1// This file is part of OpenCV project.
2// It is subject to the license terms in the LICENSE file found in the top-level directory
3// of this distribution and at http://opencv.org/license.html.
4//
5// Copyright (C) 2019 Intel Corporation
6
7#ifndef OPENCV_GAPI_GTRANSFORM_HPP
8#define OPENCV_GAPI_GTRANSFORM_HPP
9
10#include <functional>
11#include <type_traits>
12#include <utility>
13
14#include <opencv2/gapi/gcommon.hpp>
15#include <opencv2/gapi/util/util.hpp>
16#include <opencv2/gapi/garg.hpp>
17#include <opencv2/gapi/gtype_traits.hpp>
18#include <opencv2/gapi/util/compiler_hints.hpp>
19#include <opencv2/gapi/gcomputation.hpp>
20
21namespace cv
22{
23
24struct GAPI_EXPORTS GTransform
25{
26 // FIXME: consider another simplified
27 // class instead of GComputation
28 using F = std::function<GComputation()>;
29
30 std::string description;
31 F pattern;
32 F substitute;
33
34 GTransform(const std::string& d, const F &p, const F &s) : description(d), pattern(p), substitute(s) {}
35};
36
37namespace detail
38{
39
40template <typename, typename, typename>
41struct TransHelper;
42
43template <typename K, typename... Ins, typename Out>
44struct TransHelper<K, std::tuple<Ins...>, Out>
45{
46 template <typename Callable, int... IIs, int... OIs>
47 static GComputation invoke(Callable f, Seq<IIs...>, Seq<OIs...>)
48 {
49 const std::tuple<Ins...> ins;
50 const auto r = tuple_wrap_helper<Out>::get(f(std::get<IIs>(ins)...));
51 return GComputation(cv::GIn(std::get<IIs>(ins)...),
52 cv::GOut(std::get<OIs>(r)...));
53 }
54
55 static GComputation get_pattern()
56 {
57 return invoke(K::pattern, typename MkSeq<sizeof...(Ins)>::type(),
58 typename MkSeq<std::tuple_size<typename tuple_wrap_helper<Out>::type>::value>::type());
59 }
60 static GComputation get_substitute()
61 {
62 return invoke(K::substitute, typename MkSeq<sizeof...(Ins)>::type(),
63 typename MkSeq<std::tuple_size<typename tuple_wrap_helper<Out>::type>::value>::type());
64 }
65};
66} // namespace detail
67
68template <typename, typename>
69class GTransformImpl;
70
71template <typename K, typename R, typename... Args>
72class GTransformImpl<K, std::function<R(Args...)>> : public cv::detail::TransHelper<K, std::tuple<Args...>, R>,
73 public cv::detail::TransformTag
74{
75public:
76 // FIXME: currently there is no check that transformations' signatures are unique
77 // and won't be any intersection in graph compilation stage
78 using API = K;
79
80 static GTransform transformation()
81 {
82 return GTransform(K::descr(), &K::get_pattern, &K::get_substitute);
83 }
84};
85} // namespace cv
86
87#define G_DESCR_HELPER_CLASS(Class) Class##DescrHelper
88
89#define G_DESCR_HELPER_BODY(Class, Descr) \
90 namespace detail \
91 { \
92 struct G_DESCR_HELPER_CLASS(Class) \
93 { \
94 static constexpr const char *descr() { return Descr; } \
95 }; \
96 }
97
98#define GAPI_TRANSFORM(Class, API, Descr) \
99 G_DESCR_HELPER_BODY(Class, Descr) \
100 struct Class final : public cv::GTransformImpl<Class, std::function API>, \
101 public detail::G_DESCR_HELPER_CLASS(Class)
102
103#endif // OPENCV_GAPI_GTRANSFORM_HPP
104

source code of opencv/modules/gapi/include/opencv2/gapi/gtransform.hpp