Android samples are renamed

samples/android/tutorial-3-native/jni/jni_part.cpp

@@ -0,0 +1,33 @@
+#include <jni.h>
+#include <opencv2/core/core.hpp>
+#include <opencv2/imgproc/imgproc.hpp>
+#include <opencv2/features2d/features2d.hpp>
+#include <vector>
+
+using namespace std;
+using namespace cv;
+
+extern "C" {
+JNIEXPORT void JNICALL Java_org_opencv_samples_s2_Sample2View_FindFeatures(JNIEnv* env, jobject thiz, jint width, jint height, jbyteArray yuv, jintArray rgba)
+{
+    jbyte* _yuv  = env->GetByteArrayElements(yuv, 0);
+    jint*  _rgba = env->GetIntArrayElements(rgba, 0);
+
+    Mat myuv(height + height/2, width, CV_8UC1, (unsigned char *)_yuv);
+    Mat mrgba(height, width, CV_8UC4, (unsigned char *)_rgba);
+    Mat mgray(height, width, CV_8UC1, (unsigned char *)_yuv);
+
+    cvtColor(myuv, mrgba, CV_YUV420i2BGR, 4);
+
+    vector<KeyPoint> v;
+
+    FastFeatureDetector detector(50);
+    detector.detect(mgray, v);
+    for( size_t i = 0; i < v.size(); i++ )
+        circle(mrgba, Point(v[i].pt.x, v[i].pt.y), 10, Scalar(0,0,255,255));
+
+    env->ReleaseIntArrayElements(rgba, _rgba, 0);
+    env->ReleaseByteArrayElements(yuv, _yuv, 0);
+}
+
+}