This guide presumes you have [cf4ocl installed in your system](Build-and-install-from-source).

### Include header

Source files should first include the _cf4ocl_ header:

```c
#include <cf4ocl2.h>
```

### Compiling and linking

The following assumes a working installation of the [pkg-config](http://www.freedesktop.org/wiki/Software/pkg-config/)
build tool, which is usually bundled with `GLib`. If this is not the case,
or if you prefer not to use this tool, click [here](Using-cf4ocl-in-a-new-project-without-pkg-config)
for an alternative approach.

If `pkg-config` can't find _cf4ocl_, make sure the `cf4ocl2.pc` file is
in its search path. For example, if _cf4ocl2_ was installed in
`/usr/local/` (which is not a default library search path in some OSes),
one would first set the `PKG_CONFIG_PATH` environment variable with the
appropriate value:

    $ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

There are two ways of using _cf4ocl_ in your project:

* Using the [CMake](http://www.cmake.org/) build framework.
* Manually specifying compiler options in the command line.

The latter option gives a good idea of how to specify these dependencies
with other build systems.

#### CMake

If client code uses CMake as its build system, then it's very simple
to integrate _cf4ocl_. Simply add the following lines to your
`CMakeLists.txt` file:

```cmake
# Find required libraries
find_package(PkgConfig REQUIRED)
pkg_check_modules(CF4OCL2 REQUIRED cf4ocl2>=2.0.0)

# Library include directories
include_directories(${CF4OCL2_INCLUDE_DIRS})
```

Then, for each target, specify _cf4ocl_ as a link library:

```cmake
add_executable(myprog myprog.c)
target_link_libraries(myprog ${CF4OCL2_LIBRARIES})
```

CMake can then create the project or build files for several targets
such as Unix Makefiles, Visual Studio, Xcode, Eclipse, etc.

The [cf4ocl-examples](https://github.com/fakenmc/cf4ocl-examples)
project follows this approach.

#### Manually

If you prefer to manually set build options, directly in the
compiler/linker options, in a makefile or in your IDE, follow these
guidelines.

##### Compiling

Depending on how _cf4ocl_ was installed, it may be necessary to specify
the location of the _cf4ocl_ header (and the headers of the _cf4ocl_
dependencies) with the `-I` flag. These can be obtained with `pkg-config`:

    pkg-config --cflags cf4ocl2

##### Linking

It is necessary to specify _cf4ocl_ (and other libraries) with the
`-l` (and possibly `-L`) flags. Using `pkgconfig`, this is again a
simple process:

    pkg-config --libs cf4ocl2

##### Example with gcc or Clang

For example, to compile and link a simple program which uses _cf4ocl_
with gcc or clang, one could do:

    $ gcc `pkg-config --cflags cf4ocl2` myprog.c -o myprog `pkg-config --libs cf4ocl2`

### Additional notes

You can try this with the `mysum` program described in the
[tutorial](http://www.fakenmc.com/cf4ocl/docs/latest/tut.html).