How to deal with D3DX .dll hell?

Question

There's a large number of versions of the D3DX dll, from each SDK update, each version having a unique name (list of D3DX dll names).

All-too-often, people have versions missing. So even though they have a compatible version of DirectX, your D3D-based project won't run on their machine.

I want to be able to distribute games (little spare-time projects, game jam entries, etc) as a simple zip file, without the need for an installer. But a significant percentage of users run into missing D3DX .dll errors. And without an installer, Microsoft's official solution (the DirectX web installer/updater) isn't really much of a solution.

Unfortunately, Microsoft still won't give us the option of static linking to D3DX (which would be a nice clean solution). And avoiding using D3DX isn't very practical, especially if you're working with shaders (and no, I'm not switching to OpenGL, at least for now)

Does anyone have clever solutions to avoiding this DLL hell?

Answer 1

Unfortunately, there isn't a good, legal solution for this except to make an installer, because your hands are tied by the distribution rights granted to you by the DirectX SDK, which provides the D3DX DLLs. Under the terms of the license agreement you are bound to by using the SDK (which is located in (SDK Install Directory)/Documentation/License Agreements/ you are only permitted to redistribute the binary forms of certain subsets of the SDK, along with some of the sample and utility code.

As of the June 2010 SDK, you allowed to redistribute anything in the "Redist" directory and when doing so you must include certain components (DSetup32.dll, DSetup.dll, DXSetup.exe, DXupdate.cab and dxdllreg_x86.cab). The Redist directory includes the .cab files for the D3DX DLLs, but not the DLLs themselves so you are out of luck.

It isn't terribly hard to build an installer, fortunately, that just runs the appropriate D3DX web installer or whatnot that is something you redistribute. Simple .msi installers are just as easy for a user to use (double-clicking is generally all that's needed) and can be configured to allow installation into arbitrary directories, if you are concerned for some reason about "polluting" the Program Files directory with these small throw-away programs. The overhead in download size of an appropriately configured installer can be quite small, as well, so that shouldn't be too much of a problem.

EDIT: Here is a good page about DX installation stuff.

EDIT 2: Struck out the "web" bit in response to a correction in the comments.

Answer 2

Four main solutions spring to mind.

First one is to use an older version of the DirectX SDK. I seem to remember that versions from roundabout 2004 or earlier were statically linked (but if a larger executable size frightens you that might not be an option), and it's also the case that if you use a version from 2006/2007 or earlier then the D3DX DLLs you need will stand a much higher chance on being on the machine. Downside of this is that you'll be missing out on bugfixes, performance enhancements and improved functionality in the newer SDKs (it also rules out any version of D3D other than 9).

Second solution is to use LoadLibrary and GetProcAddress on the D3DX functions. You pick a maximum and minimum supported version (say, from _42 to _34), then go into a loop from max to min, construct the DLL name, and attempt to LoadLibrary it. If you load it OK, you then do a bunch of GetProcAddress calls and use your function pointers instead of the raw D3DX functions. Kind of like OpenGL extensions, if you know what I'm talking about. This one's potentially a little hairy, and you might still have to deal with the case where you can't find any DLL in your range. But I have used this one in the past and it works well enough.

Third solution is to just not use D3DX. Might be an option in some cases, might not be an option in your case.

Fourth and final solution is to just tell your users to upgrade their Direct 3D. They really should be doing this anyway, it's a small and fast download from Microsoft, and it's an instant problem solver. Your users may not like to have to do so, and you may have to deal with questions like "I've already got D3D11, why do I need to upgrade my D3D9", but on balance it may work out more economical overall to take it on the nose.