Rectangle Textures MINIMUM size?

OpenGL OpenGL: Basic Coding
1

Hi all,

Do rectangle textures (specifically ARB_texture_rectangle and EXT_texture_rectangle) have a minimum size limit?

I know the minimum POT size is 64, but have been unable to discover if there is a minimum limit for the rectangle extensions.

Cheers, charliejay

2

Minimum size of a texture (any texture) is 1x1. Where did you get 64 for POT from?

3

Got 64 from the GL Red Book. You reckon I should be able to define a base (zero) level 32 x 16 texture, for instance, that isn’t a mipmap level, then?

I could have sworn that the Red Book said that the texture dimensions were >required< to be “at least 64”, whereas the opengl specs site (specifically http://www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/teximage2d.html ) certainly says something a little different.

It’s not that I’m having trouble with small dimensions for rectangle textures, I just want to know if I can reasonably expect that to be the case on other systems, too…

4

I think 64 is the minimum value for MAX_TEXTURE_SIZE.

It’s a minmax sort of thing…

5

I think some testing with POT textures is in order, then. It certainly sounds like small dimensions shouldn’t be a problem for rectangle textures, if they aren’t for POT textures…

Thanks for the replies, folks.

6

Yeah, did the Red Book a dis-service, there - it says the same thing as the online spec.

7

The GL3 spec ups the minmax to 1024 - same low price.