Textures

[TiX0]

Taking the first steps in OGL-programming I tried some texture binding - and didn't succeed with my own bmp-file. Binding the bmp of a sample-code brought the wanted result. NeHe claims that not every bitmap-size is allowed. So, what do I have to consider regarding the bitmaps size?

Thanks for your reply!!!

TiX0

[Azdo]

Originally posted by TiX0: So, what do I have to consider regarding the bitmaps size?


Your textures' size must be powers of two: 16,32,64,128,256...

[jimmi]

if your bitmap hasn't got dimensions which are a power of 2, you can use gluScaleImage to resize it.

jimmi

[Furrage]

I thought the minimum texture size was 64. In that case 32 and 16 don't count.
Originally posted by Azdo:
Your textures' size must be powers of two: 16,32,64,128,256...

[Mazy]

The minimum is 1*1, the max is queryable.

[Furrage]

Is that with mipmapping or you can load a 1*1 bitmap and create a level 0 texture with it? Chapter 9 of the Redbook in the definition of glTexImage2D() states "Both width and height must have the form 2m+2b, where m is a nonnegative integer (which can have a different value for width than for height) and b is the value of border. The maximum size of a texture map depends on the implementation of OpenGL, but it must be at least 64 × 64 (or 66 × 66 with borders)."
Originally posted by Mazy:
The minimum is 1*1, the max is queryable.

[Gavin]

so what is 2^0 furrage? :-)

[Deiussum]

Read your quote again, Furrage..

"The maximum size of a texture map depends on the implementation of OpenGL, but it must be at least 64 × 64 (or 66 × 66 with borders)."

Basically it's saying that the smallest an implementation can use for the MAXIMUM value is 64, not that the minimum must be 64. http://www.opengl.org/discussion_boards/ubb/smile.gif

In other words, you are guaranteed to at least have support up to 64x64.