\psfig macro performs the following
Xoperations:
XFirst, if bounding box information (see below) is omitted from the list
Xof arguments, the
Xfile containing the figure
Xis searched and the information recovered from the bounding box
Xcomment. Then,
Xif both height and width are missing they are computed to
Xbe the height and width of the bounding box. If only one is missing,
Xit is set to be the appropriate value such that there is no distorted
Xscaling.
XIf rheight or rwidth (see below) is missing it is presumed to
Xbe the same as the height and width.
X
X The \psfig{figure=input} macro
Xuses a vbox in TEX to reserve the space.
XThe actual inclusion of files is preformed with a
X\special command to the dvips postprocessor.
XPresently, dvips is the only supported post-processor,
Xbut it shouldn't be to difficult to port psfig to
Xa different postprocessor, presuming similar capabilities and/or
Xaccess to source code.
Xpsfig depends on certain PostScript function calls; these are downloaded
Xwith the \psfiginit macro. Do not use page-reversing on your
Xoutput if you are manually initializing psfig with \psfiginit, or
Xare using \psglobal.
XIt is possible to include these
Xdefinitions into the standard dvips (or whatever) header file; this
Xhas been done on our systems and users need not do a
X\psfiginit.
X