OSG-3.4.0 简要说明(Readme)

欢迎来到OpenSceneGraph(OSG)世界.

Welcome to the OpenSceneGraph (OSG).

对于项目最新信息, 以及如何编译和运行库和示例的更多细节, 可以查看OSG网站上的文档:

For up-to-date information on the project, in-depth details on how to
compile and run libraries and examples, see the documentation on the
OpenSceneGraph website:

http://www.openscenegraph.org/index.php/documentation

对于订阅我们的公共邮件列表或论坛，见如下网址:

For support subscribe to our public mailing list or forum, details at:

http://www.openscenegraph.org/index.php/support

为了快速了解，在下文中, 我们把快速构建说明分成三个部分：

1) 构建OSG的一般说明
  2) OSX发行说明
  3) iOS发行说明

For the impatient, we've included quick build instructions below, these
are are broken down is three parts:

1) General notes on building the OpenSceneGraph
  2) OSX release notes
  3) iOS release notes

如果下文细节不足, 可以查阅 openscenegraph.org 上的 Documentation/GettingStarted 和 Documentation/PlatformSpecifics 节以获得更多的细节.

Robert Osfield.
项目领导人
2015-08-12.

If details below are not sufficient then head over to the openscenegraph.org
to the Documentation/GettingStarted and Documentation/PlatformSpecifics sections for
more indepth instructions.

Robert Osfield.
Project Lead.
12th August 2015.

--

一. 如何构建 OpenSceneGraph

Section 1. How to build the OpenSceneGraph
==========================================

OSG使用CMake构建系统来生成平台相关构建环境. CMake遍历OpenSceneGraph目录读取所有CMakeLists.txt文件, 检查已经安装的依赖项, 并生成相关构建系统.

The OpenSceneGraph uses the CMake build system to generate a
platform-specific build environment.  CMake reads the CMakeLists.txt
files that you'll find throughout the OpenSceneGraph directories,
checks for installed dependenciesand then generates the appropriate
build system.

如果你没有安装CMake, 你可以从http://www.cmake.org下载2.4.6及以上版. OpenSceneGraph的CMake细节见:

If you don't already have CMake installed on your system you can grab
it from http://www.cmake.org, use version 2.4.6 or later.  Details on the
OpenSceneGraph's CMake build can be found at:

http://www.openscenegraph.org/projects/osg/wiki/Build/CMake

在类unices系统下(如Linux, IRIX, Solaris, Free-BSD, HP-Ux, AIX, OSX), 使用cmake或ccmake命令行工具. 注意: 为了最终库(应用程序)最好的性能,‘cmake .’命令默认构建发行版.

Under unices (i.e. Linux, IRIX, Solaris, Free-BSD, HP-Ux, AIX, OSX)
use the cmake or ccmake command-line utils. Note that cmake . defaults
to building Release to ensure that you get the best performance from
your final libraries/applications.

cd OpenSceneGraph
    cmake .
    make
    sudo make install

或者, 你可以创建一个源文件之外的构建目录, 并在该目录中执行cmake或ccmake. 这样做能避免CMake产生的临时文件污染OSG源文件目录, 这样也可以在多个目录中构建独立目标. 在与OSG并列的目录中, 使用如下命令:

Alternatively, you can create an out-of-source build directory and run
cmake or ccmake from there. The advantage to this approach is that the
temporary files created by CMake won't clutter the OpenSceneGraph
source directory, and also makes it possible to have multiple
independent build targets by creating multiple build directories. In a
directory alongside the OpenSceneGraph use:

mkdir build
    cd build
    cmake ../OpenSceneGraph
    make
    sudo make install

在Windows下, 可以使用CMake-GUI构建VisualStudio文件. 下面的wiki页会帮助你使用CMake以完成构建过程.

Under Windows use the GUI tool CMakeSetup to build your VisualStudio
files. The following page on our wiki dedicated to the CMake build
system should help guide you through the process:

http://www.openscenegraph.org/index.php/documentation/platform-specifics/windows

在OSX 下, 可以使用上文所列CMake, 也可以使用OpenSceneGraph/Xcode目录下的Xcode项目.

Under OSX you can either use the CMake build system above, or use the
Xcode projects that you will find in the OpenSceneGraph/Xcode
directory. See release notes on OSX CMake build below.

更多的编译,安装和平台相关细节见"新手入门"指南:

For further details on compilation, installation and platform-specific
information read "Getting Started" guide:

http://www.openscenegraph.org/index.php/documentation/10-getting-started

Section 2. Release notes on OSX build, by Eric Sokolowsky, August 5, 2008
=========================================================================

There are several ways to compile OpenSceneGraph under OSX.  The
recommended way is to use CMake 2.6 to generate Xcode projects, then use
Xcode to build the library. The default project will be able to build
Debug or Release libraries, examples, and sample applications. Here are
some key settings to consider when using CMake:

BUILD_OSG_EXAMPLES - By default this is turned off. Turn this setting on
to compile many great example programs.

CMAKE_OSX_ARCHITECTURES - Xcode can create applications, executables,
libraries, and frameworks that can be run on more than one architecture.
Use this setting to indicate the architectures on which to build OSG.
Possibilities include ppc, ppc64, i386, and x86_64. Building OSG using
either of the 64-bit options (ppc64 and x86_64) has its own caveats
below.

OSG_BUILD_APPLICATION_BUNDLES - Normally only executable binaries are
created for the examples and sample applications. Turn this option on if
you want to create real OSX .app bundles. There are caveats to creating
.app bundles, see below.

OSG_WINDOWING_SYSTEM - You have the choice to use Carbon or X11 when
building applications on OSX. Under Leopard and later, X11 applications,
when started, will automatically launch X11 when needed. However,
full-screen X11 applications will still show the menu bar at the top of
the screen. Since many parts of the Carbon user interface are not
64-bit, X11 is the only supported option for OSX applications compiled
for ppc64 or x86_64.

There is an Xcode directory in the base of the OSG software
distribution, but its future is limited, and will be discontinued once
the CMake project generator completely implements its functionality.

APPLICATION BUNDLES (.app bundles)

The example programs when built as application bundles only contain the
executable file. They do not contain the dependent libraries as would a
normal bundle, so they are not generally portable to other machines.
They also do not know where to find plugins. An environmental variable
OSG_LIBRARY_PATH may be set to point to the location where the plugin
.so files are located. OSG_FILE_PATH may be set to point to the location
where data files are located. Setting OSG_FILE_PATH to the
OpenSceneGraph-Data directory is very useful when testing OSG by running
the example programs.

Many of the example programs use command-line arguments. When
double-clicking on an application (or using the equivalent "open"
command on the command line) only those examples and applications that
do not require command-line arguments will successfully run. The
executable file within the .app bundle can be run from the command-line
if command-line arguments are needed.

64-BIT APPLICATION SUPPORT

OpenSceneGraph will not compile successfully when OSG_WINDOWING_SYSTEM is
Carbon and either x86_64 or ppc64 is selected under CMAKE_OSX_ARCHITECTURES,
as Carbon is a 32bit only API. A version of the osgviewer library written in
Cocoa is needed. However, OSG may be compiled under 64-bits if the X11
windowing system is selected. However, Two parts of the OSG default
distribution will not work with 64-bit X11: the osgviewerWX example
program and the osgdb_qt (Quicktime) plugin. These must be removed from
the Xcode project after Cmake generates it in order to compile with
64-bit architectures. The lack of the latter means that images such as
jpeg, tiff, png, and gif will not work, nor will animations dependent on
Quicktime. A new ImageIO-based plugin is being developed to handle the
still images, and a QTKit plugin will need to be developed to handle
animations.

Section 3. Release notes on iOS build, by Thomas Hoghart
=========================================================

* Run CMake with either OSG_BUILD_PLATFORM_IPHONE or OSG_BUILD_PLATFORM_IPHONE_SIMULATOR set:
  $ mkdir build-iOS ; cd build-iOS
  $ ccmake -DOSG_BUILD_PLATFORM_IPHONE_SIMULATOR=YES -G Xcode ..
* Check that CMAKE_OSX_ARCHITECTURE is i386 for the simulator or armv6;armv7 for the device
* Disable DYNAMIC_OPENSCENEGRAPH, DYNAMIC_OPENTHREADS
  This will give us the static build we need for iPhone.
* Disable OSG_GL1_AVAILABLE, OSG_GL2_AVAILABLE, OSG_GL3_AVAILABLE,
  OSG_GL_DISPLAYLISTS_AVAILABLE, OSG_GL_VERTEX_FUNCS_AVAILABLE
* Enable OSG_GLES1_AVAILABLE *OR* OSG_GLES2_AVAILABLE *OR* OSG_GLES3_AVAILABLE (GLES3 will enable GLES2 features)
* Ensure OSG_WINDOWING_SYSTEM is set to IOS
* Change FREETYPE include and library paths to an iPhone version
  (OpenFrameworks has one bundled with its distribution)
* Ensure that CMake_OSX_SYSROOT points to your iOS SDK.
* Generate the Xcode project
* Open the Xcode project
  $ open OpenSceneGraph.xcodeproj
* Under Sources -> osgDB, select FileUtils.cpp and open the 'Get Info' panel, change File Type
  to source.cpp.objcpp

Here's an example for the command-line:
$ cmake -G Xcode \
-D OSG_BUILD_PLATFORM_IPHONE:BOOL=ON \
-D CMAKE_CXX_FLAGS:STRING="-ftree-vectorize -fvisibility-inlines-hidden -mno-thumb -arch armv6 -pipe -no-cpp-precomp -miphoneos-version-min=3.1 -mno-thumb" \
-D BUILD_OSG_APPLICATIONS:BOOL=OFF \
-D OSG_BUILD_FRAMEWORKS:BOOL=OFF \
-D OSG_WINDOWING_SYSTEM:STRING=IOS \
-D OSG_BUILD_PLATFORM_IPHONE:BOOL=ON \
-D CMAKE_OSX_ARCHITECTURES:STRING="armv6;armv7" \
-D CMAKE_OSX_SYSROOT:STRING=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.2.sdk \
-D OSG_GL1_AVAILABLE:BOOL=OFF \
-D OSG_GL2_AVAILABLE:BOOL=OFF \
-D OSG_GLES1_AVAILABLE:BOOL=ON \
-D OSG_GL_DISPLAYLISTS_AVAILABLE:BOOL=OFF \
-D OSG_GL_FIXED_FUNCTION_AVAILABLE:BOOL=ON \
-D OSG_GL_LIBRARY_STATIC:BOOL=OFF \
-D OSG_GL_MATRICES_AVAILABLE:BOOL=ON \
-D OSG_GL_VERTEX_ARRAY_FUNCS_AVAILABLE:BOOL=ON \
-D OSG_GL_VERTEX_FUNCS_AVAILABLE:BOOL=OFF \
-D DYNAMIC_OPENSCENEGRAPH:BOOL=OFF \
-D DYNAMIC_OPENTHREADS:BOOL=OFF .

Known issues:
* When Linking final app against ive plugin, you need to add -lz to
  the 'Other linker flags' list.
* Apps and exes don't get created
* You can only select Simulator, or Device projects. In the XCode
  project you will see both types but the sdk they link will
  be the same.