[XeTeX] height and depth of characters

[Will Robertson]

On 26 Mar 2005, at 8:58 AM, Stephen Moye wrote:

> Xetex tells me that the depth of \box0 is 54pt. Is there any way to 
> get a correct answer?

As JK will no doubt reply, the answer is unfortunately no.
XeTeX doesn't retrieve this information from ATS and places every 
character in a box of constant height. The reason for this is that in 
XeTeX, ATS itself places accents above characters, and this is the only 
low level reason for knowing the height and depth of a single 
character. Making XeTeX use the actual height/depth info would slow it 
down (noticeably?) for little gain.

Having said that, sometimes it is nice to know how big characters are 
so if the situation stays as it is I proposed once that an extra XeTeX 
primitive could be added to measure the heights and depths of 
characters on a one-off basis.

W