View Full Version : texture dimensions from texture handle

Mikkel Gjoel
10-31-2009, 12:10 PM
Is it possible to get the dimensions of a texture, having only the texture-id? (handle, object...)

The reason why I need this, is because I can only access the texture-handle from an FBO, not the texture target (GL_TEXTURE_2D etc). It just returns GL_TEXTURE or GL_RENDERBUFFER etc. So maybe I'm missing something there.


10-31-2009, 12:50 PM
What kind of image do you load ?
You could get the dimensions by there. :)

10-31-2009, 04:11 PM
So maybe I'm missing something there.

Yea one thing, you don't have to get something you already have, just save away the dimensions or whatever data you need when you load/create the texture or when you otherwise tell openGL what it does, and there you go.

Mikkel Gjoel
10-31-2009, 07:52 PM
Thanks for the replies. zeaoverlord - yea, doing that already. This is for debugging to see if everything is setup as it should be. Problem only arises if I am checking FBO-attachments - I can check that it's a texture using GetFramebufferAttachmentParameter... but not which kind (texture2d, rectangle etc.).

Horribly embarrassed even asking about this :D
(but then I remembered, there are no stupid questions... only stupid people :p)

Mikkel Gjoel
11-02-2009, 02:48 AM
Specifically the problem is the following statement in the framebuffer extension (http://www.opengl.org/registry/specs/ARB/framebuffer_object.txt):

If the value of FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE at a particular attachment point is TEXTURE, the sizes may be determined by calling GetTexParameter, as described in section 6.1.3.
Section 6.1.3 uses GetTexParameter which requires a target (tex2d/rect...) that doesn't seem obtainable from an FBO alone. It does seem the intention was to make texture-state for fbo queryable using regular texture functions.