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View Full Version : AlphaBlending in a single pass ?



pech
03-12-2002, 12:40 PM
Does anybody know how I could code a query to ask my system if my 3D card can handle :
- alphablending in one pass
- lightmapping in one pass ?
- blending in one pass etc...

ask for the 3D card model and match with a data base of card performances doesn't fit me because, when a brand knew card is sold I will have to update the data base.

I could look at the extensions supported but they are not very explicit...

Rob The Bloke
03-12-2002, 12:49 PM
In what regard? alpha blending is supported by most graphics cards (as in all of them) and even software drivers in one pass. Lightmapping is presumably dependent on having at least multitexturing capabilities and possibly capabilities for texture env combine (which most cards in the last 4 years support, with voodoo cards as thee exception). Blending is the same as alpha blending you just specify different parameters as to what you want to blend with. Again, that is supported by all cards that support openGL.

So whats the problem? If you need to do all at once then you will be reliant on pixel shader extensions offered by nvidia or ati, So you will need to check the extensions for the availability of what you want to use.

pech
03-12-2002, 01:03 PM
Ok, thanks.
What about the Max-Min resolution supported by the card ?
Is there a way to know them without knowing the model or even the vendor ?

I thaught about a Windows-specific function, but i didn't find it.

DFrey
03-12-2002, 01:18 PM
Look at the spec for DescribePixelFormat. It is very easy to use that to enumerate all supported pixel formats. To enumerate all supported display settings, use EnumDisplaySettings. Note different contexts may support different pixel formats, so to enumerate all pixel formats you must enumerate them for each display setting.