Modes which don't support hardware

Barn Door · 2002-09-03T21:12:40

Hi, It says in the doc that you need to query an adapter for the modes(resolution, bit format) it supports. Then, if you want to use &#111ne of these modes whilst using hardware acceleration, you need to query to see if the mode supports hardware acceleration. Now, assuming I haven't misinterpreted this, why should some display modes of an adapter not support hardware acceleration? What are they good for? Thanks, BD. [edited by - Barn Door &#111n September 2, 2002 9:17:06 PM]

Graphics and GPU Programming Programming

Started by Barn Door September 02, 2002 08:13 PM

13 comments, last by Barn Door 21 years, 7 months ago

Syrillix

122

September 03, 2002 07:00 PM

quote:Original post by Barn Door
I don't see what the format is being validated against in a call to CheckDeviceType and thus why it and any modes which support it might be rejected?

It doesn't seem to make sense that its a simple case of - does this card support this format - because in the SDK sample, the display modes of the adapters are enumerated and an array of pixel formats is built up. These formats come from the card! So why would you then need to check them in a call to CheckDeviceType ?

i'll take a wild shot in dark with this... perhaps when the diplay modes are enumerated, ALL the modes are returned even the ones that cant use hardware acceleration for reasons mentioned above.
also, some cards just dont support all the modes and X1R5G5B5 might have been one of them....
but im probably wrong

Get busy livin' or get busy dyin'... - Shawshank Redemption

[edited by - Syrillix on September 3, 2002 8:01:52 PM]

Get busy livin' or get busy dyin'... - Shawshank RedemptionIf a man is talking in the forest, and no woman is around to hear him, is he still wrong? - UnknownFulcrum

Barn Door

140

Author

September 03, 2002 07:06 PM

Thanks for your reply.

quote:
to make sure that the *specific* firmat (+resolution) can use hardware acceleration or not

But the call to CheckDeviceType doesn''t involve any mention of resolution! It only mentions a pixel format in the 3rd and 4th parameters.

Barn Door

140

Author

September 03, 2002 07:27 PM

Anyone think that this has got nothing to do with resolution and nothing to do even with modes and that actually the doc is WRONG?

Maybe, instead of ...

'If required, the application checks for the presence of hardware acceleration in each enumerated display mode by calling IDirect3D8::CheckDeviceType,'

it should be...

'If required, the application checks for the presence of hardware acceleration in each enumerated FORMAT by calling IDirect3D8::CheckDeviceType,'

So CheckDeviceType just works out whether the given format is compatible with the card AND the device type.

BD.

[edited by - Barn Door on September 3, 2002 8:30:09 PM]

IFooBar

906

September 03, 2002 08:50 PM

first this is from the sdx docs

quote:
IDirect3D8::CheckDeviceType
Verifies whether or not a certain device type can be used on this adapter and expect hardware acceleration using the given formats.

ive underlines all the necessary bits.

quote:
But the call to CheckDeviceType doesn''t involve any mention of resolution! It only mentions a pixel format in the 3rd and 4th parameters.

i put "+resolution" in brackets because im not sure about it. and i would assume that directX knows which resolution the computer is in, *after* you create the IDirect3D interface. but again im not sure of this. just trying to help out.

quote:
''If required, the application checks for the presence of hardware acceleration in each enumerated display mode by calling IDirect3D8::CheckDeviceType,''

it should be...

''If required, the application checks for the presence of hardware acceleration in each enumerated FORMAT by calling IDirect3D8::CheckDeviceType,''

i guess ur right. send it in to MS

. but this is what is usually done. I myself dont check each format individually because it would just require extra code in my for loop, whereas checking each displaymode dosnt required any extra code, amd it dosnt make a difference (to the best of my knowledge that is)

"For us it''s a natural disaster....For him/she it''s a damn memory leak...