adding ant build instructions

Compilation-guide-(android-from-windows).md

@@ -1,4 +1,4 @@
-### Prerequisites
+## Prerequisites
 
 You need a complete android development environment ready to develop native apps. That means:
 * Cygwin
@@ -13,7 +13,7 @@ export NDK_ROOT=/cygdrive/d/Dev/Libs/Android/android-ndk-r8e
 export PATH=$NDK_ROOT:$PATH
 ```
 
-### Building libretro cores
+## Building libretro cores
 ```bash
 git clone https://github.com/libretro/libretro-super.git
 cd libretro-super
@@ -22,7 +22,7 @@ cd libretro-super
                                  # see https://github.com/libretro/libretro-super/issues/10
 ```
 
-### Building RetroArch
+## Building RetroArch
 The RetroArch repo is fetched into the libretro-super folder as retroarch by `./libretro-fetch.sh` above.
 ```bash
 cd retroarch/android/native
@@ -32,13 +32,31 @@ cd ../phoenix
 cp -R ../native/libs/* libs                     # copy native libs
 cp -R ../../../dist/android/* libs              # copy libretro cores
 ```
-
 When you need to rebuild the native code, run this from retroarch/android/native:
 ```bash
 ndk-build APP_ABI="armeabi-v7a mips x86" APP_PLATFORM=android-17
 cp -R -f libs/* ../phoenix/libs
 ```
 
+## Building the .apk
+You can choose to use the Eclipse gui or the command line tool `ant`
+### Building with ant
+From the android/phoenix directory in the RetroArch repo:
+```bash
+android update project --path libs/googleplay/
+android update project --path libs/appcompat/
+```
+Now edit local.properties to point to the location of your ndk directory by adding a line like this: `ndk.dir=/complete/path/to/android-ndk-r9d`
+```bash
+ant clean
+ant debug
+```
+If all goes well this will spit out an .apk, `bin/retroarch-debug.apk`. Put it on your device with
+```bash
+adb -d install bin/retroarch-debug.apk
+```
+
+### Building with eclipse
 In Eclipse, set your workspace root to .../RetroArch/android. Then do "Import... - General - Existing Projects into Workspace" to get the native and phoenix projects in your workspace. I also copied the project.properties from phoenix to native, and created a src directory in native, to stop Eclipse from complaining, but that may just be because I'm using a really old version.
 
 Then, when you want to deploy to your device (make sure USB debugging is enabled) right-click on the phoenix project and select "Run As - Android Application" or use Debug to attach the debugger. When the native libs change I will tend to Clean before doing Run, to make sure the libs were repackaged in the apk. Google for more info about running and debugging Android apps in Eclipse.