Keith Packard <[EMAIL PROTECTED]> さんは書きました: > Around 0 o'clock on Feb 18, Mike FABIAN wrote: > >> Wouldn't it be nice to be able to switch between the auto-hinter >> and the byte code interpreter with a run time option? > > If you have the bytecode interpreter, why would you ever use the > auto-hinter for fonts with hints?
And for fonts without hints? What if you have both fonts with and without hints? Is it conceivable that it might be useful to add rules to /etc/fonts/fonts.conf to switch on the byte code interpreter for some fonts (which have good hinting) and use the auto hinter for other fonts (which have bad or no hints)? When comparing rendering results of the Bitstream Vera Sans font with freetype 2.1.3 with and without byte code interpreter, most people looking at the screenshots claimed that it looks better without the byte code interpreter. Here are some screenshots (Freetype 2.1.3): http://www.suse.de/~mfabian/misc/keith-20030218/Bitstream-Vera-Sans-12-pixel-byte-code-interpreter.png Sharp and not much gray because the byte code interpreter snaps the stems to grid positions. But there is quite a lot of distortion of the glyphs, especially the dots in the "ä" (German ae-umlaut) are shifted to the left quite a lot. Looks like more than 2 pixels shifted. Why? Is this a bug? If yes, is it a bug in the font or in the byte code interpreter? And the spacing looks a bit wrong, the "u" and the "n"were widened to fit to the grid and the first "t" was moved very close to the "ä". Freetype 2.0.9 with byte code interpreter gives pixel for pixel the same screenshot by the way. http://www.suse.de/~mfabian/misc/keith-20030218/Bitstream-Vera-Sans-12-pixel-auto-hinter.png Most test persons said this looks better. It has a lot more gray and looks more blurry of course. But the "ä" is not distorted and the spacing looks better. http://www.suse.de/~mfabian/misc/keith-20030218/Bitstream-Vera-Sans-12-pixel-without-any-hinting.png Everybody agrees that this is ugly. http://www.suse.de/~mfabian/misc/keith-20030218/Bitstream-Vera-Sans-16-pixel-Linux-byte-code-interpreter.png a somewhat bigger size. Now the byte code interpreter suddenly shifts the dots on the "ä" to the right and makes each dot use 4 completely black pixels. Most viewers thought this looks very strange as well. Using the autohinter gives a decent result at this size as well. We also compared how Mac OSX rendered the same Bitstream Vera Sans font and found that the results were rather close to the results using the Freetype 2.1.3 with the auto hinter on Linux. Certainly the rendered glyphs on Mac OSX had more gray and were more blurry than the glyphs rendered by Freetype 2.1.3 with byte code interpreter. Looks almost as if Mac OSX isn't using a byte code interpreter, although there should be not patent problems for Apple. > Supplying the byte code interpreter in binary form is viewed by some > as an issue with the relevant US and UK patents. -- Mike Fabian <[EMAIL PROTECTED]> http://www.suse.de/~mfabian 睡眠不足はいい仕事の敵だ。 _______________________________________________ XFree86 mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xfree86
