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
|
/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtQuick3D module 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 "floatingitem.h"
#include "floatingitemeffect.h"
QT_BEGIN_NAMESPACE
/*!
\qmlclass FloatingItem FloatingItem
\brief The FloatingItem item defines the depth that a 2D element will be placed at in the 3D visual field.
\since 4.8
\ingroup qt3d::qml3d
Stereo viewing is enabled in QML using the StereoView element:
\snippet declarative/stereo/stereo.qml 1
\dots
\snippet declarative/stereo/stereo.qml 2
\bold{Note:} StereoView is not supported with Qt Quick 2.0 as the
standard view classes are already stereo-aware.
\image stereo-screenshot-qml.png
2D items are placed within the 3D visual field using the
FloatingItem element and the \l depth property:
\snippet declarative/stereo/stereo.qml 5
Negative depth values define distances behind the
\i{center of focus} of our scene, and positive depth
values define distances in front of the center of focus.
The center of focus corresponds to where the left and right
eye images coincide at depth 0. Usually the most important
item on the screen is placed at depth 0 so that the user's
attention is immediately drawn to it. Other items then
\i{float above} (positive depth) or \i{appear behind}
(negative depth) the center of focus.
FloatingItem defines the depth for 2D elements. 3D elements
should be rendered inside a \l Viewport with the camera's
\l{Camera::eyeSeparation}{eyeSeparation} set to a non-zero value:
\snippet declarative/stereo/stereo.qml 6
\dots
\snippet declarative/stereo/stereo.qml 7
\sa StereoView, Viewport, {QML Stereo Viewing Example}
*/
/*!
\internal
*/
FloatingItem::FloatingItem(QDeclarativeItem *parent)
: QDeclarativeItem(parent)
, m_depth(0.0f)
{
// The actual stereo adjustment is done with a QGraphicsEffect.
m_effect = new FloatingItemEffect(this);
setGraphicsEffect(m_effect);
}
/*!
\internal
*/
FloatingItem::~FloatingItem()
{
}
/*!
\qmlproperty real FloatingItem::depth
This property defines the depth within the 3D field where children
of this item will appear. The default value of zero indicates
that the left and right eye images will co-incide at the center of
focus. Items with a negative depth appear behind the center
of focus and items with a positive depth float above the center
of focus.
The value indicates the number of pixels that separate the left
and right eye images on a 100 dpi display. The value is corrected
for the dpi of the actual display if it is not 100 dpi. Thus,
a depth of 1 always corresponds to 0.254 millimeters of image
separation at the surface of the display.
It is assumed that the distance of the viewer from the display
is the same for all displays showing the same application.
For example, a stereoscopic application designed for viewing
on a handheld device should have the same depth cues on
another handheld device with a different dpi, when held at
the same arms-length distance from the viewer.
*/
void FloatingItem::setDepth(qreal depth)
{
if (m_depth != depth) {
m_depth = depth;
emit depthChanged();
update();
}
}
QT_END_NAMESPACE
|
