First steps¶

This sections demonstrates the basic features of Dawn. Before getting started, make sure that development environment is set up to compile the included set of test cases.

Compiling the library¶

Linux¶

On Linux, you’ll need to install a C++11 toolchain (e.g gcc or clang) as well as CMake (>= 3.3). In addition, you will need Protobuf (>= 3.4). For example, on Ubuntu the following will install the necessary dependencies

sudo apt-get install g++ cmake

Note that most Ubuntu distributions don’t ship the latest Protobuf library which means you need to compile it yourself (don’t worry it’s super easy!). First, grab the latest release of Protobuf from GitHub, configure it with CMake (the CMakeLists.txt file is located in the cmake/ subdirectory) and then build it

git clone https://github.com/google/protobuf.git
cd protobuf
mkdir build
cd build
export PROTOBUF_INSTALL_DIR="$(pwd)/install"
cmake ../cmake/ -DCMAKE_INSTALL_PREFIX="$PROTOBUF_INSTALL_DIR"
make install -j 4

which will install the library locally into build/install. Next, we can build Dawn. Note that we need to point CMake to the protobuf-config.cmake file of Protobuf (which is located in ${PROTOBUF_INSTALL_DIR}/lib/cmake/protobuf/) via the CMake variable Protobuf_DIR.

git clone https://github.com/MeteoSwiss-APN/dawn
mkdir build
cd build
cmake .. -DProtobuf_DIR="$PROTOBUF_INSTALL_DIR/lib/cmake/protobuf/"
make install -j 4

The last line will both install and compile the library locally in <dawn-dir>/install/.

Mac OS¶

On Mac OS, you’ll need to install Xcode as well as CMake (>= 3.3). In addition, you will need Protobuf (>= 3.4). First, make sure you have the Xcode Command Line Tools installed

xcode-select --install

If you are using Homebrew, use the following to install Protobuf and CMake

brew update
brew install cmake protobuf

After installing the prerequisites, run

mkdir build
cd build
cmake ..
make install -j 4

The last line will both install and compile the library locally in <dawn-dir>/install/.

Linking the library¶

We suggest using CMake for a smooth integration with your project. The installation of Dawn provides a find configuration script (which can be used with find_package) that should be installed into your system.

In your projects CMakeLists.txt, simply add

find_package(Dawn)

to import all the necessary information.

Note

The script is located in <dawn-install-dir>/cmake. If CMake has trouble finding the script you may pass this location directly to CMake by adding -DDawn_DIR=<dawn-install-dir>/cmake to the command line flags.

If Dawn is found, the following CMake variables will be defined

Variable	Explanation
`DAWN_FOUND`	True if headers and libraries of Dawn were found.
`DAWN_ROOT`	Installation prefix of Dawn.
`DAWN_VERSION`	Version of Dawn (format X.Y.Z).
`DAWN_ASSERTS`	True if Dawn was compiled with asserts.
`DAWN_INCLUDE_DIRS`	Dawn include directories.
`DAWN_LIBRARY_DIRS`	Link directories for Dawn libraries.
`DAWN_LIBRARY`	Library to link against (this is an alias of `DAWN_STATIC_LIBRARY`).
`DAWN_STATIC_LIBRARY`	Static library of Dawn.
`DAWN_HAS_SHARED_LIBRARY`	True if the shared library of Dawn is available.
`DAWN_SHARED_LIBRARY`	Shared library of Dawn.

Finally, just link the static library of Dawn to your own library or executable

target_link_libraries(${target} ... PUBLIC ${DAWN_STATIC_LIBRARY})

or use DAWN_SHARED_LIBRARY instead of DAWN_STATIC_LIBRARY if you want to linkt against the shared library.

Example¶

If we want to link our file (foo.cpp) against the static library of Dawn, we may use something like

# Find the Dawn library (abort if we cannot find it!)
find_package(Dawn REQUIRED)

# Expose the Dawn include directories
include_directories(SYSTEM ${DAWN_INCLUDE_DIRS})

# Compile foo and link against Dawn
add_executable(foo foo.cpp)
target_link_libraries(foo PUBLIC ${DAWN_STATIC_LIBRARY})

# Dawn requires atleast C++11 (you can also set this globally!)
set_property(TARGET foo PROPERTY CXX_STANDARD 11)

Using the library¶

TODO:

#include <dawn/Dawn.h>

int main() {

  return 0;
}