freetype-gl doesn't do LCD subpixel rendering right

The freetype-gl documentation states and shows that demo-subpixel should look 
like this:

    http://i.imgur.com/F6P1NrB.png
    http://i.imgur.com/RJjbAfO.png (zoomed in) 

But when I build it myself I get the following, which has much more subtle LCD 
subpixel antialiasing and looks worse (less crisp), due to subpixels getting 
mixed too much (colors being converted to nearly gray):

    http://i.imgur.com/bJ4xikd.png
    http://i.imgur.com/nCPOlNH.png 

When I look at the glyph bitmap generated by FreeType for the simple '|' glyph 
in the debugger, it looks more or less like I would expect, and there isn't 
this subpixel graying (e.g. the first and third pixels aren't nearly as gray as 
they look on screen):

    http://i.imgur.com/h4swpIO.png 

I don't know if this is relevant, but when I look at the freetype-gl text 
fragment shader file (text.frag), it has evidence of a number of experimental 
edits having been done, with things commented out. I tried all previous 
versions of text.frag from the repository and none of them yields the expected 
results. I get similar behavior when trying the other demos that are part of 
that package. This is with the most recent version of FreeType (v2.5.2) as of 
this writing, and with all relevant options enabled. I see that that there are 
some other reports of problems similar to this, and I wonder if they were 
resolved but not committed to https://github.com/rougier/freetype-gl.

(images are also attached)

Original issue reported on code.google.com by ppedri...@gmail.com on 14 Jan 2014 at 10:22

Attachments:

Sly14 / freetype-gl

freetype-gl doesn't do LCD subpixel rendering right #66