basic questions of GPU opengl in qt

[wagmare]

hi friends,
I want to know some details regarding Qt with GPU cards say NVidia,ATI cards.
1- if i install a GPU driver after installing qt . did i have to make any changes in qt settings or i have to reinstall qt.
2- how qt mkspecs will detect the newly installed GPU opengl libraries.
3- how i can configure the new gpu libraries with the qt application apart from QT += opengl in .pro file.
4- GPU cards will accelerate the qt application only when opengl module is used.right now im accelerating the window with graphicsview opengl viewport.

can anyone please help me giving some details regarding GPU with qt.
Im using Windows 7 - qt-4.8.4 with vc++ 10 compiler .

[wysota]

1- if i install a GPU driver after installing qt . did i have to make any changes in qt settings or i have to reinstall qt.
You don't have to do anything.

2- how qt mkspecs will detect the newly installed GPU opengl libraries.
They will not. There is no need for that.

3- how i can configure the new gpu libraries with the qt application apart from QT += opengl in .pro file.
No need.


4- GPU cards will accelerate the qt application only when opengl module is used.right now im accelerating the window with graphicsview opengl viewport.
I don't see a question here.


can anyone please help me giving some details regarding GPU with qt.
Details regarding what exactly?

[wagmare]

first thx for the reply .. im clear with all ..
just one question ..


4- GPU cards will accelerate the qt application only when opengl module is used.right now im accelerating the window with graphicsview opengl viewport.
I don't see a question here.

i know this question is stupid but just to clarify.
I want to know whether a normal qt application (without opengl) performance will be improve wit GPU installation in system.


You don't have to do anything.
2- how qt mkspecs will detect the newly installed GPU opengl libraries.
They will not. There is no need for that.
can u please explain a bit about how qt manages the opengl library .. if u wish ..

[wysota]

I want to know whether a normal qt application (without opengl) performance will be improve wit GPU installation in system.

In regular conditions, not really.

[wagmare]

You don't have to do anything.
2- how qt mkspecs will detect the newly installed GPU opengl libraries.
They will not. There is no need for that.
can u please explain a bit about how qt manages the opengl library .. if u wish ..

[wysota]

Qt doesn't manage the OpenGL library in any way. If you use OpenGL calls in your program (either directly or through QPainter with a device using OpenGL as a backend) then OpenGL is used. Otherwise it is not used.

[Radek]

There exists a "hardware abstraction layer" (HAL) in your operating system. The layer supplies an unified interface to physical devices (graphics, sound and similar). In case of winblows and graphics, it is DirectX.

The "user" applications (including your OpenGL Qt apps) do not access the physical devices directly but they use HAL instead. HAL then passes the request to the corresponding physical device driver which in turn accesses the device. If you install a new piece device in your comp, you are installing a new physical device drivers and register them with HAL. The rest of the CD are no use demos, games, advertisings and perhaps a control program (which will use HAL, too).

The result is that all your apps will start using the new video card on rebooting your comp after installation. Nothing has changed for them and they do not need any modifications (unless you want to exploit new possibilities offered by your new video card). If something does not work and it should then the problem is with DirectX or with settings of your winblows. Therefore, answers to all your question are "don't care" :)

[wagmare]

ur post is neat and clear as wysota .. thank you Radek and wysota ..:)