home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Black Box 4
/
BlackBox.cdr
/
progc
/
gs24src.arj
/
README.DOC
< prev
next >
Wrap
Text File
|
1992-03-24
|
6KB
|
168 lines
Copyright (C) 1990, 1991 Aladdin Enterprises. All rights reserved.
Distributed by Free Software Foundation, Inc.
This file is part of Ghostscript.
Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY. No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing. Refer
to the Ghostscript General Public License for full details.
Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License. A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities. It should be in a file named COPYING. Among other
things, the copyright notice and this notice must be preserved on all
copies.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This file, readme.doc, describes problems and new features in the current
release of Ghostscript. This file describes version 2.4 of Ghostscript.
For an overview of Ghostscript and a list of the documentation files, see
README.
New features
============
Note: this is not a complete list of new features. See the most recent
section of history.doc for full details.
The default MS-DOS configuration now includes VGA (default), EGA, VESA
(SuperVGA), Epson, BubbleJet, PaintJet, DeskJet, and LaserJet drivers.
The VESA driver is new. There are several other new drivers as well.
A new file landscap.ps makes it easy to display landscape-mode output
rotated by 90 degrees.
It is now possible to select the resolution dynamically for printers.
If one includes -dDISKFONTS in the command line, Ghostscript loads
individual characters from fonts dynamically. This may allow one to fit
more fonts in RAM, at the expense of slower rendering. This works both
for Ghostscript's own fonts (except for the Courier family), and for any
Type 1 fonts that do not use eexec encryption.
Type 1 fonts now do look at the Metrics information. The Ghostscript
fonts now have the same character spacing as the Adobe fonts.
clip and eoclip now intersect the new clipping path with the old one, as
they should.
Transfer functions work for images.
The X11 driver includes the changes to support Ghostview.
You can now put .PFB fonts in the Fontmap directly -- you no longer need
to run pfbtogs.
You can now send printer output to the printer directly, to a set of
files, or (on Unix systems) to a pipe; see use.doc for details.
You can precompile fonts into C and link them into the executable. They
don't run any faster, but you eliminate the loading time. (Don't attempt
this on MS-DOS systems, unless you are using the Watcom compiler or
running under Windows.) See fonts.doc for details.
Ghostscript now implements essentially all the facilities of Display
PostScript that are also in Level 2 PostScript, except for garbage
collection: binary tokens, rectangles, user paths, insideness testing, and
a variety of other odds and ends. (The garbage collection operators are
provided, but they have no effect.)
Changes
-------
Some of the Ghostscript extensions have changed, specifically
makeimagedevice, and some have been removed. See history.doc for details.
For driver authors only: There have been incompatible changes in the
gx_device structure, and in the specification of the map_rgb_color,
map_color_rgb, copy_mono, and copy_color driver procedures; also, the
fill_ and tile_trapezoid procedures have been removed, and new get_bits,
get_props, and put_props procedures have been added. See drivers.doc for
details.
Known problems
==============
Interpreter
-----------
The interactive interpreter requires that every statement fit on a line,
i.e., you can't have an unpaired ( or {.
On a MS-DOS system, interrupting Ghostscript by typing ^C doesn't restore
the display mode.
Operators
---------
The Ghostscript language does not include the following operators of the
PostScript language:
resetfile
banddevice, renderbands
The following are not implemented completely:
%statementedit (file name): interpreted as equivalent to
%lineedit.
Most of the new color operators, particularly those that support the CMYK
color model, are implemented as Ghostscript language procedures, and they
essentially emulate CMYK using RGB.
The following operators that expect arrays won't accept packed arrays:
definefont (Subrs (type 1 fonts))
setdash (dash pattern)
setcachedevice (bounding box)
makeimagedevice (palette)
The file operator only recognizes modes r and w, not the newer modes r+,
w+, a, and a+.
Limitations
-----------
Floating point exceptions terminate Ghostscript, rather than producing a
rangecheck error.
Some access checks aren't implemented.
copypage does nothing in the MS-DOS implementation, and merely
synchronizes the X connection in the Unix implementation. showpage is a
procedure that does a copypage and then beeps the bell and waits for the
user to hit a key. (copypage does do the right thing for printers.)
Graphics bugs
-------------
strokepath produces incorrect output for dashed lines.
The implementation only looks at the PaintType of the font when doing
show, not when doing charpath. Because of this, stroked fonts don't work
correctly with charpath.
arcto gives an error for negative radii.
Halftone screens that aren't parallel to the coordinate axes may produce
incorrect output: the cell is rotated, but not the tiling pattern.
Changing the contents of the Encoding array or the Metrics dictionary of a
font dynamically doesn't produce the expected result (may have no effect)
if character caching is enabled.
Halftone patterns "flip over" at the 50% coverage point, producing
anomalous visual effects on some color devices.
Non-graphics bugs
-----------------
restore doesn't properly undo currentgstate.
copy doesn't handle gstates.