[Freetype] Fractional point sizes are rounded to pixel sizes

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I am trying to use FreeType to render text on screen with accurate pixel 
positioning and smooth animation, but I am having trouble, especially with 
small font sizes.  I have switched off hinting to achieve smooth scaling, but 
the problem is in setting the font size.

FT_Set_Char_Size accepts fractional point sizes, but I can see from the code 
that it performs rounding to set the EM square to whole pixel values.

Since the EM square is often smaller than the glyphs produced, it doesn't seem 
to be possible to render text at all pixel heights.

If the EM square is set to whole pixel sizes in order to change the font, and 
the EM square is smaller than the glyphs, then there is not a sufficiently fine 
granularity to render the glyphs at a full range of pixel heights.

The problem is worse at small sizes, since the relative rounding error is 
greater.

Can I use affine transformations to scale the glyphs to precise pixel heights?