some correction to make xfeature2d compilation work and adding 2d cuda features back

modules/xfeatures2d/CMakeLists.txt

 set(the_description "Contributed/Experimental Algorithms for Salient 2D Features Detection")
-ocv_define_module(xfeatures2d opencv_core opencv_imgproc opencv_features2d opencv_calib3d opencv_shape opencv_highgui opencv_videoio opencv_ml)
+ocv_define_module(xfeatures2d opencv_core opencv_cudaarithm opencv_imgproc opencv_features2d opencv_calib3d opencv_shape opencv_highgui opencv_videoio opencv_ml)

modules/xfeatures2d/perf/perf_surf.cuda.cpp

@@ -86,8 +86,7 @@ PERF_TEST_P(Image, CUDA_SURF,
     }
     else
     {
-        cv::SURF surf;
-
+        cv::xfeatures2d::SURF surf;
         std::vector<cv::KeyPoint> cpu_keypoints;
         cv::Mat cpu_descriptors;
 

modules/xfeatures2d/src/precomp.hpp

@@ -43,11 +43,14 @@
 #ifndef __OPENCV_PRECOMP_H__
 #define __OPENCV_PRECOMP_H__
 
+#include "opencv2/xfeatures2d/cuda.hpp"
+
 #include "opencv2/xfeatures2d.hpp"
 #include "opencv2/imgproc.hpp"
 
 #include "opencv2/core/utility.hpp"
 #include "opencv2/core/private.hpp"
+#include "opencv2/core/private.cuda.hpp"
 
 //#include "opencv2/nonfree/cuda.hpp"
 //#include "opencv2/core/private.cuda.hpp"

modules/xfeatures2d/src/surf.cuda.cpp

@@ -42,7 +42,7 @@
 
 #include "precomp.hpp"
 
-#if 0
+#if 1
 
 using namespace cv;
 using namespace cv::cuda;
@@ -115,7 +115,7 @@ namespace
     class SURF_CUDA_Invoker
     {
     public:
-        SURF_CUDA_Invoker(SURF_CUDA& surf, const GpuMat& img, const GpuMat& mask) :
+        SURF_CUDA_Invoker(cv::cuda::SURF_CUDA& surf, const GpuMat& img, const GpuMat& mask) :
             surf_(surf),
             img_cols(img.cols), img_rows(img.rows),
             use_mask(!mask.empty())

modules/xfeatures2d/test/test_surf.cuda.cpp

@@ -94,7 +94,7 @@ CUDA_TEST_P(SURF, Detector)
     std::vector<cv::KeyPoint> keypoints;
     surf(loadMat(image), cv::cuda::GpuMat(), keypoints);
 
-    cv::SURF surf_gold;
+    cv::xfeatures2d::SURF surf_gold;
     surf_gold.hessianThreshold = hessianThreshold;
     surf_gold.nOctaves = nOctaves;
     surf_gold.nOctaveLayers = nOctaveLayers;
@@ -130,7 +130,7 @@ CUDA_TEST_P(SURF, Detector_Masked)
     std::vector<cv::KeyPoint> keypoints;
     surf(loadMat(image), loadMat(mask), keypoints);
 
-    cv::SURF surf_gold;
+    cv::xfeatures2d::SURF surf_gold;
     surf_gold.hessianThreshold = hessianThreshold;
     surf_gold.nOctaves = nOctaves;
     surf_gold.nOctaveLayers = nOctaveLayers;
@@ -160,7 +160,7 @@ CUDA_TEST_P(SURF, Descriptor)
     surf.upright = upright;
     surf.keypointsRatio = 0.05f;
 
-    cv::SURF surf_gold;
+    cv::xfeatures2d::SURF surf_gold;
     surf_gold.hessianThreshold = hessianThreshold;
     surf_gold.nOctaves = nOctaves;
     surf_gold.nOctaveLayers = nOctaveLayers;