Hi Robin, That's a huge puzzle you're trying to assemble, and I'm not sure adding two big topics like C++ and OpenGL is the best idea...
Anyway, I have recently created a github repo which allows to start experimenting with Harfbuzz in a "relatively easy" way: https://github.com/arielm/Unicode HTH and good luck with your exploration, Ariel http://chronotext.org On Tue, Jan 28, 2014 at 2:32 AM, Robin Skahjem-Eriksen < [email protected]> wrote: > I have started to investigate into the matter and I find that there is > very sparse information readily available. Microsoft had a very interesting > document, which I have been trying to understand: > http://www.microsoft.com/typography/OpenTypeDev/tibetan/intro.htm > In the section "Examples of Tibetan" (bottom of document), the first > example shows how a sequence of eight code points are strung together to > form a Tibetan "syllable". It's not really a syllable. It's called a > tsheg-bar in Tibetan and a Tibetan word can consist of multiple of these. > Anyways, all the code points from the second one up to and including the > fourth one are as far as I can tell formed into a ligature. I have opened > the MS Himalaya font in Fontforge and seen that this ligature is defined as > "tibSa_Ga_Rata_Shapkyu" in a location outside of the Unicode address space. > > Now, if a user is to work with Tibetan text like any other user of a roman > script language, the user of Tibetan script would be very disappointed. The > reason for this is that it is impossible to place the caret and select > individual characters in this ligature. As of now, you can only select the > entire stack as a whole selection. This is partly because the glyphs have > been transmuted into a ligature, but perhaps also because there seems to be > no definitions of vertical caret ligatures anywhere. > > How would one go about defining such an important feature? Should this be > implemented in the font? Should it be implemented in the software that > handles the type face? Or perhaps both? While digging through the MS > Himalaya font, I found that there is a value for a Ligature Caret Count. > What is this value supposed to be used for? For the ligatures that are > supposed to represent stacks of multiple glyphs, the Ligature Caret Count > had values up to 4, which I hope can mean that the font itself contains the > information I am looking for. Is my assumption correct? > > Also. I am highly willing to learn more about the inner bowels of typeface > rendering. I have taken a course on Computer design and understand how > everything are bits and how Asssembly language and C handles this. I also > understand the general idea about Unicode and how this is defined on a low > level. I've also understood that fonts are basically Bézier curves which > are rasterized to the screen buffer. There is still a lot of this process > which I still find very murky, so if anybody knows any in depth reading > material, I would be very happy to start reading those. I have read State > of Text Rendering by Behdad Esfahbod, which was a great overview of the > text rendering stack. But I would really like to get more in depth > understanding of each layer in the stack. > > I would really like to also learn more about Harfbuzz and how to work on > it. I would really love to spend some time working on it, if I am at a > level where my code submission would be acceptable to the standards of this > project. Is there any documentation for Harfbuzz? I've taken a quick glance > at the source code and run some scripts and make commands, but I honestly > don't know what's going on. Why are the C files named .cc and some of the > header files named .hh? I can recognize some font lingo and have a slight > understanding of what might be going on, but it would be really helpful to > have something like this for an Openfont file: http://imgur.com/a/JEObT#0. > I must also say that I have no idea of what harfbuzz is supposed to do and > how I test or use it once it's compiled. I've tried running some shell > scripts and bin files that were compiled, but I really have no clue. > > Is there somewhere I can learn how to get a handle on understanding the > technicalities of the Harfbuzz project and learn what I need to start > contributing? > > Sincerely, > Robin Skahjem-Eriksen > _______________________________________________ > HarfBuzz mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/harfbuzz >
_______________________________________________ HarfBuzz mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/harfbuzz
