Re: [ft] sub pixel rendering does not work

[Werner LEMBERG]

> I enable cleartype by uncomment macro
> FT_CONFIG_OPTION_SUBPIXEL_RENDERING and write follow :
>
> FT_Load_Glyph(Face, glyph.FtIndex, FT_LOAD_TARGET_LCD);
> FT_Render_Glyph(Face->glyph, FT_RENDER_MODE_LCD);
>
> the font become very large that is descriped by the comment
>
>  “For example, using FT_RENDER_MODE_LCD when calling FT_Render_Glyph
>   still generates a bitmap that is 3 times wider than the original
>   size in case this macro isn't defined;”
>
> what is the problem?

There is no problem.  The horizontally enlarged pixmap must be folded
back into a `normal' pixmap by applying a proper color filter.
You've obviously missed this comment in the description of `FT_Render_Mode':

  The LCD-optimized glyph bitmaps produced by FT_Render_Glyph can be
  filtered to reduce color-fringes by using @FT_Library_SetLcdFilter
  (not active in the default builds).  It is up to the caller to
  either call @FT_Library_SetLcdFilter (if available) or do the
  filtering itself.


    Werner