Re: [ft] anti-aliasing question

[Dave Calkins]

> You have to define FT_CONFIG_OPTION_SUBPIXEL_RENDERING so that you can
> select one of the three available colour filters with
> FT_Library_SetLcdFilter.  There is no callback hook to add a new,
> external colour filter function.
>
> To get acquainted with subpixel rendering, please read
>
>    http://www.grc.com/cleartype.htm
>
> which gives an excellent introduction to the topic.
>
>
>      Werner
>    

Based on that article it seems the sub-pixel rendering is most effective 
when dealing with white text on a black background or visa versa.  Any 
thoughts on the recommended approach for dealing with colored text?  I 
know FreeType isn't designed to render, say, a blue glyph, so this is 
beyond the scope of what FreeType is doing.

But suppose you do use the sub-pixel rendering and end up with a nice 
color rendered glyph using this technique.  However, now you want the 
text to appear blue to the user.  It seems like shifting the color 
toward blue would mess up the sub-pixel rendering.  Do you just have to 
abandon sub-pixel rendering in this case?  I guess I'll have to do some 
tests and see how GDI acts in this case.

Also I would guess its dependent on the background color as well right?  
White text on black background would work great, but even white text on 
a blue background would likely disturb the sub-pixel rendering technique 
I would think.

In our case, we don't have a clear-cut foreground/background color since 
we're rendering on top of a 3D OpenGL scene, so you never know nor can 
you control what color will be behind the text.  The text could be 
displayed over a blue 3D model, or over the black background and this 
could change as you rotate the view through the scene.

Anyway, just curious as to your thoughts on arbitrary colors in light of 
the sub-pixel rendering.