264     Quat q = fusion->x0;  in fusionPredict()  local
344     mat44Apply(&fusion->x0, &O, &q);  in fusionPredict()
423 static void getF(struct Vec4 F[3], const struct Vec4 *q) {  in getF()  argument
424     F[0].x = q->w;      F[1].x = -q->z;         F[2].x = q->y;  in getF()
425     F[0].y = q->z;      F[1].y = q->w;          F[2].y = -q->x;  in getF()
426     F[0].z = -q->y;     F[1].z = q->x;          F[2].z = q->w;  in getF()
427     F[0].w = -q->x;     F[1].w = -q->y;         F[2].w = -q->z;  in getF()
489     struct Vec4 q;  in fusionUpdate()  local
490     q.x = fusion->x0.x + 0.5f * (F[0].x * dq.x + F[1].x * dq.y + F[2].x * dq.z);  in fusionUpdate()
491     q.y = fusion->x0.y + 0.5f * (F[0].y * dq.x + F[1].y * dq.y + F[2].y * dq.z);  in fusionUpdate()
492     q.z = fusion->x0.z + 0.5f * (F[0].z * dq.x + F[1].z * dq.y + F[2].z * dq.z);  in fusionUpdate()
493     q.w = fusion->x0.w + 0.5f * (F[0].w * dq.x + F[1].w * dq.y + F[2].w * dq.z);  in fusionUpdate()
495     fusion->x0 = q;  in fusionUpdate()