Update to 2.0.0 tree from current Fremantle build

[opencv] / interfaces / swig / python / cvswigmacros.i

diff --git a/interfaces/swig/python/cvswigmacros.i b/interfaces/swig/python/cvswigmacros.i
new file mode 100644 (file)
index 0000000..0f54613
--- /dev/null
+++ b/interfaces/swig/python/cvswigmacros.i
@@ -0,0 +1,75 @@
+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                        Intel License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2000, Intel Corporation, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of Intel Corporation may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Intel Corporation or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+/* This file contains swig macros that are used in several typemap files */
+
+
+%define %myshadow(function)
+%ignore function;
+%rename (function) function##_Shadow;
+%enddef
+
+// Elsewhere in this wrapper, the cvRelease* functions are mapped to 
+// the destructors for the corresponding OpenCV object wrapper.  This
+// is done in order to let Python handle memory management.  If the 
+// reference count of the Python object wrapping the OpenCV object 
+// goes to 0, the garbage collector will call the destructor, and 
+// therefore the cvRelease* function, before freeing the Python object.
+// However, if the user explicitly calls the cvRelease* function, we 
+// must prevent the Python garbage collector from calling it again when
+// the refcount reaches 0 -- otherwise a double-free error occurs.
+//
+// Thus, below, we redirect each cvRelease* function to the 
+// corresponding OpenCV object's destructor.  This has the effect of:
+// (1) Calling the corresponding cvRelease* function, and therefore 
+//     immediately releasing the OpenCV object.
+// (2) Telling SWIG to disown memory management for this OpenCV object.  
+//
+// Thus, when the refcount for the Python object reaches 0, the Python
+// object is garbage collected, but since it no longer owns the OpenCV 
+// object, this is not freed again.
+%define %myrelease(module, Function, Type)
+%ignore Function;
+%rename (Function) Function##_Shadow;
+%pythoncode %{
+Function = _##module##.delete_##Type
+%}
+%enddef