Merge pull request #26259 from Kumataro:fix26258

core: C-API cleanup: RNG algorithms in core(4.x) #26259

- replace CV_RAND_UNI and NORMAL to cv::RNG::UNIFORM and cv::RNG::NORMAL.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

modules/core/src/rand.cpp

@@ -409,7 +409,7 @@ void RNG::fill( InputOutputArray _mat, int disttype,
                (((_param2.rows == 1 || _param2.cols == 1) &&
                 (_param2.rows + _param2.cols - 1 == cn || _param2.rows + _param2.cols - 1 == 1 ||
                 (_param1.size() == Size(1, 4) && _param1.type() == CV_64F && cn <= 4))) ||
-                (_param2.rows == cn && _param2.cols == cn && disttype == NORMAL)));
+                (_param2.rows == cn && _param2.cols == cn && disttype == RNG::NORMAL)));
 
     Vec2i* ip = 0;
     Vec2d* dp = 0;
@@ -421,7 +421,7 @@ void RNG::fill( InputOutputArray _mat, int disttype,
     int n1 = (int)_param1.total();
     int n2 = (int)_param2.total();
 
-    if( disttype == UNIFORM )
+    if( disttype == RNG::UNIFORM )
     {
         _parambuf.allocate(cn*8 + n1 + n2);
         double* parambuf = _parambuf.data();
@@ -535,7 +535,7 @@ void RNG::fill( InputOutputArray _mat, int disttype,
         }
         CV_Assert( func != 0 );
     }
-    else if( disttype == CV_RAND_NORMAL )
+    else if( disttype == RNG::NORMAL )
     {
         _parambuf.allocate(MAX(n1, cn) + MAX(n2, cn));
         double* parambuf = _parambuf.data();
@@ -586,7 +586,7 @@ void RNG::fill( InputOutputArray _mat, int disttype,
     float* nbuf = 0;
     float* tmpbuf = 0;
 
-    if( disttype == UNIFORM )
+    if( disttype == RNG::UNIFORM )
     {
         buf.allocate(blockSize*cn*4);
         param = (uchar*)(double*)buf.data();
@@ -637,7 +637,7 @@ void RNG::fill( InputOutputArray _mat, int disttype,
         {
             int len = std::min(total - j, blockSize);
 
-            if( disttype == CV_RAND_UNI )
+            if( disttype == RNG::UNIFORM )
                 func( ptr, len*cn, &state, param, tmpbuf, smallFlag );
             else
             {
@@ -753,12 +753,31 @@ void cv::randShuffle( InputOutputArray _dst, double iterFactor, RNG* _rng )
 
 #ifndef OPENCV_EXCLUDE_C_API
 
+// Related with https://github.com/opencv/opencv/issues/26258
+// To suppress cast-user-defined warning for casting CvRNG to cv::RNG& with GCC14.
+// ( CvRNG is uint64, and cv::RNG has only status member which is uint64. )
+
+#if defined(__GNUC__) && __GNUC__ >= 14
+#define CV_IGNORE_CAST_USER_DEFINED_WARNING
+#endif
+
 CV_IMPL void
 cvRandArr( CvRNG* _rng, CvArr* arr, int disttype, CvScalar param1, CvScalar param2 )
 {
     cv::Mat mat = cv::cvarrToMat(arr);
+
+#ifdef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-user-defined"
+#endif
+
     // !!! this will only work for current 64-bit MWC RNG !!!
     cv::RNG& rng = _rng ? (cv::RNG&)*_rng : cv::theRNG();
+
+#ifdef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#pragma GCC diagnostic pop
+#endif
+
     rng.fill(mat, disttype == CV_RAND_NORMAL ?
         cv::RNG::NORMAL : cv::RNG::UNIFORM, cv::Scalar(param1), cv::Scalar(param2) );
 }
@@ -766,10 +785,25 @@ cvRandArr( CvRNG* _rng, CvArr* arr, int disttype, CvScalar param1, CvScalar para
 CV_IMPL void cvRandShuffle( CvArr* arr, CvRNG* _rng, double iter_factor )
 {
     cv::Mat dst = cv::cvarrToMat(arr);
+
+#ifdef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-user-defined"
+#endif
+
     cv::RNG& rng = _rng ? (cv::RNG&)*_rng : cv::theRNG();
+
+#ifdef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#pragma GCC diagnostic pop
+#endif
+
     cv::randShuffle( dst, iter_factor, &rng );
 }
 
+#ifdef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#undef CV_IGNORE_CAST_USER_DEFINED_WARNING
+#endif
+
 #endif  // OPENCV_EXCLUDE_C_API