83     ab.y = a->y + b->y;
  84     ab.z = a->z + b->z;
  85
  86     *result = ab;
  87     return result;
  88 }
  89
  90 static inline fpVector3_t * vectorScale(fpVector3_t *result, const fpVector3_t *a, const float b)
  91 {
  92     fpVector3_t ab;
  93
  94     ab.x = a->x * b;
  95     ab.y = a->y * b;
  96     ab.z = a->z * b;
  97
  98     *result = ab;
  99     return result;
 100 }
 101
 102 static inline fpVector3_t * vectorNormalize(fpVector3_t *result, const fpVector3_t *v)
 103 {
 104     float normSq = vectorNormSquared(v);
 105     if (normSq > 0) {              // Hopefully sqrt(nonzero) is quite large
 106         return vectorScale(result, v, 1.0f / sqrtf(normSq));
 107     } else {
 108         return vectorZero(result);
 109     }
 110 }
 111
 112 static inline fpVector3_t * matrixVectorMul(fpVector3_t * result, const fpMat33_t * mat, const fpVector3_t * a)
 113 {
 114     fpVector3_t r;
 115
 116     r.x = mat->m[0][0] * a->x + mat->m[0][1] * a->y + mat->m[0][2] * a->z;
 117     r.y = mat->m[1][0] * a->x + mat->m[1][1] * a->y + mat->m[1][2] * a->z;
 118     r.z = mat->m[2][0] * a->x + mat->m[2][1] * a->y + mat->m[2][2] * a->z;
 119
 120     *result = r;
 121     return result;
 122 }
 123
 124 static inline fpVector3_t * matrixTrnVectorMul(fpVector3_t * result, const fpMat33_t * mat, const fpVector3_t * a)
 125 {
 126     fpVector3_t r;
 127
 128     r.x = mat->m[0][0] * a->x + mat->m[1][0] * a->y + mat->m[2][0] * a->z;
 129     r.y = mat->m[0][1] * a->x + mat->m[1][1] * a->y + mat->m[2][1] * a->z;
 130     r.z = mat->m[0][2] * a->x + mat->m[1][2] * a->y + mat->m[2][2] * a->z;
 131
 132     *result = r;
 133     return result;
 134 }
 135
 136 static inline float vector2Cross(const fpVector2_t *a, const fpVector2_t *b)
 137 {
 138     return a->x * b->y - a->y * b->x;
 139 }
 140
 141 static inline float vector2Dot(const fpVector2_t *a, const fpVector2_t *b)
 142 {
 143     return a->x * b->x + a->y * b->y;
 144 }
 145
 146 static inline float vector2Mag(const fpVector2_t *a)
 147 {
 148     return sqrtf(sq(a->x) + sq(a->y));
 149 }