1 // Video support for Windows Runtime
2 
3 // Copyright (c) Microsoft Open Technologies, Inc.
4 // All rights reserved.
5 //
6 // (3 - clause BSD License)
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10 //
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12 // following disclaimer.
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14 // following disclaimer in the documentation and/or other materials provided with the distribution.
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26 
27 #include <ppl.h>
28 #include <functional>
29 #include <concrt.h>
30 #include <agile.h>
31 
32 using namespace Windows::UI::Xaml::Controls;
33 
34 namespace cv
35 {
36 
37 //! @addtogroup videoio_winrt
38 //! @{
39 
40 enum {
41     OPEN_CAMERA = 300,
42     CLOSE_CAMERA,
43     UPDATE_IMAGE_ELEMENT,
44     SHOW_TRACKBAR
45 };
46 
47 /********************************** WinRT API ************************************************/
48 
49 template <typename ...Args>
50 CV_EXPORTS void winrt_startMessageLoop(std::function<void(Args...)>&& callback, Args... args);
51 
52 template <typename ...Args>
53 CV_EXPORTS void winrt_startMessageLoop(void callback(Args...), Args... args);
54 
55 /** @brief
56 @note
57     Starts (1) frame-grabbing loop and (2) message loop
58     1. Function passed as an argument must implement common OCV reading frames
59        pattern (see cv::VideoCapture documentation) AND call cv::winrt_imgshow().
60     2. Message processing loop required to overcome WinRT container and type
61        conversion restrictions. OCV provides default implementation
62        Here is how the class can be used:
63 @code
64     void cvMain()
65     {
66         Mat frame;
67         VideoCapture cam;
68         cam.open(0);
69 
70         while (1)
71         {
72             cam >> frame;
73 
74             // don't reprocess the same frame again
75             if (!cam.grab()) continue;
76 
77             // your processing logic goes here
78 
79             // obligatory step to get XAML image component updated
80             winrt_imshow();
81         }
82     }
83 
84     MainPage::MainPage()
85     {
86         InitializeComponent();
87 
88         cv::winrt_setFrameContainer(cvImage);
89         cv::winrt_startMessageLoop(cvMain);
90     }
91 @endcode
92 */
93 template
94 CV_EXPORTS void winrt_startMessageLoop(void callback(void));
95 
96 /** @brief
97 @note
98     Must be called from WinRT specific callback to handle image grabber state.
99     Here is how the class can be used:
100 @code
101     MainPage::MainPage()
102     {
103         // ...
104         Window::Current->VisibilityChanged += ref new Windows::UI::Xaml::WindowVisibilityChangedEventHandler(this, &Application::MainPage::OnVisibilityChanged);
105         // ...
106     }
107 
108     void Application::MainPage::OnVisibilityChanged(Platform::Object ^sender,
109         Windows::UI::Core::VisibilityChangedEventArgs ^e)
110     {
111         cv::winrt_onVisibilityChanged(e->Visible);
112     }
113 @endcode
114 */
115 CV_EXPORTS void winrt_onVisibilityChanged(bool visible);
116 
117 /** @brief
118 @note
119     Must be called to assign WinRT control holding image you're working with.
120     Code sample is available for winrt_startMessageLoop().
121 */
122 CV_EXPORTS void winrt_setFrameContainer(::Windows::UI::Xaml::Controls::Image^ image);
123 
124 /** @brief
125 @note
126     Must be called to update attached image source.
127     Code sample is available for winrt_startMessageLoop().
128 */
129 CV_EXPORTS void winrt_imshow();
130 
131 //! @} videoio_winrt
132 
133 } // cv