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 <algos/quat.h>
18 #include <nanohub_math.h>
19
clamp(float x)20 static float clamp(float x) {
21 return x < 0.0f ? 0.0f : x;
22 }
23
initQuat(Quat * q,const struct Mat33 * R)24 void initQuat(Quat *q, const struct Mat33 *R) {
25 float Hx = R->elem[0][0];
26 float My = R->elem[1][1];
27 float Az = R->elem[2][2];
28
29 q->x = sqrtf(clamp(Hx - My - Az + 1.0f) * 0.25f);
30 q->y = sqrtf(clamp(-Hx + My - Az + 1.0f) * 0.25f);
31 q->z = sqrtf(clamp(-Hx - My + Az + 1.0f) * 0.25f);
32 q->w = sqrtf(clamp(Hx + My + Az + 1.0f) * 0.25f);
33 q->x = copysignf(q->x, R->elem[1][2] - R->elem[2][1]);
34 q->y = copysignf(q->y, R->elem[2][0] - R->elem[0][2]);
35 q->z = copysignf(q->z, R->elem[0][1] - R->elem[1][0]);
36 }
37
quatToMatrix(struct Mat33 * R,const Quat * q)38 void quatToMatrix(struct Mat33 *R, const Quat *q) {
39 float q0 = q->w;
40 float q1 = q->x;
41 float q2 = q->y;
42 float q3 = q->z;
43 float sq_q1 = 2.0f * q1 * q1;
44 float sq_q2 = 2.0f * q2 * q2;
45 float sq_q3 = 2.0f * q3 * q3;
46 float q1_q2 = 2.0f * q1 * q2;
47 float q3_q0 = 2.0f * q3 * q0;
48 float q1_q3 = 2.0f * q1 * q3;
49 float q2_q0 = 2.0f * q2 * q0;
50 float q2_q3 = 2.0f * q2 * q3;
51 float q1_q0 = 2.0f * q1 * q0;
52
53 R->elem[0][0] = 1.0f - sq_q2 - sq_q3;
54 R->elem[1][0] = q1_q2 - q3_q0;
55 R->elem[2][0] = q1_q3 + q2_q0;
56 R->elem[0][1] = q1_q2 + q3_q0;
57 R->elem[1][1] = 1.0f - sq_q1 - sq_q3;
58 R->elem[2][1] = q2_q3 - q1_q0;
59 R->elem[0][2] = q1_q3 - q2_q0;
60 R->elem[1][2] = q2_q3 + q1_q0;
61 R->elem[2][2] = 1.0f - sq_q1 - sq_q2;
62 }
63
quatNormalize(Quat * q)64 void quatNormalize(Quat *q) {
65 if (q->w < 0.0f) {
66 q->x = -q->x;
67 q->y = -q->y;
68 q->z = -q->z;
69 q->w = -q->w;
70 }
71
72 float invNorm =
73 1.0f / sqrtf(q->x * q->x + q->y * q->y + q->z * q->z + q->w * q->w);
74
75 q->x *= invNorm;
76 q->y *= invNorm;
77 q->z *= invNorm;
78 q->w *= invNorm;
79 }
80
81