2D using 3D. Why not DX5 instead of DX7 ? [Archive] - Indiegamer Developer Discussion Boards

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Jason Chong

11-09-2005, 04:43 AM

I am curious, why is there a need to go to DX7.

I just went through the DX5 documentation.

Isn't it good enough for these operations ?

We only really need hardware rotation, scaling, and alpha blending with texture alphas.

Why is there a need to use DX7 when DX5 can do these just fine ?

Wouldn't you be able to support more machines ?

PeterM

11-09-2005, 05:57 AM

The "What's new" section of the D3D7 docs pretty much covers it. Hope this helps:
Support for Visual Basic applications
Hardware-accelerated transformation and lighting
Environment mapping with cubic environment maps
Geometry Blending
Device-state blocks
Improved texture management
Enhanced software emulationHW T&L support is probably the biggie. There's also the D3DX library, which helps with loading textures and so on.

Pete

soniCron

11-09-2005, 11:09 AM

HW T&L support is probably the biggie. How many freakin sprites do you have where you'd need hardware transformation and lighting?! ;)

PeterM

11-09-2005, 11:22 AM

Quite a lot (which is your point, and you're right).

For pre-transformed geometry, or geometry which doesn't need transformed, HW T&L has somewhat limited use.

Dynamic 2D geometry (like sprites or text) will render only slightly quicker using HW T&L than SW T&L, since the vertices need to be stored in system RAM anyway.

Static geometry will render much quicker using HW T&L since the vertices can be stored in video RAM.

vjvj

11-09-2005, 11:52 AM

Wow, DX5... Now that's going back a ways.

More important is the question: What does going back to DX5 buy you? Windows has been shipping their OSs with D3D included for quite some time now. I would find out how far back DX7 goes (I really can't recall, but I'm guessing Windows ME shipped with it). I'm nearly positive all XP users start out with at least DX7 support (most likely 8 or 9).

To be honest, I'd just use DX7 if I were you.

PeterM

11-09-2005, 12:12 PM

The shipped DirectX versions (http://www.indiewiki.org/tiki-index.php?page=Shipped+DirectX+Versions) page at the Indie Wiki gives great info about which version comes installed with which OS.

soniCron

11-09-2005, 02:05 PM

The shipped DirectX versions (http://www.indiewiki.org/tiki-index.php?page=Shipped+DirectX+Versions) page at the Indie Wiki gives great info about which version comes installed with which OS. Hmmm... Looks like Windows 98 shipped with DirectX 5.0. That's a pretty good reason to support 5.0, if you ask me.

gosub

11-10-2005, 12:26 AM

The number of people hitting my fathers web site who are using windows 98:

http://www.sitemeter.com/default.asp?action=stats&site=s14doctorspiller&report=19

2% (today)

The number of them that will not download your game because they have to install DirectX 7.0 first*:

50

The number of them that would actually buy your game:

0

-Jeremy

* To fall in to this catagory, they must 1) Download games, 2) Not have installed DirectX 7.0, 3) Not have ever played a game that requires DirectX 7.0 (on that computer)

soniCron

11-10-2005, 01:13 AM

The number of people hitting my fathers web site who are using windows 98: 2% (today) Apparently only 2% have MacOSX, and yet many developers on here will tell you they sell to Mac users an order of magnitude more than PC users.

gpetersz

11-10-2005, 01:21 AM

And even the Amiga scene is alive. Some hardcore users might still remain, and for some games maybe DX5 is just enough.

Nexic

11-10-2005, 01:24 AM

I think that is mainly because Mac users only go to sites that say "WE DO MAC GAMES", because they know most sites only do PC. Where as the Win98 people will still go to most sites, as there is still a good chance that stuff downloaded from there will work for them.

My stats show only about 1.2% Win98 users.

gosub

11-10-2005, 02:15 AM

Windows 98 does not compare to Mac because you're including a bunch of Macs that are new and already have everything installed. It also doesn't compare if you think about the types of people buying Macs versus those who are TODAY still running Windows 98.

Windows 98 does not compare to Amiga.

There are no hard core users of Windows 98 who don't have DirectX 7.0.

Most people who still use Windows 98 AND have not bothered to upgrade to DirectX 7.0 are not downloading games. They're doing word processing, swearing at how slow the computer is, playing solitaire, swearing at how often the computer crashes, and maybe browsing the internet on Netscape 4.0 (and swearing at how slow the internet is).

Actually, this is the dumbest thing in the world to argue about. I don't know why I even bothered posting on this thread in the first place. What was I thinking???

-Jeremy

soniCron

11-10-2005, 02:18 AM

Most people who still use Windows 98 AND have not bothered to upgrade to DirectX 7.0 are not downloading games. They're doing word processing, swearing at how slow the computer is, playing solitaire, swearing at how often the computer crashes, and maybe browsing the internet on Netscape 4.0 (and swearing at how slow the internet is). ...and playing Bejeweled...

gosub

11-10-2005, 02:48 AM

...and playing Bejeweled...
...all two of them...

gosub

11-10-2005, 03:01 AM

FYI Bejeweled 2 requires DirectX 7.0:

http://get.games.yahoo.com/proddesc?gamekey=bejeweled2
http://www.amazon.com/exec/obidos/tg/detail/-/B0006HUH00/002-9370013-6124865?v=glance&vi=tech-data&me=ATVPDKIKX0DER

-Jeremy

soniCron

11-10-2005, 04:04 AM

...all two of them... You might want to rethink that (http://www.igda.org/casual/IGDA_CasualGames_Whitepaper_2005.pdf)...

Look, the guy doesn't need anything better than DirectX 5.0, he's willing to use DirectX 5.0, and there is no reason to support DirectX 7.0 over 5.0.

Jason Chong

11-10-2005, 06:13 AM

haha relax guys. OK answers seem fair enough, but I guess I've decided to go with DX7 instead, because it would be easier to implement 2D using 3D because of D3dX.

My other question is, why is there a need for us to use D3d7 barebones when we can use D3DX to do what we wanted, that is, alpha blending, texture alpha, rotation, scaling, mirroring in hardware?

I just checked out the popcap sdk framework and they did a LOT of work in their D3d part of the engine to get it to work for 2D, and they didn't use D3dX at all. Why not ?

electronicStar

11-10-2005, 07:44 AM