1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
// Cyphesis Online RPG Server and AI Engine
// Copyright (C) 2000,2001 Alistair Riddoch
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
// $Id: Quaternion.cpp,v 1.8 2006-10-26 00:48:07 alriddoch Exp $
#include "Quaternion.h"
#include "Vector3D.h"
// The arguments to this function have been swapped over because in
// the form provided in the example code, the result appeared to be
// a rotation in the wrong direction. This may be a bug in my apogee
// code, or it may be this code.
template<class V>
const Quaternion quaternionFromTo(const V & from, const V & to)
{
float cosT = Dot(from, to);
if (cosT > 0.99999f) {
return Quaternion(1.f, 0.f, 0.f, 0.f);
} else if (cosT < -0.99999f) {
V t(0.0, from.x(), -from.y());
if (t.sqrMag() < 1e-12) {
t = V(-from.z(), 0.0, from.x());
}
t.normalize();
return Quaternion(0.f, t.x(), t.y(), t.z());
}
V t = Cross(from, to);
t.normalize();
float ss = sqrtf(0.5 * (1.0 - cosT));
float x = t.x() * ss;
float y = t.y() * ss;
float z = t.z() * ss;
float w = std::sqrt(0.5 * (1.0 + cosT));
return Quaternion(w, x, y, z);
}
template
const Quaternion quaternionFromTo<Vector3D>(const Vector3D &, const Vector3D&);
|
