NORM@IONAACAD.BITNET (Norman Walsh) (05/08/91)
Greetings,
Looking into the format of the PK and GF files, I understand most of
the parameters. However, the horizontal and (in the long preamble
format) vertical escapement values mystify me. What are they? Who
uses them?
Thanks, in advance,
ndwdhosek@euler.claremont.edu (Don Hosek) (05/08/91)
In article <3E4729D620005637@Post-Office.UH.EDU>, NORM@IONAACAD.BITNET (Norman Walsh) writes: > Greetings, > Looking into the format of the PK and GF files, I understand most of > the parameters. However, the horizontal and (in the long preamble > format) vertical escapement values mystify me. What are they? Who > uses them? The escapement is how much the reference point is moved when the character is typeset. Normally the vertical escapement is zero. -dh -- Don Hosek | To retrieve files from ymir via the mailserver, dhosek@ymir.claremont.edu | send a message to mailserv@ymir.claremont.edu Quixote Digital Typography | with a line saying send [DIRECTORY]FILENAME 714-625-0147 | where DIRECTORY is the FTP directory (sans ---------------------------+ "anonymous") and FILENAME is the filename, e.g. "send [tex]00readme.txt". There is a list of files in each directory under the name 00files.txt. Binary files are not available by this technique.
XITIJSCH@DDATHD21.BITNET (05/09/91)
Norman Walsh wrote: > Looking into the format of the PK and GF files, I understand most of > the parameters. However, the horizontal and (in the long preamble > format) vertical escapement values mystify me. What are they? Who > uses them? The escapements are the width and the height of the character in pixel values. I.e., they are not the bounding boxes for the bitmaps, but the values that the reference point on the output device must be moved. These values are needed because they may differ from the pixel values computed from the TFM widths: A font designer may choose to overwrite them. This is done e.g. in the Computer Modern family for low resolutions. Of course the values must be used by DVI drivers. Or, to say it clearly: They must not be ignored in DVI drivers. A DVI driver which computes the pixel widths from the TFM widths instead of taking the horizontal escapement is simply not functional. You may want to take a look at the proposed level 0 of the DVI driver standard. You may fetch it from the Heidelberger Listserver (listserv@dhdurz1.bitnet, filelist driver) or from mailserv@ymir. Note that it is subject to change within the next two weeks as I have to rephrase a few sentences. (But it will not change substantially.) -- Joachim =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Joachim Schrod Email: xitijsch@ddathd21.bitnet Secretary of TUG DVI standards committee