slc@hoptoad.uucp (Steve Costa) (09/05/89)
Using PixelScript (nee PrintScript), I have been dabbling with PostScript lately. I would like to know what the relationship of "Encapsulated PostScript" is to regular PostScript. Is it a subset, a variant, some kind of encoding, or what? Thanks for any help / Steve Costa
ain@mentor.cc.purdue.edu (Pat-bob White) (09/05/89)
In article <8443@hoptoad.uucp> slc@hoptoad.UUCP (Steve Costa) writes: >Using PixelScript (nee PrintScript), I have been dabbling with >PostScript lately. I would like to know what the relationship >of "Encapsulated PostScript" is to regular PostScript. Is it a >subset, a variant, some kind of encoding, or what? [Please don't flame me if I'm a bit wrong on this -- I'm only scanning the Encapsulated Postscript document for this info...] In short, Encapsulated PostScript is a PS file with a bounding box that tells how big the image is. It is designed to be imported into another PS (or EPS) file.. and therefore should be very careful about mucking with any global parameters and settings that will not be restored by the including PS program. Also, it may optionally have a bitmap with it for previewing purposes. To quote the EPS document from Adobe (without permission.. :-( ) " Fundamentally, an EPS file is a standard PostScript language file with a bitmap screen preview optionally in the format. ... The bitmap is normally discarded when printing, and the PostScript language segment of the file is used instead. An EPS file should conform to at least Version 2.0 of the Adobe Document Structuring Conventions. This does not explicitly require any of the structuring comments to be employed, but if used, they should be in accordance with that specification. Aditionally, and EPS file is required to contain the %%BoundingBox comment,..." ... The file must also be a single page (not a multiple-page document)... Required Comments: The first comment in te header (and the first line in the file) should be: %!PS-Adobe-2.0 EPSF-2.0 %%BoundingBox: LLx LLy URx URy The values are in the PostScript default user coordinate system.. with the origin at the lower left corner. [BTW, this is the end result; as if you printed the EPS file and then measured the bounding box from the paper] Optional Comments: %%Title: included_document_title %%Creator: creator_name %%CreationDate: date_and_time %%EndComments [There are a whole slew of other comments defined.. I'm not going to list them all as that would entail typing in most of the rest of the document.. but there are Font Management comments, File Management comments and Color comments] Operators to avoid: grestoreall initgraphics initmatrix initclip erasepage copypage banddevice framedevice nulldevice renderbands setpageparams note exitserver setscreen* settransfer* [*only allowed under certain restrictions] All of the PostScript interpreter's stacks (including the dictionary stack) should be left in the state that they were in before the imported PostScript language code was executed. It is recommended that the imported EPS file create its own dictionary instead of writing into whatever the current dictionary might be. The EPS file should assume that the graphics state is in its default state, even though it may not be. An importing program may choose to scale the coordinate system or to change the transfer function to change the behavior of the EPS file somewhat. The importing application is responsible for returning the color to black, the current dash pattern, line endings, adn other miscellaneous aspects of the graphics state to their default condition. The exact format of this screen representation [the bitmap mentioned earlier] is machine specific. ... An interchange representation is specified that should be implemented by everyone, and any environment-specific formats can be supported in addition.. " Well, that's about it.. I've left a whole lot of stuff out, but this is the gist of it. hope this helps.. Pat White (ain@mentor)
warb@faatcrl.UUCP (Dan Warburton) (09/09/89)
Adobe runs a mail-response server so you can get the document yourself by sending mail to ps-file-server@adobe. To get thier description of Encapsulated PostScript the text of your message should contain: send documents EPSF.ps You should receive a postscript file in the mail. Try send help and send index. Use seperate messages.