Capture unity screen in native code using DirectX capture

I want to capture game in Native code using DirectX capture. I use staging buffer to capture the screen. But I only get black screen after capture. Any input on what I am doing wrong in code attached?

Code (C++):

1. // Check out http://docs.unity3d.com/Documentation/Manual/NativePluginInterface.html
2. // for additional documentation about this process.
3.  
4. #include "UnityPlugin.h"
5. #include "GraphicsInclude.h"
6.  
7. #if _WIN32
8. #include "Capture/DXCapture.h"
9. #include <d3d11.h>
10. #include <DXGI.h>
11. #endif
12.  
13.  
14. #include <string>
15. #include <iostream>
16.  
17.  
18. #if _WIN32
19. // DirectX states
20. ID3D11Device* g_d3d_Device;
21. ID3D11DeviceContext* g_d3d_DeviceContext;
22. ID3D11RenderTargetView* g_renderTargetView[1];
23. ID3D11Texture2D* g_backBuffer;
24. #endif
25.  
26. // For now width and height are hardcoded
27. int width = 1280;
28. int height = 720;
29. int bpp = 4;
30.  
31. #pragma once
32.  
33. #pragma warning (push)
34.  
35. #if _MSC_VER && !__INTEL_COMPILER
36. // Disable warnings about macro re-definitions if we're using the DX SDK
37. // http://stackoverflow.com/questions/19336841/i-get-a-lot-of-macro-redefinition-when-using-directx-10
38. #pragma warning (disable: 4005)
39. #endif
40.  
41. #if _WIN32
42. #include <d3d11.h>
43. #endif
44.  
45. #pragma warning (pop)
46.  
47. typedef void(*FuncPtr)(const char *);
48.  
49. FuncPtr Debug;
50.  
51. static void DebugLog (const char* str)
52. {
53. #if UNITY_WIN
54.     OutputDebugStringA (str);  
55.     //Debug(str);
56. #else
57.     printf ("%s", str);
58. #endif
59. }
60.  
61. extern "C"
62. {
63.     EXPORT_API void SetDebugFunction(FuncPtr fp)
64.     {
65.         Debug = fp;
66.     }
67. }
68.  
69. // If exported by a plugin, this function will be called when graphics device is created, destroyed,
70. // and before and after it is reset (ie, resolution changed).
71. extern "C" void EXPORT_API UnitySetGraphicsDevice( void* device, int deviceType, int eventType )
72. {
73.     char log[256];
74.  
75. #if _WIN32
76.     ID3D11DepthStencilView* depthViews[1];
77.     ID3D11Resource* targetResource;
78.     D3D11_RENDER_TARGET_VIEW_DESC targetView;
79.     // Assign default values.
80.     g_d3d_Device = (ID3D11Device*)device;
81.     g_d3d_Device->GetImmediateContext(&g_d3d_DeviceContext);
82.  
83.     g_d3d_DeviceContext->OMGetRenderTargets(1, g_renderTargetView, depthViews);
84.  
85.     if (g_renderTargetView[0] == nullptr){
86.         DebugLog("No debug target view found\n");
87.     }
88.  
89.     g_renderTargetView[0]->GetResource(&targetResource);
90.  
91.     g_renderTargetView[0]->GetDesc(&targetView);
92.  
93.     sprintf(log, "Format is %d\n", targetView.Format);
94.     DebugLog(log);
95.  
96.     // Try to initialize screen capture methods.
97.     // We try them explicitly one by one until we find one that works
98.  
99.     DebugLog("Trying DirectX capture method\n");
100.     g_screenCapture = new DXCapture(g_d3d_Device, g_d3d_DeviceContext, targetResource, width, height, targetView.Format);
101.     if (!g_screenCapture->supported())
102.     {
103.         DebugLog("Cannot initialize DirectX capture method\n");
104.         delete g_screenCapture;
105.         g_screenCapture = NULL;
106.     }
107.     else
108.     {
109.         DebugLog("Using DirectX Capture method\n");
110.         goto foundCaptureMethod;
111.     }
112.  
113.     // at this point, couldn't find any capture methods
114.     DebugLog("Could not initialize any capture methods");
115.  
116. foundCaptureMethod:
117.     DebugLog("Initialize capture methods");
118.  
119. #endif
120.  
121.  
122. }
123.  
124.  
125. // If exported by a plugin, this function will be called for GL.IssuePluginEvent script calls.
126. // The function will be called on a rendering thread; note that when multithreaded rendering is used,
127. // the rendering thread WILL BE DIFFERENT from the thread that all scripts & other game logic happens!
128. // You have to ensure any synchronization with other plugin script calls is properly done by you.
129. extern "C" void EXPORT_API UnityRenderEvent ( int eventID )
130. {
131.  
132.         // Capture the frame using our current capture method
133.         const unsigned char* theFrame = g_screenCapture->capture();
134.         g_screenCapture->endCapture(); // Done with capture data
135.  
136. }
137.  
138.  

DXCapture.cpp

Code (C++):

1.  
2.  
3. #include "DXCapture.h"
4.  
5. DXCapture::DXCapture(ID3D11Device* d3DDevice, ID3D11DeviceContext* d3DDeviceContext,
6.                                          ID3D11Resource* backbuffer,
7.                      int backbufferWidth, int backbufferHeight,
8.                                          DXGI_FORMAT format)
9.     : _d3D11Device(d3DDevice),
10.       _d3D11DeviceContext(d3DDeviceContext),
11.       _backbuffer(backbuffer),
12.       _backbufferWidth(backbufferWidth),
13.       _backbufferHeight(backbufferHeight),
14.           _format(format)
15. {
16. }
17.  
18. bool DXCapture::supported()
19. {
20.     try
21.     {
22.         // Create a staging resource
23.         D3D11_TEXTURE2D_DESC stagingTextureDesc;
24.         stagingTextureDesc.Width = _backbufferWidth;
25.         stagingTextureDesc.Height = _backbufferHeight;
26.         stagingTextureDesc.MipLevels = stagingTextureDesc.ArraySize = 1;
27.         //stagingTextureDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
28.                 stagingTextureDesc.Format = _format;
29.         stagingTextureDesc.SampleDesc.Count = 1;
30.         stagingTextureDesc.SampleDesc.Quality = 0;
31.         stagingTextureDesc.Usage = D3D11_USAGE_STAGING;
32.         stagingTextureDesc.BindFlags = 0;
33.         stagingTextureDesc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
34.         stagingTextureDesc.MiscFlags = 0;
35.  
36.         if (!SUCCEEDED(_d3D11Device->CreateTexture2D(&stagingTextureDesc, NULL, &_stagingBuffer)))
37.             return false;
38.  
39.         return true;
40.     }
41.     catch (...)
42.     {
43.         return false; // Something went wrong, we can't set up DX capture
44.     }
45. }
46.  
47. CapturePixelFormat DXCapture::getCapturePixelFormat()
48. {
49.     return CAPTURE_PIXELFORMAT_R8G8B8A8; // Always
50. }
51.  
52. const unsigned char* DXCapture::capture()
53. {
54.     // Copy the frame to the staging buffer
55.     _d3D11DeviceContext->CopyResource(_stagingBuffer, _backbuffer);
56.  
57.     // Lock the staging buffer and post it to the host app for encoding
58.     D3D11_MAPPED_SUBRESOURCE mappedBuffer;
59.     HRESULT bufferMapResult = _d3D11DeviceContext->Map(_stagingBuffer, 0, D3D11_MAP_READ, 0, &mappedBuffer);
60.     if (SUCCEEDED(bufferMapResult))
61.     {
62.         unsigned char* pixel_bytes = (unsigned char*)mappedBuffer.pData;
63.         return pixel_bytes;
64.     }
65.  
66.     return NULL;
67. }
68.  
69. void DXCapture::endCapture()
70. {
71.     // Unmap this buffer, the application is done with the capture
72.     _d3D11DeviceContext->Unmap(_stagingBuffer, 0);
73. }
74.  
75. DXCapture::~DXCapture()
76. {
77.     if (_stagingBuffer != NULL)
78.     {
79.         _stagingBuffer->Release();
80.         _stagingBuffer = NULL;
81.     }
82. }
83.  
84.  

 

I know the issues. I should us D3D11_RTV_DIMENSION_TEXTURE2D for copyresource.

 

I tried using ResolveSubresource as per sample code from https://github.com/walbourn/directx-sdk-samples/blob/master/DirectXTK/Src/ScreenGrab.cpp but I am getting black frames on client side.

Can someone help me with this?

 

I try your method and use ScreenGrab, here is the code:

Code (CSharp):

1. void App3Main::SaveScreenshot()
2. {
3.     auto file = ref new Platform::String(Windows::Storage::ApplicationData::Current->TemporaryFolder->Path->Data()) + "\\Screenshot.png";
4.  
5.  
6.  
7.     /*
8.     ComPtr<ID3D11Texture2D> backBuffer;
9.     DX::ThrowIfFailed(m_deviceResources->GetSwapChain()->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&backBuffer));
10.     */
11.  
12.     ID3D11RenderTargetView* targets[] = { nullptr, nullptr };
13.     m_sceneRenderer->GetContext()->OMGetRenderTargets(ARRAYSIZE(targets), targets, nullptr);
14.     D3D11_RENDER_TARGET_VIEW_DESC targetView;
15.     targets[0]->GetDesc(&targetView);
16.     ID3D11Resource* targetResource;
17.     targets[0]->GetResource(&targetResource);
18.  
19.     auto hResult = SaveWICTextureToFile(m_sceneRenderer->GetContext(), targetResource, GUID_ContainerFormatPng, file->Data());
20. }

Eventually, I succeeded. Good luck!!!