Obtaining baseline

[lazingor]

If the library is used to render a single line, say \text{Let } f(x) = \int_0^x g(t) dt, is there a convenient way to pull out the baseline position of that line, i.e. the vertical position just below the L?

I thought it might be TeXRender::getBaseline(), but I find it hard to read what this function actually returns. The code is

((_box->_height * _textSize + 0.99f + _insets.top) /
          ((_box->_height + _box->_depth) * _textSize + 0.99f + _insets.top + _insets.bottom));

The denominator here is almost the value of getHeight(), except that getHeight() has another + 0.99f. Does the numerator somehow give the actual baseline?

Or is there some other way to retrieve the baseline?

[NanoMichael]

First I'm sorry to respond to you so late, I'm very busy these days 😅 .

Yes, I got your point. Do you mean to retrieve the ascent? The getHeight() and getBaseline() is confusing 😅 , the getBaseline() actually is the ratio of the ascent and the height, and the 0.99 is almost 1 pixel (for round purpose), this should be removed.

The most convenient way to get the ascent should be:

const int height = render.getHeight(); // total height of the box = ascent + descent
const int depth = render.getDepth();   // depth = descent
const int ascent = height - depth;

I'm going to remove the round factor 0.99 and make the getBaseline() deprecated.

[lazingor]

No worries about the delay - I always appreciate your comments! What I'm after is the actual baseline on which the glyphs are drawn: I think this probably works out the same as height - depth from what you say.

The baselines were slightly off when calculated by this method; I just discovered that it was because of the rounding (int) in getHeight() etc!