CSG is a file format used by the open source CAD modelling tool
[OpenSCAD](https://www.openscad.org). CSG is a subset of the SCAD language,
equivalent in the kinds of geometries that can be expressed, but with fewer
primitives (OpenSCAD can export `.scad` files to `.csg`). SCAD code is easier to
read and write by humans; CSG files are easier to parse and process by software.
Dependencies:
## Build
-[PEGTL](https://github.com/taocpp/PEGTL) for parsing
-[Catch2](https://github.com/catchorg/Catch2) for testing framework
-[CGAL](https://www.cgal.org) for geometry computation
> :warning: **Requires C++17, such as GCC 7.x or later, or Clang 5.x or later**.
### CMake
#### Installing conan for the first time
## How to Build
python3 -m pip install conan
### Build dependencies
#### Building using CMake
- C++17 compiler (GCC >=7.x, Clang >=5.x)
- CMake >=3.14
- Conan (CMake will try to install Conan if `conan` is not in `PATH`)
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --target unit_tests_csg
cd build
make -j
CMake will try to install [Conan](https://conan.io) if `conan` is not in `PATH`.
However, installing Conan (`pip install conan`) is recommended for faster builds.
#### Running unit tests
#### Build
ctest
```shell
> cmake -S.-B build -DCMAKE_BUILD_TYPE=Release
> cmake --build build
```
#### Run tests
## Using the library in other projects
```shell
>cd build
> ctest
```
### Include in the code
* Include the header file
#include "csg.hpp"
## Using CSG-EB in your project
* Create a function object
- Include the header file `csg.hpp`
- Call `csg::get_csgif` with the path to a CSG file to create an [Implicit Function object](https://amrex-codes.github.io/amrex/docs_html/EB.html#implicit-function).
auto csg_if = csg::get_csgif(<path_to_file_with_csg_extension>, is_internal_flow);
```cpp
#include<csg.hpp>
* Above returns an implicit function which can be operated on a 3D point coordinate (x, y, z) as