Add an INSTALL file for MacOSX

INSTALL-MacOSX.md

@@ -0,0 +1,60 @@
+# Compile and install instructions on MacOSX
+
+To compile Colobot on MacOS X, you need to first get all tools, all
+building dependencies (including the recompilation of some of them), and
+finally compile colobot.
+
+* Install git from [git-osx-installer on Google Code](https://code.google.com/p/git-osx-installer/)
+* Install Xcode through the Mac AppStore
+* Accept the Xcode license
+
+        xcodebuild -license
+
+* Download and install Apple's Command Line Developer Tools from within Xcode (Preferences, Download, Components)
+* Download and install [Mac Ports](http://www.macports.org/install.php#requirements)
+* Install GCC 4.8 through MacPorts
+
+        sudo port install gcc48
+
+* Install all colobot build depends
+
+        sudo port install cmake libsdl libsdl_image libsdl_ttf boost libsndfile glew libicns librsvg
+
+  > [po4a](http://po4a.alioth.debian.org/) should also be installed for the translation of levels, but the [MacPorts' Portfiles have not been accepted yet](http://trac.macports.org/ticket/41227).
+
+* Rebuild libtiff locally
+
+  This is needed because of the following error:
+
+  > libtiff.5.dylib (for architecture x86_64) because larger updated load
+  > commands do not fit (the program must be relinked, and you may need to
+  > use -headerpad or -headerpad_max_install_names)
+
+  MacPorts changed the default linker flag, a simple local rebuild suffices:
+
+        sudo port -ns upgrade --force tiff
+
+* Rebuild boost with the same gcc that we want to use
+
+  This is needed because boost is compiled against Mac's system libstdc++
+  which is older than the one used by gcc-4.8
+
+        sudo port -ns upgrade --force boost configure.compiler=macports-gcc-4.8
+
+* Build colobot with gcc-4.8
+
+        mkdir -p build
+        cd build
+        CC=/opt/local/bin/gcc-mp-4.8 CXX=/opt/local/bin/g++-mp-4.8 cmake ..
+        make
+
+* Build a Colobot drag-n-drop package
+
+        make package
+
+* Open the package
+
+        open colobot-*.dmg
+
+* Once opened, drag the Colobot application and drop it in the
+  Application directory. Then just launch it as any other application.