Hi guys,

probably this has been asked before, just want to know if anybody have experience with both OpenGL and D3D, how easy/difficult would be to make such a wrapper ?, I know OpenGL but nothing about D3D, I would appreciate if someone can point out some tutorials/docs on learning D3D.

Many Thanks.

Good point Richard, although I would like to learn D3D anyway..

I want to get an idea of how much effort is required to do it, Just want to make basic sprite bliting (2D textures) with some blendings, nothing fancy I guess..

Thing 1.0. Let me know if its helpful.

If you're going to piece apart the D3D source code I would start in conf.cpp in the initD3D function and then move onto bitmap_d3d.cpp (look at bitmap.h for the 'purpose' of each method).

I also started with this article:
http://www.gamedev.net/reference/articles/article2283.asp

The article has some holes in it that you'll have to figure out on your own though. Feel free to ask me anything.

Is there a particular reason you want to wrap OpenGL and D3D? OpenGL is already available on every platform D3D is, plus more. nVidia drivers handle OpenGL splendidly, Intel has released open source drivers so you can expect OpenGL support to become better for those cards/chipsets, and ATi (AMD) has promised open source drivers (not that their OpenGL support is that terrible to begin with, though it can admittedly be better).

Worse than that, it'll restrict your design to have to take into account both APIs and how they handle a given feature. So if they have radically different ways to handle the same feature, you'll be that much more seperated from either.

OpenGL is already designed to handle differences in hardware. The only things you really need to worry about is GLX vs. WGL, but that's comparitively small (and you'd have to handle that anyway).

Enlighten us.

Then that sounds like its the buyers fault and problem.

So what would be gained by wrapping nothing (OpenGL) with crap (DirectX)? At best, you have crap (actually slightly worse crap, because it has to abstract what is already poor with something the chipset doesn't have support for).

If you go with D3D, you have Windows + those corner-case cards. If you go with OpenGL, you have Windows + corner-case users (ie. Linux, FreeBSD, etc. users; some of whom have very capable cards). By using a D3D+OpenGL wrapper, you marginalize those corner case cards, thereby losing what you may have gained with pure D3D.

Simple.. Neon Wars doesn't work in OpenGL on this chipset, but does work in DirectX in a medium quality mode (not low, medium). It is perfectly playable in DirectX on this chipset, yet the game would NEVER be playable if I only had OpenGL support.

By your rationale, the game would never be playable on this chipset.

A D3D+OpenGL wrapper is perfectly capable of doing good 2D accelerated games such as you can do with OpenLayer.

Yes, they can. Not the latest games for sure, but they would expect to be able to play games that aren't too intensive. There are issues with other integrated chipsets with OpenGL as well, but supporting D3D and OpenGL makes more games playable.

I do not buy into the arguement that it is the customers fault for buying an integrated chipset. Most people don't have the expertise to know the pros and cons of hardware.

Isn't that making technology get held back... because people are cutting back on hardware upgrades or they are buying the cheapest thing available?
So there are costs for programming software (and hardware) to be backwards compatible and accomodating for old hardware/software?

But the status quo is warm and comfy.
_{I agree, by the way}

wow, I did not expect this to become a discussion..

I second Richard arguments. Personally I don't like DirectX, it's really ugly, but I see it from the users side, if the game does not run then the user won't play the game. Period. If the reason is because OGL is not supported but D3D is, then you may have a chance if you support it. That's it, as a vendor you just get more chances in selling the game.

Anyway, thanks for the replies, it's good info.

I use neither. Go figure.