Hi, If further tweak is needed for CJK bluezone, the code would be unmatured, I will disable it by default. In fact, the original demonstration was given by 11pt glyph of WenQuanYi-ZenHei, but your new tweak seems to change the dist value for the glyphs smaller than 17pt I think 17pt is unstable/temporal tuning value and not determined deducively. It makes me afraid that the code includes some ad-hoc parameters and they are not tested well.
How long do you need to find stable values for the tunable parameters? If it is difficult to estimate, I will propose new API to manipulate the parameters by FT2 clients. Regards, mpsuzuki On Mon, 09 May 2011 00:23:58 +0800 Just Fill Bugs <mozbug...@yahoo.com.au> wrote: >Now that the CJK blue zone code are in the freetype repository, further >tweak on the parameters can be performed. > >One thing that I can think of is that the threshold of best_dist0 used >in the af_cjk_hints_compute_blue_edges(). best_dist0 is used to >initialize the snap distant from edges to one of the blue zones. > >It's initially set to 1/40 of EM, and scaled to the rendering size. That >means any edge that is closer to 1/40 of the EM (1024 or something) >points toward a blue zone will snap to the blue zone. > >At smaller rendering size, we can have much less possible different >edges in limited space. For example, at 16 pixel, we can only have >1/16 different edges, less than the 1/40. (more different edges when >considering anti-alias rendering, but that's fuzzy.) > >Therefore, we can force a bigger snap distance so that we can have more >uneven edges aligned. Especially when we deliberately merge some glyph >features at the smaller font size. > >What's the suitable snap distance will vary over fonts. I wrote a patch >to set the distance at 1/24 for 16px or smaller font size. Different >numbers can be used to experiment with all kind of fonts. > >More dynamic adjustment can be archived by linking the best_dist0 value >to the delta between filled/unfilled blue zones. > > _______________________________________________ Freetype-devel mailing list Freetype-devel@nongnu.org https://lists.nongnu.org/mailman/listinfo/freetype-devel
