Re: Printing and Displaying Dependent Vowels

From: Antoine Leca (
Date: Mon Mar 29 2004 - 06:13:30 EST

  • Next message: John Cowan: "Re: [OT] proscribed words... (was:What is the principle?)"

    On Sunday, March 28, 2004 12:03 AM, James Kass wrote:
    > So, if the question is how to make an OpenType font *not* display the
    > dotted circle on Windows with Uniscribe, one idea would be to add a
    > spacing glyph to U+25CC (DOTTED CIRCLE) in the font.

    If you do so, you will end with defeating the normal behaviour that is to
    draw a circle when someone makes an error while typing. Depending on the
    intent of the font, it may or may not be a good idea.

    Since Avarangal seems to be now under "non disclosure agreement" with
    Microsoft, we do not know for sure what is his intent.
    We also do not know if there are variations between releases (I hear there
    are, but do not feel it is my job to investigate it), or generally what are
    the real specifications in this area (the official being that the sequence
    SP+ZWJ+some_mark renders without displaying the circle, but we know it is
    not always enforced).

    In the general case of a font intended for general use, and if the rendering
    without the circle is intended in special cases like drawing a keyboard
    layout for reference, I still believe it is better to have the circle and
    resort to special manipulations, like SP+ZWJ+vowel or drawing directly with
    ExtTextOut(ETO_GLYPH_INDEX), in order to draw the keyboard layout. At least,
    because complexing a font to cure a defect into a version of one (the)
    rendering engine does not seem to me an engineering solution. (I since read
    your other post that rather seems to agree with me)

    > Another approach is to simply use a non-OpenType Unicode TrueType
    > font for Tamil. The dotted circles don't seem to ever appear unless the
    > font-in-use has OpenType tables covering the script-in-use.

    Right. (The only remaining problem will then be the overhang and centering).


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