Switch instructions to do an out-of-tree build, as is generally

recommended these days.

README-OSX.md

@@ -23,26 +23,26 @@ This project has two ways to build: one with make and the other with Xcode.  The
 ### Make
 1. In the root of the repository, generate the Makefile with cmake (Release is also a valid build type):
 ```
-cmake . -DCMAKE_BUILD_TYPE="Debug"
+cmake -DCMAKE_BUILD_TYPE=Debug -B build .
 ```
-1. Copy the vanilla game assets (UFO/TFTD) into the repository's `bin/` directory.
+1. Copy the vanilla game assets (UFO/TFTD) into the build's `bin/` directory.
 1. Build the project (2 being the number of threads to run):
 ```
-make -j2
+cmake --build build -j2
 ```
 1. Make sure that you set up your [Data directory](https://github.com/OpenXcom/OpenXcom#directory-locations) properly.
-1. Your artifact will be named `openxcom.app` in the root of the repository.
+1. Your artifact will be named `openxcom.app` in the build target directory.
 
 
 ### Xcode
-1. In the root of the repository, generate the Makefile with cmake (Release is also a valid build type):
+1. In the root of the repository, generate the XCode project file with cmake (Release is also a valid build type):
 ```
-cmake . -DCMAKE_BUILD_TYPE="Debug" -G Xcode
+cmake -DCMAKE_BUILD_TYPE=Debug -G Xcode -B build .
 ```
 1. Open the `OpenXcom.xcodeproj` in Xcode.
-1. Copy the vanilla game assets (UFO/TFTD) into the repository's `bin/` directory.
+1. Copy the vanilla game assets (UFO/TFTD) into the build's `bin/` directory.
 1. Build with cmd-B
-1. Your artifact will be named `openxcom.app` in the build target directory (Debug or Release) from the root of the repository.
+1. Your artifact will be named `openxcom.app` in the build target directory (Debug or Release).
 
 ## Additional Help
 Should you require any further assistance regarding the OSX build - feel free to ask around on the official forums - https://openxcom.org/forum/ or contact us directly on GitHub - [@rcreasey](http://github.com/rcreasey)