Mixed raw pointers and Ptr<> in features2d java wrappers #11268
Description
System information (version)
- OpenCV => 3.4.1-dev (master)
- Operating System / Platform => Windows 64 Bit
- Compiler => ming64
Detailed description
both FlannBasedMatcher and BFMatcher have a public constructor and a create() method, the 1st constructs a new FlannBasedMatcher , the 2nd a new Ptr<Ptr<FlannbasedMatcher>>.
since the internal wrapper code expects the latter, using an instance created from a constructor will segfault
when being deferenced like this:
Ptr<cv::DescriptorMatcher>* me = (Ptr<cv::DescriptorMatcher>*) self;
a similar problem occurs in the BOWKMeansTrainer class, which can only be invoked from a constructor, but the internal code uses dereferenced Ptr
java example code:
FlannbasedMatcher matcher = new FlannbasedMatcher();
matcher.match(descriptor1, descriptor2, matches); // segfaults
BOWKMeansTrainer trainer = new BOWKMeansTrainer(100);
Mat vocab = trainer.cluster(descriptors); // segfaults
generated jni code:
JNIEXPORT jlong JNICALL Java_org_opencv_features2d_FlannBasedMatcher_FlannBasedMatcher_10
(JNIEnv* env, jclass )
{
static const char method_name[] = "features2d::FlannBasedMatcher_10()";
try {
LOGD("%s", method_name);
cv::FlannBasedMatcher* _retval_ = new cv::FlannBasedMatcher( makePtr<flann::KDTreeIndexParams>(), makePtr<flann::SearchParams>() );
return (jlong) _retval_;
} catch(const std::exception &e) {
throwJavaException(env, &e, method_name);
} catch (...) {
throwJavaException(env, 0, method_name);
}
return 0;
}
JNIEXPORT void JNICALL Java_org_opencv_features2d_DescriptorMatcher_knnMatch_11
(JNIEnv* env, jclass , jlong self, jlong queryDescriptors_nativeObj, jlong trainDescriptors_nativeObj, jlong matches_mat_nativeObj, jint k)
{
static const char method_name[] = "features2d::knnMatch_11()";
try {
LOGD("%s", method_name);
std::vector< std::vector<DMatch> > matches;
Mat& matches_mat = *((Mat*)matches_mat_nativeObj);
Ptr<cv::DescriptorMatcher>* me = (Ptr<cv::DescriptorMatcher>*) self; //TODO: check for NULL
Mat& queryDescriptors = *((Mat*)queryDescriptors_nativeObj);
Mat& trainDescriptors = *((Mat*)trainDescriptors_nativeObj);
(*me)->knnMatch( queryDescriptors, trainDescriptors, matches, (int)k );
vector_vector_DMatch_to_Mat( matches, matches_mat );
return;
} catch(const std::exception &e) {
throwJavaException(env, &e, method_name);
} catch (...) {
throwJavaException(env, 0, method_name);
}
return;
}