Building with CMake for Android

This article describes the steps to build OCCT libraries for Android from a complete source package with GNU make (makefiles) on Windows 7 and Ubuntu 15.10.

The steps on Windows and Ubuntu are similar. There is the only one difference: makefiles are built with mingw32-make on Windows and native GNU make on Ubuntu.

Required tools (download and install if it is required):

• CMake v3.0+ http://www.cmake.org/cmake/resources/software.html
• Cross-compilation toolchain for CMake https://github.com/taka-no-me/android-cmake
• Android NDK rev.10+ https://developer.android.com/tools/sdk/ndk/index.html
• GNU Make: MinGW v4.82+ for Windows (http://sourceforge.net/projects/mingw/files/), GNU Make 4.0 for Ubuntu.

Generation of makefiles

Run GUI tool provided by CMake: cmake-gui

Tools configuration

• Specify the root folder of OCCT ($CASROOT, which contains CMakelists.txt file) by clicking Browse Source.
• Specify the location (build folder) for Cmake generated project files by clicking Browse Build.

Click Configure button. It opens the window with a drop-down list of generators supported by CMake project.

Select "MinGW MakeFiles" item from the list

• Choose "Specify toolchain file for cross-compiling"
• Click "Next"
  
• Specify a toolchain file at the next dialog by android.toolchain.cmake . It is contained by cross-compilation toolchain for CMake
• Click "Finish"
  

If ANDROID_NDK environment variable is not defined in current OS, add cache entry ANDROID_NDK (entry type is PATH) – path to the NDK folder ("Add Entry" button)

If on Windows the message is appeared: "CMake Error: CMake was unable to find a build program corresponding to "MinGW Makefiles" CMAKE_MAKE_PROGRAM is not set. You probably need to select a different build tool.", specify CMAKE_MAKE_PROGRAM to mingw32-make executable.

OCCT Configuration

How to configure OCCT, see "OCCT Configuration" section of Building with CMake taking into account the specific configuration variables for android:

• ANDROID_ABI = armeabi-v7a
• ANDROID_NATIVE_API_LEVEL = 15
• ANDROID_NDK_LAYOUT is equal to CMAKE_BUILD_TYPE variable
• BUILD_MODULE_Draw = OFF

Generation of makefiles

Click Generate button and wait until the generation process is finished. Then makefiles will appear in the build folder (e.g. D:/tmp/occt-android ).

Building makefiles of OCCT

Open console and go to the build folder. Type "mingw32-make" (Windows) or "make" (Ubuntu) to start build process.

mingw32-make

or

make

Parallel building can be started with using **"-jN"** argument of "mingw32-make/make", where N is the number of building threads.

mingw32-make -j4

or

make -j4

Install built OCCT libraries

Type "mingw32-make/make" with argument "install" to place the libraries to the install folder (see "OCCT Configuration" section of Building with CMake)

mingw32-make install

or

make install