Canny via OpenVX, Node wrapper extended (query/set attribute), some naming fixes

modules/core/src/ovx.cpp

@@ -0,0 +1,72 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+// Copyright (C) 2016, Intel Corporation, all rights reserved.
+// Third party copyrights are property of their respective owners.
+
+// OpenVX related functions
+
+#include "precomp.hpp"
+#include "opencv2/core/ovx.hpp"
+#include "opencv2/core/openvx/ovx_defs.hpp"
+
+namespace cv
+{
+
+bool haveOpenVX()
+{
+#ifdef HAVE_OPENVX
+    static int g_haveOpenVX = -1;
+    if(g_haveOpenVX < 0)
+    {
+        try
+        {
+        ivx::Context context = ivx::Context::create();
+        vx_uint16 vComp = ivx::compiledWithVersion();
+        vx_uint16 vCurr = context.version();
+        g_haveOpenVX =
+                VX_VERSION_MAJOR(vComp) == VX_VERSION_MAJOR(vCurr) &&
+                VX_VERSION_MINOR(vComp) == VX_VERSION_MINOR(vCurr)
+                ? 1 : 0;
+        }
+        catch(const ivx::WrapperError&)
+        { g_haveOpenVX = 0; }
+        catch(const ivx::RuntimeError&)
+        { g_haveOpenVX = 0; }
+    }
+    return g_haveOpenVX == 1;
+#else
+    return false;
+#endif
+}
+
+bool useOpenVX()
+{
+#ifdef HAVE_OPENVX
+    CoreTLSData* data = getCoreTlsData().get();
+    if( data->useOpenVX < 0 )
+    {
+        // enabled (if available) by default
+        data->useOpenVX = haveOpenVX() ? 1 : 0;
+    }
+    return data->useOpenVX > 0;
+#else
+    return false;
+#endif
+}
+
+void setUseOpenVX(bool flag)
+{
+#ifdef HAVE_OPENVX
+    if( haveOpenVX() )
+    {
+        CoreTLSData* data = getCoreTlsData().get();
+        data->useOpenVX = flag ? 1 : 0;
+    }
+#else
+    CV_Assert(!flag && "OpenVX support isn't enabled at compile time");
+#endif
+}
+
+} // namespace cv