In my case I am re-learning DX from earlier experience of the FFP days, and am using XNA Game Studio 4 to do this - since this only support up to DX9 I can't take advantage of the DX10 API. Using deferred rendering and HLSL isn't a DX10 exclusive thing, and DX9 doesn't equal FFP, so I think the XNA/DX9 route is a valid way to learn. I know there is a shed of stuff (geometry shaders for instance) which look really good in DX10, but I figure that the DX10 feature set (not API or programming model) is going to be a superset of DX9 so learning in a easy DX9 toolkit like XNA wont tell you how to write a game/3d program structurally, but the techniques will be readily adaptable.

I'm a .net guy and I've looked into SlimDX and SharpDX and they look very much like the old MDX implementations (i.e. a wrapper on DX), and I've gradually moved my learning project away from the XNA Game Pipeline into purely using the XNA namespaces and API to do rendering. I reckon thats a valid technique for a newbie. SlimDX/SharpDX are nice looking but for all its faults, and doubtful future, XNA does have a lot of historical resources behind it, whereas if I wanted to learn about the other two, I'm basically back to trying to interpret the C++ API documentation.

Just my pov

Phillip

XNA indeed is fine, but Microsoft is not working on it anymore. It seems to be going to have a very similar fate as MDX.

Is directX 9 supported in Vista/Windows7? Probably people use directX 9 because there are much more documenation and it is easier for developing purposes. Moreover for many people graphic from directx9 is OK and when they create game they don't want to have better one as they can achieve in directx 10, 11. I have been developing game since 2 years in directx 9. I chose it from the reasons above. However I don't use fixed function pipeline so maybe adaptation to directx10/11 wouldn't be hard for me, however I don't care of it now, I will take care if for example when microsoft release directx package in which backward support is not available, so if somebody install this package he cannot run games which are created on directx lower than 10.

I will take care if for example when microsoft release directx package in which backward support is not available, so if somebody install this package he cannot run games which are created on directx lower than 10.

I don't think this will happen in foreseeable future. Actually, you can still run games based on much older DX versions that 9, e.g. Unreal 1 (D3D5? D3D6?) still runs fine on Win 7.

I have played recently System Shock 2 (which is dx6 i believe) on win7

Is directX 9 supported in Vista/Windows7?

Sure.

That's one of the points here, 9.0c runs kinda on everything nowadays. DX1x require Vista and above (without exceptions) and a DX1x compatible GPU (this is actually not 100% needed, but then you are limited to SM2.0 which is even worse than what you can have in 9.0c).

As per the current Steam hardware survey at http://store.steampowered.com/hwsurvey/, and specifically, http://store.steampowered.com/hwsurvey/directx/

Around 7.5% of PCs with Steam are on XP. I guess you can make up your mind if 7.5% (and shrinking) is a market worth supporting.

Video card survey: http://store.steampowered.com/hwsurvey/videocard/

Almost 96% of GPUs accessing Steam support DirectX10 or 11 (over 65% support DirectX 11).

As the DirectX market is growing and the older markets will only be shrinking, I'm coding for DirectX11 right now, though I'm just learning at present, so I imagine the market will skew further in my favour by the time it matters.