Application controlled Anti-aliasing

OpenGL OpenGL: Advanced Coding
1

The drivers always have an option for the application to control its own anti-aliasing settings.

Fine, but how do we control it from OpenGL? I know the GL_ARB_multisample extension, but this one appears not to have an option to specify 2x, 4x or more.

Do you know how to do an application controlled AA?

Thanks

2

You need to choose a pixelformat with the appropriate number of samples.
http://developer.nvidia.com/attach/6709

The NV_multisample_filter_hint extension also gives extra control over filtering modes:
http://www.nvidia.com/dev_content/nvopenglspecs/GL_NV_multisample_filter_hint.txt

-S.

Originally posted by vince:
[b]The drivers always have an option for the application to control its own anti-aliasing settings.

Fine, but how do we control it from OpenGL? I know the GL_ARB_multisample extension, but this one appears not to have an option to specify 2x, 4x or more.

Do you know how to do an application controlled AA?

Thanks[/b]

3

In the iAttribs of wglChoosePixelFormatARB() you set the value of WGL_SAMPLES_EXT(_ARB) to the number samples you wish to use (1,2,4,8,16…).

You can only do this during the creation of your window/rendering context. Once the window is created, you can enable/disable Multisampling using glEnable/glDisable and GL_MULTISAMPLE_ARB.

4

Cool, but when I create a list of possible buffers using wglGetPixelFormatAttribivARB, it returns I can have 0, 2, 4 or 8 multisamples. Can I really get 8? The NVidia driver only allows to go up to 4. I’d like much better to crank it up to 8.

5

Here is an extra question on the same topic.

For SimonGreen and rgpc intervention to work, I need to set the driver AA option to “application controlled”. Is there a way to query if this is set or not?

6

The AA option is almost certainly a registry setting that you could query. You just have to figure out where the setting is stored and which setting it is. Good luck! :smiley:

In reality though there’s little point in knowing. If a user has specified “Force AA to x” then that’s what they want. If they have selected “Application Controlled” then you can set what you want…