Comment 68 for bug 862964

(In reply to comment #55)

> > if (n > 1)
> > return 1 << (qMax(last,5) + 1);
> > return 1 << qMax(last,6);
>
> I'll try this first

Fair enough, btw. what GPU are we talking about and does it actually have
glxinfo | grep GL_ARB_texture_rectangle

(In reply to comment #57)
> Forgive me, but not sure what you mean here w/GL_TEXTURE_RECTANGLE_ARB .. is
> this and env var ?
No, a texture format that doesn't require textures to be POT (power of two dimensions) but predates and is rather inferior to the "legal" NPOT textures.
If supported and used when loading the texture, this would skip the prescaling to POT dimensions (thus those offset issues) but also break eg. clamping.

Since it's however also used by the GL_texture_from_pixmap conversion, that's actually no argument (as least as that the format is probably slower than POT textures)

If you've support i'll pass you another patch attempt.