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
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation 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.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\page qt-embeddedLinux-accel.html
\target Hardware Acceleration with Qt for Embedded Linux
\title Qt for Embedded Linux Hardware Accelerated Graphics
\ingroup qt-embedded-linux
\input platforms/emb-hardwareacceleration.qdocinc
\section1 Windowing on Embedded Linux with Hardware Accelerated Graphics
Qt for Embedded Linux includes its own windowing system, QWS. QWS was
designed in 1999, well before graphics acceleration was available for
embedded devices. It does a great job providing a lightweight window
manager including all the expected functionality such as arbitrary
windows that can be moved, resized, minimized, etc. Getting QWS to work
with GPUs is very challenging, particularly with OpenGL and OpenVG
because there is no standard way in Linux to share textures across
processes. Some silicon vendors provide private APIs to allow texture
sharing, others do not. These limitations are documented under the
sections describing each type of accelerated hardware APIs. The simplest
most generic support for accelerated graphics is a full screen single
process single window.
\section2 General options
\list
\o QWS, not accelerated, allows arbitrary windowing with multiple
processes drawing on the screen.
\o X11 with an accelerated X11 driver provided by the silicon
vendor. Like QWS, this allows arbitrary windows with multiple
processes drawing on the screen. Our experience is that there is
some overhead from X11 which will adversely affect framerates.
Additionally, our experience is that the drivers from silicon
vendors are still maturing.
\o Full screen single process single window. This will always work.
Some additional capabilities are available and are documented in
the acceleration specific API sections.
\endlist
\section1 Supported Hardware Accelerated Graphics APIs
This table shows which Hardware Accelerated Graphics APIs currently
supported by Qt.
\table
\header
\o Supported APIs
\o API Version
\row
\o \l {Qt for Embedded Linux and OpenGL}{OpenGL ES}
\o 1.x and 2.x
\row
\o \l {Qt for Embedded Linux and OpenVG}{OpenVG }
\o 1.1
\row
\o \l {Qt for Embedded Linux and DirectFB}{DirectFB}
\o 2.0
\endtable
*/
|
