Open sourcing VTT



  • I also believe there's the case, Khaled.

    I also understood that macO and iOS sorta interpret, rather than faithfully execute, hints, but with the latest "blurry fonts" user outrage I guess maybe something changed. 
  • John HudsonJohn Hudson Posts: 1,931
    FreeType has different rendering modes, some of them ignore font hinting completely (with or without auto-hinting) and I think that is what Android is using.

    Does anyone have stats on ppi resolution of Android devices reckoned to be in current use? I'm presuming they're mostly high resolution phones?
  • John HudsonJohn Hudson Posts: 1,931
    Hinting only matters for Windows users...
    What about varieties of Unix users? It's still possible to walk into an electronics store and buy a low resolution desktop monitor like the HP W2082a model (92ppi), and plug it into a PC running any chip compatible operating system.

    Then there's the whole world of embedded display systems...
  • … which, as we know, are just a tiny minority. :#
    From the market share, no.
    For me, hinting would become something more like a semantic marking of shape parts.
  • I actually think releasing vtt may not be as high impact as making a Python hinting engine, so we can have hinting extensions to all editors.
  • I was under the impression that python was too slow or CPU-intensive to make a hinting engine in it...or at least that's what people said several years ago.
  • I actually think releasing vtt may not be as high impact as making a Python hinting engine, so we can have hinting extensions to all editors.
    What exactly do you mean by "hinting engine"?
  • Autohinter, I believe @Dave Crossland means.
  • No, I believe a general purpose version of the truetype byte code interpreter, with support for  high level representations, such as vttalk and the one in Fontlab 5, and/or an autohi
  • You would need several components to build a full hinting system that can be plugged into editors:
    • Compiler from high-level instructions (glyf and CVT program) to assembly
    • Compiler from assembly to bytecode
    • Autohinter that generates high-level instructions
    • Instruction processor (applies instructions to deform a given glyph outline)
    • Rasterizer (translates the hinted outline into pixels)
    • UI for visual instruction editing
    • Storage format for high-level instructions in font source files
    The Font Programs (fpgm table) of VTT and FontLab fall most certainly under copyright as computer programs, so to do any practical hinting you would either need to have someone write new font programs, or convince FontLab and MS to release theirs under a libre licence.

    As for the instruction processor, it’s surely possible to write one in Python following the TrueType instruction manual (I have done so in a limited way), but it may differ from real-world processors which selectively ignore some instructions or interpret them differently (ClearType subpixel sampling for example).

    For rasterizers, the same applies. The big advantage of VTT is that it uses the same rasterizer(s) that will be used on the biggest target platform that displays the font.
  • Yes, there is interest. Having an open source version would be more than great.

    The UI has its issues (which would be easier to fix if open sourced) but I guess some crucial parts cannot be open sourced. If there was a way to plug in freetype instead that would be great as well.
    Oh god no. The eternal struggle of all off-brand renderers being inaccurate to the Microsoft bilevel renderer. Not again.
  • Thomas PhinneyThomas Phinney Posts: 1,890

    Jens: FontLab VI and up also use a real Microsoft ClearType rasterizer (on any OS). Run it on MacOS and you also get real Apple rendering as well as real Microsoft rendering.
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