Illustrator Scripting: How to Accurately Position/Size Text Based on Glyph Bounds, Not Bounding Box?

Illustrator’s scripting API doesn’t expose glyph bounds directly for live text — only frame or geometric bounds. The most accurate workaround is your current method: duplicate the text, run `createOutline()`, measure the path bounds, and use that to calculate the vertical offset. Then delete the outline and adjust your live text’s `position` based on that offset. Unfortunately, there’s no native property to align by visual glyph height.

I think it would help if Illustrator had alignment functions that allowed a selected text object to be aligned to other objects via its baseline. Currently this has to be done manually with the aid of Smart Guides or other snapping functions.

Aligning text objects via the letter's physical shape (aka glyph bounds) work's only so well. The approach is fine with clean, sans serif typefaces like Helvetica. A live dummy letter like "E" can be scaled to desired size (using font height options) and aligned to another object accurately since the bottom and top edges of the letter are perfectly horizontal. Actual type can replace the dummy "E" once it's in the right position. Most other typefaces that are not geometric or "grotesque" in nature routinely have parts of glyphs overshoot below the baseline and rise above the cap height line (or even fall short of the cap height line). Script typefaces are especially challenging in that regard.

I thought it should be simple for graphics software to be able to size and position lettering in font files according to capital letter size or lowercase letter size since font files have built in dimensions for baseline, cap height line, x-height (lowercase), ascender and descender. Just take in the defined distance in UPM numbers from the baseline to cap height line and use that. I assumed sign making applications like Flexi used this approach. After opening some existing font files in font editing software I learned many fonts don't always have their glyphs aligning with those boundaries. Some fonts have the tops of their capital letters undershoot the cap height line by considerable distances. The type designer probably had good reasons to set those dimension lines like that. Unfortunately it complicates the situation for sizing and aligning letters according to physical glyph size.

Hi @hans_4621, I've written a function that does this. Pass it a TextRange and it will give you an object with `fontBounds` and `bounds`. See this post for the script listing.

- Mark

Edit: in case it wasn't obvious, to get the distance between the top left of the text frame and the top left of the first glyph, you can get the bounds of the first character using my function and subtract the text frame's top left which will give you the distance as [dx, dy]. Something like this:

(function () {

    var doc = app.activeDocument;
    var tf = doc.textFrames[0];
    var delta = getGlyphDistanceFromTextFrameTopLeft(tf);

    // for demonstration only, draw the delta
    drawRectangle(doc, [tf.position[0], tf.position[1], tf.position[0] + delta[0], tf.position[1] + delta[1]], { fillColor: makeColor([255, 0, 0]), opacity: 30 });

})();

/**
 * Returns the distance between the first glyph of `textFrame`, and the top,left of `textFrame`.
 * @param {TextFrame} textFrame - an Illustrator TextFrame.
 * @returns {Array<Number>} - [dx, dy].
 */
function getGlyphDistanceFromTextFrameTopLeft(textFrame) {

    var dimensions = getTextBounds(textFrame.textRange.characters[0]);

    if (!dimensions)
        throw new Error('getGlyphDistanceFromTextFrameTopLeft: bad `textFrame` supplied.');

    return [
        dimensions.bounds[0] - textFrame.geometricBounds[0],
        dimensions.bounds[1] - textFrame.geometricBounds[1],
    ];

};

 (Note: above code must be used with the functions in the original script.)

Hans,

I believe you can use this combination in the process,

1) Effect > Path > Outline Object,

2) General Preferences > Tick Use Preview Bounds.

including a reversal of both, to avoid their causing unforeseen issues with unrelated things.

This is a way to bypass the fundamental alignment of live Type.

You can say that it is the reverse of Snap to Glyph,

https://helpx.adobe.com/illustrator/using/snap-to-glyph.html

so you can also consider whether there is a way to use that in reverse.

Or consider a feature request to that effect.