/*!

@page build Building programs using GLFW

@tableofcontents

This is about compiling and linking programs that use GLFW.  For information on
how to *write* such programs, start with the [introductory tutorial](@ref quick).


@section build_include Including the GLFW header file

In the files of your program where you use OpenGL or GLFW, you should include
the GLFW 3 header file, i.e.:

@code
#include <GLFW/glfw3.h>
@endcode

This defines all the constants, types and function prototypes of the GLFW API.
It also includes the chosen client API header files (by default OpenGL), and
defines all the constants and types necessary for those headers to work on that
platform.

For example, under Windows you are normally required to include `windows.h`
before including `GL/gl.h`.  This would make your source file tied to Windows
and pollute your code's namespace with the whole Win32 API.

Instead, the GLFW header takes care of this for you, not by including
`windows.h`, but rather by itself duplicating only the necessary parts of it.
It does this only where needed, so if `windows.h` *is* included, the GLFW header
does not try to redefine those symbols.

In other words:

 - Do *not* include the OpenGL headers yourself, as GLFW does this for you
 - Do *not* include `windows.h` or other platform-specific headers unless you
   plan on using those APIs directly
 - If you *do* need to include such headers, do it *before* including
   the GLFW one and it will detect this

If you are using an OpenGL extension loading library such as
[GLEW](http://glew.sourceforge.net/), the GLEW header should also be included
*before* the GLFW one.  The GLEW header defines macros that disable any OpenGL
header that the GLFW header includes and GLEW will work as expected.


@subsection build_macros GLFW header option macros

These macros may be defined before the inclusion of the GLFW header and affect
how that header behaves.

`GLFW_INCLUDE_GLCOREARB` makes the header include the modern `GL/glcorearb.h`
header (`OpenGL/gl3.h` on OS X) instead of the regular OpenGL header.

`GLFW_INCLUDE_ES1` makes the header include the OpenGL ES 1.x `GLES/gl.h` header
instead of the regular OpenGL header.

`GLFW_INCLUDE_ES2` makes the header include the OpenGL ES 2.0 `GLES2/gl2.h`
header instead of the regular OpenGL header.

`GLFW_INCLUDE_ES3` makes the header include the OpenGL ES 3.0 `GLES3/gl3.h`
header instead of the regular OpenGL header.

`GLFW_INCLUDE_NONE` makes the header not include any client API header.

`GLFW_INCLUDE_GLU` makes the header include the GLU header *in addition to* the
OpenGL header.  This should only be used with the default `GL/gl.h` header
(`OpenGL/gl.h` on OS X), i.e. if you are not using any of the above macros.

`GLFW_DLL` is necessary when using the GLFW DLL on Windows, in order to explain
to the compiler that the GLFW functions will be coming from another executable.
It has no function on other platforms.


@section build_link Link with the right libraries

@subsection build_link_win32 With MinGW or Visual C++ on Windows

The static version of the GLFW library is named `glfw3`.  When using this
version, it is also necessary to link with some libraries that GLFW uses.

When linking a program under Windows that uses the static version of GLFW, you
must link with `opengl32`.  If you are using GLU, you must also link with
`glu32`.

The link library for the GLFW DLL is named `glfw3dll`.  When compiling a program
that uses the DLL version of GLFW, you need to define the `GLFW_DLL` macro
*before* any inclusion of the GLFW header.  This can be done either with
a compiler switch or by defining it in your source code.

A program using the GLFW DLL does not need to link against any of its
dependencies, but you still have to link against `opengl32` if your program uses
OpenGL and `glu32` if it uses GLU.


@subsection build_link_cmake_source With CMake and GLFW source

You can use the GLFW source tree directly from a project that uses CMake.  This
way, GLFW will be built along with your application as needed.

Firstly, add the root directory of the GLFW source tree to your project.  This
will add the `glfw` target and the necessary cache variables to your project.

    add_subdirectory(path/to/glfw)

To be able to include the GLFW header from your code, you need to tell the
compiler where to find it.

    include_directories(path/to/glfw/include)

Once GLFW has been added to the project, the `GLFW_LIBRARIES` cache variable
contains all link-time dependencies of GLFW as it is currently configured.  To
link against GLFW, link against them and the `glfw` target.

    target_link_libraries(myapp glfw ${GLFW_LIBRARIES})

Note that `GLFW_LIBRARIES` does not include GLU, as GLFW does not use it.  If
your application needs GLU, you can add it to the list of dependencies with the
`OPENGL_glu_LIBRARY` cache variable, which is implicitly created when the GLFW
CMake files look for OpenGL.

    target_link_libraries(myapp glfw ${OPENGL_glu_LIBRARY} ${GLFW_LIBRARIES})


@subsection build_link_cmake_pkgconfig With CMake on Unix and installed GLFW binaries

CMake can import settings from pkg-config, which GLFW supports.  When you
installed GLFW, the pkg-config file `glfw3.pc` was installed along with it.

First you need to find the PkgConfig package.  If this fails, you may need to
install the pkg-config package for your distribution.

    find_package(PkgConfig REQUIRED)

This creates the CMake commands to find pkg-config packages.  Then you need to
find the GLFW package.

    pkg_search_module(GLFW REQUIRED glfw3)

This creates the CMake variables you need to use GLFW.  To be able to include
the GLFW header, you need to tell your compiler where it is.

    include_directories(${GLFW_INCLUDE_DIRS})

You also need to link against the correct libraries.  If you are using the
shared library version of GLFW, use the `GLFW_LIBRARIES` variable.

    target_link_libraries(simple ${GLFW_LIBRARIES})


If you are using the static library version of GLFW, use the
`GLFW_STATIC_LIBRARIES` variable instead.

    target_link_libraries(simple ${GLFW_STATIC_LIBRARIES})


@subsection build_link_pkgconfig With pkg-config on OS X or other Unix

GLFW supports [pkg-config](http://www.freedesktop.org/wiki/Software/pkg-config/),
and `glfw3.pc` file is generated when the GLFW library is built and installed
along with it.  

A typical compile and link command-line when using the static may look like this:

    cc `pkg-config --cflags glfw3` -o myprog myprog.c `pkg-config --static --libs glfw3`

If you are using the shared library, simply omit the `--static` flag.

    cc `pkg-config --cflags glfw3` -o myprog myprog.c `pkg-config --libs glfw3`

You can also use the `glfw3.pc` file without installing it first, by using the
`PKG_CONFIG_PATH` environment variable.

    env PKG_CONFIG_PATH=path/to/glfw/src cc `pkg-config --cflags glfw3` -o myprog myprog.c `pkg-config --static --libs glfw3`

The dependencies do not include GLU, as GLFW does not need it.  On OS X, GLU is
built into the OpenGL framework, so if you need GLU you don't need to do
anything extra.  If you need GLU and are using Linux or BSD, you should add
`-lGLU` to your link flags.

See the manpage and other documentation for pkg-config and your compiler and
linker for more information on how to link programs.


@subsection build_link_xcode With Xcode on OS X

If you are using the dynamic library version of GLFW, simply add it to the
project dependencies.

If you are using the static library version of GLFW, add it and the Cocoa,
OpenGL and IOKit frameworks to the project as dependencies.


@subsection build_link_osx With command-line on OS X

If you do not wish to use pkg-config, you need to add the required frameworks
and libraries to your command-line using the `-l` and `-framework` switches,
i.e.:

    cc -o myprog myprog.c -lglfw -framework Cocoa -framework OpenGL -framework IOKit

Note that you do not add the `.framework` extension to a framework when adding
it from the command-line.

The OpenGL framework contains both the OpenGL and GLU APIs, so there is nothing
special to do when using GLU.  Also note that even though your machine may have
`libGL`-style OpenGL libraries, they are for use with the X Window System and
will *not* work with the OS X native version of GLFW.

*/
