add fucntion to control tegra optimizations in run-time

modules/core/include/opencv2/core/private.hpp

@@ -269,6 +269,15 @@ typedef enum CvStatus
 }
 CvStatus;
 
+#ifdef HAVE_TEGRA_OPTIMIZATION
+namespace cv { namespace tegra {
+
+CV_EXPORTS bool useTegra();
+CV_EXPORTS void setUseTegra(bool flag);
+
+}
+#endif
+
 //! @endcond
 
 #endif // __OPENCV_CORE_PRIVATE_HPP__

modules/core/src/precomp.hpp

@@ -236,6 +236,9 @@ struct CoreTLSData
 {
     CoreTLSData() : device(0), useOpenCL(-1), useIPP(-1), useCollection(false)
     {
+#ifdef HAVE_TEGRA_OPTIMIZATION
+        useTegra = -1;
+#endif
 #ifdef CV_COLLECT_IMPL_DATA
         implFlags = 0;
 #endif
@@ -246,6 +249,9 @@ struct CoreTLSData
     ocl::Queue oclQueue;
     int useOpenCL; // 1 - use, 0 - do not use, -1 - auto/not initialized
     int useIPP; // 1 - use, 0 - do not use, -1 - auto/not initialized
+#ifdef HAVE_TEGRA_OPTIMIZATION
+    int useTegra; // 1 - use, 0 - do not use, -1 - auto/not initialized
+#endif
     bool useCollection; // enable/disable impl data collection
 
 #ifdef CV_COLLECT_IMPL_DATA

modules/core/src/system.cpp

@@ -1257,6 +1257,36 @@ void setUseIPP(bool flag)
 
 } // namespace ipp
 
+#ifdef HAVE_TEGRA_OPTIMIZATION
+
+namespace tegra {
+
+bool useTegra()
+{
+    CoreTLSData* data = getCoreTlsData().get();
+
+    if (data->useTegra < 0)
+    {
+        const char* pTegraEnv = getenv("OPENCV_TEGRA");
+        if (pTegraEnv && (cv::String(pTegraEnv) == "disabled"))
+            data->useTegra = false;
+        else
+            data->useTegra = true;
+    }
+
+    return (data->useTegra > 0);
+}
+
+void setUseTegra(bool flag)
+{
+    CoreTLSData* data = getCoreTlsData().get();
+    data->useTegra = flag;
+}
+
+} // namespace tegra
+
+#endif
+
 } // namespace cv
 
 /* End of file. */