ndk/docs/STABLE-APIS.TXT - platform/development - Git at Google

 Android NDK Stable APIs:
 ========================

 This is the list of stable APIs/ABIs exposed by the Android NDK.

 I. Purpose:
 -----------

 Each API corresponds to a set of headers files, and a shared library file
 that contains the corresponding implementation, and which must be linked
 against by your native code.

 For example, to use system library "Foo", you would include a header
 like <foo.h> in your code, then tell the build system that your native
 module needs to link to /system/lib/libfoo.so at load-time by adding
 the following line to your Android.mk file:

   LOCAL_LDLIBS := -lfoo

 Note that the build system automatically links the C library, the Math
 library and the C++ support library to your native code, there is no
 need to list them in a LOCAL_LDLIBS line.

 There are several "API Levels" defined. Each API level corresponds to
 a given Android system platform release. The following levels are
 currently supported:

     android-3      -> Official Android 1.5 system images
     android-4      -> Official Android 1.6 system images
     android-5      -> Official Android 2.0 system images

 II. Android-3 Stable Native APIs:
 ---------------------------------

 All the APIs listed below are available for developing native code that
 runs on Android 1.5 system images and above.

 The C Library:
 --------------

 The C library headers, as they are defined on Android 1.5 are available
 through their standard names (<stdlib.h>, <stdio.h>, etc...). If one header
 is not there at build time, it's because its implementation is not available
 on a 1.5 system image.

 The build system automatically links your native modules to the C library,
 you don't need to add it to LOCAL_LDLIBS.

 Note that the Android C library includes support for pthread (<pthread.h>),
 so "LOCAL_LIBS := -lpthread" is not needed. The same is true for real-time
 extensions (-lrt on typical Linux distributions).


 ** VERY IMPORTANT NOTE: ******************************************************
 *
 *  The kernel-specific headers in <linux/...> and <asm/...> are not considered
 *  stable at this point. Avoid including them directly because some of them
 *  are likely to change in future releases of the platform. This is especially
 *  true for anything related to specific hardware definitions.
 *
 ******************************************************************************


 The Math Library:
 -----------------

 <math.h> is available, and the math library is automatically linked to your
 native modules at build time, so there is no need to list "-lm" through
 LOCAL_LDLIBS.


 C++ Library:
 ------------

 An *extremely* minimal C++ support API is available. For Android 1.5, this is
 currently limited to the following headers:

    <cstddef>
    <new>
    <utility>
    <stl_pair.h>

 They may not contain all definitions required by the standard. Notably,
 support for C++ exceptions and RTTI is not available with Android 1.5 system
 images.

 The C++ support library (-lstdc++) is automatically linked to your native
 modules too, so there is no need to list it through LOCAL_LDLIBS


 Android-specific Log Support:
 -----------------------------

 <android/log.h> contains various definitions that can be used to send log
 messages to the kernel from your native code. Please have a look at its
 content in (build/platforms/android-3/common/include/android/log.h), which
 contain many informative comments on how to use it.

 You should be able to write helpful wrapper macros for your own usage to
 access this facility.

 If you use it, your native module should link to /system/lib/liblog.so with:

   LOCAL_LDLIBS := -llog


 ZLib Compression Library:
 -------------------------

 <zlib.h> and <zconf.h> are available and can be used to use the ZLib
 compression library. Documentation for it is at the ZLib page:

     http://www.zlib.net/manual.html

 If you use it, your native module should link to /system/lib/libz.so with:

   LOCAL_LDLIBS := -lz


 III. Android-4 Stable Native APIs:
 ----------------------------------

 All the APIs listed below are available for developing native code that runs
 on Android 1.6 system images and above,


 The OpenGL ES 1.x Library:
 --------------------------

 The standard OpenGL ES headers <GLES/gl.h> and <GLES/glext.h> contain the
 declarations needed to perform OpenGL ES 1.x rendering calls from native
 code.

 If you use them, your native module should link to /system/lib/libGLESv1_CM.so
 as in:

   LOCAL_LDLIBS := -lGLESv1_CM.so


 The '1.x' here refers to both versions 1.0 and 1.1 of the OpenGL ES APIs.
 Please note that:

   - OpenGL ES 1.0 is supported on *all* Android-based devices.
   - OpenGL ES 1.1 is fully supported only on specific devices that
     have the corresponding GPU.

 This is because Android comes with a 1.0-capable software renderer that can
 be used on GPU-less devices.

 Developers should query the OpenGL ES version string and extension string
 to know if the current device supports the features they need. See the
 description of glGetString() in the specification to see how to do that:

     http://www.khronos.org/opengles/sdk/1.1/docs/man/glGetString.xml

 Additionally, developers must put a <uses-feature> tag in their manifest
 file to indicate which version of OpenGL ES their application requires. See
 the documentation linked below for details:

  http://developer.android.com/guide/topics/manifest/uses-feature-element.html

 Please note that, at the moment, native headers and libraries for the EGL APIs
 are *not* available. EGL is used to perform surface creation and flipping
 (instead of rendering). The corresponding operations must be performed in your
 VM application instead, for example with a GLSurfaceView, as described here:

 http://android-developers.blogspot.com/2009/04/introducing-glsurfaceview.html

 The "san-angeles" sample application shows how you can do that, while
 rendering each frame in native code. This is a small Android port of the
 excellent "San Angeles Observation" demo program. For more information about
 it, see:

     http://jet.ro/visuals/san-angeles-observation/


 IV. Android-5 Stable Native APIs:
 ----------------------------------

 All the APIs listed below are available for developing native code that runs
 on Android 2.0 system images and above.


 The OpenGL ES 2.0 Library:
 --------------------------

 The standard OpenGL ES 2.0 headers <GLES2/gl2.h> and <GLES2/gl2ext.h> contain the
 declarations needed to perform OpenGL ES 2.0 rendering calls from native code.
 This includes the ability to define and use vertex and fragment shaders using the
 GLSL language.

 If you use them, your native module should link to /system/lib/libGLESv2.so
 as in:

   LOCAL_LDLIBS := -lGLESv2.so

 Not all devices support OpenGL ES 2.0, developers should thus query the
 implementation's version and extension strings, and put a <uses-feature>
 tag in their Android manifest. See Section III above for details.

 Please note that, at the moment, native headers and libraries for the EGL APIs
 are *not* available. EGL is used to perform surface creation and flipping
 (instead of rendering). The corresponding operations must be performed in your
 VM application instead, for example with a GLSurfaceView, as described here:

 http://android-developers.blogspot.com/2009/04/introducing-glsurfaceview.html

 The "hello-gl2" sample application demonstrate this. It is used to draw a very
 simple triangle with the help of a vertex and fragment shaders.

 IMPORTANT NOTE:
     The Android emulator does not support OpenGL ES 2.0 hardware emulation
     at this time. Running and testing code that uses this API requires a
     real device with such capabilities.
	Android NDK Stable APIs:
	========================

	This is the list of stable APIs/ABIs exposed by the Android NDK.

	I. Purpose:
	-----------

	Each API corresponds to a set of headers files, and a shared library file
	that contains the corresponding implementation, and which must be linked
	against by your native code.

	For example, to use system library "Foo", you would include a header
	like <foo.h> in your code, then tell the build system that your native
	module needs to link to /system/lib/libfoo.so at load-time by adding
	the following line to your Android.mk file:

	LOCAL_LDLIBS := -lfoo

	Note that the build system automatically links the C library, the Math
	library and the C++ support library to your native code, there is no
	need to list them in a LOCAL_LDLIBS line.

	There are several "API Levels" defined. Each API level corresponds to
	a given Android system platform release. The following levels are
	currently supported:

	android-3 -> Official Android 1.5 system images
	android-4 -> Official Android 1.6 system images
	android-5 -> Official Android 2.0 system images

	II. Android-3 Stable Native APIs:
	---------------------------------

	All the APIs listed below are available for developing native code that
	runs on Android 1.5 system images and above.

	The C Library:
	--------------

	The C library headers, as they are defined on Android 1.5 are available
	through their standard names (<stdlib.h>, <stdio.h>, etc...). If one header
	is not there at build time, it's because its implementation is not available
	on a 1.5 system image.

	The build system automatically links your native modules to the C library,
	you don't need to add it to LOCAL_LDLIBS.

	Note that the Android C library includes support for pthread (<pthread.h>),
	so "LOCAL_LIBS := -lpthread" is not needed. The same is true for real-time
	extensions (-lrt on typical Linux distributions).


	VERY IMPORTANT NOTE: ****************************************************
	*
	* The kernel-specific headers in <linux/...> and <asm/...> are not considered
	* stable at this point. Avoid including them directly because some of them
	* are likely to change in future releases of the platform. This is especially
	* true for anything related to specific hardware definitions.
	*
	******************************************************************************


	The Math Library:
	-----------------

	<math.h> is available, and the math library is automatically linked to your
	native modules at build time, so there is no need to list "-lm" through
	LOCAL_LDLIBS.



	C++ Library:
	------------

	An extremely minimal C++ support API is available. For Android 1.5, this is
	currently limited to the following headers:

	<cstddef>
	<new>
	<utility>
	<stl_pair.h>

	They may not contain all definitions required by the standard. Notably,
	support for C++ exceptions and RTTI is not available with Android 1.5 system
	images.

	The C++ support library (-lstdc++) is automatically linked to your native
	modules too, so there is no need to list it through LOCAL_LDLIBS



	Android-specific Log Support:
	-----------------------------

	<android/log.h> contains various definitions that can be used to send log
	messages to the kernel from your native code. Please have a look at its
	content in (build/platforms/android-3/common/include/android/log.h), which
	contain many informative comments on how to use it.

	You should be able to write helpful wrapper macros for your own usage to
	access this facility.

	If you use it, your native module should link to /system/lib/liblog.so with:

	LOCAL_LDLIBS := -llog


	ZLib Compression Library:
	-------------------------

	<zlib.h> and <zconf.h> are available and can be used to use the ZLib
	compression library. Documentation for it is at the ZLib page:

	http://www.zlib.net/manual.html

	If you use it, your native module should link to /system/lib/libz.so with:

	LOCAL_LDLIBS := -lz


	III. Android-4 Stable Native APIs:
	----------------------------------

	All the APIs listed below are available for developing native code that runs
	on Android 1.6 system images and above,


	The OpenGL ES 1.x Library:
	--------------------------

	The standard OpenGL ES headers <GLES/gl.h> and <GLES/glext.h> contain the
	declarations needed to perform OpenGL ES 1.x rendering calls from native
	code.

	If you use them, your native module should link to /system/lib/libGLESv1_CM.so
	as in:

	LOCAL_LDLIBS := -lGLESv1_CM.so


	The '1.x' here refers to both versions 1.0 and 1.1 of the OpenGL ES APIs.
	Please note that:

	- OpenGL ES 1.0 is supported on all Android-based devices.
	- OpenGL ES 1.1 is fully supported only on specific devices that
	have the corresponding GPU.

	This is because Android comes with a 1.0-capable software renderer that can
	be used on GPU-less devices.

	Developers should query the OpenGL ES version string and extension string
	to know if the current device supports the features they need. See the
	description of glGetString() in the specification to see how to do that:

	http://www.khronos.org/opengles/sdk/1.1/docs/man/glGetString.xml

	Additionally, developers must put a <uses-feature> tag in their manifest
	file to indicate which version of OpenGL ES their application requires. See
	the documentation linked below for details:

	http://developer.android.com/guide/topics/manifest/uses-feature-element.html

	Please note that, at the moment, native headers and libraries for the EGL APIs
	are not available. EGL is used to perform surface creation and flipping
	(instead of rendering). The corresponding operations must be performed in your
	VM application instead, for example with a GLSurfaceView, as described here:

	http://android-developers.blogspot.com/2009/04/introducing-glsurfaceview.html

	The "san-angeles" sample application shows how you can do that, while
	rendering each frame in native code. This is a small Android port of the
	excellent "San Angeles Observation" demo program. For more information about
	it, see:

	http://jet.ro/visuals/san-angeles-observation/


	IV. Android-5 Stable Native APIs:
	----------------------------------

	All the APIs listed below are available for developing native code that runs
	on Android 2.0 system images and above.


	The OpenGL ES 2.0 Library:
	--------------------------

	The standard OpenGL ES 2.0 headers <GLES2/gl2.h> and <GLES2/gl2ext.h> contain the
	declarations needed to perform OpenGL ES 2.0 rendering calls from native code.
	This includes the ability to define and use vertex and fragment shaders using the
	GLSL language.

	If you use them, your native module should link to /system/lib/libGLESv2.so
	as in:

	LOCAL_LDLIBS := -lGLESv2.so

	Not all devices support OpenGL ES 2.0, developers should thus query the
	implementation's version and extension strings, and put a <uses-feature>
	tag in their Android manifest. See Section III above for details.

	Please note that, at the moment, native headers and libraries for the EGL APIs
	are not available. EGL is used to perform surface creation and flipping
	(instead of rendering). The corresponding operations must be performed in your
	VM application instead, for example with a GLSurfaceView, as described here:

	http://android-developers.blogspot.com/2009/04/introducing-glsurfaceview.html

	The "hello-gl2" sample application demonstrate this. It is used to draw a very
	simple triangle with the help of a vertex and fragment shaders.

	IMPORTANT NOTE:
	The Android emulator does not support OpenGL ES 2.0 hardware emulation
	at this time. Running and testing code that uses this API requires a
	real device with such capabilities.