# Building Slic3r++ on Mac OS

To build Slic3r++ on Mac OS, you will need the following software:

- XCode
- CMake
- git
- gettext

XCode is available through Apple's App Store, the other three tools are available on
[brew](https://brew.sh/) (use `brew install cmake git gettext` to install them).

### Dependencies

Slic3r++ comes with a set of CMake scripts to build its dependencies, it lives in the `deps` directory.
Open a terminal window and navigate to Slic3r++ sources directory and then to `deps`.
Use the following commands to build the dependencies:

    mkdir build
    cd build
    cmake ..
    make

This will create a dependencies bundle inside the `build/destdir` directory.
You can also customize the bundle output path using the `-DDESTDIR=<some path>` option passed to `cmake`.

**Warning**: Once the dependency bundle is installed in a destdir, the destdir cannot be moved elsewhere.
(This is because wxWidgets hardcodes the installation path.)

FIXME The Cereal serialization library needs a tiny patch on some old OSX clang installations
https://github.com/USCiLab/cereal/issues/339#issuecomment-246166717


### Building Slic3r++

If dependencies are built without errors, you can proceed to build Slic3r++ itself.
Go back to top level Slic3r++ sources directory and use these commands:

    mkdir build
    cd build
    cmake .. -DCMAKE_PREFIX_PATH="$PWD/../deps/build/destdir/usr/local"

The `CMAKE_PREFIX_PATH` is the path to the dependencies bundle but with `/usr/local` appended - if you set a custom path
using the `DESTDIR` option, you will need to change this accordingly. **Warning:** the `CMAKE_PREFIX_PATH` needs to be an absolute path.

The CMake command above prepares Slic3r++ for building from the command line.
To start the build, use

    make -jN

where `N` is the number of CPU cores, so, for example `make -j4` for a 4-core machine.

Alternatively, if you would like to use XCode GUI, modify the `cmake` command to include the `-GXcode` option:

    cmake .. -GXcode -DCMAKE_PREFIX_PATH="$PWD/../deps/build/destdir/usr/local"

and then open the `Slic3r++.xcodeproj` file.
This should open up XCode where you can perform build using the GUI or perform other tasks.

### Note on Mac OS X SDKs

By default Slic3r++ builds against whichever SDK is the default on the current system.

This can be customized. The `CMAKE_OSX_SYSROOT` option sets the path to the SDK directory location
and the `CMAKE_OSX_DEPLOYMENT_TARGET` option sets the target OS X system version (eg. `10.14` or similar).
Note you can set just one value and the other will be guessed automatically.
In case you set both, the two settings need to agree with each other. (Building with a lower deployment target
is currently unsupported because some of the dependencies don't support this, most notably wxWidgets.)

Please note that the `CMAKE_OSX_DEPLOYMENT_TARGET` and `CMAKE_OSX_SYSROOT` options need to be set the same
on both the dependencies bundle as well as Slic3r++ itself.

Official Mac Slic3r++ builds are currently built against SDK 10.9 to ensure compatibility with older Macs.

_Warning:_ XCode may be set such that it rejects SDKs bellow some version (silently, more or less).
This is set in the property list file

    /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Info.plist

To remove the limitation, simply delete the key `MinimumSDKVersion` from that file.