On 7/13/2009 2:34 PM, Mark D Lew wrote:
Thanks for the correction. But is it not true that to be optimized for ClearType display they must have data in them that the ClearType renderer reads? Did OpenType fonts have this data all along, or is it new?
My understanding is that there is no "extra" data used by the ClearType rendering engine. ClearType is essentially a method of font smoothing which uses the existing curves and hints in the font file to make the screen display look better. The difference between ClearType and earlier smoothing technologies is that it makes explicit use of the fact that a pixel on an LCD monitor is actually 3 separate RGB pixels crammed in next to each other. So it is able to fool our eyes by smoothing at a subpixel level. There's a good discussion of this here: <http://www.grc.com/ct/ctwhat.htm>
The proof of this is that ClearType makes all TrueType fonts look better, not just those optimized for the technology. The only kind of font ClearType can't work with is the really old bitmapped fonts; a bitmapped font contains specific recipes to place pixels at specific font sizes, whereas TrueType et al. define curves to be filled in by pixels. (I'm simplifying a little.)
For example, the default Windows font for menus and so forth used to be a bitmapped font called MS Sans Serif. I think as early as Windows 2000 they started also shipping a font caleld Microsoft Sans Serif, which was just a TrueType version of the earlier font. Newer versions of Windows use Tahoma or Segoe, both TrueType fonts. Anyway, you may have had the experience of using an older application alongside newer ones, and the text in the dialog boxes of the older app looks *awful*. This is because the older app is probably hardcoded to use MS Sans Serif, which can't be improved by ClearType, and it looks particularly bad next to the smooth goodness in other apps.
As to "optimized for ClearType", my understanding is that those particular fonts were designed with an understanding of how the ClearType display algorithms would work on them, and so the curves were plotted in such a way that they would look particularly good after they were run through ClearType.
Aaron. _______________________________________________ Finale mailing list Finale@shsu.edu http://lists.shsu.edu/mailman/listinfo/finale
