ChangeLog

v1.8 2007/04/09
	(2007/04/08) PS1 - portability: use 'test' instead of '[' in shell
	scripts.
	(2007/04/08) PS1 - test suite: run PDF checks as a separate test.
	(2007/04/06) PS1 - fixed logical expressions in flate.c
	(2007/02/19) PS1 - portability: replacements for inline and M_PI
	(2007/01/16) PS1 - test suite: added checks for rotation in
	PostScript, PDF, and PGM backends
	(2007/01/16) PS1 - pdf backend: added rotation
	(2007/01/16) PS1 - pdf backend: renamed shipcom() function
	(2007/01/14) PS1 - autoconf: check if getopt_long reorders its
	arguments.
	(2007/01/13) PS1 - made pseudo-random number generation
	thread-safe and much faster.
	(2006/12/20) PS1 - renamed some structures in lzw.c, main.h
	(2006/12/20) PS1 - portability: fixed some compiler issues for
	Amiga, reported by Andreas Kleinert.
	(2006/12/20) PS1 - main.c: changed some return types to void.
	(2006/08/14) PS1 - made curve.c:privcurve_free_members() static.
	(2005/12/22) PS1 - renamed README.win as README-WIN
	(2005/11/11) PS1 - portability: use binary file i/o in Cygwin.
	Suggested by Henry He.
	(2005/06/24) PS1 - potracelib: fixed allocation bug, reported by
	Jung Shin.
	(2005/06/23) PS1 - potracelib_demo.c: free resources properly.
	(2005/06/23) PS1 - initialize unused private state to 0.
	(2005/06/23) PS1 - decompose.c: improved memory allocation scheme.
	(2005/05/06) PS1 - added "alphacurve" field to private curve
	structure, so that backends that don't use the public interface
	(such as the EPS backend) can be warned of non-conforming curves.

v1.7 2005/03/06
	(2005/03/05) PS1 - fixed progress bar subrange bug.

v1.6 2005/02/27
	(2005/02/22) PS1 - added "epsilon" feature to progress bar.
	(2005/02/22) PS1 - documentation: changed potracelib documentation
	to TeX format.
	(2005/02/07) PS1 - tweaked progress bar
	(2005/01/24) PS1 - added --progress option to potrace frontend.
	(2005/01/24) PS1 - potracelib: added progress bar interface.
	(2005/01/23) PS1 - fixed overflow bug in fast summing code.
	(2005/01/23) PS1 - rewrote trace.c:bestpolygon(). This speeds up
	potrace by 20% on typical data and up to 60% in some bad cases.
	(2004/12/07) PS1 - documentation: added potracelib.txt
	(2004/12/07) PS1 - renamed aux.h as auxiliary.h, since aux is an
	invalid filename in Windows.
	(2004/12/06) PS1 - API: added default parameters
	(2004/12/06) PS1 - API: added potrace_state_t
	(2004/12/06) PS1 - API: added "const" qualifiers
	(2004/12/06) PS1 - removed conv and areac fields from privpath_t.
	(2004/12/06) PS1 - changed bounding box handling in decompose.c
	(2004/12/06) PS1 - split curve_t into public and private parts.
	(2004/12/06) PS1 - moved curve/path allocation to curve.c.
	(2004/12/06) PS1 - renamed a type in lzw.h.
	(2004/12/06) PS1 - renamed source files.
	(2004/12/04) PS1 - split path_t into public and private parts.
	(2004/12/03) PS1 - split core functionality from user interface.
	(2004/12/03) PS1 - moved parts of bitmap.h to potracelib.h. Split
	bitmap.c into bitmap.c and bitmap_io.c. Moved path decomposition
	auxiliary functions from bitmap.c to path.c.
	(2004/12/03) PS1 - converted some stray local functions to static
	(2004/12/01) PS1 - moved basic curve data type definitions to
	potracelib.h
	(2004/12/01) PS1 - collected some repeatedly used macros in aux.h
	(2004/12/01) PS1 - started to create API to potrace core
	functionality in potracelib.c and potracelib.h. Also added new
	libpotrace.a target.
	(2004/12/01) PS1 - made curve.c and path.c reentrant by removing
	global variable "info".
	(2004/11/28) PS1 - made a85* auxiliary functions static in
	flate.c.
	(2004/11/28) PS1 - pdf backend: removed arbitrary page limit.
	(2004/11/24) PS1 - pdf backend: replaced ftell() by explicit byte
	count to work correctly with stdout.
	(2004/11/24) PS1 - portability: use binary file i/o in MinGW.
	(2004/10/08) PS1 - minor cleanup in backend_pdf.c.
	(2004/09/21) PS1 - replace -O3 compilation default by -O2; inlined
	critical functions manually instead.
	(2004/09/18) PS1 - slightly optimized multiplications in
	curve.c:bezier(). Thanks to Thomas M.Ott for suggesting it.
	(2004/09/16) PS1 - list of backends in help message is now
	generated.
	(2004/09/16) PS1 - test suite: added test for pdf backend.
	(2004/09/14) PS1 - removed bits.c, renamed bits.h to bitops.h, and
	use static inline functions instead of macros.
	(2004/09/14) PS1 - test suite: adjusted tolerances.
	(2004/09/12) PS1 - mkbitmap: when reading plain pbm files, use
	colors 0 and 255, not 0 and 1.
	(2004/09/12) PS1 - potrace and mkbitmap: don't complain about
	"junk at the end of file" if the junk is whitespace and
	comments. Treat files which contain only whitespace and comments
	as empty.
	(2004/08/05) TA1 - added pdf backend.

v1.5 2004/07/08
	(2004/07/08) PS1 - removed dependency on external "compress"
	program. Removed ztops.c, added lzw.c, bits.c.
	(2004/03/17) PS1 - don't leave temporary file /tmp/have_compress.*
	lying around.
	(2004/03/06) PS1 - fixed a type error in have_compress.c:28.

v1.4 2004/03/06
	(2004/03/05) PS1 - removed the compile-time check for the
	"compress" program and replaced it by a run-time check.
	(2004/03/03) PS1 - ztops.c: fixed compression bug where garbage
	was added after the end of stream.
	(2004/02/09) PS1 - further optimized the speed of the function
	path.c:pathlist_to_tree, which now takes less than 0.1% of total
	running time.
	(2004/02/09) PS1 - distribution: removed potrace.{ps,pdf} from
	distribution, changed textfiles to DOS mode in Cygwin distribution
	(2004/01/19) PS1 - corrected a bug in 1.2 which caused an enormous
	slowdown in the function path.c:pathlist_to_tree.
	(2004/01/17) PS1 - test suite: better quoting in shell scripts to
	be more robust against spaces in filenames etc.
	(2004/01/17) PS1 - test suite and ztops.c: respect TEMPDIR
	environment variable, if set.
	
v1.3 2004/01/15
	(2004/01/14) PS1 - test suite: adjusted tolerances.
	(2004/01/13) PS1 - when reading a bitmap of width or height 0,
	pretend the offending dimension is 1. This is not 100% logical
	in all cases, but better than producing garbage.
	(2004/01/13) PS1 - fixed bounding box in xfig backend.
	(2004/01/13) PS1 - added missing gsave/grestore to ps backend.
	(2004/01/07) PS1 - autoconf: search for zlib.h in
	${prefix}/include and for libz.so in ${prefix}/lib, in case they
	are not found elsewhere.
	(2004/01/07) PS1 - eliminated some unused variables.
        (2004/01/07) PS1 - portability: eliminated typeof() from
	mkbitmap.c
	(2004/01/07) PS1 - test suite: added a test for empty bitmaps.
	(2003/12/25) PS1 - fixed bug #866223: potrace crashes when applied
	to an empty bitmap.
	(2003/12/25) PS1 - when options -2 or -3 are unsupported, ignore
	them rather than failing, for improved compatibility.
	(2003/12/25) PS1 - autoconf: added --disable-zlib configuration
	option and improved error messages for missing zlib.h or libz.so
	(2003/12/25) PS1 - portability: eliminated dynamic arrays in
	mkbitmap.c
	(2003/12/25) PS1 - test suite: added a check for mkbitmap.
	(2003/12/25) PS1 - test suite: more portable filesize checking in
	backend-check.sh

v1.2 2003/12/23
	(2003/12/23) PS1 - added an xfig backend.
	(2003/12/23) PS1 - added --group option to group related shapes
	together in SVG backend.
	(2003/12/23) PS1 - added --opaque option to paint white shapes
	opaquely, instead of leaving them transparent, in PS/EPS and SVG
	backends.
	(2003/12/23) PS1 - rewrote path decomposition algorithm to
	calculate path containment tree, to be used for grouping.
	(2003/12/23) PS1 - test suite: added a check of postscript output
	using ghostscript.
	(2003/09/18) PS1 - autoconf: added tests for -lm and -lz
	libraries, and for zlib.h header file.
	(2003/09/18) PS1 - portability: cleaned up code so that it can be
	compiled with a C++ compiler.
	(2003/09/17) PS1 - code cleanup in main.c:main().
	(2003/09/17) PS1 - added mkbitmap program.
	(2003/09/17) PS1 - added -ffloat-store compiler flag for improved
	floating point predictability.
	(2003/09/12) PS1 - test suite: added test for BMP runlength
	encoding.
	(2003/09/12) PS1 - fixed frontend for BMP runlength encoding.
	(2003/09/11) PS1 - autoconf: added test to work around gcc
	compiler bug 12243, which affected curve.c:adjust_vertices().
	(2003/09/11) PS1 - renamed pbm.c as bitmap.c, pgm.c as greymap.c
	(2003/09/11) PS1 - moved some bitmap details from path.c to pbm.c
	(2003/09/10) PS1 - renamed pbm.h macros to start with BM_
	(2003/09/02) PS1 - portability: added missing fallback value for
	M_PI to backend_pgm.c.
	(2003/08/28) PS1 - specialized matrix solving code for n=2.
	(2003/08/28) PS1 - portability (and scalability): eliminated
	dynamic arrays.
	(2003/08/28) PS1 - portability: replaced vsnprintf by vsprintf.
	(2003/08/28) PS1 - portability: provided fallback value for M_PI
	(2003/08/27) PS1 - autoconf: now checks whether the compress
	program works, not just whether it exists.
	(2003/08/27) PS1 - test suite: wrote three tests for "make check"
	(2003/08/27) PS1 - portability: fixed some floating point errors
	on DEC Alpha: division by zero and log of zero.
	(2003/08/27) PS1 - changed bitmap representation to take advantage
	of 64-bit architectures.
	(2003/08/27) PS1 - changed default scaling in ps and eps modes for
	small page sizes.
	(2003/08/26) PS1 - allow arguments of command line options -b, -z,
	-P to be abbreviated by "unambiguous prefix".
	(2003/08/26) PS1 - added rotation to gimppath backend.
	(2003/08/24) PS1 - portability: removed GNU extensions from printf
	format strings in backend_eps.
	(2003/08/22) PS1 - converted --unit to double value.
	(2003/08/22) PS1 - added experimental gimppath backend.
	(2003/08/20) PS1 - close paths in postscript/eps backend.
	(2003/08/20) PS1 - fixed bug in parsing command line options: long
	options --cleartext, --level2, --level3 did not work properly.
	Thanks to George Williams for reporting this bug.
	
v1.1 2003/08/18	
	(2003/08/17) PS1 - replaced calc_lon algorithm by a faster
	implementation. This results in speedups of up to factor 3.3 for
	certain large input files.
	(2003/08/17) PS1 - added --invert option.
	(2003/08/17) PS1 - improved error messages on wrong file format.
	(2003/08/17) PS1 - code cleanup to build under fussier compilers.
	Thanks to Nelson Beebe for submitting compiler logs for a large
	number of setups.
	(2003/08/17) PS1 - renamed curve.c:quad as quadform to avoid name
	clash on IBM AIX, Compaq/DEC ODF/1.
	(2003/08/17) PS1 - autoconf: let user override CFLAGS at configure
	time, and use -Wall and -O3 only for gcc compiler
	(2003/08/16) PS1 - added --blacklevel option to control
	image-to-bitmap conversion
	(2003/08/16) PS1 - added ability to read BMP files. Changed error
	reporting in case of empty files, or if there is junk at the end
	of a file in multipage mode.
	(2003/08/14) PS1 - as a convenience, now also read files in PGM
	and PPM format and convert to bitmap by simple threshold method.
	This is because many programs, including the Gimp and the *topnm
	tools, produce PNM output which must be further converted to PBM.
	(2003/08/14) PS1 - rearranged order of options in usage message.
	(2003/08/14) PS1 - implemented -d1 option for SVG backend. This
	outputs a jaggy bitmap with no smoothing.
	(2003/08/14) PS1 - autoconf: improved handling of
	--enable-compress
	(2003/08/14) PS1 - added SVG backend.
	(2003/08/14) PS1 - renamed old -s option as -S
	(2003/08/12) PS1 - added README.win
	(2003/08/12) PS1 - autoconf: fixed bug #787182: added non-standard
	compile time options to help message for ./configure script
	
v1.0 2003/08/10	
	(2003/08/10) PS1 - added file i/o code
	(2003/08/08) PS1 - optimized number of times the penalty3 function
	is called. Speedups of factor 2.7 were observed on large files.
	(2003/08/08) PS1 - added --opttolerance and --alphamax options.
	(2003/08/07) PS1 - autoconf: changed configure.in so that test for
	compress is omitted when the user overrides it - this prevents a
	wrong cached value to be read.
	(2003/08/07) PS1 - keep output flushed in postscript mode
	(2003/08/07) PS1 - fixed memory leak in multiple page mode
	(2003/08/06) PS1 - replaced --opticurve by --longcurve option;
	opticurve is now the default
	(2003/08/06) PS1 - added opticurve sensitivity to pgm backend
	(2003/08/06) PS1 - restricted opticurves to be bounded away from
	180 degrees
	(2003/08/06) PS1 - allow margins and papersize to determine width
	if it is not defined by other means in postscript mode
	(2003/08/06) PS1 - added ability to read multiple bitmaps in
	postscript mode
	(2003/08/05) PS1 - new --longcoding option
	(2003/08/05) PS1 - new optimized eps backend which works with
	opticurve.
	(2003/07/31) PS1 - replaced O(n^3) calc_lon algorithm by a new
	O(n^2) algorithm. Observed speedups of factor 80.
	(2003/07/27) PS1 - added --opticurve option and integrated
	opticurve code in curve.c
	(2003/06/04) PS1 - made bm_to_pathlist a lot more efficient by
	scanning and clearing only bounding box of mask in inner scan.
	(2002/11/17) PS1 - changed bm_to_pathlist prototype to use
	explicit return value.
	(2002/10/09) PS1 - autoconf: added automake/autoconf scripts in
	preparation for public distribution.
