Implement cv.gin and multiple output for python

modules/gapi/misc/python/pyopencv_gapi.hpp

@@ -1,3 +1,8 @@
+#ifndef OPENCV_GAPI_PYOPENCV_GAPI_HPP
+#define OPENCV_GAPI_PYOPENCV_GAPI_HPP
+
+#ifdef HAVE_OPENCV_GAPI
+
 using gapi_GKernelPackage = cv::gapi::GKernelPackage;
 
 template<>
@@ -12,6 +17,67 @@ PyObject* pyopencv_from(const std::vector<GCompileArg>& value)
     return pyopencv_from_generic_vec(value);
 }
 
+template<>
+bool pyopencv_to(PyObject* obj, GRunArgs& value, const ArgInfo& info)
+{
+    return pyopencv_to_generic_vec(obj, value, info);
+}
+
+static PyObject* from_grunarg(const GRunArg& v)
+{
+    switch (v.index())
+    {
+        case GRunArg::index_of<cv::Mat>():
+        {
+            const auto& m = util::get<cv::Mat>(v);
+            return pyopencv_from(m);
+        }
+
+        case GRunArg::index_of<cv::Scalar>():
+        {
+            const auto& s = util::get<cv::Scalar>(v);
+            return pyopencv_from(s);
+        }
+
+        default:
+            return NULL;
+    }
+    GAPI_Assert(false);
+}
+
+template<>
+PyObject* pyopencv_from(const GRunArgs& value)
+{
+    size_t i, n = value.size();
+
+    // NB: It doesn't make sense to return list with a single element
+    if (n == 1)
+    {
+        PyObject* item = from_grunarg(value[0]);
+        if(!item)
+        {
+            PyErr_SetString(PyExc_TypeError, "Failed to unpack GRunArgs");
+            return NULL;
+        }
+        return item;
+    }
+
+    PyObject* list = PyList_New(n);
+    for(i = 0; i < n; ++i)
+    {
+        PyObject* item = from_grunarg(value[i]);
+        if(!item)
+        {
+            Py_DECREF(list);
+            PyErr_SetString(PyExc_TypeError, "Failed to unpack GRunArgs");
+            return NULL;
+        }
+        PyList_SetItem(list, i, item);
+    }
+
+    return list;
+}
+
 template <typename T>
 static PyObject* extract_proto_args(PyObject* py_args, PyObject* kw)
 {
@@ -19,13 +85,19 @@ static PyObject* extract_proto_args(PyObject* py_args, PyObject* kw)
 
     GProtoArgs args;
     Py_ssize_t size = PyTuple_Size(py_args);
-    for (int i = 0; i < size; ++i) {
+    for (int i = 0; i < size; ++i)
+    {
         PyObject* item = PyTuple_GetItem(py_args, i);
-        if (PyObject_TypeCheck(item, reinterpret_cast<PyTypeObject*>(pyopencv_GScalar_TypePtr))) {
+        if (PyObject_TypeCheck(item, reinterpret_cast<PyTypeObject*>(pyopencv_GScalar_TypePtr)))
+        {
             args.emplace_back(reinterpret_cast<pyopencv_GScalar_t*>(item)->v);
-        } else if (PyObject_TypeCheck(item, reinterpret_cast<PyTypeObject*>(pyopencv_GMat_TypePtr))) {
+        }
+        else if (PyObject_TypeCheck(item, reinterpret_cast<PyTypeObject*>(pyopencv_GMat_TypePtr)))
+        {
             args.emplace_back(reinterpret_cast<pyopencv_GMat_t*>(item)->v);
-        } else {
+        }
+        else
+        {
             PyErr_SetString(PyExc_TypeError, "cv.GIn() supports only cv.GMat and cv.GScalar");
             return NULL;
         }
@@ -43,3 +115,51 @@ static PyObject* pyopencv_cv_GOut(PyObject* , PyObject* py_args, PyObject* kw)
 {
     return extract_proto_args<GProtoOutputArgs>(py_args, kw);
 }
+
+static PyObject* pyopencv_cv_gin(PyObject* , PyObject* py_args, PyObject* kw)
+{
+    using namespace cv;
+
+    GRunArgs args;
+    Py_ssize_t size = PyTuple_Size(py_args);
+    for (int i = 0; i < size; ++i)
+    {
+        PyObject* item = PyTuple_GetItem(py_args, i);
+        if (PyTuple_Check(item))
+        {
+            cv::Scalar s;
+            if (pyopencv_to(item, s, ArgInfo("scalar", true)))
+            {
+                args.emplace_back(s);
+            }
+            else
+            {
+                PyErr_SetString(PyExc_TypeError, "Failed convert tuple to cv::Scalar");
+                return NULL;
+            }
+        }
+        else if (PyArray_Check(item))
+        {
+            cv::Mat m;
+            if (pyopencv_to(item, m, ArgInfo("mat", true)))
+            {
+                args.emplace_back(m);
+            }
+            else
+            {
+                PyErr_SetString(PyExc_TypeError, "Failed convert array to cv::Mat");
+                return NULL;
+            }
+        }
+    }
+
+    return pyopencv_from_generic_vec(args);
+}
+
+static PyObject* pyopencv_cv_gout(PyObject* o, PyObject* py_args, PyObject* kw)
+{
+    return pyopencv_cv_gin(o, py_args, kw);
+}
+
+#endif  // HAVE_OPENCV_GAPI
+#endif  // OPENCV_GAPI_PYOPENCV_GAPI_HPP