I don’t belive that gluBuild2DMipmaps does’t work!
Use (for testing) GL_LINEAR_MIPMAP_LINEAR for minification - so
You will see a smooth fade from one mipmap level to other. If there is a error
You will see that. (But be warned that it may be wery slow.)
Be sure you tell your texture format right. If You say …
… and your texture format is GL_RGBA You will see some crap on screen.
> I don’t need to have any strange intermediate ones, do I?
> Also, I’m creating all of my levels from my first one …
That is not good. Use previous one (easier to scale).
> … rather than taking the level before and scaling it …
How? MipMaping makes no sence if You skip some texels.
> … to make the next.
> Is this correct, or does it not matter at all?
What do you mean with “does not matter at all”?
Of couse it does matter how You build mipmaps -
as You may make them wronq (and I think that is the case ).
At last I will guide You to a page that may help. So from … http://www.opengl.org
-> OpenGL Programming Guide Version 1.0
-> Chapter 9 Texture Mapping
It’s the best guide i have ever seen (short - only important things).
… and there You find code that works.
NB! My english is bad - so be patient .