android android-ndk cross-compiling freetype2

Cross-compiling Freetype 2.5.3 for Android

I'm trying to cross-compile Freetype 2.5.3, so I could use it with my Android NDK Opengl ES 2 project, but I'm not sure how to do it. I'm using Cygwin on Windows. I already searched and read a lot of stuff about it, but I still need help.

I exported some flags in cygwin:

$ export NDK_TOOLCHAIN=/cygdrive/d/Development/Android/ndk-standalone-15
$ export PATH="$NDK_TOOLCHAIN/bin/:$PATH"
$ export HOST=arm-linux-androideabi
$ export CC=$HOST-gcc
$ export CXX=$HOST-g++
$ export AR=$HOST-ar
$ export LD=$HOST-ld
$ export AS=$HOST-as
$ export NM=$HOST-nm
$ export STRIP=$HOST-strip
$ export RANLIB=$HOST-ranlib
$ export OBJDUMP=$HOST-objdump
$ export CPPFLAGS="--sysroot=$NDK_TOOLCHAIN/sysroot -I$NDK_TOOLCHAIN/sysroot/usr/include -I$NDK_TOOLCHAIN/include"
$ export LDFLAGS="-L$NDK_TOOLCHAIN/sysroot/usr/lib -L$NDK_TOOLCHAIN/lib"

And then I tried to cross-compile freetype:

$ ./configure --with-sysroot=/cygdrive/d/Development/Android/ndk-standalone-15/sysroot --host=$HOST --prefix=/ft2tmp --build=$BUILD --without-zlib --with-png=no

But I got an error:

FreeType build system -- automatic system detection

The following settings are used:

platform unix compiler
arm-linux-androideabi-gcc configuration directory ./builds/unix configuration rules ./builds/unix/unix.mk

If this does not correspond to your system or settings please remove the file `config.mk' from this directory then read the INSTALL file for help.

Otherwise, simply type make' again to build the library, ormake refdoc' to build the API reference (the latter needs python).

cd builds/unix; /bin/sh ./configure '--with-sysroot=/cygdrive/d/Development/Android/ndk-standalone-15/sysroot' '--host=arm-linux-androideabi' '--prefix=/ft2tmp' '--build=' '--without-zlib' '--with-png=no' checking build system type... x86_64-unknown-cygwin checking host system type... arm-unknown-linux-androideabi checking for arm-linux-androideabi-gcc... arm-linux-androideabi-gcc checking whether the C compiler works... no configure: error: in /cygdrive/d/Development/tmp/freetype2/builds/unix': configure: error: C compiler cannot create executables Seeconfig.log' for more details builds/unix/detect.mk:86: recipe for target 'setup' failed make: * [setup] Error 77

Some of the config.log file:

gcc version 4.8 (GCC) configure:2925: $? = 0 configure:2914: arm-linux-androideabi-gcc -V >&5 arm-linux-androideabi-gcc.exe: error: unrecognized command line option '-V' arm-linux-androideabi-gcc.exe: fatal error: no input files compilation terminated. configure:2925: $? = 1 configure:2914: arm-linux-androideabi-gcc -qversion >&5 arm-linux-androideabi-gcc.exe: error: unrecognized command line option '-qversion' arm-linux-androideabi-gcc.exe: fatal error: no input files compilation terminated. configure:2925: $? = 1 configure:2945: checking whether the C compiler works configure:2967: arm-linux-androideabi-gcc --sysroot=/cygdrive/d/Development/Android/ndk-standalone-15//sysroot -I/cygdrive/d/Development/Android/ndk-standalone-15//sysroot/usr/include -I/cygdrive/d/Development/Android/ndk-standalone-15//include -L/cygdrive/d/Development/Android/ndk-standalone-15//sysroot/usr/lib -L/cygdrive/d/Development/Android/ndk-standalone-15//lib conftest.c >&5 d:/development/android/ndk-standalone-15/bin/../lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld.exe: error: cannot open crtbegin_dynamic.o: No such file or directory d:/development/android/ndk-standalone-15/bin/../lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld.exe: error: cannot open crtend_android.o: No such file or directory d:/development/android/ndk-standalone-15/bin/../lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld.exe: error: cannot find -lc d:/development/android/ndk-standalone-15/bin/../lib/gcc/arm-linux-androideabi/4.8/../../../../arm-linux-androideabi/bin/ld.exe: error: cannot find -ldl collect2.exe: error: ld returned 1 exit status configure:2971: $? = 1 configure:3009: result: no configure: failed

So my question is how should I do this properly?

EDIT:

I used unset on CPPFLAGS and LDFLAGS and used ./configure with --with-sysroot flag, and now it's doing okay. Next problem is that when I use

make

I get the following error:

$ make ./builds/unix/libtool --mode=compile arm-linux-androideabi-gcc -pedantic -ansi -I/cygdrive/d/Development/tmp/freetype2/objs -I./builds/unix -I/cygdrive/d/Development/tmp/freetype2/include -c -Wall -g -O2 -DFT_CONFIG_OPTION_SYSTEM_ZLIB -DFT_CONFIG_CONFIG_H="" -DFT2_BUILD_LIBRARY -DFT_CONFIG_MODULES_H="" -o /cygdrive/d/Development/tmp/freetype2/objs/ftsystem.lo /cygdrive/d/Development/tmp/freetype2/src/base/ftsystem.c libtool: compile: arm-linux-androideabi-gcc -pedantic -ansi -I/cygdrive/d/Development/tmp/freetype2/objs -I./builds/unix -I/cygdrive/d/Development/tmp/freetype2/include -c -Wall -g -O2 -DFT_CONFIG_OPTION_SYSTEM_ZLIB "-DFT_CONFIG_CONFIG_H=" -DFT2_BUILD_LIBRARY "-DFT_CONFIG_MODULES_H=" /cygdrive/d/Development/tmp/freetype2/src/base/ftsystem.c -fPIC -DPIC -o /cygdrive/d/Development/tmp/freetype2/objs/.libs/ftsystem.o arm-linux-androideabi-gcc.exe: error: /cygdrive/d/Development/tmp/freetype2/src/base/ftsystem.c: No such file or directory arm-linux-androideabi-gcc.exe: fatal error: no input files compilation terminated. /cygdrive/d/Development/tmp/freetype2/builds/freetype.mk:207: recipe for target '/cygdrive/d/Development/tmp/freetype2/objs/ftsystem.lo' failed make: * [/cygdrive/d/Development/tmp/freetype2/objs/ftsystem.lo] Error 1

Solution

You have to set the Windows-style path providing where freetype2 is located. Here is how to include in your windows environment path the libraries and files that you are using for your development in Android. The same thing you need to do for the freetype2.

You may find useful to check these references:

As you will probably observe, most of the best material available to develop Android Apps are on Linux:

In case you are really serious about Android development, it would be worth to consider moving your development to a Linux platform.

You should also have a look on the OpenGL Getting Started, that provides several tutorials on how work with OpenGL on Linux, Windows and MacOS. Taking a gentle step by step approach is more productive to successfully grow your OpenGL development skills.