create simple skia app for android using jni

experimental/HelloSkia/jni/Android.mk

+LOCAL_PATH := $(call my-dir)
+
+# set this to wherever your skia directory is located, with out trailing slashes

[djsollen, 2013/06/04 00:26:35]

I think that for clarity we should have them copy the headers into
jni/skia/include.  That way if they update their skia tree it is clear that they
would also need to update these files.

Additionally, have them put the shared library in jni/skia/ as well.

Now this file won't be dependent upon any variables being set, just that they
did the work ahead of time to put content into the correct directories.

+SKIA_HOME :=
+
+
+##
+# sets up a module for the skia shared object to be copied into the apk. Be sure to copy an
+# appropriate build of libskia_android.so for your architecture into this directory.
+##
+
+include $(CLEAR_VARS)
+
+# name for referencing this module in other modules
+LOCAL_MODULE := skia_android
+
+# local filename of the skia shared object
+LOCAL_SRC_FILES := libskia_android.so
+
+# makes this module into shared object that is simply copied into the apk
+include $(PREBUILT_SHARED_LIBRARY)
+
+
+##
+# sets up the JNI module that our app calls into to draw things with skia.
+##
+
+include $(CLEAR_VARS) # clear out the variables of the previous module
+
+# name of the module that the app will reference with System.loadLibrary
+LOCAL_MODULE := hello_skia_ndk
+
+# list of the source files compiled for this module
+LOCAL_SRC_FILES := helloskia.cpp
+
+# makes the skia shared object get pulled in as a reference
+LOCAL_SHARED_LIBRARIES := skia_android
+
+# jnigraphics defines the function AndroidBitmap_lockPixels, which we need in order to draw into
+# android.graphics.Bitmap
+LOCAL_LDLIBS := -ljnigraphics
+
+LOCAL_C_INCLUDES := $(SKIA_HOME)/include/config \
+                    $(SKIA_HOME)/include/core
+
+include $(BUILD_SHARED_LIBRARY)