   Copyright (C) 1989, 1992 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, NEWS, describes the changes in the various releases of
Ghostscript.  (This file was formerly named history.doc.)

For an overview of Ghostscript and a list of the documentation files, see
README.

Version 2.5.2 (9/20/92)
=============

This is yet another bug fix release to (finally!) get the PCL drivers
working again.

Procedures
----------

Fixes bugs:
	- The comment in devs.mak for cdjcolor said it used 8 bits
per pixel, rather than the correct 24.

Adds gsbj/dj/lj/lp and gslp.ps to the installed files on Unix
systems.

Removes dps.dev and level2.dev from the standard configurations on
all platforms, since the presence of the setcolor operator was
causing the output of some common applications to fail.

Utilities
---------

Fixes bugs:
	- font2c produced invalid output for any font that didn't use
StandardEncoding or ISOLatin1Encoding.

Platforms
---------

Fixes bugs:
	- gp_sysv.c required an extern long timezone.

Drivers
-------

Fixes bugs:
	- The PCL drivers were *still* doing the wrong thing about
zeroing the seed row for Mode 3 compression.
	- Setting the resolution with -r didn't work under Windows.
	- The Windows driver got a stack overflow if it was ever
asked to display a bit image wider than 32 pixels.
	- The Tseng driver didn't sense the model (ET3000 vs. ET4000)
correctly.

Adds the eps9high device to the standard MS-DOS makefiles.

Interpreter
-----------

Fixes bugs:
	- gs_run_string used gs_user_errors (a global) rather than
user_errors (its argument) to control error handling.  (This does not
affect normal operation of Ghostscript, only use as a server.)
	- eexec popped the top element of the dictionary stack
afterwards even if the encrypted code had pushed something onto it.
This caused problems for some badly written PostScript code.
	- The printed form of real numbers didn't always include a
decimal point, causing compatibility problems.

Makes -s and -d work for device properties.

Increases the cache limit on large-memory systems.

Adds a check to ensure that the revision of gs_init.ps matches that
of the interpreter.

Adds the .knownget operator.

Library
-------

Fixes bugs:
	- The raster computation in clist_render_init, and the
computation of state_size in clist_open, didn't widen an operand to
long, leading to possibly incorrect operation for 24-bit-per-pixel
printers on MS-DOS systems.
	- The flatness was set too large for Type 1 characters,
leading to visible straight edges instead of curves at large sizes.
	- Type 1 fonts that contained out-of-range coordinates would
produce garbled output.  (This was not a problem with the standard
Ghostscript fonts, or with Adobe Type Manager fonts.)
	- gschar0.c wouldn't compile, because it referred to a
non-existing structure member penum->chr.  (This had no effect on
Ghostscript's operation.)
	- The curve flattener required line segments to be no more
than 8 x the flatness in length, leading to an enormous number of
segments.
	- pathforall would cause an addressing fault if the path
consisted of only a moveto.

Refactors some header files so that std.h is always included before
any system header file that might include sys/types.h.

Adds logic for removing top and bottom blank rows in cached
characters.  (This is the beginning of compression for the cache.)

Changes the arguments of memswab2/4 from char * to byte *, for more
accurate type conformance.

Version 2.5.1 (9/11/92)
=============

This is the usual bug fix re-release.

Procedures
----------

Fixes bugs:
	- The makefile rules for compiled fonts had a circular
dependency.
	- `make begin' didn't work properly on all platforms.

Ensures that all batch files end with a newline.  (The absence of the
newline was confusing the GNU diff program.)

Documents the fact that the -dASCIIOUT switch no longer exists.

Utilities
---------

Fixes bugs:
	- pstoppm didn't `bind' its internal procedures.
	- grestoreall would undo the output device selected by
pstoppm.

Changes the utilities for reading and writing Type 1 character
outlines so they can work with stack representations as well as
arrays.

Removes the pfbtogs.ps, phonbook.ps, and showpbm.ps utilities from
the distribution.

Adds a gslj utility to parallel gslp and gsdj.

Platforms
---------

Adds the DeskJet 500C drivers (cdeskjet/cdj*) to the MS-DOS / Borland
C++, MS-DOS / Watcom C/386, and MS-Windows configurations.

Removes the PCX file driver from the MS Windows executable, because
the static data segment exceeded 64K.

Makes some changes in the Unix System V platform file (gp_sysv.c) and
in time_.h and unixtail.mak to accommodate the 3B1.

Fonts
-----

Fixes bugs:
	- The Charter-Italic font was named bchi.pfa rather than
bchri.pfa.
	- The Cyrillic fonts (cyr.gsf, cyri.gsf) were omitted from
the fileset.
	- Ghostscript incorrectly assumed that all Type 1 fonts had a
FontInfo dictionary.
	- .loadfont used false PFBDecode, so a few .PFB fonts would
get errors because the first eexec byte would be whitespace.

Changes font2c and its supporting code so that compiled fonts are
location-independent.

Drivers
-------

Fixes bugs:
	- The margins for the H-P printers were still wrong.
	- The H-P drivers accidentally cleared the compression seed
row when switching compression modes.
	- Some of the H-P drivers used the wrong control codes for
skipping blank lines.

Adds user-supported drivers for the AT&T 3B1 console device, and for
the NEC P6+ printer.

Updates the SunView driver with a new version supplied by a(nother)
user.

Changes the X Windows driver so the Ghostscript window doesn't get
input focus.

Changes the common code for the printer drivers so that if it can
allocate a full bitmap but there isn't at least a minimum amount of
memory left afterwards, it switches to banding.

Changes the Windows driver so it handles devices with more than 8
bits per pixel.  (We haven't been able to test this.)

Adds a read-only PageCount device property (for printer devices
only).

Changes all Aladdin-supported drivers to clip drawing requests to the
((0,0), (width,height)) rectangle of device space.

Interpreter
-----------

Fixes bugs:
	- Closing a NullEncode filter always gave an ioerror.
	- If a single-character name occurred 1 character before the
end of an input buffer, the character would be doubled.
	- The procedures in gs_statd.ps didn't use "bind".
	- Setting the page size didn't work properly with devices
with rotated coordinate systems.
	- If an error occurred, and the error object wasn't the last
element of its procedure, the interpreter would re-execute the error
object after running the error handler.
	- Memory devices didn't get resized if HWSize was changed,
leading to out-of-bounds memory accesses.

Moves revision and revisiondate from gs_init.ps to iinit.c.  Adds a
-v switch that just prints these out.

Arranges things so that if Ghostscript is reading from a pipe (`-'
switch on the command line) and encounters an error, it exits with
status 1 rather than 0.

Changes the interpreter interface so the caller explicitly passes a
pointer for storing an error object.

Library
-------

Fixes bugs:
	- The automatic adjustment of the scaling for variant paper
sizes caused the image to get expanded when it should have been
contracted, and vice versa.
	- The curve flattener insisted that each line segment be no
more than 2 x the flatness in length, leading to an enormous number
of segments even when not necessary for accuracy.
	- flattenpath and strokepath discarded a trailing moveto.
	- strokepath treated "0-width" lines as really having a width
of zero, rather than one pixel.
	- Buffered devices weren't closed and reopened if the amount
of buffer space was changed.
	- stroke used the line cap at the beginning of each subpath
even if the subpath was closed.

Removes the requirement that the clipping rectangle fall in the
non-negative quadrant of device space.  (This was causing problems
for Ghostview, but removing it required adding the extra clipping
step to the drawing routines in the drivers.)

Version 2.5 (8/18/92)
===========

This version adds Type 1 hinting, CCITTFax encoding and decoding, and
Microsoft Windows support, as well as the usual minor improvements
and bug fixes.

Procedures
----------

Fixes bugs:
	- GSIMPATH, SLZWD, and SLZWE were omitted from the VMS
makefiles, and GSIM2OUT was not removed.
	- landscap.ps messed up the current path.

Adds new switches:
	-dSAFER disables file writing and directory modification.
	-dESTACKPRINT causes errors to print the execution stack with
== instead of =.
	-sOutputFile=<string> replaces -sOUTPUTFILE (which is still
recognized) for setting the output file or pipe for the default
(printer) device.
	-sPAPERSIZE=<sizename> initializes the paper size.
	-dBufferSpace=<number> sets the buffer size for the default
(printer) device.

For Unix systems, changes the directories in GS_LIB_DEFAULT from
`pwd` to $(gsdatadir), i.e., normally $(datadir)/ghostscript, where
datadir is normally /usr/local/lib.

Adds a note in the header file to the effect that the X Windows
driver expects to find header files in $(XINCLUDE)/X11, not in
$(XINCLUDE).

Changes -q so it defines QUIET as true instead of null (so it can be
used in the middle of the command line as well as at the beginning).

Renames the history.doc file as NEWS.

Utilities
---------

Platforms
---------

Fixes bugs:
	- The stack size was not getting increased on the Watcom
platform.

Removes "b" from the scratch file opening modes in gp_unix.c and
(conditionally) in gdevprn.c, to pacify the DECstation Ultrix system.

Adds a makefile (bcwin.mak) and a platform file (gp_mswin.c) for
Microsoft Windows.

On MS-DOS platforms (including Windows), uses the TEMP environment
variable to designate the directory for scratch files.

Changes std.h so that the VMS C compiler uses function prototypes and
'const'.

Changes the VMS cc makefile so it doesn't use ansi2knr.

Fonts
-----

Fixes bugs:
	- findfont left an extra entry on the stack if it couldn't
find the default font.

Renames bchi, ncri, and puti as bchri, ncrri, and putri, to conform
with the naming scheme for other fonts.

Adds $(CCFLAGS) to the command line used for compiling fonts.

Converts the .pfa fonts (CharterBT, IBM Courier, and Utopia) to .gsf,
by removing eexec encryption and also removing some mysterious
unmapped characters from Courier.  This makes these fonts work with
DISKFONTS.

Changes the implementation of compiled fonts so they are read-only
and sharable (no external references).  (They are, however, not
position-independent.)

Provides a way to use compiled fonts on platforms that limit the
number of characters in an identifier.

Adds public-domain Cyrillic and Cyrillic-Italic fonts.

Adds a 'userdict begin' to .loadfont, because Type 3 fonts produced
by Fontographer expect a writable dictionary on the top of the stack.

Changes definefont for Type 1 fonts to insert UnderlinePosition and
UnderlineThickness entries in FontInfo if they are absent, because
many word processors incorrectly assume these entries are present.

Drivers
-------

Fixes bugs:
	- The documentation in use.doc said that the densities for
9-pin Epson printers were 60x60 to 240x60, rather than 60x72 to
240x72.
	- gdevprn.c smashed one byte beyond the end of the string
given as the OutputFile device property.
	- The X11 driver used XVisualIDFromVisual, which is not
defined in X11R3.
	- The SunView driver modified the input data, which was
declared as const.
	- The LaserJet IIP and III drivers shifted the page 185
pixels to the left and 0.25" down, because the initialization string
was incorrect.
	- The PCX driver wrote 16-bit values using the byte ordering
of the platform, rather than always LSB first.
	- For vertical spacing, the LaserJet and DeskJet drivers used
a command that spaces N/300", rather than N scan lines, but gave it a
parameter in scan lines.
	- The VESA driver didn't allocate a full 256-byte buffer for
reading the mode information from the BIOS, causing the stack to get
smashed by newer VESA implementations.
	- The VESA driver didn't use the scan line length returned by
the BIOS, causing garbage output for some cards and some resolutions.
	- The generic printer driver didn't free the bitmap when
closing the device, if it fit entirely in memory.
	- The PaintJet driver allocated its data areas on the stack
instead of with gs_malloc.
	- The generic printer driver didn't attempt to increase the
buffer size if it was too small.
	- The band list driver didn't split large bitmaps properly,
leading to garbled characters at high resolutions.
	- The GIF and PCX drivers used a color map that often turned
gray colors into non-grays.

Changes the default put_props procedure so that if the device is
open, setting HWSize and/or HWResolution closes the device and
reopens it.

Adds a driver for Microsoft Windows 3.n.

Updates the 'cdj' and 'dj500c' DeskJet 500C drivers with new versions.
(This are user-contributed drivers.)

Changes gdev_prn_put_props so OutputFile can be changed dynamically.

Updates the DEC LN03 driver to also handle the LA50 and LA75.  (This
is a user-contributed driver with a FSF copyright.)

Changes the LaserJet/DeskJet driver so that -DA4 in the makefile
makes A4 paper the default.  The driver now also sends an appropriate
page size selection command to the printer if the printer supports it.

Changes all the Aladdin-supported drivers to return appropriate error
codes rather than -1.

Adds a driver for the S3 86C911, a PC graphics accelerator used in
the popular Diamond Stealth board.  This is the first driver that
uploads character bitmaps to a device; others will probably follow.

Adds user-supplied code to the Epson driver so it will do triple
passes on 9-pin printers for higher resolution.

Adds user-supplied code for the PaintJet XL to the PaintJet driver.

Interpreter
-----------

Fixes bugs:
	- zdps1.c didn't include alloc.h.
	- On 32-bit systems, if maxlength of a dictionary was less
than the actual allocated space, length could become larger than
maxlength.
	- flushfile didn't actually flush data when reading.
	- The ASCII85Decode filter signalled EOF prematurely.
	- The scanner interpreted .3D.glorp as the number 0.3, rather
than as a name.
	- Closing a file freed the stream structure, creating
dangling references if there were other file objects pointing to the
same stream.
	- eexec called handleerror if an error occurred, instead of
letting the error propagate to an enclosing stopped.
	- gs.h made perror illegal, instead of defining it in terms
of strerror.
	- One-character names weren't being allocated at
initialization, so they could be left dangling after a restore.
	- Internal gsaves (i.e., the ones in show and setcachedevice)
didn't also save istate, so setfont inside a BuildChar procedure
might cause the font outside to get changed.
	- The allocator incorrectly freed objects in the current
chunk that were older than the current save.
	- mark was just an object, rather than an operator, so 'bind'
didn't bind it.  (This is theoretically a problem for null, true, and
false also, but even more unlikely to be a problem in practice.)
	- packed_get didn't cast packed integers to int, so negative
integer elements of packed arrays came out wrong.
	- quit just did a gs_exit, instead of returning to the driver
in an orderly way.
	- Because check_type_access checked for errors in the wrong
order, sometimes type errors were reported as access errors.
	- eq didn't check for stack underflow.
	- Some of the stream_procs structures weren't properly
declared const, leading to link errors on VMS.

Implements currentcolor, currentcolorspace, setcolor, and
setcolorspace (for DeviceGray, DeviceRGB, and DeviceCMYK only).

Implements the dictionary form of image and imagemask.  All the pairs
in the Decode array must be the same; Interpolate is ignored.  The
only supported color spaces are DeviceGray, DeviceRGB, and
DeviceCMYK.

Implements files as allowable sources for the image operators.

Removes the index field from the name structure, moving it to the
'size' field of name refs.

Changes the unread/sungetc operation to require that the character be
the same as the last one read from the file.

Adds fflush calls to some debugging printout routines, because Unix
sometimes buffers terminal output.

Implements the CCITTFaxEncode and CCITTFaxDecode filters.  Implements
the general case of the SubFileDecode filter.

Changes definefont to treat a UniqueID of 0 as equivalent to no
UniqueID, because Fontographer output apparently often violates the
specification in this way.

Changes the default printer screen from 32.5 to 46 cells/inch.  (The
old value was appropriate for a hand-rotated cell with two spots in
it.)

Changes the utility routines to allow an integral real wherever an
integer parameter is expected in a dictionary, because Fontographer
produces fonts that violate the Adobe specification in this way.

Adds a `dosio' feature that provides direct access to memory and to
I/O ports under MS-DOS.  (This feature is not included in the
standard executables, of course.)

Changes the default character cache limit to a 1/4" x 1/4" character
at the default resolution, rather than basing it on the preallocated
cache size.

Removes support for t_color objects, which haven't actually been used
for several releases.

Implements setcmykcolor and currentcmykcolor as operators, so they
will interact properly with setcolorspace and currentcolorspace.

Changes the name of the file.h header file to files.h, to work around
a bug in the VMS header library.

Adds command line switches @file (to treat file as more command line,
to get around the DOS 128-character command line limit) and -ffile
(so one can specify file names that begin with - or @).

Changes the PFBDecode filter so it takes an additional boolean that
says whether or not to convert binary packets to hex.  (Conversion to
hex and back to binary accounted for a substantial amount of the time
required to load .PFB fonts.)

Splits off `copydevice' as a separate operator again.

Library
-------

Fixes bugs:
	- In the VMS environment, string_.h used its own prototypes
for the str... and mem... functions instead of <string.h>
	- gx_alloc_char_bits declared cdsize as long, but didn't
shorten it when passing it to shorten_cached_char.
	- Stroking didn't suppress fattening of the lines.
	- kshow didn't update the cached CTM information in the show
enumerator when returning from the callout, so further characters
could get drawn in the wrong place.
	- When a memory device returned its initial matrix, it
smashed the padding fields, which contained the interpreter's type
information.
	- setcachedevice didn't set the initial matrix in the cache
memory device.
	- image_set_rgb (in the image operators) didn't do a
gx_color_from_rgb, so in principle one could sometimes get incorrect
colors in an image.
	- The decision about whether or not to cache a character
bitmap incorrectly compared the character size against cmax rather
than cdata_size.
	- show didn't reset the in_cachedevice flag in the graphics
state, so characters rendered by a recursive show were never cached.
	- clip and eoclip didn't release the intermediate flattened
clip path, causing memory to be lost.
	- The tile_diff routine didn't handle the case of two
identical tiles properly; this produced garbage in the band list
file.
	- stringwidth didn't round the character origin to an
integral pixel; this interacted badly with hinting, causing
improperly hinted characters to wind up in the cache.
	- Bitmaps (including characters) were displaced, as well as
being clipped, if they intersected the top of a clipping region.
	- In gxclist and gdevmem1, the raster computation (although
not the result) could overflow an int on 16-bit machines.

Implements decoding (sample mapping) for image and imagemask.

Implements hinting for Type 1 fonts, based on (but not copying) the
algorithms from the X11R5 tape.

Changes curve rasterizing to use sampling, rather than recursive
subdivision, for characters.  This produces noticeably better output.
Speed penalty for non-cached characters is less than 10% at display
resolutions, up to 50% for 300 dpi printers.

Implements gs_setcmykcolor and gs_currentcmykcolor.  These are
semi-fake, since they simply convert the color to and from RGB, but
the former does set the current color space properly.

Changes clipping regions so they use the any-part-of-pixel rule
rather than the center-of-pixel rule.  This helps avoid dropouts when
using very small regions.

Implements stroke adjustment.

Version 2.4.2 (5/8/92)
=============

This is another quick release.  It finally fixes rotated halftone
screens, and cleans up a few minor problems from 2.4.1.

This release is being distributed only to beta testers and commercial
licensees, since I don't want to be distracted from working on 2.5.

Procedures
----------

Fixes bugs:
	- UTRACE still appeared in the VMS makefiles.
	- The support files (*.bat, *.doc, *.gsf, *.ps, Fontmap,
COPYING, README) weren't included in the MS-DOS tar file.
	- The Unix install script didn't install landscap.ps.

Replaces the type1imagepath operator with PostScript code (impath.ps,
type1ops.ps) based on the new .imagepath operator.

Renames LICENSE as COPYING.

Utilities
---------

Fixes bugs:
	- pcharstr.ps had an occurrence of Subrs rather than /Subrs,
causing it to not print the Subrs, or to get an error if there were
none.
	- font2c.ps didn't get the const declarations for string
dictionaries quite right.
	- The missing newline at the end of gsbj.bat confused GNU
diff.
	- ansi2knr would go into an infinite loop if a statement
exceeded its internal buffer size.
	- Compiled fonts would get processed by ansi2knr, which
messed them up.

Platforms
---------

Fixes bugs:
	- Ghostscript didn't supply equivalents for rename and
gettimeofday, which some System V platforms lack.
	- The missing newline at the end of gp_dosfb.c confused GNU
diff.

Changes the Borland makefiles so that stack checking is only enabled
if DEBUG or TDEBUG is set.

Fonts
-----

Changes the names of the Utopia fonts from utrg/utb/utbi/uti to
putr/putb/putbi/puti, for consistency with the rest of the font names.
Changes cour/courb/courbi/couri to ncrr/ncrb/ncrbi/ncri likewise.

Replaces the Charter fonts with the CharterBT fonts donated by
Bitstream to the X11R5 distribution.

Adds font aliasing capability to Fontmap.  Replaces
Courier-[Bold]Oblique and ZapfChancery-MediumItalic by aliases.

Changes the FontBBox of the Hershey fonts to be an executable, rather
than a literal, array.

Drivers
-------

Fixes bugs:
	- The GIF driver omitted a `private' on the definition of
gif_print_page.
	- The GIF driver wrote 16-bit values using the byte ordering
of the platform, rather than always LSB first.
	- George Cameron's DeskJet 500C driver had an incorrect
control sequence for skipping blank lines.

Adds 'const' in many places, including the tile and bitmap arguments
of the tile_rectangle, copy_mono, and copy_color driver routines.
THIS IS A DRIVER INTERFACE CHANGE.  (Printer drivers are not
affected, since they don't implement these routines.)

Adds a driver for the Trident TVGA.

Interpreter
-----------

Fixes bugs:
	- alloc_free sometimes incorrectly chose to put an unaligned
block in an old segment on a freelist.
	- The default undercolor removal function returned its
argument rather than returning 0.

Adds NullEncode and SubFileDecode to the standard filters, since
bdftops uses the latter.

Adds RunLengthEncode and RunLengthDecode to the optional filters.

Removes the type1imagepath operator.  (It is still available as
PostScript code, impath.ps.)  Replaces it with a simpler outline
tracing operator .imagepath.

Adds 'const' in many places.

Makes fileposition (but not setfileposition) legal for NullEncode
filters.

Changes the default transfer function for high-resolution devices
from the identity function to the square root function.

Moves array_get from zgeneric.c to iutil.c.

Changes uses of fopen to add a "b" to the access mode, rather than
relying on the _fmode global variable on MS-DOS platforms.

Allows use of the -Z switch even when gsmain.c wasn't compiled with
-DDEBUG, since other modules might have been.

Reorganizes gs.c and gsmain.c so that the latter can be used in
server environments.

Replaces all uses of stdin/out/err with gs_stdin/out/err.

Makes the number of permanent entries on the dictionary stack a
parameter, to allow inserting globaldict in the future.

Changes BlueShift in the Type 1 font Private dictionary to allow real
numbers.  (This differs from the Adobe specification, but at least
one commercial font has a real number for BlueShift.)

Library
-------

Fixes bugs:
	- The doubling check in init_ht (gxht.c) still sometimes
thought there was enough room to double the tile when there actually
wasn't.
	- Rotated halftone screens didn't work.
	- gxarith.h used #ifdef vax, rather than #if
!arch_floats_are_IEEE, to test whether IEEE floats were being used.
	- pathforall didn't report a trailing moveto.

Replaces gs_type1imagepath with gs_imagepath.

Allows sOUTPUTFILE=-, meaning output to stdout.

Adds 'const' in many places.

Replaces all uses of stdin/out/err with gs_stdin/out/err.

Version 2.4.1 (4/21/92)
=============

This is a quick release to fix minor problems discovered in 2.4, and
to add a few improvements that didn't quite make it into 2.4.  It
also adds GIF and PCX file support.

Procedures
----------

Fixes bugs:
	- Some makefile dependencies, and the ccgs script, caused trouble
for parallel versions of `make'.
	- Compiling genarch with -O with gcc on the RS/6000 produced a
buggy executable.

Fixes some minor problems in make.doc.

Adds DEVICE_DEVS2..5 to handle long device lists.

Removes the need to set GS_RUN_EXE when using the Watcom compiler on
MS-DOS systems.

Gets rid of gs_ccfnt.ps, merging its function into gs_fonts.ps.

Gets rid of gconfig.ps; this information is now compiled in gconfig.c.

Utilities
---------

Fixes bugs:
	- The palette for pstoppm in 8-bit mode didn't contain all 8
primary colors.
	- font2c used just values_ to mean &values_[0]; some compilers
couldn't handle this.

Makes font2c insert `const' in many appropriate places.

Drivers
-------

Fixes bugs:
	- The SunView driver had not been updated properly for 2.4 and was
pretty thoroughly broken.
	- None of the printer drivers worked properly with the Watcom
compiler, because stdprn was doing \n -> \r\n substitution.
	- If the generic printer driver couldn't allocate the requested
size command list buffer, it gave up rather than trying to allocate a
smaller buffer.
	- The SuperVGA drivers (except for the VESA driver) didn't
work with the Watcom compiler, because a couple of places in the
drivers weren't truncating the offset of "segmented" pointers
properly.
	- Some of the H-P used <esc>*b#Y rather than <esc>*p+#Y for
vertical positioning; this apparently is wrong, at least for the
LJIIp.

Removes the dependence of the X Windows driver on Xt, Xext, and Xmu.  As a
result, Ghostscript will not install a standard colormap itself, but it
will use one if one is already installed.

Adds a set of drivers for Portable Bitmap, Graymap, and Pixmap file
formats.

Adds drivers for monochrome, EGA/VGA-style, and SuperVGA-style PCX
file formats.

Adds drivers for monochrome and 256-color GIF file formats.

Fonts
-----

Adds ZapfChancery-MediumItalic as a copy of ZapfChancery-Oblique.

Interpreter
-----------

Fixes bugs:
	- A value with l_new set could 'escape' to save level 0 on a
stack; if stored, it prevented the slot from being saved and restored
properly.
	- 16#7fffffff + 1 gave the floating point equivalent of -2^31, not
2^31.
	- The PFBDecode filter computed the packet length incorrectly if
the 0x8000-bit of the length was set.
	- 5-byte numbers in Type 1 CharStrings complained of a rangecheck
if they exceeded 16 bits, rather than if they exceeded the integer part of
a fixed.
	- (, ), and \ appearing in file name arguments in the command
line did not work properly.

Adds 'const' in many places.

Changes the random number generator to be the same as the one used in
Level 2 PostScript (as reported by Ed Taft on comp.lang.postscript).

Exits with code 1 rather than code 0 on an unrecoverable error detected at
the PostScript level.

Makes dictionaries expand automatically when they fill up.

Adds gp_exit to complement gp_init.

Changes dictionaries to always allocate a power of 2 entries on
32-bit machines.  Changes the name table to allocate indices
scattered, so dictionary lookup doesn't have to do a multiply to
scramble the index.

Changes the handling of currentfile to do "shallow binding" so stack
searching is almost never required.

Library
-------

Fixes bugs:
	- arc and arcn got a numeric exception if the radius was zero.
	- The undocumented 15 opcode in Type 1 fonts wasn't ignored.
	- PaintType 3 wasn't allowed.  (It isn't clear what it should
mean; we treat it as equivalent to 0.)
	- The VAX/VMS C compiler was generating incorrect code for the
chi_bits and cmask macros in gdevmem, producing incorrect output.
	- If the result of the slow algorithm for intersecting clipping
paths was a rectangle, the wrong thing happened (cbox didn't get set).
	- gx_path_is_rectangle didn't recognize open rectangles.
	- clist_change_tile didn't check properly whether the tile
size had changed, so changing the screen could produce invalid band
files.
	- The image operators did the wrong thing in the 1-for-1
case, interleaving N bytes of data with 7*N bytes of garbage.
	- stroke sometimes handled bevel and miter joins wrong in
reflected coordinate systems.
	- init_ht checked incorrectly whether there was enough room
to Y-replicate tiles, so sometimes it did it when it shouldn't have.
	- stroke sometimes thought lines were thin when they weren't.

Adds 'const' in many places.

Adds support for 2- and 4-bit-per-pixel memory devices.

Version 2.4 (3/25/92)
===========

This is a major release that adds SuperVGA support, support for Metrics,
settable device properties, and incremental font loading.  It also
includes important performance improvements, based on rewrites of some key
algorithms, and quite a few new Level 2 / Display PostScript facilities.

Procedures
----------

Fixes bugs:
	- The rule for compiling gconfig.c didn't include the -I switches.
	- .bat files were being distributed with a \n line terminator
rather than \r\n.
	- A CLOSE MODULE_LIST was needed after END_COMPILE: in the VMS
command files.
	- Unix systems couldn't handle multiple drivers with overlapping
sets of files.
	- -s<name> defined <name> as a null, rather than as an empty string.

Adds gconfig.ps to the list of needed configuration files.

Changes the way that the makefile handles nested .h files, so that it
doesn't have to `touch' them.

Adds the loadallfonts procedure to gs_fonts.ps.

Changes the standard DOS configuration to include VGA, EGA, VESA, Epson,
BubbleJet, and H-P printer drivers.

Renames ghost.mak as gs.mak, and gdevs.mak as devs.mak.

Adds a USE_ASM flag so that one can build a DOS version of Ghostscript
without having an assembler.

Splits off common code from the two MS-DOS makefiles into tccommon.mak.

Replaces the COPYING and LICENSE files with a new LICENSE file containing
version 2 of the GNU General Public License.

Removes DEVICES and DEVICE_OBJS from the makefiles, since they are no
longer needed.

Adds a GS_DEVICE environment variable to supply a default device name if
desired.

Adds ansihead.mak and unix-ansi.mak, to parallel [g]cc-head.mak and
unix-[g]cc.mak, for other ANSI C compilers.

Changes the way that optional features are defined in the makefiles, so
that they actually work.

Adds support for the Watcom C/386 compiler.

Allows # in the command line as equivalent to =, to compensate for
brain-damaged MS-DOS shell.

Adds -sOUTPUTFILE= to set the output file or pipe.

Adds -dWRITESYSTEMDICT to leave systemdict writable.

Utilities
---------

Fixes bugs:
	- pcharstr.ps insisted on having Subrs be present in the font.
	- pcharstr.ps decoded negative numbers between -108 and -1131
incorrectly.
	- pfbtogs.ps didn't handle packets longer than 64K correctly.

Changes the bdftops utility so that it makes entries for UnderlinePosition
and UnderlineThickness in FontInfo, and so that it always records a
FullName (the FontName if no other is provided).

Changes the name of the pfbtops utility to pfbtogs, because groff already
includes a program called pfbtops.

Adds the gslp utility for doing "line printing" of text files, similar to
enscript + lpr.

Adds a new variable DITHERPPI that enables a different dither pattern,
claimed to be better for printers.

Adds the font2c utility for compiling Type 1 fonts into C, so they can be
linked into an executable rather than loaded dynamically.

Drivers
-------

Fixes bugs:
	- gdev_prn_copy_scan_lines was erroneously masking the last byte
of data even on color printers, as was paintjet_print_page.
	- The TruFax driver had a couple of compilation errors, since it
hadn't been compiled in a while.
	- The BGI driver sometimes didn't consult BGIPATH when looking for
.BGI files.
	- initclip did the wrong thing with memory devices.
	- The BGI driver didn't look in BGIDIR for .BGI files.
	- The Epson driver didn't set the right margin properly with
ESC+Q.
	- The BJ-10e driver was badly broken.
	- gdev_prn_open/close_printer didn't reset the command list file,
so it was taking quadratic time to print multi-page documents.

Adds color to the SunView driver.

Adds selectable resolution (75, 100, 150, or 300 DPI) to the
DeskJet/LaserJet driver.

Changes gssetdev so that drivers can specify special libraries to be
loaded, as well as object files.

Adds a driver for VESA-compliant SuperVGA displays.  This driver handles
all resolutions from 640 x 400 up to 1280 x 1024, in 256-color mode.  The
default is VGA resolution (640 x 480).

Adds a driver for the ATI Wonder SuperVGA card, and for SuperVGA cards
using the Tseng Labs ET3000 or ET4000 chip such as the STB VGA EM-16 and
the Orchid ProDesigner II (256-color modes only).

Adds a driver for Trident and Tseng Labs SuperVGA cards in 800 x 600,
16-color modes (for cards with only 256K of memory).

Adds user-contributed drivers for the Ricoh 4081, DEC LN03, Canon LBP-8II,
and H-P DeskJet 500C printers.

Adds Tim Theisen's Ghostview changes to the X11 driver.

MAKES NON-BACKWARD-COMPATIBLE CHANGES TO THE DRIVER PROCEDURE INTERFACE as
follows:

	- Changes map_rgb_color and map_color_rgb to always work in a
	    16-bit color value space, rather than a space defined by the
	    maximum number of distinct colors provided by the device.

	- Adds an argument to the output_page procedure to indicate
	    whether the procedure is being called for copypage or
	    showpage, and a num_copies argument.

	- Adds a gx_bitmap_id to the copy_ and tile_ procedures, so that
	    drivers can cache bitmaps in the server or device if they want
	    to.

	- Removes fill_trapezoid and tile_trapezoid.

	- Adds a new get_bits procedure for reading the bits back from the
	    driver buffer (when possible), replacing copy_scan_lines.
	    This procedure takes a new argument describing padding and
	    byte swapping, and returns a different value from
	    copy_scan_lines.

	- Adds get_props and put_props procedures for accessing arbitrary
	    additional properties of devices.  The interface is quite
	    complex, but provides a great deal of flexibility.

See drivers.doc for details.

Changes gdev_mem_bytes_per_scan_line to gdev_prn_bytes_per_scan_line.

Adds a user-contributed driver for DigiBoard, Inc.'s fax software.

Fonts
-----

Changes Type1BuildChar so it uses the information from the Metrics
dictionary in the font, if Metrics is present.

Changes findfont (.loadfont) so it recognizes .PFB fonts and can load them
directly.  Also changes .loadfont to disable packing temporarily, because
some fonts rely on procedures being writable (!).

Interpreter
-----------

Fixes bugs:
	- The hypot function is not available on some Unix systems.
	- Ghostscript didn't flush and close files when exiting.
	- In statusdict, the /margins procedure used .leftmargin, but
/setmargins used .lmargin.
	- An out-of-range putinterval would simply do nothing, rather than
reporting an error.
	- If an attempt to allocate a block larger than the allocator's
chunk size (20K) failed, the allocator would erroneously think it had
succeeded.
	- The bind operator made the top-level procedure read-only, as
well as interior procedures.
	- gs.c copied 1 extra character for the value of strings defined
on the command line with -s...=, which could smash the first byte of the
next object in memory.
	- copying a dictionary erroneously required the maxlength of the
destination to be greater than or equal to the maxlength of the source,
rather than the length of the source.
	- undef didn't correctly decide when to mark a deleted entry as
deleted vs. free; as a result, some keys couldn't be looked up properly
after an undef.
	- type1encrypt and type1decrypt didn't set the size of the result
properly.
	- cvi and cvr didn't allow leading or trailing whitespace in
strings.
	- cvs didn't cause an error if the destination string was too
short.
	- Many operators didn't check correctly for stack underflow (off
by 1).
	- `for' used reals, rather than integers, if the limit was a real,
even if the initial value and increment were integers.
	- `restore' didn't properly invalidate copies of the save object
being restored from; `save dup restore restore' would crash.
	- `restore' sometimes didn't undo stores into matrices that were
stored into by operators.  (The identity matrix always had l_new set.)
	- readline gave a rangecheck if the input line exactly filled the
string.
	- `--' as the last switch on the command line caused a crash
rather than an error message.
	- On MS-DOS systems, filenameforall didn't handle patterns with a
drive or directory specifier properly.
	- stroke sometimes called gz_draw_line_fixed even if the line went
outside the clipping box by 1 pixel.

Changes the loop that binds procedure "operators" to entirely disable the
handling of the typecheck error, rather than to use stopped.  This cuts
initialization time significantly, and also eliminates about 35K of wasted
space (for saving the stacks).

Changes the version "operator" so it returns 47.0.  Adds "revision" to
define the Ghostscript version # x 100.

Adds gscurrentresolution and gssetresolution procedures for getting and
setting the device resolution.

Adds -r<res> and -r<xres>x<yres> as command line options for setting
device resolution.

Adds a facility for incrementally loading the individual CharStrings of a
Ghostscript font from the disk.  This can save a lot of memory, at the
expense of slower rendering.  (It is intended primarily for MS-DOS
systems.)

Changes findlibfile to return the name of the file that was actually
opened, as well as the file itself, when the operation succeeds.

Changes the name of the main entry to the interpreter from interpret to
gs_interpret, because of a conflict with a Data General library procedure.

Adds the .setmetrics operator to set the metrics for the current
character for Type 1 fonts.

Adds more LaserWriter-specific entries to statusdict.

Gives names to all the internal `operators', so they will print out
reasonably when an error occurs.

Extends the status operator to accept a string and return file
information, as defined for Level 2 PostScript.

Adds the filter operator and some specific filters: ASCII85Encode,
ASCII85Decode, ASCIIHexEncode, ASCIIHexDecode, eexecDecode, NullEncode,
PFBDecode, and the null case of SubFileDecode.

Extends the scanner to recognize the Level 2 << and >> tokens.

Adds a facility for extracting the text strings from a PostScript file and
writing them out in a simple format (selected by -dASCIIOUT, implemented
by gs_2asc.ps).

Implements all of the remaining Display PostScript facilities that are
also in Level 2 (i.e., everything in section A.1.3 of the PostScript
Language Reference Manual, Second Edition, that is not also in section
A.1.2).  The virtual memory operations are all stubs; the new halftone
options are not fully implemented.

Changes makeimagedevice to use a string of gray or RGB values, rather than
an array of color objects, to specify the palette.  Removes
currentgscolor and setgscolor from the interpreter, but leaves t_color
objects in, since they may be useful later.

Adds getdeviceprops and putdeviceprops for manipulating device properties.
Currently defined properties for all devices: InitialMatrix, HWResolution,
HWSize, Name.  Currently defined properties for printers: BufferSpace,
MaxBitmap, OutputFile.  OutputFile allows |command for piping on Unix
systems.

Removes deviceparams and makedevice.  Adds devicedefaultmatrix.

Implements reversepath.

Makes copy work on devices.

MS-DOS specific
- - - - - - - -

Fixes bugs:
	- iutilasm.asm wouldn't assemble with newer versions of MASM if
CPU_TYPE was set to 286 or above.
	- CPU_TYPE=386 didn't properly substitute the faster
multiply/divide routines under Turbo C++ or Borland C++, only under the
original Turbo C.

Library
-------

Fixes bugs:
	- A curve whose first and last points were the same wouldn't get
drawn at all.
	- A bug in the Turbo C++ compiler generated bad code when shifting
a long right by 1 bit.
	- If stroking a dashed line ever encountered a segment that was
completely blank, Ghostscript would indirect through a null pointer.
	- arc and arcn gave an error if the radius was negative.
	- stroke always used the general algorithm, even if the line was
guaranteed to be thin.
	- arc and arcn erroneously reduced the angles mod 360.
	- Very large or negative 32-bit numbers in Type 1 fonts didn't
work properly on MS-DOS systems (the ff0000 bits got set to zero). 
	- Color printer devices rendering entirely in memory only
allocated a monochrome-sized bitmap.
	- clip and eoclip didn't intersect the paths properly in the
general case.
	- charpath erroneously rounded the current point to an integral
value, causing characters to be spaced improperly.
	- The definition of max_color_param got some compilers confused.
	- charpath always used quadratic time and space, and dropped all
but the last character when used with a Type 3 font.
	- Stroking a path with a 180 degree angle would incorrectly miter
instead of beveling.
	- Type 1 fonts used the current flatness for curves, which could
produce bad (and inconsistent) results.
	- Stroking a degenerate line segment produced incorrect results.

Changes the character cache to use the UniqueID as the key, when
available, instead of the font pointer.  This dramatically improves
performance when fonts are getting removed and reloaded because of page
isolation with save/restore.

Removes some unnecessary casts to (float) from gsmatrix.c and gscoord.c.

Changes the Type 1 interpreter so that it rounds line and curve endpoints
to the center of the nearest half-pixel, and omits null line segments.
This both speeds up rendering at small sizes and improves output quality.

Changes gs_deviceparams to return resolution as well as extent; changes
gs_makedevice to accept resolution as well as extent.

Replaces the algorithm for approximating circular arcs with curves with a
more accurate one.

Changes gs_point and gs_rect to use doubles rather than floats.

Adds gs_setmetrics, for overriding Type 1 font metrics for the current
character.

Changes clipping to use lists of rectangles rather than path intersection.
 This makes a big difference when clipping bitmaps (including characters).

Changes the character cache to discard entries incrementally, rather than
clearing the entire cache when it fills up.

Changes the implementation of transfer functions to use a cached map,
built when the transfer function is set.  This makes transfer functions
work properly in all situations, including images.

Defines a .quit operator that takes an exit code, and redefines quit in
terms of it.

Adds support for 16-bit-per-pixel devices in gdevmem.

Adds gs_copydevice and gs_deviceinitialmatrix; removes gs_deviceparams and
gs_makedevice.

Changes setscreen to ensure that the cell is always at least 4x4 pixels in
size.

Version 2.3 (8/28/91)
===========

This is a minor release to fix two bugs and add the PaintJet driver, which
didn't make it into 2.2.

Utilities
---------

Changes the pstoppm utility so it counts pages correctly even in the
presence of arbitrary saves and restores.

Drivers
-------

Adds a new, "supported" PaintJet driver.

Changes the Epson driver to use ESC+D rather than ESC+\ for horizontal
positioning, since many printers don't support the latter.

Adds horizontal double-density (two-pass) printing to the Epson driver, so
it can do 240 x 60 and 360 x 180 densities.  (Vertical double density is
not supported yet.)

Version 2.2 (6/1/91)
===========

The purpose of this release is to add save/restore, and a few
miscellaneous Level 2 P*stScr*pt features such as undef.  It also includes
major improvements in graphics quality and in handling of high-resolution
printers.

Procedures
----------

Changes the version numbering to M.mpp rather than M.m.p, so that
`version' can be a real number for those programs that insist on it.

Renames ghost.ps as gs_init.ps, gfonts.ps as gs_fonts.ps, and statusd.ps
as gs_statd.ps.  The initialization files now all are named gs_*.ps.

Renames gdevs.{c,h,tl} as gconfig.{c,h,tl}.

Changes the relevant makefiles and command files so that a single build
can contain several drivers that share code, e.g., the Epson driver and
the DeskJet driver.

Changes gs_init.ps so it relies on an external gconfig.ps file rather than
making a specific test for the presence of Level 2 features.

Adds an entry for uglyr.gsf to the makefile.

Removes the distinction between CCA and CCNA, since most of the files now
contain constructs that require non-ANSI compilation on MS-DOS platforms.

Adds a `man' page for the ansi2knr utility.

Changes the documentation (use.doc) to show how to use -sDEVICE=<device>,
or the selectdevice procedure, to select devices by name.

Adds DEVICE_DEVS to the makefiles (analogous to DEVICES and DEVICE_OBJS).
This finally makes the make procedure fully automatic.

Adds the name of the initialization file (gs_init.ps) as a
platform-specific makefile parameter, GS_INIT.

Removes the test program gt.{c,tr} from the fileset, since it is not
useful to users.

Moves the Symbol encoding vector to a separate file (symbol_e.ps), from
which it is loaded when first used.

Changes the error handler so it can handle errors that occur while reading
the initialization files.

Extends ansi2knr so it can handle `void' and `...' in parameter lists.

Adds quit.ps to the set of installed files.

MS-DOS-specific changes
- - - - - - - - - - - -

Adds the VGA and BGI drivers to the standard MS-DOS configuration, and
makes VGA the default.

Adds a `+' and a newline at the end of gs.tr, to avoid problems with file
transfer programs or editors that add a newline at the end of files.

Changes the name of msdos.mak to turboc.mak, and creates a new tbcplus.mak
makefile for use with Turbo C++ and Borland C++.

Changes the extension of the loader response files from .tl to .tr.

Changes the default search path from c:/ghost and c:/ghost/fonts to c:/gs
and c:/gs/fonts.

Changes the directory separator from `|' back to ';', since it appears
that DOS can handle a ; in a command line if it is prefixed with \.

Unix-specific changes
- - - - - - - - - - -

Changes the uses of install in unixtail.mak so they only install a single
file at a time, which is all that the standard Unix install allows.

Removes the duplicate files (README/readme, LICENSE/license,
COPYING/copying, Fontmap/fontmap).

Changes the ld flags from LDPLAT to LDFLAGS.

Adds XCFLAGS and XLDFLAGS.  These are concatenated with CFLAGS and LDFLAGS
respectively.  The intention is that they be set from the `make' command
line if desired.

VMS-specific changes
- - - - - - - - - -

Repairs the omission of ZPACKED from the VMS build lists.

Drivers
-------

Fixes bugs:
	- The SunView driver produced semi-garbage on little-endian
platforms (Sun-386i) because it didn't swap the bit order.
	- The X driver would dump core if it couldn't open the display and
the DISPLAY environment variable wasn't set.
	- The X driver relied on white = 0, black = ones in a couple of
places;
	- The X driver would return an error, instead of clipping, if
asked to display outside the window.
	- The X driver would create inappropriately sized windows, because
it believed the server's report of the screen resolution.

Adds Fran Taylor's Private Eye driver to gdevs.mak and the fileset (not
supported by Aladdin Enterprises).

Adds Neil Ostroff's TruFax driver to gdevs.mak and the fileset (not
supported by Aladdin Enterprises).

Makes the scratch file template for the printer drivers a per-platform
quantity (gp_scratch_file_name_template).  Puts the default scratch files
for Unix in /usr/tmp rather than /tmp.

Changes the SunView driver to prevent the Ghostscript window from being
destroyed (which badly confuses the interpreter).

Extends the Epson driver to handle a variety of print densities in both X
and Y, to handle 24-pin as well as 8-pin graphics, and to allow optional
specification of default density in the makefile (gdevs.mak).

Refactors the printer drivers so that a single driver handles both DeskJet
and LaserJet.  Adds LaserJet drivers that use the new compression modes on
the LJ IId/IIp and LJ III.

Changes all the printer drivers to use band lists rather than bitmap
paging as the buffering method.  (The individual drivers need only a
one-line change to replace mem_copy_scan_lines with
gdev_prn_copy_scan_lines with a different argument.)

Adds the halftone phase as additional arguments to tile_rectangle and
tile_trapezoid.

Adds an entirely new and much simpler PaintJet driver, using the new band
list interface.

Adds margin information to the device structure.  This is currently only
relevant for printer devices.

Adds BGIPATH and BGIUSER environment variables, allowing additional
control of the BGI driver.

Changes the x/y_pixels_per_inch member of the device structure from int to
float.

Fonts
-----

Patches gs_fonts.ps so definefont will add an isFixedPitch entry to
FontInfo if there isn't one there.

Removes the old "type 7 path" encoding code from gs_fonts.ps.

Changes bdftops so it puts isFixedWidth and ItalicAngle entries in the
FontInfo dictionary of the fonts it creates, since some P*stScr*pt
programs rely on this.

Changes bdftops so it synthesizes as many missing characters as possible
out of the ones that are there (in particular: synthesizes accents out of
punctuation marks, and accented characters using seac.)  The results
aren't all that good, but they're a lot better than having characters
missing out of the font.

Utilities
---------

Adds a pfbtops utility for converting .PFB fonts to standard Ghostscript
fonts.

Fixes bugs:
	- ps2image didn't reset things properly between pages for
multi-page documents.

Interpreter
-----------

Makes Ghostscript recognize `-' alone as meaning that it should read from
standard input as though it were a file.  This allows Ghostscript to
accept a pipe as input.

Fixes bugs:
	- seac in type1addpath used the current font's encoding, not
StandardEncoding.
	- type1decryptfile (eexec) didn't recognize binary (as opposed to
hex) representation.
	- Mentioning a name whose value was a no-access object caused an
invalidaccess error.
	- There was a bogus definition of `run' in zfile.c.
	- The interpreter didn't handle end-of-file on stdin properly.
	- Real numbers with an 'e' or 'E' but no decimal point were not
recognized.
	- On MS-DOS systems, inside strings, \ followed by a newline was
not discarded properly.
	- On MS-DOS systems, the long unsigned divide routine sometimes
gave incorrect answers.  Among other things, this caused alternate-radix
numbers sometimes to crash the interpreter.
	- cvrs didn't do the right thing about reals or negative integers.
	- .echo.mode was being reset with def instead of store, and was
defined in systemdict rather than userdict.
	- setgray and settransfer didn't interact properly.
	- 16#80000000 was being interpreted as a signed integer (and
converted to a real) rather than an unsigned one.
	- atan returned 0 sometimes when it should have returned 180.
	- currentcmykcolor was defined wrong.

Removes the filename operator, since no standard Ghostscript code used it,
and it caused problems with some P*stScr*pt files.

Implements new operators: filenameforall, selectfont (as a procedure),
stringmatch, undef.

Adds new standard procedures: selectdevice.

For MS-DOS, requires that the operand and execution stacks be located in
the data segment, and uses short pointers to address them.  This produces
significantly smaller and faster code.  (These changes are not visible to
users or library clients.)

Changes the assignment of attribute bits, and adds new bits for
save/restore and the garbage collector.  Changes many of the macros in
store.h to support save/restore.  (These changes are not visible to users
or library clients.)  Implements save and restore.

Moves type names from gs_init.ps to ghost.h and ztype.c.

Moves error names from gs_init.ps to errors.h and iinit.c.

Introduces gp.h as a documented interface to the platform-specific files.

Adds the -- switch, which allows Ghostscript programs to take arguments
from the command line.

Changes many uses of the name `name' to something else, to avoid upsetting
the Microsoft C compiler.

Really implements packed arrays -- they took the same amount of space as
ordinary arrays in previous versions.

Changes exitserver in serverdict so that it just clears the stacks.  (This
isn't the correct fix, but it will do as a workaround.)

Makes many miscellaneous small changes to pacify various compilers.

Changes gs_fonts.ps so that when "quiet" mode is selected (-q switch),
Ghostscript doesn't print anything when loading fonts or when substituting
for undefined characters.

Defines the name consisting of just a control-D as a no-op, because some
P*stScr*pt-generating applications put control-Ds in their output.

Implements halftone phase (sethalftonephase and currenthalftonephase
operators).

Removes the -E switch, since it is no longer useful.

Changes the -w and -h switches to a single -g (geometry) switch, with
usage -g<width>x<height>.  Makes the -h switch, and a new -? switch, print
usage help.

Implements correct handling of stack overflow errors (makes an array out
of the contents of the overflowing stack, and resets the stack, before
invoking the error handler).

Adds t_oparray (`operators' defined as procedures) and the makeoperator
operator.  This is so that programs like the Distillery that rely on all
operators being bound by `bind' will work properly.

Adds a new NOPAUSE flag to suppress the prompt and pause at copypage and
showpage.

Library
-------

Fixes bugs:
	- gs_type1_interpret didn't store the encryption state or the skip
count before returning to let the client handle a seac or an endchar in
the middle of a seac.
	- The definition of the Type 1 operator ce_testadd was based on
wrong information; the operator takes only 2 operands and does something
unknown.
	- mem_true24_copy_mono wasn't incrementing the destination pointer
if the color was transparent, leading to garbled characters.
	- gx_lookup_fm_pair would sometimes look at one entry beyond the
end of the cached font/matrix pair area.  (This probably had no practical
effect.)
	- gs_type1_interpret didn't save the current point when returning
to the client for a callothersubr, causing some characters to be rendered
displaced (such as some of the chess pieces in chess.ps).
	- gs_setgray, gs_sethsbcolor, gs_setrgbcolor, gs_setflat, and
gs_setlinewidth gave errors for out-of-range operands rather than forcing
them into range.
	- Transfer functions were not actually supported.
	- The area fill algorithm failed on certain complex paths.
	- The current point was sometimes defined when a BuildChar
procedure was called.
	- Stroking a degenerate line didn't display anything for round
caps or joins.
	- If the ends of a curve had exactly the same X coordinate, the
curve sometimes wouldn't be displayed.
	- Very thin lines that went outside the clipping region would
sometimes be displayed as dashed, or not at all.
	- The translation in a FontMatrix was ignored.
	- Very wide, shallow lines would color extraneous pixels when
using bevel or miter joins.
	- Dashed lines didn't join properly at the beginning of a closed
path.
	- 0-degree arcs didn't add the appropriate line (possibly
degenerate) to the path.
	- gs_type1_interpret didn't reset the callsubr stack when starting
the base character of a seac, which caused confusion if the accent's
endchar fell inside a Subr.
	- Non-monochrome memory memory devices weren't checking the
arguments of the drawing procedures properly.
	- The initial clipping rectangle for memory devices was being
computed wrong.
	- Null devices had a semi-infinite clipping rectangle instead of
an empty one.
	- gs_setlinewidth was treating negative arguments as zero, instead
of taking the absolute value.
	- imagemask with a dithered color used a solid color rather than
the dithered one.

Tweaks the area fill and image rendering algorithms to be a little more
liberal with paint when being used to render characters.

Changes the name of the 8-bit mapped color memory device from
mem_mapped_color_device to mem_mapped8_color_device.

Changes the memory devices so that on little-endian platforms, they can
store the bytes within a word in either order.  (Little-endian order
allows efficient 32-bit updating, big-endian is required when displaying
or writing to a printer or a file.)

Implements halftone phase.

Replaces the trapezoid fill algorithm with a much more accurate one
inspired by a contribution from Paul Haeberli.  This also changes the
graphics convention back to filling only pixels whose center falls within
the region to be filled.

Changes the character cache to allocate headers and bits contiguously out
of a single ring buffer.

Changes gs_imagemask and gs_imagemask_init to take a thickness adjustment
parameter.

Changes gs_setcachedevice and gs_setcharwidth to take the graphics state
as a parameter.

Renames gx_device_memory_bitmap_size as gdev_mem_bitmap_size,
mem_copy_scan_lines as gdev_mem_copy_scan_lines, and
mem_bytes_per_scan_line as gdev_mem_bytes_per_scan_line.

Version 2.1.1 (1/15/91)
=============

This is a sub-release distributed to fix a few early bugs in 2.1, just in
time for the new GNU master tape.

Build procedures
----------------

Removes all of the (undebugged) Level 2 code from the fileset, as well as
the (unused) file gdevvga.c.

Changes the tar file so that the files are stored in the directory
gs<version> rather than simply gs, e.g., gs211.

Interpreter
-----------

Changes the scanner so that \ is recognized within strings regardless of
whether the scanner is reading from a string or from a file.  This is
compatible with newer P*stScr*pt interpreters, and with the newer
P*stSc*pt language specification, but not with the older specification in
the original PostScript Language Reference Manual.

Drivers
-------

Fixes the max_value macro in gdevmem.c so that compilers won't complain
about a left shift by 32.

Adds 'byte' to the list of types that gdevx.c must sidestep because header
files use them.

Library
-------

Changes the computation of penum->unpack in gsimage.c so as not to upset
compilers that don't treat procedures and pointers to procedures as
compatible types for conditional expressions.

Version 2.1 (12/31/90)
===========

This is primarily a bug fix release to clean up problems in 2.0.  It also
implements a first cut at the new color operators.

Build procedures
----------------

Changes the separator for multiple directories in MS-DOS from ';' to '|',
since there is no way to include a ';' in a command line.

Adds <dir>/fonts to the default search path, where <dir> is c:/ghost for
MS-DOS systems and `pwd` for Unix systems.

Adds new documentation describing how to direct output to the printer.

Changes the PROCTYPE and USE8087 options in MSDOS.MAK to CPU_TYPE and
FPU_TYPE.  The latter now indicates the type of FPU to generate code for,
if any.

Drivers
-------

Adds a driver for the Canon BubbleJet BJ10e.

Modifies the EGA driver to handle (non-standard) frame buffers larger than
64K.  Adds drivers for the VGA and for the EIZO MDB-10 (a 1024 x 768 frame
buffer).

Changes the X driver so that it clips to the window dimensions, rather
than reporting an error.

Notes that the H-P LaserJet driver, like the DeskJet driver, works under
Unix as well as MS-DOS.

Adds support for 120 X DPI mode, and for the LQ-1500, to the Epson driver.

Fonts
-----

Fixes bugs in bdftops:
	- It was using /UniqueId instead of /UniqueID as the key for the
font unique ID.  This effectively disabled the font cache.
	- The definition for .notdef was bogus -- an invalid CharString.

Changes ghost.ps and gfonts.ps so that NullFont is the initial font,
rather than Ugly.

Arranges things so that when attempting a font substitution, if the
default font is not found, NullFont is used instead.

Extends bdftops so that if certain easily synthesized characters are
missing from a font, it will attempt to synthesize them using available
characters.

Interpreter
-----------

Extends the -T switch to allow specifying a printf template for the
arguments of the procedure being traced.

Fixes bugs:
	- /0 was interpreted as equivalent to 0 (a number) rather than a
literal name.
	- packedarray was defined as being like array, instead of like
array followed by astore.
	- Many minor and harmless type mismatches (and a couple of very
minor genuine bugs) were upsetting the Apollo C compiler.
	- exp was incorrectly failing in certain cases with a negative
first argument.
	- copyscanlines incorrectly required at least 4 elements on the
operand stack, although it correctly only used the top 3.
	- readhexstring incorrectly read 1 byte even if the string length
was zero.
	- Not every place that expected an array would accept a packed
array.
	- Very complex paths (and infrequently other things) could produce
a 'memory leak'.
	- / alone would skip following whitespace and gather following
characters, rather than creating an empty name.
	- ghost.ps left newerror defined as true in $error, which resulted
in an erroneous error report if a program executed a 'stop'.
	- The definition of exitserver in serverdict didn't clear the
stack.
	- currentfile returned an executable file, rather than a literal
one.
	- setfont for Type 1 fonts didn't check the UniqueID in the font
dictionary against the one in the font's Private dictionary.
	- A value stored in a dictionary under the key /xxx couldn't be
retrieved using the key (xxx), and vice versa.
	- charpath with a Type 1 font on a string containing a 'space'
would produce garbage (it released the parent path inappropriately).
	- bytesavailable did not work properly for terminal input.

Changes the interface to the memory allocator so that it always takes an
element size and an element count, like calloc instead of malloc (but note
that alloc does *not* clear just-allocated blocks).  Gets rid of the
special 'dynamic' allocation procedures.

Changes the random number operators to use a better implementation.

Changes the idiv operator so it will accept any numbers, not just
integers, as arguments.  (The PostScript manual doesn't allow this, but
implementations apparently do.)

Provides semi-fake but usable definitions for all of the color PostScript
extensions, including a real implementation of colorimage.

No longer uses the name 'null', which is apparently reserved by Microsoft
C.  Makes a number of other minor changes required to pacify the Microsoft
C compiler.

Implements %statementedit and %lineedit.  (%statementedit is equivalent to
%lineedit, which is wrong.)  Changes the interactive interpreter to use
%statementedit.

Changes the scanner to accept null, ctrl-K (vertical tab), and ctrl-L
(form feed) as whitespace.  Ctrl-L terminates a comment, null and ctrl-K
do not.

Allows a literal string as the 'proc' argument(s) for image, imagemask,
and colorimage.

Adds the following operators/procedures: arct, cleardictstack, deletefile,
renamefile.

Defines =print as a synonym for =, for the benefit of LaserPrep.

Implements non-zero PaintType for the show operators (but not for
charpath) for Type 1 fonts.

Adds the ISOLatin1Encoding encoding vector.

Renames currentcolor and setcolor as currentgscolor and setgscolor, to
avoid conflict with the Level 2 PostScript names.  Removes colorhsb,
colorrgb, hsbcolor, and rgbcolor.

Library
-------

Fixes bugs:
	- In a couple of places, a 0 was being passed as a pointer
argument without casting, which confused the Microsoft C compiler.
	- Image devices were not recognized properly in debugging
configurations.
	- Inverted-color monochrome image devices were not recognized
properly.
	- Images that exactly fill the drawing area rendered very slowly,
because they erroneously used the general clipping algorithm.
	- Images that are 1-for-1 with the device were incorrectly scaled
by a factor of 8 in X.
	- Rounding artifacts sometimes caused characters to be unevenly
offset vertically by 1 pixel.
	- Type 1 fonts that used the Flex feature resulted in garbled
images.
	- The show operator routines would incorrectly fill or stroke a
path that existed at the time the show was started.
	- setscreen truncated the cell size instead of rounding, which
could produce off-by-1 anomalies.
	- stroke would sometimes produce garbage (or nothing at all) for
very narrow lines.
	- path filling would only color the pixels whose centers fell
inside the path: the Adobe specification requires coloring a pixel if any
part of it falls inside the path.

Changes the Epson printer driver so that it drives the printer directly
rather than writing to a file.

Changes pathbbox so that if the path is empty but there is a current
point, it returns a null rectangle at the current point.

Changes gs_image_init to take an additional parameter (after bps) giving
the number of samples per pixel (1, 3, or 4), and an indication of whether
the samples for each pixel are together or separated (-3 or -4).

Renames the gs_image_data and gs_imagemask_data procedures as gs_image and
gs_imagemask, and removes the old versions of the latter.

Adds gs_colorimage.

Replaces Snoopy's color dithering algorithm with one contributed by Paul
Haeberli.

Changes gs_setgray, gs_[set]hsbcolor, and gs_[set]rgbcolor so that they
coerce arguments outside the range [0..1] back into the range, instead of
signalling an error.

Makes a number of minor changes required to pacify the Microsoft C
compiler.

Changes gs_arcto so that if the last argument is a null pointer, the
tangent points are not returned.

Removes gs_type1addpath, which is not useful.  (Clients must call
gs_type1_init and gs_type1_interpret directly.)

Implements the 'seac' opcode for Type 1 fonts, allowing fonts with accented
characters to display properly.

Implements the undocumented 'testadd' opcode for Type 1 fonts, which is
used by some Adobe fonts.

Renames gs_currentcolor and gs_setcolor as gs_currentgscolor and
gs_setgscolor.  Removes gs_colorhsb, gs_colorrgb, gs_hsbcolor, and
gs_rgbcolor.

Version 2.0 (9/12/90)
===========

The main purpose of this release is to add fonts, support for multiple
devices, and imaging into memory.  It also fixes a number of miscellaneous
bugs.  (Unfortunately, accurate records of the bugs fixed are not
available.)  The changes were so extensive that we chose to increment the
major version number.

Miscellaneous
-------------

Doesn't attempt to open the .MAP file on Unix systems.

Adds mention of statusd.ps to interp.doc.

Notes that Turbo C 2.0, not 1.5, is required for building the MS-DOS
version.

Adds a DEVICES= line to the makefile, and allows multiple devices.

Documents, in interp.doc, the X Windows resources that Ghostscript
recognizes.

Adds three PostScript masters to the fileset: chess.ps (+ cheq.ps),
golfer.ps, and escher.ps.

Drivers
-------

Changes the names of all the device drivers.  See gdevs.mak for the
updated list.

Adds a (working) driver for SunView.

Adds drivers for the Sony NeWS frame buffer, and the Sony Microsystems
NWP533 printers.  These drivers were contributed by users, so we aren't
prepared to answer questions about them.

Adds a driver for the Borland Graphics Interface (BGI) for MS-DOS systems.
Note that to use this driver with a non-EGA/VGA display, you need a .BGI
file appropriate for your hardware.  (The Ghostscript executable includes
the EGA/VGA driver.)

Adds a driver for Epson printers.  The driver has only been tested on an
LX-800, and on an H-P DeskJet in FX-80 emulation mode, but may work on
other models.  The driver could be adapted to work on Unix systems, but as
distributed, it only works on MS-DOS systems.

Adds a driver for the Hewlett-Packard DeskJet printer.  The driver could
be adapted to work on Unix systems, but as distributed, it only works on
MS-DOS systems.

The X Windows driver no longer waits for the user to type a character
before bringing up the initial display.

Adds information to drivers.doc describing how to change the definition of
the device structure and procedure table.

Extends the tile_rectangle and tile_trapezoid driver procedures to
interpret color0 = color1 = gx_no_color_index as meaning that the tile is
actually colored, not a mask.

Build procedures
----------------

Changes the tar file so it puts everything in a directory called gs.

Removes the -ansi switch for gcc (this was causing problems with <math.h>
on some systems).

Changes LDPLAT to the string -X, which is appropriate for most Unix
systems (but not for SunOS 4.n).

Adds EXTRALIBS to the makefile, for specifying additional libraries to be
linked in.

Adds a 'clean' target for 'make', to get rid of all temporary files, the
binaries, and the executable.

Changes names of system-specific files from gp-xxx.c to gp_xxx.c.

Adds support for VMS (gp_vms.c and ghost.dcl).

Creates a new file gdevs.mak, and reorganizes the other makefiles, so that
the choice of which device driver(s) to include is isolated in a single
line in the platform-specific makefile.

Changes the standard MS-DOS makefile so it builds for 8088/86 (not 80386),
with neither -DNOPRIVATE nor -DDEBUG.

Changes the name of the MS-DOS makefile from dos-ega.mak to msdos.mak, and
the Unix makefiles from ux-[g]cc-x.mak to unix-[g]cc.mak.

Updates drivers.doc to describe how to add new drivers in gdevs.mak.

Removes gdevs.ps: the drivers are now responsible for specifying the size
of the imaging region.

Interpreter
-----------

Adds a makefile macro GS_LIB_DEFAULT and an environment variable GS_LIB to
define a search path for the library (initialization and font) files, and
implements the -I switch for the same purpose (replacing -sLIB=, which was
never actually implemented).  See interp.doc for details.

No longer clears the operand stack between interactive inputs.  No longer
prints the contents of the operand stack after every input in debug mode.

Doesn't "eat" the character that the user types to proceed after a
showpage, unless it's an isolated <return>.

Changes the prompt so that it says
	GS>
if the operand stack is empty, or
	GS<n>
if there are n > 0 elements on the operand stack.

Adds -w and -h switches to the command line, equivalent to -dWIDTH= and
-dHEIGHT= except that they require numeric arguments.

Adds -q (quiet startup) switch to the command line, which suppresses some
initial messages and also has an effect equivalent to -dQUIET.

Fixes bugs:
	- = and == caused an error on some kinds of objects if the object
didn't have read access.
	- cvs didn't print operator names.
	- The definition of dynamic_begin in iscan.c caused the DEC VMS C
compiler to produce incorrect code.
	- mul didn't return a correct (real) result when multiplying a
very large integer by an integer that wasn't very large.
	- eq and ne didn't work on files, fonts, save objects, and some
operators.
	- The scanner would sometimes blow up on floating point numbers
beginning with a '.'.
	- flushfile didn't pop its argument from the stack.
	- put and putinterval would store into a packed array.
	- a few operators didn't check properly for stack underflow.
	- cvrs produced wrong output for radix values greater than 10.
	- The scanner would convert upper-case letters in alternate-radix
numbers wrong on Unix systems.
	- String comparisons other than equality often produced the wrong
result if the strings were of different lengths.
	- An ifelse as the last thing inside a forall would confuse the
execution stack.
	- There were some omitted casts and 'private' declarations that
made the GNU compiler unhappy.
	- There was a memory leak in the image[mask] operators that caused
516 bytes to be permanently lost each time one of them was used.
	- Quoted strings of length greater than 50 and less than 100 would
get mangled when being read in.
	- The scanner didn't consume the whitespace character following a
token, so programs that read data out of the program file could get
confused.
	- Under rare circumstances, an object of size between 249 and 255
bytes could get allocated on top of another object.

Allows bind to bind packed arrays, even though they aren't normally
writable.

Changes the length operator to allow a name as the argument.  (The
PostScript manual doesn't allow this, but implementations apparently do.)

Changes the setcachedevice operator to allow the bounding box to be
specified as a 4-element array instead of 4 scalars.  (The PostScript
manual doesn't allow this, but implementations apparently do.)

Removes a line from ghost.ps that accidentally disabled the font cache.

Implements memory devices (makeimagedevice, copyscanlines, and makedevice
for image devices).  makeimagedevice is implemented only for 1, 8, 24, and
32 bits per pixel.

Changes the deviceparams operator so it pushes a mark on the stack below
the parameters.  This is to allow for devices that have more than the
standard set of parameters.

Replaces defaultdevicename with two new operators, getdevice and
devicename.

Adds a flushpage operator that flushes any outstanding buffered output to
the screen.  This is not the same as copypage: on printers, copypage
actually prints a page, whereas flushpage may do nothing; on displays,
flushpage and copypage may both flush output to a server.

Adds an unread operator for pushing back a character into a file.

Adds a description of proposed grayimage and colorimage operators to
ghost.doc, even though they aren't implemented yet.

Changes the name of the currentfileposition operator to fileposition.

Removes the framedevice operator, since the new device operators supersede
it.

Adds a writeppmfile operator, for writing the contents of a memory device
to a ppm file.

Makes Ghostscript work even when the >> operator doesn't sign-extend
negative numbers.  (This has not been tested.)

Adds the Symbol encoding to ghost.ps.

Adds two new file-related operators, filename and findlibfile.  See
ghost.doc and interp.doc for details.

Adds type1encrypt and type1decrypt operators for manipulating Adobe Type 1
encoded fonts.

Changes the imagecharpath and addcharpath operators to type1imagepath and
type1addpath.  These operators now work with the Adobe Type 1 font
encoding.

Adds the type1decryptfile operator for reading Adobe Type 1 encrypted
fonts.

Library
-------

Fixes bugs:
	- curveto and lineto didn't check for the current point being
defined.
	- stringwidth would fail if there was no current point.
	- There were omitted casts that made the GNU compiler unhappy.
	- Line caps and joins didn't always work.
	- Dashed lines didn't work at all.
	- If you read out the current matrix while inside a BuildChar
procedure, the result was garbage.
	- image[mask] would crash if you gave it a single string with more
than 64K-1 pixels (MS-DOS only).
	- Filling with a gray pattern sometimes wrote into pixels beyond
the right edge of the region (MS-DOS only).
	- The font cache would mistake fonts for each other if both fonts
had a default (unsupplied) "unique ID".
	- When a character was entered into the font cache for the first
time, sometimes it would display as garbage and/or displaced vertically
from its proper position.

Implements gs_makeimagedevice, gs_copyscanlines, gs_getdevice,
gs_devicename, gs_flushpage, gs_writeppmfile, gs_type1encrypt,
gs_type1decrypt, gs_type1imagepath, and gs_type1addpath procedures
corresponding to the new operators in the interpreter (see preceding
section).

Changes [gs_]setdevice so that it does an erasepage when it first opens
the device.

Changes definition of gx_device structure as follows.  NOTE: THIS AFFECTS
ALL DRIVERS.

	- Removes bits_from_MSB (which wasn't actually used, in any case).
	    Ghostscript now assumes officially, as it always did in
	    practice, that device bitmaps are stored MSB first, i.e., X=0
	    corresponds to the 0x80 bit in the first byte.

	- Removes the initial_matrix member, which wasn't actually being
	    set up.

	- Adds a new member 'name', a string giving the device name.

	- Adds new members 'x_pixels_per_inch' and 'y_pixels_per_inch'.
	    These are only used by the default initial_matrix procedure
	    (see below).

	- Adds a new procedure 'output_page'.  The default implementation
	    (gx_default_output_page) just calls the sync_output procedure.

	- Adds a new procedure 'get_initial_matrix'.  The default
	    procedure uses the width, height, and x/y_pixels_per_inch
	    members to compute the matrix, assuming that X values run from
	    right to left, and Y values run from top to bottom.

Changes the names of the allocation procedure types gs_proc_alloc and
gs_proc_free to proc_alloc_t and proc_free_t, and moves them from gs.h to
std.h.

Makes Ghostscript work even when the >> operator doesn't sign-extend
negative numbers.  (This has not been tested.)

Version 1.3 (6/20/89)
===========

This release should have had a lot more things in it, but time pressure
and the already long delay in getting it out made it necessary to push it
out the door in an incomplete state (e.g., no testing on X systems
whatsoever).

Interpreter
-----------

Makes -d and -D equivalent on the command line.  Adds a new switch -s / -S
that defines a name as a string rather than a token.

Arranges things so that if -sLIB=_a_prefix_ is defined on the command
line, (filename) run will look for _a_prefix_filename before giving up if
filename isn't the name of an accessible file.

Changes showpage from an operator to a procedure.  The definition of
showpage in ghost.ps does a copypage, beeps the console, waits for the
user to type a character (normally a <return>, since line buffering is
always enabled), and then does an erasepage and an initgraphics.

Adds a new initialization file, gdevs.ps, containing device-dependent
parameters.  The default window size for X Windows is properly set to 612
x 792, i.e., 8.5" x 11".

Adds a new optional initialization file, statusd.ps, that provides dummy
definitions for the names found in statusdict on LaserWriters.

Adds a new operator, getenv, to get information from the shell
environment.

Adds a new predefined operator, defaultdevicename, that returns either (X)
or (EGA) according to how the interpreter was built.

Adds a new type, devicetype, and new operators deviceparams, getscanlines,
makedevice, makeimagedevice, and setdevice.  Changes currentdevice to
return a device object rather than a set of parameters.

Makes the scanner recognize reals with 'e' exponent notation, and handle
reals with more than 9 digits.

Fixes a bug that made names starting with digits read incorrectly.

Fixes a bug in the exp operator that made it not pop its first argument
from the stack.

Fixes a bug in the rand operator that made it return negative values about
half the time.

Fixes a bug in equality comparison (eq, ne, and several other operators)
that made unequal operator objects occasionally appear to be equal on DOS
systems.

Fixes a bug in the bind operator that made it not work on packed arrays.

Changes the internal representation of dictionaries so they can be
expanded or contracted dynamically.  Adds a new operator, setmaxlength, to
change the allocated size of a dictionary.

Changes sstorei.h so that non-DOS compilers don't encounter the #pragma
directive used by Turbo C.

Restores the display mode (on MS-DOS systems) when exiting.

Fonts
-----

Makes undefined characters in the standard font display as tilde rather
than blank (or causing an error).  Unmapped character codes (those mapped
to .notdef in the encoding) still display as nothing, per the PostScript
manual.

Library
-------

Adds a new header file, gxbitmap.h, with some new documentation describing
the internal storage format for bitmaps.

Makes numerous internal changes in the character / font cache, affecting
many of the routines in gxcache.c.

Fixes a bug in gz_draw_line / gz_fill_trapezoid that made nearly
horizontal lines display wrong.

Fixes a bug in gs_scale that made scaling not work if the coordinate
system was rotated or skewed.

Extends the font cache so it will handle characters rotated by multiples
of 90 degrees.

Changes the second argument of gx_path_bbox and gx_path_is_rectangle to be
a gs_fixed_rect * rather than a fixed [4].

Changes gs_matrix_rotate so it handles multiples of 90 degrees as a
special case.

Changes the definition of the gx_device structure to accommodate the new
device operators, and adds corresponding library calls.

Changes the type for a device color index from int to gx_color_index
(equivalent to unsigned long).  ***NOTE***: this affects existing clients
and drivers in a non-trivial way on MS-DOS systems.

Changes gs_malloc and gs_free to take a client name string as an argument.

Usage procedures
----------------

Changes the compilation rules for Unix systems to not use the -o and -c
compiler flags together, to be compatible with more versions of cc.

Changes the gcc makefile to use $(GCC) rather than gcc as the compiler
name.

Moves the -1 flag for the MS-DOS compiler from the cc*.bat files to the
makefile.

Changes CCDEBUG to CCFLAGS, and adds ASMFLAGS, in DOS makefile.

Adds -DFOR80386 and /DFOR80386 to enable use of 80386 instructions in
assembly code on DOS systems.

Merges the DEBUG and gs_DEBUG switches.  There is now only a single DEBUG
switch that affects both the interpreter and the library.

Adds a new compilation switch, -DNOPRIVATE, that makes private (static)
variables and procedures public for debugging and profiling (only needed
on DOS systems).

Adds the DOS executable (gs.exe and gs.map) to the distribution fileset.

Adds new platform-specific code files, gp-*.c, for a few things like
reading the clock.

Adds a new documentation file, drivers.doc, that describes the interface
between Ghostscript and device drivers.

Version 1.2 (2/22/89)
===========

Interpreter
-----------

Adds the new facilities in version 25 of PostScript: //name for immediate
lookup, packed arrays (setpacking, currentpacking, packedarray operators),
and new font cache parameters (setcacheparams, currentcacheparams
operators).

Adds new operators (setfileposition, currentfileposition) for random
access to files.

Extends readhexstring to take either a string or a file, just like token.

Fixes a bug that caused the 'for' operator (and a couple of others) to
randomly smash memory locations on PC platforms.

Library
-------

Renames the init_device driver procedure as open_device, and adds a
corresponding close_device.

Adds new procedures to read and set the cache limit values (implementing
the currentcacheparams and setcacheparams operators).

Usage procedures
----------------

Changes the name of the Unix makefile to ux-cc-x.mak, and adds a new Unix
makefile, ux-gcc-x.mak, for using gcc instead of cc.  (The latter doesn't
actually work yet.)

Changes the name of the single built-in font from uglyfont.cp to
ugly10.cp.

Version 1.1 (2/12/89)
===========

Interpreter
-----------

Makes the scanner treat ^Z (ASCII code 26) as whitespace: it erroneously
treated ^R (ASCII code 22, or octal 26) as whitespace.

Makes the token and readline operators, and the syntax for comments,
recognize \r (code 13), \n (code 10), and \r\n as equivalent end-of-line
indicators.  The token and readline operators will skip over any of these
sequences at the end of a token or line respectively, and a comment will
read through any of these sequences.  The other file operators (read,
write, readstring, writestring) do nothing special with these characters.

Changes the debug switch name from -D to -Z.  Adds a -D switch for
defining names in systemdict from the command line.  Defines -DDEBUG for
printing out debugging information during initialization, and -DNODISPLAY
for suppressing display output.

Corrects a bug that prevented the error machinery from working -- in
version 1.0, errors always dumped the stacks and aborted interpretation.

Corrects a bug that made eq and ne not work for strings.

Makes the atan (arctangent) operator normalize its results according to
the PostScript convention.

Makes the div operator check for zero divisor.

Makes unimplemented operators (resetfile, echo, save, restore, strokepath,
reversepath) truly undefined.

Makes the interactive loop exit gracefully on end-of-file: in version 1.0
this caused an infinite loop.

Implements the status operator.

Corrects a bug that made the 'for' operator deliver garbage values if one
or more of the operands (start, increment, end) was a real.

Corrects a bug that made the arc and arcn operators not pop their operands
from the stack.

Corrects a bug that made the kshow operator crash the interpreter.

Corrects a bug that made the print operator fail on machines that don't
pass structure arguments by simply pushing the contents of the structure.

Adds a new operator, imagecharpath, to convert images to
addcharpath-compatible outlines.

Changes alloc and alloc_free to use char * rather than byte *, and
alloc_free to return void rather than int, making them compatible with the
library's expectations and with malloc/free.

Explicitly casts all expressions of the form (ptr1 - ptr2) used as
procedure arguments to unsigned, to handle an incompatibility between
Turbo C versions 1.5 and 2.0.

Changes some of the internal conventions for operators: operators that
push on the operand stack must check for overflow explicitly, and
operators that modify the execution stack must return a special code.
(See oper.h for details.)

Initialization (ghost.ps, gfonts.ps)
--------------

Modifies ghost.ps and gfonts.ps so they print debugging information only
if the name DEBUG is defined.  (Presumably the user will set this from the
command line with -DDEBUG.)

Changes ghost.ps so it initializes the nominal screen size to 640 x 350 on
MS-DOS systems as before, but to 612 x 792 on Unix systems, which is an
8.5" x 11" page at 72 pixels per inch.

Library
-------

Corrects a bug that made the fill and eofill operators (gs_fill and
gs_eofill) not perform a newpath afterward.

Corrects the bug that made thin, nearly horizontal lines display wrong (as
a series of disconnected dots) in the MS-DOS implementation.

Fixes a bug in the EGA driver that often made it fill rectangular regions
with black around information being displayed in white.

Completely changes the internal representation of outline fonts, and
changes btoi.ps (a Ghostscript language program for converting bitmaps to
outlines) to use a new library call, gs_imagecharpath.

Changes the extension for outline font files from .gf to .cp.

Adds a new debugging switch, q, that traces all rectangle fill operations.

Adds a new debugging switch, v, that traces all device-level output calls.

Explicitly casts pointer differences passed as procedure arguments, as in
the interpreter.

Makes stringwidth work if there is no current point.  In version 1.0, this
gave a nocurrentpoint error.

Usage procedures
----------------

Changes the name of the 'read me' file from READ.ME to README.

Removes a bogus line (invoking the 'mcopy' utility) from the makefile.

Splits up the makefile into a generic part (ghost.mak) and
platform-specific parts (dos-ega.mak, unix-x11.mak).  The latter are what
is actually executed.

Puts the definitions of the DEBUG and gs_DEBUG compilation flags into the
makefile instead of in ghost.h and gx.h respectively.

Changes the names of the documentation files to be a little less cryptic.
Changes all the file names to lower-case in the documentation.  Adds
installation information to make.doc.

Changes all function definitions (but not prototype declarations) to ANSI
syntax, and adds a preprocessing step (ansi2knr) to convert them to K&R
syntax on Unix systems.

Changes the normal MS-DOS link configuration to not assume the presence of
an 80x87 coprocessor, and describes how to increase performance if a
coprocessor is present.

Changes the names of all the interpreter .c files, except stream.c, to
begin with 'i'.

Version 1.0 (8/11/88)
===========

First version released to the public.
