How to check video memory statistics?

[mkalex777]

I need to load a lot of different images, so I want to get some kind of video memory statistics to implement some cache which will unload unused images. I need to know when available amount of video memory is too low.
So, is there any way to get total available video memory and used video memory?

[dabbertorres]

Either OpenGL vendor extensions or OS system functions. There is no standard.

[Mario]

Leave it to OpenGL. If you want to, provide the user some texture preset (like low, medium, high). You don't have to manually unload/reload textures, they'll be cached anyway, and in case the graphics card runs out of memory, the driver will unload unused textures and reupload them in case they're used again.