Size of text box doesn't correspond exactly to fontSize

MauriceMeilleur

,Here's something interesting I found while writing code to generate the dimensions of a canvas based on the amount and size of the text I want to set in a square-ish field on the canvas.

fontFamily = 'kast_4_a'
fontStyle = 'top_0'
fSize = 1000
test_string = FormattedString()
test_string.append('a', fontSize = fSize, font = fontFamily + '-%s' %fontStyle)
print(test_string.size())

yields the following:

<NSSize width=692.0 height=1001.0>

I can confirm that DrawBot's size() returns a height of any fontSize + 1.

I was hoping to use the size of the text box to calculate the height of the canvas, but now I have to adjust that it seems. What's happening here?

gferreira

@MauriceMeilleur the size of a text box is influenced by the lineHeight too. this produces the expected result:

test_string.append('a', fontSize=fSize, lineHeight=fSize, font='%s-%s'%(fontFamily,fontStyle))

cheers!

MauriceMeilleur

Good to know, thanks. But that means that default linespacing = fontSize + 1?

gferreira

But that means that default linespacing = fontSize + 1?

not really… it depends on the vertical metrics in the font.

here’s a test with other fonts:

from random import choice
fontName = choice(installedFonts())
txt = FormattedString()
txt.append('a', fontSize=1000, font=fontName)
print(fontName)
print(textSize(txt)[1])

line height is tricky see 1 2 3 4