View Full Version : FBO + multisampling + non-power-of-two

09-17-2009, 11:58 AM

I have two questions:

1. If my main window was created using for example
4x multisampling (WGL_SAMPLES_ARB == 4), will my FBO's
renderbuffers also be multisampled (automatically)?

First I thought "no, I have to use this glRenderbufferStorageMultisampleEXT function with the
same sample count as my main window".

But then I read this forum post (http://www.gamedev.net/community/forums/topic.asp?topic_id=468653) where the author writes:

FBO (not using glRenderbufferStorageMultisampleEXT) = 292 FPS
FBO (using glRenderbufferStorageMultisampleEXT with 1 sample) = 230 FPS
FBO + Multisampling 4x = 195 FPS
The last setup with 195 FPS includes Multisampling but
no glRenderbufferStorageMultisampleEXT? This would imply
multisampling could be done without the special function.

2. I have never used non power of two textures yet.
Everytime I rendered my scene to an offscreen
location (pBuffer) I modified the projection matrix
to get the same aspect ratio in the power-of-two texture.

But now since I try to use more modern stuff like the FBO
I think about getting rid of this hacky stuff with the
projection matrix and so on and instead use

Then I can just allocate an FBO with the same dimensions
as my main window, right? This sounds really cool to me,
but my question is... I read that many people had trouble
with hardware not supporting this and so on.

What is the current state in that discussion?
It this extension "safe" today or do I miss
half of the graphic cards currently in use?

Your thoughts are really appreciated :)