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OpenGL The Great Windows Graphics Programming Mess

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Hi all, apologies that this is partly a rant, but it's a little frustrating. I've been looking at writing a heightmap editor and texture painter as well as a couple of other tools with the aim of eventually including them within a basic XNA game just to get back into graphics programming having mostly done web stuff and application development for many years now. Ideally of course, I'd just use XNA for rendering onto a panel in the editors and C# with Windows Forms for the tool interface itself. Another editor I intend to write requires decent performing 2D rendering, so that rules out GDI and XNA's 2D support isn't particularly ideal as it seems to focus mostly on loading in 2D assets than rendering primitives manually. The problem I've got is that quite frankly, rendering in Windows seems a complete and utter mess now- in fact, it seems to consist of such a disjoint set of technologies all overlapping but neither quite achieving anything I'm intrigued to know people's opinions. Effectively these are the problems I've noticed from my initial research: - XNA is poor for 2D primitives, and whilst it works with Windows forms, isn't so great. If you want to use C# for 3D rendering you're supposed to use XNA nowadays as managed DirectX is deprecated. - We all know GDI and GDI+ are slow in many cases, Microsoft recommends whilst you use XNA for 3D with C#, you use WPF for 2D. XNA does not really work at all with WPF right now so you can't mix and match. - Direct3D works great for 3D but you need to use C++ due to the afformentioned problem of managed DirectX being deprecated - For 2D Microsoft have now introduced Direct2D. Of course, the goal of any developer is to find the tool that's going to offer them the most rapid development whilst offering great reusability. I can't see the best way to achieve that here - if I write the game in XNA, I can write the 3D editor in XNA + Windows forms, but then I have to start from scratch and build the 2D editor as a WPF application. I can use Direct3D and Direct2D to produce the tools, but then if I want to deploy to the XBox's indie games section I've still got to write the game in XNA. Of course, I could build the tools into the game engine but then you have to write a lot of your own UI code, and you have the problem of not so great 2D primitives support in XNA still. Can anyone shed some light on the reasoning behind this madness? Is there any reason Microsoft feel it's sensible to have GDI/GDI+, WPF, Direct2D, Direct3D, XNA, Managed DirectX all at different stages of existence, neither allowing you to produce a toolchain and game with one API and one language? I can't help but think things were actually simpler back in the Win32 API or MFC + DirectX or OpenGL days because then you at least had a unified set of technologies from start to finish. Is this a problem anyone else has encountered or do you all generally just stick to C++ and DirectX/OpenGL not bothering with XBox indie games deployment? Has anyone else faced this situation and if so do you have any advice on the benefits/pitfalls of the route you took? Maybe there's something I've missed and some of the forum threads/comments/press releases from MS and so forth are now outdated and things have improved? Comments, advice, and so on much appreciated. Thanks in advance!

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I don't see what is problem with using XNA +WinForms to do 2D rendering.
Or if you don't want to use XNA for 2D graphics, but prefer Direct3D API, you can use in C# WinForms + SlimDX, which is wrapper around native DirectX functionality. Ok you loose xbox portability, but who cares for that with level editor/modeler?

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SlimDX looks like an option certainly, but still leaves the requirement to rewrite a fair bit more code than would be ideal for the XBox version itself.

Another issue I forgot to mention with XNA is you can't load most content from file at run time either to use with the XNA framework, at least, in a particularly elegant, portable manner anyhow.

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use Qt and OpenGL for 3D and 2D and your life will be all flowers and whistles :D. Plus you get portability across several systems.


Yeah, this is a strongly biased oppinion because i´m more of an opengl guy. But i agree with you that rendering on windows is a bit of a mess. I can´t really give you advice on this so i better shut up.

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This isn't a problem with Windows, this is a problem across all platforms. Rather, it's more like a "fact a life" than a problem... Windows may have slightly more complexity to it though, since it has DirectX.

Fundamentally there's still only Direct3D and OpenGL on Windows (excluding the GDI libraries, since they are not hardware accelerated and generally not suitable for most games people are building these days). XNA runs on Direct3D, as does Direct2D.

Quote:

- XNA is poor for 2D primitives, and whilst it works with Windows forms, isn't so great. If you want to use C# for 3D rendering you're supposed to use XNA nowadays as managed DirectX is deprecated.

Yes, XNA is mainly a 3D API (but so is Direct3D, which it sits on top of on Windows). The problem of doing 2D with a 3D API is a common and well-solved one, however. As for MDX being deprecated, that's why there is SlimDX.

Quote:

- We all know GDI and GDI+ are slow in many cases, Microsoft recommends whilst you use XNA for 3D with C#, you use WPF for 2D. XNA does not really work at all with WPF right now so you can't mix and match.

GDI[+]'s not hardware accelerated generally. You can get it to run at a usable clip for some kinds of simple 2D games though. But yes, it's not a viable option for fast 3D.

As for WPF, I don't buy that it's a great for 2D either. I think it fits in the same category as GDI -- you can do it, and make it decently fast, but it's not going to be the best way to go about things, just a (more or less) easy one.

Quote:

Direct3D works great for 3D but you need to use C++ due to the afformentioned problem of managed DirectX being deprecated

SlimDX.

Quote:

For 2D Microsoft have now introduced Direct2D.

Sits on top of Direct3D. Remember, Direct2D is also not intended to be targeted primarily at game developers, and even then isn't intended to be a scalable solution for all the things a 2D game might need. It's more for application developers. See their audience breakdown -- games really only fit into the last bullet point there, and even then its just UI stuff. Doing 2D games with a real 3D API can give you a lot more flexibility and room to explore really cool visuals.

Quote:

Can anyone shed some light on the reasoning behind this madness? Is there any reason Microsoft feel it's sensible to have GDI/GDI+, WPF, Direct2D, Direct3D, XNA, Managed DirectX all at different stages of existence, neither allowing you to produce a toolchain and game with one API and one language?

Each of them exist because they were designed to fulfill certain roles. I think what you're getting hung up on is the assumption that they're all designed to fulfill the role you need, or be used in the context that you want. For some of them this is only tangentially true.

I think the really key differentiators are: native or managed?

If native, you've got Direct3D, OpenGL, and Direct2D. D3D/GL is really down to personal preference unless you want/need to port, in which case GL is probably better. I wouldn't consider Direct2D unless you are doing a very simple 2D game or are curious about the API itself.

If managed, you have the option of the 360... so then you decide if you want PC-only or PC/360. If the latter, you use XNA and cope with its shortcomings w.r.t to interop into Windows Forms or WPF for tool development. If you don't care about the 360, use SlimDX.

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What sort of 2D things are you looking to do in XNA? There's a lot of user-created libraries out there that do some neat things, and I might be able to point you in the right direction. [smile]

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What's wrong with using C++ and Direct3D? There's hundreds (if not thousands) of libraries out there that provide all the 2D functionality that you could ever want. Why not use the same language and API that is generally used for what you are trying to do?

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Original post by Jason Z
What's wrong with using C++ and Direct3D? There's hundreds (if not thousands) of libraries out there that provide all the 2D functionality that you could ever want. Why not use the same language and API that is generally used for what you are trying to do?
I think he wants to deploy to the Xbox as well. XNA can do pretty much anything that "native" D3D can do, especially when it comes to 2D stuff.

I think the real problem here has more to do with developing tools than actually developing games. If you're writing a game in XNA, the usual way to do an editor (that's not in-game anyway) would be to embed your engine in a Windows Forms application. I'm not sure what kind of UI stuff would require "decent performing 2D rendering" but in my experience GDI+/WinForms is actually not all that bad in terms of performance.

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Yes, the issue is that for building XBox community games you're really forced into using C# and XNA. This isn't in itself a bad thing as I'm a big fan of C# and XNA is great for rapidly developing games.

The issue does indeed stem from tool building, the reason I'm after decent performing 2D is for visual management of game flow by moving objects around and so forth and also for management of decision trees for certain AI. I have experimented with GDI+, in fact I've used it at work for graph rendering, but found that even something as simple as rendering a graph and allowing picking of points on the graph with the graph section picked being highlighted and GDI struggles to redraw fast enough without horrible flicker, of course, it becomes even worse and even more apparent when debugging also.

My gripe is effectively this, I could use as ArKano says something like Qt and OpenGL to build my game, my toolchain and so on. I could share code between the game, the tools and everything, I wouldn't need to switch language, development environment, API, whatsoever, and I'd have cross platform support. Similarly I have the same situation with Java and OpenGL or even just with Java3D. Even back in the old days I could develop with Win32 API and OpenGL and have a set of tools that worked from start to finish on all Windows platforms, or if I used SDL instead would even work across multiple platforms. So why is it that now, 10 to 15 years on, we're here in this situation with Microsoft's platforms where although the languages have moved on (Managed code rather than C/C++ etc.), the libraries seem to have taken a step backwards in that they all fill specific niches for specific languages rather than having a unified API that just works? An example solution would've been simply to continue managed DirectX for C# rendering purposes and use that or at least, components of that, as the platform for XBox community games rather than build up XNA which is great for XBox stuff, but poor for tools stuff?

Of course, it'd all be easier if I just ditched the idea of XBox development, but I'm a big fan of it and the ease of publishing attracts me. I don't intend to ever give up the day job, I want to develop games as a hobby and be able to play them on my console with my friends on their consoles it may or may not also net a little extra cash on the side. The concept of XBox community games allows me to do all this without worrying much about marketing or distribution but also if I'm to enable friends to help develop the game content itself, then being able to produce a good set of Windows tools is really the easiest way forward for this.

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      The same technique is applied for the rest of the faces (obviously, with the proper rotations / translations).
      The matrix that result from the multiplication of R and T (in that particular order) is send to my vertex shader as `r_Grid'.
      // spherify vec3 V = normalize((r_Grid * vec4(r_Vertex, 1.0)).xyz); gl_Position = r_ModelViewProjection * vec4(V, 1.0); The `r_ModelViewProjection' matrix is generated on the CPU in this manner.
      // No the most efficient way, but it works. glm::dmat4 Camera::getMatrix() { // Create the view matrix // Roll, Yaw and Pitch are all quaternions. glm::dmat4 View = glm::toMat4(Roll) * glm::toMat4(Pitch) * glm::toMat4(Yaw); // The model matrix is generated by translating in the oposite direction of the camera. glm::dmat4 Model = glm::translate(glm::dmat4(1.0), -Position); // Projection = glm::perspective(fovY, aspect, zNear, zFar); // zNear = 0.1, zFar = 1.0995116e12 return Projection * View * Model; } I managed to get rid of z-fighting by using a technique called Logarithmic Depth Buffer described in this article; it works amazingly well, no z-fighting at all, at least not visible.
      Each frame i'm rendering each node by sending the generated matrices this way.
      // set the r_ModelViewProjection uniform // Sneak in the mRadiusMatrix which is a matrix that contains the radius of my planet. Shader::setUniform(0, Camera::getInstance()->getMatrix() * mRadiusMatrix); // set the r_Grid matrix uniform i created earlier. Shader::setUniform(1, r_Grid); grid->render(); My planet's radius is around 6400000.0 units, absurdly large, but that's what i really want to achieve;
      Everything works well, the node's split and merge as you'd expect, however whenever i get close to the surface
      of the planet the rounding errors start to kick in giving me that lovely stairs effect.
      I've read that if i could render each grid relative to the camera i could get better precision on the surface, effectively
      getting rid of those rounding errors.
       
      My question is how can i achieve this relative to camera rendering in my scenario here?
      I know that i have to do most of the work on the CPU with double, and that's exactly what i'm doing.
      I only use double on the CPU side where i also do most of the matrix multiplications.
      As you can see from my vertex shader i only do the usual r_ModelViewProjection * (some vertex coords).
       
      Thank you for your suggestions!
       
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