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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "trackball.h"
#include "scene.h"
//============================================================================//
// TrackBall //
//============================================================================//
TrackBall::TrackBall(TrackMode mode)
: m_angularVelocity(0)
, m_paused(false)
, m_pressed(false)
, m_mode(mode)
{
m_axis = QVector3D(0, 1, 0);
m_rotation = QQuaternion();
m_lastTime = QTime::currentTime();
}
TrackBall::TrackBall(float angularVelocity, const QVector3D& axis, TrackMode mode)
: m_axis(axis)
, m_angularVelocity(angularVelocity)
, m_paused(false)
, m_pressed(false)
, m_mode(mode)
{
m_rotation = QQuaternion();
m_lastTime = QTime::currentTime();
}
void TrackBall::push(const QPointF& p, const QQuaternion &)
{
m_rotation = rotation();
m_pressed = true;
m_lastTime = QTime::currentTime();
m_lastPos = p;
m_angularVelocity = 0.0f;
}
void TrackBall::move(const QPointF& p, const QQuaternion &transformation)
{
if (!m_pressed)
return;
QTime currentTime = QTime::currentTime();
int msecs = m_lastTime.msecsTo(currentTime);
if (msecs <= 20)
return;
switch (m_mode) {
case Plane:
{
QLineF delta(m_lastPos, p);
m_angularVelocity = 180*delta.length() / (PI*msecs);
m_axis = QVector3D(delta.dy(), -delta.dx(), 0.0f).normalized();
m_axis = transformation.rotateVector(m_axis);
m_rotation *= QQuaternion::fromAxisAndAngle(m_axis, delta.length());
}
break;
case Sphere:
{
QVector3D lastPos3D = QVector3D(m_lastPos.x(), m_lastPos.y(), 0.0f);
float sqrZ = 1 - QVector3D::dotProduct(lastPos3D, lastPos3D);
if (sqrZ > 0)
lastPos3D.setZ(sqrt(sqrZ));
else
lastPos3D.normalize();
QVector3D currentPos3D = QVector3D(p.x(), p.y(), 0.0f);
sqrZ = 1 - QVector3D::dotProduct(currentPos3D, currentPos3D);
if (sqrZ > 0)
currentPos3D.setZ(sqrt(sqrZ));
else
currentPos3D.normalize();
m_axis = QVector3D::crossProduct(currentPos3D, lastPos3D);
float angle = asin(sqrt(QVector3D::dotProduct(m_axis, m_axis)));
m_angularVelocity = 180*angle / (PI*msecs);
m_axis.normalize();
m_axis = transformation.rotateVector(m_axis);
m_rotation *= QQuaternion::fromAxisAndAngle(m_axis, angle);
}
break;
}
m_lastPos = p;
m_lastTime = currentTime;
}
void TrackBall::release(const QPointF& p, const QQuaternion &transformation)
{
// Calling move() caused the rotation to stop if the framerate was too low.
move(p, transformation);
m_pressed = false;
}
void TrackBall::start()
{
m_lastTime = QTime::currentTime();
m_paused = false;
}
void TrackBall::stop()
{
m_rotation = rotation();
m_paused = true;
}
QQuaternion TrackBall::rotation() const
{
if (m_paused || m_pressed)
return m_rotation;
QTime currentTime = QTime::currentTime();
float angle = m_angularVelocity * m_lastTime.msecsTo(currentTime);
return m_rotation * QQuaternion::fromAxisAndAngle(m_axis, angle);
}
|
