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OpenGL Direct X Dependency

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I have written a little basic program in Direct X which I based on example code from www.DirectXTutorial.com. I don't know if anyone is familiar with this tutorial. I have previously done some programming with OpenGL. I got relatively far with that as I completed and assignment using it for one of my University modules on 3D Graphics. I was curious to compare programming between Direct X and OpenGL and see how they differed. I have found that switching between the two is not so difficult. I created a little program which draws a Dodecahedron. I have been trying to show it to my brother-in-law because he is a Maths teacher and I had consulted him on the calulations required to work out the 3D vertex positions in a Dodecahedron (I figured that out myself in the end which I am quite proud of). The problem is that it has ended up being an absolute pain to try and get the program to run on any computer other than the one I developed on. The development computer has the March 2008 version of the Direct X SDK running on it. The Tutorial makes use of an expansion library for Direct X which has meant that the program I created relies on d3dx9_37.dll. I can live with that and that dependency can be satisfied by either putting the dll with the file (dirty approach I know but it works) or by installing the most up to date version of DirectX 9C. I thought that this was all ther was too it. Unfortunately there seems to be some other dependency. Even with the latest version of Direct X installed and even if I put d3dx9_37.dll with the program it still would not work on Windows XP SP3 which I have installed at home. My home system is dual boot with my primary operating system being Windows XP x64 and has Visual Studio installed as well as my other programming tools. I got the program to work on that Operating system when I updated my installed version of Direct X. On regular XP SP3 though I just kept getting an error saying the program could not start because it was not configured correctly. I figured this was most likely some missing library or something but the error message did not provide any enlightening detail. In despairation I installed Vistual C++ express with hopes that the debugger from that might give me a more explicit error as to what is causing the program to be unable to start. This did not work out as I expected. Once Visual C++ 2008 express was installed the program then just started working. The problem is I don't want to have my brother in law have to go to the length of installing Visual Studio Express just to be able to run my little program. I would guess that there is something in Visual Studio which satisfied the dependency to make this program work. The problem is I don't know what. The program is just native Win32 API so I would not expect the presence of .Net to make any difference though I could be wrong. In spite of the initial ease of switching to .Net now seeing the seeming DLL Hell I have to go through just to get a little example program to run I would feel a bit put of using it. After all the OpenGL program I created just worked on whatever computer I ran it on (As long as it was NT based i.e. W2K, XP or Vista) without any extra libraries being needed. I did compile the executable for release in Visual Studio so I would expect that the executable producted should not have been created with Visual Studio dependencies. Those with more DirectX experience would probably have a better idea of DirectX dependencies / prerequisites. Can anyone help?

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Original post by Carl JoklOn regular XP SP3 though I just kept getting an error saying the program could not start because it was not configured correctly.


That's an indication that you're missing the Visual C++ runtime on that system. The application configuration error comes up when there's an issue finding the runtime DLLs that should normally be in your WinSxS folder.

Try either compiling your project with the Multithreaded (non-DLL) runtime or run the Visual C++ 2008 Redistributable on the target system:

Visual C++ 2008 Runtime (x64)
Visual C++ 2008 Runtime (x86)

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If it is the VC2008 runtime you're missing, then you'd need that for OpenGL apps too - it's not a DirectX specific thing.

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Original post by Carl Jokl
The Tutorial makes use of an expansion library for Direct X which has meant that the program I created relies on d3dx9_37.dll. I can live with that and that dependency can be satisfied by either putting the dll with the file (dirty approach I know but it works)
So long as you're only distributing the program to people you know. It's against the EULA (illegal?) to package the DLL with your exe, for security reasons. The reason D3DX is a DLL now (A few years ago it was a static .lib), is that if there's ever a security problem found in D3DX, the DLL can be patched through Windows Update. Unfortunately, Windows Update can't check every DLL on the system, so if you have a copy of the DLL in your application's directory, it won't be patched. Furthermore, when your app starts up, this unpatched DLL will be used. That means that even though the user has downloaded the security update, they're not protected.

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Thank you. After digging around in Visual Studio's extensive configuration I managed to switch it to use the Multi-threaded (non DLL) option and have built with that instead.

Would it be safe to say this is something which changed between Visual Studio 2005 and Visual Studio 2008? I ask because I must admit back when I was doing the OpenGL coding I was using Visual Studio 2005 (2008 had not been launched yet).

I will take the produced executable home and try it out. The question will be whether Uninstalling Visual Studio Express will remove it properly to make it behave as it did before and make it like the platform I am trying to have it used on. As regards distributing a DLL, I know it is bad practice but this is only a little example program and if I were to make any proper application in DirectX I would be deploying it in a more professional manner.

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Original post by Carl Jokl
Thank you. After digging around in Visual Studio's extensive configuration I managed to switch it to use the Multi-threaded (non DLL) option and have built with that instead.

Would it be safe to say this is something which changed between Visual Studio 2005 and Visual Studio 2008? I ask because I must admit back when I was doing the OpenGL coding I was using Visual Studio 2005 (2008 had not been launched yet).
I'd recommend using the DLL version, since it can be patched if needed (via Windows Update again), and it gives you a smaller executable size. I'd just link the user to the VC2008 redistributable.
This has always been the case for VC2005 and VC2008, it's just that it's more likely that another application has installed the VC2005 runtime on the target machine for you, and it Just Works. If you tried your VC2005 app on a clean install of XP, it would probably have the same problem.

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Original post by Carl Jokl
I will take the produced executable home and try it out. The question will be whether Uninstalling Visual Studio Express will remove it properly to make it behave as it did before and make it like the platform I am trying to have it used on.
Uninstalling VC2008 probably won't remove the VC2008 runtimes, since they're a fairly critical component. You can think of it as getting a free update with VC2008's installer.

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IMO you might as well start getting used to the idea of packaging your app in an installer that will make sure the target system has all the prerequisite DLL's. No it's not pretty or fun or convenient, but it's just one of the burdens you'll have to deal with as a Windows programmer.

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Thanks. It is worth bearing in mind I suppose.

I haven't got to the point of using installers yet though that said I am not sure how much Native Win32 development I will be doing. Job wise I am a C# .Net developer. Hobby wise I use mainly Java. I started looking into DirectX because I was on a project doing some development for a Pocket PC and noticed that the .Net Compact Framework included some packages for using .Net. I thought it might be interesting to see what can be done with DirectX on a PDA but I can visualise my PDA screaming in pain not being designed for 3D graphics. It seems that the decent mobile graphics processors seem to be appearing faster in Phones than PDAs. Meanwhile I have moved on to a completely different project at work anyway and so it might be a while before I am back developing for the Pocket PC again.

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      This post gives more details about the resource binding model in Diligent Engine.
      Setting the Pipeline State and Committing Shader Resources
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      The next step is to bind all required shader resources to the GPU pipeline, which is accomplished by IDeviceContext::CommitShaderResources() method:
      m_pContext->CommitShaderResources(m_pSRB, COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES); The method takes a pointer to the shader resource binding object and makes all resources the object holds available for the shaders. In the case of D3D12, this only requires setting appropriate descriptor tables in the command list. For older APIs, this typically requires setting all resources individually.
      Next-generation APIs require the application to track the state of every resource and explicitly inform the system about all state transitions. For instance, if a texture was used as render target before, while the next draw command is going to use it as shader resource, a transition barrier needs to be executed. Diligent Engine does the heavy lifting of state tracking.  When CommitShaderResources() method is called with COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES flag, the engine commits and transitions resources to correct states at the same time. Note that transitioning resources does introduce some overhead. The engine tracks state of every resource and it will not issue the barrier if the state is already correct. But checking resource state is an overhead that can sometimes be avoided. The engine provides IDeviceContext::TransitionShaderResources() method that only transitions resources:
      m_pContext->TransitionShaderResources(m_pPSO, m_pSRB); In some scenarios it is more efficient to transition resources once and then only commit them.
      Invoking Draw Command
      The final step is to set states that are not part of the PSO, such as render targets, vertex and index buffers. Diligent Engine uses Direct3D11-syle API that is translated to other native API calls under the hood:
      ITextureView *pRTVs[] = {m_pRTV}; m_pContext->SetRenderTargets(_countof( pRTVs ), pRTVs, m_pDSV); // Clear render target and depth buffer const float zero[4] = {0, 0, 0, 0}; m_pContext->ClearRenderTarget(nullptr, zero); m_pContext->ClearDepthStencil(nullptr, CLEAR_DEPTH_FLAG, 1.f); // Set vertex and index buffers IBuffer *buffer[] = {m_pVertexBuffer}; Uint32 offsets[] = {0}; Uint32 strides[] = {sizeof(MyVertex)}; m_pContext->SetVertexBuffers(0, 1, buffer, strides, offsets, SET_VERTEX_BUFFERS_FLAG_RESET); m_pContext->SetIndexBuffer(m_pIndexBuffer, 0); Different native APIs use various set of function to execute draw commands depending on command details (if the command is indexed, instanced or both, what offsets in the source buffers are used etc.). For instance, there are 5 draw commands in Direct3D11 and more than 9 commands in OpenGL with something like glDrawElementsInstancedBaseVertexBaseInstance not uncommon. Diligent Engine hides all details with single IDeviceContext::Draw() method that takes takes DrawAttribs structure as an argument. The structure members define all attributes required to perform the command (primitive topology, number of vertices or indices, if draw call is indexed or not, if draw call is instanced or not, if draw call is indirect or not, etc.). For example:
      DrawAttribs attrs; attrs.IsIndexed = true; attrs.IndexType = VT_UINT16; attrs.NumIndices = 36; attrs.Topology = PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; pContext->Draw(attrs); For compute commands, there is IDeviceContext::DispatchCompute() method that takes DispatchComputeAttribs structure that defines compute grid dimension.
      Source Code
      Full engine source code is available on GitHub and is free to use. The repository contains two samples, asteroids performance benchmark and example Unity project that uses Diligent Engine in native plugin.
      AntTweakBar sample is Diligent Engine’s “Hello World” example.

       
      Atmospheric scattering sample is a more advanced example. It demonstrates how Diligent Engine can be used to implement various rendering tasks: loading textures from files, using complex shaders, rendering to multiple render targets, using compute shaders and unordered access views, etc.

      Asteroids performance benchmark is based on this demo developed by Intel. It renders 50,000 unique textured asteroids and allows comparing performance of Direct3D11 and Direct3D12 implementations. Every asteroid is a combination of one of 1000 unique meshes and one of 10 unique textures.

      Finally, there is an example project that shows how Diligent Engine can be integrated with Unity.

      Future Work
      The engine is under active development. It currently supports Windows desktop, Universal Windows and Android platforms. Direct3D11, Direct3D12, OpenGL/GLES backends are now feature complete. Vulkan backend is coming next, and support for more platforms is planned.
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