[Freetype] Can I get FreeType to generate a bitmap (not including the space around it) of a specified size?

[Niklas Hoglund]

I'm rendering a font I load using freetype with OpenGL, as textures on
quads.  The problem I have is that OpenGL wants all textures to have
width and height both a power of two.  Is there a way to tell FreeType
to render a (scalable) font at an exact power of two size?  I tried
using FT_Set_Pixel_Sizes(face, 256, 256), but that makes the entire
character a power of two, not just the bitmap. (Of course, I could use
this and copy the bitmap into the corner of a larger bitmap, but this
is wasteful of graphics memory.)

Thanks in advance for any help.

-- 
                                                Niklas