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POUsing Cython to wrap a C++ class that uses OpenCV types as parameters
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2013-09-07T19:08:18.103
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2013-09-07T21:00:28.057
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I'm trying to use Cython to wrap a C++ class that uses some OpenCV types as parameters, then I intend to use this wrapped class from Python. A simplified version of the C++ class looks like: "transform.h" <pre><code>#include "opencv2/core/core.hpp" namespace geom { class Transform { public: Transform(cv::Vec3d &euler, cv::Vec3d &t); void set_euler(cv::Vec3d &euler); cv::Vec3d get_euler(); } } </code></pre> Vec3d is defined in OpenCV as: <pre><code>template<typename _Tp, int n> class Vec : public Matx<_Tp, n, 1> {...}; typedef Vec<double, 3> Vec3d; </code></pre> and Matx is defined as: <pre><code>template<typename _Tp, int m, int n> class Matx {...}; </code></pre> My first attempt to the cython wrapper looks like this: "geom_gateway.pyx" <pre><code>cdef extern from "opencv2/core/core.hpp" namespace "cv": cdef cppclass Matx[_Tp, int m, int n]: Matx() Matx(_Tp v0, _Tp v1, _Tp v2) cdef extern from "opencv2/core/core.hpp" namespace "cv": cdef cppclass Vec[_Tp, int n](Matx[_Tp, n, 1]): Vec() Vec(_Tp v0, _Tp v1, _Tp v2) ctypedef Vec<double, 3> Vec3d cdef extern from "transform.h" namespace "geom": cdef cppclass Transform: Transform(cv::Vec3d &euler, cv::Vec3d &t) void set_euler(cv::Vec3d &euler) cv::Vec3d get_euler() </code></pre> This wrapper is unfinished but I just wanted to build it and check that I get the syntax right. Unfortunately, when I build it I don't get too far, I get: <pre><code>cdef extern from "opencv2/core/core.hpp" namespace "cv": cdef cppclass Matx[_Tp, int m, int n]: ^ ------------------------------------------------------------ ../basics/geom_gateway:3:29: Expected ']', found 'm' </code></pre> what's wrong? I imagine that it's possible to have multiple value templates in Cython? otherwise how could I wrap in Cython a C++ class that uses these templated types from OpenCV? I suspect I may have other problems in this piece of code, please feel free to point out.
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<c++><python><opencv><cython>
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Using Cython to wrap a C++ class that uses OpenCV types as parameters
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