578615 - line-height needs to use rounded value

Status: RESOLVED DUPLICATE of bug 442139

(Core :: Layout, defect)

Description

[John Daggett (:jtd)]

Attachment: testcase, animate line-height from <1em to >1em

We appear to be placing text lines using multiples of the raw line-height value rather than the rounded value.  In other words, the calculation appears to be:

  y = round(line-height * # lines)

rather than 

  y = round(line-height) * # lines

The effect of this difference is that it produces gaps and unevenness when rendering lines of text with line-heights that don't convert to integer pixel values.  When the attached testcase is run, you'll see gaps at different places as the line-height is varied by amounts < 1px.

Originally posted on Typophile:
http://www.typophile.com/node/72215

Comment 1

[j.j.]

This bug is old and has duplicates