These are some release notes that deal with new features and backward compatibility of the plotutils package, on both user and programmer levels. Release 2.5, dated 12/2005 -------------------------- This is primarily a bug fix release, but the number of bug fixes is large. The biggest change is to the X11 driver. The font support in X11 (the X Window System) is in a state of overturn, and previous releases of the plotutils package do not produce good-looking output (of rotated text strings, especially) on many current X11 displays. This is for the following reason. The traditional `core' X fonts stored on any X11 display, each of which has a long name (a so-called XLFD name), are going away. The new model is for fonts to be stored on the client side, and to be rasterized by the FreeType rasterizer via the Xft library. Even in advance of this change, X servers such as XFree86 are starting to drop support for the more sophisticated features of the core X font subsystem, such as its ability to supply rotated or sheared glyphs. So the libplot library now produces its own rotated and sheared glyphs. It still uses the core X fonts, but it no longer requests rotation or shearing when retrieving rasterized characters (glyphs) from those fonts. Instead, it rotates or shears them itself. The result looks fairly good. For example, the output from the `rotating A' sample program in the plotutils manual looks as good as it always did, and takes no longer to generate. The command-line graphics utilities (e.g., `graph') support a `--rotation' option, to rotate graphics within their `viewport' or `plotting box'. (For X11 output, requested by `-T X', this viewport is simply the popped-up X window.) The argument of this option can now be an arbitrary number, interpreted as a counterclockwise rotation in degrees. (It used to be required to be 0,90,180, or 270.) You can now do this sort of thing: echo 0 0 1 1 2 0 | graph -T X -C -L 'A Postmodern Plot' -W 0.01 --rotation 45 The same thing can be done in any other output format (e.g., as requested by `-T ps' or `-T svg'.) This enhancement is independent of the rewriting of the X11 driver, but was suggested by it. A bad bug in the output of the PS driver, which prevented its being displayed by some versions of ghostscript/ghostview/gv, has been fixed. The output of the SVG driver has been improved, to be more compatible with the SVG parsers in Firefox and the ImageMagick package. Unfortunately, font handling in both of them is somewhat broken. If you have trouble using the standard builtin `Postscript' fonts (meaning, Adobe's standard set of 35 fonts such as Helvetica, Times-Roman, Courier, etc.), you should use the builtin Hershey fonts instead. Each character in any Hershey font is `stroked': it is made up of line segments. The Hershey fonts look quite good in Firefox, for example, due to its anti-aliasing. To check the drawing of SVG text strings, first do echo 0 0 1 1 2 0 | graph -T svg -C -L 'A Postmodern Plot' -W 0.01 --rotation 45 > plot.svg to obtain an SVG plot. To display it using Firefox and the ImageMagick package respectively, do firefox file:${PWD}/plot.svg display plot.svg If there are problems with your copy of Firefox or the `display' application, some of the axis labels may be missing or displaced. If so, add the option `-F HersheySerif' to the `graph' command, to request the HersheySerif font rather than the default font (Helvetica). Release 2.4.1, dated 7/2000 --------------------------- The `--page-size' option supported by the command-line graphics utilities has been extended, to allow precise specification of viewport size and location in the output, e.g., on a printed page. For example, `--page-size=letter,xsize=5in,ysize=3in,xorigin=1in,yorigin=2in' is now a possible command-line option. Previously, only `xoffset' and `yoffset' fields were supported. You can get some interesting visual effects by setting xsize or ysize to a negative value. For example, echo 0 0 1 1 2 0 | graph -Tps --page-size letter,xsize=-8in,ysize=8in will write to standard output a Postscript graph for a letter-size page. The graph will be drawn into a viewport that has the same size as usual (8in x 8in), but it will be reflected from left to right. The ability to specify a custom viewport size should be useful when producing SVG or WebCGM graphics for Web pages. When producing SVG or WebCGM output, only the xsize,ysize fields are meaningful; xorigin, yorigin, xoffset, and yoffset are ignored. The syntax of the libplot Plotter parameter `PAGESIZE' has been similarly extended. Libplot version number is now 4.1. Release 2.4, dated 6/2000 ------------------------- SVG output is now supported. SVG is a new XML-based vector graphics format being developed by the W3 Consortium. The command-line plotting utilities now support `-T svg --bg-color none' and `-T cgm --bg-color none' options, to turn off the background (which by default is white) in SVG and WebCGM output. This is useful when generating graphics files for use in Web pages. Similarly, in libplot, SVG and CGM Plotters now allow the parameter `BG_COLOR' to equal "none". PNG output is now supported. A PNG driver will be installed in libplot, and made available to the command-line plotting utilities, if libpng and libz are found at installation time. The version number of libpng must be 0.95 or larger (libpng 0.95 was released in March 1997). If the PNG driver is included, you must now include the additional options `-lpng -lz' when compiling and linking a program with libplot or libplotter. `configure' now supports a `--without-libpng' option to disable PNG support. ReGIS output is now supported, for display on older graphics terminals like the VT340 (color), the VT330 (monochrome), and emulators. The ReGIS driver contains a blemish: paths that extend beyond the boundary of a ReGIS display are never filled, even if filling is requested, because they need to be clipped against the boundary, and the required clipping code hasn't yet been written. Colors may now be specified, both on the command line and when using the libplot API, by their 24-bit RGB representation, expressed as six hexadecimal digits. For example, "#ffffff" is equivalent to "white". The command-line plotting utilities now support an `--emulate-color yes' option, and all Plotters now support a corresponding parameter, "EMULATE_COLOR". If emulation is performed, all colors in the output will be replaced by grayscale approximations. This is particularly useful when producing PCL 5 output to be printed on a monochrome PCL 5 device, such as a monochrome LaserJet. Many monochrome PCL 5 devices, on their own, do a poor job of emulating color (they print every nonwhite solid color as black). libplot now supports compound paths, i.e. paths that are made up of multiple simple paths, so long as the simple paths do not intersect each other (they are allowed to intersect themselves). You draw each simple path of a compound path in the usual way, but you end each one by calling endsubpath(). The compound path is terminated and drawn by calling endpath(). Just as when traditional non-compound paths are drawn, the call to endpath() can usually be omitted. So the libplot API has been expanded to include endsubpath(), and orientation() too. orientation() specifies the direction in which circles/ellipses/boxes are traversed. (Specifying this, for any circle/ellipse/box that is a subpath of a compound path, affects the filling of the compound path by determining which points are `inside' or `outside'.) Handling of device-resident HP vector fonts ("stick fonts"), when drawing text strings in HP-GL/2 output, has been improved. Previously, no account was taken of device-resident font kerning. That's appropriate when producing PCL 5 output for a LaserJet with an HP-GL/2 emulation module, since LaserJets don't do sophisticated kerning of stick fonts, even when they support them. But any full-featured HP-GL/2 plotter can do kerning of variable-width stick fonts. So when producing HP-GL/2 output, we now take that into account when computing the width of text strings. This affects the positioning of text strings on an output page. The StickANK and ArcANK HP vector fonts, which provide JIS ASCII and half-width Katakana, are now available when producing HP-GL/2 output. The miter limit (for line joins) which is placed in any HP-GL/2 or PCL 5 output file is now always rounded to the closest integer, downward. That's because at least one HP-GL/2 pen plotter (the HP 7550B, which was HP's first) had buggy firmware that couldn't parse a non-integer miter limit. When HPGL_VERSION is set to 1 or 1.5, the filling of solid regions now uses cross-hatching, instead of the filling with a single pen color that used to be used. This occurs whenever the fill color is not one of the defined pen colors. The algorithm employed, for emulating shading by cross-hatching, is the one used by HP's HP-GL/2 pen plotters. A new function, fsetmatrix(), has been added to the libplot/libplotter API, as an alternative to space(). It sets the transformation matrix from user coordinates to NDC (normalized device coordinates). In NDC space, the graphics display, i.e. viewport, has corners (0,0), (1,0), (1,1), (0,1). space() and/or fsetmatrix() no longer need to be called at the beginning of each page of graphics. The alabel() function in the libplot/libplotter API now accepts a new vertical positioning option, `C', to request alignment of a text string's cap line with the present vertical position. Color drawing on X displays has been speeded up. If the X display uses a truecolor `visual', pixel value computations are performed in libplot itself, rather than in the X server. This removes the need to call XAllocColor() whenever a new pen color or fill color is selected (which used to require a round-trip to the server, slowing things down). Also, a Plotter parameter `XDRAWABLE_VISUAL' has been added. It should be set by the programmer if a non-default colormap is used. libplot can determine from it whether or not the visual is of the truecolor class. Libplot version number is now 4.0. Release 2.3, dated 10/1999 -------------------------- CGM output is now supported. By default, a CGM Plotter emits binary-encoded version-3 CGM format, conforming to the WebCGM profile. (For information on WebCGM, see http://www.cgmopen.org .) The CGM format version number may be reduced by setting the libplot parameter (or environment variable) CGM_MAX_VERSION. Irrespective of version, a human-readable CGM file, i.e., one encoded as clear text, may be produced by setting CGM_ENCODING to "clear_text". Clear text CGM files are valid CGM files, though technically they don't conform to the WebCGM profile (a WebCGM file is meant to be binary). The package is now based on libplot version 3.0, which has new thread-safe C and C++ APIs, i.e. APIs which (1) maintain no global state, and (2) are pthread-aware. The names of all new thread-safe libplot functions end in "_r", for `reentrant' or `revised'. Each of them takes a pointer to an opaque plPlotter object as its first argument. There are new functions in both libplot and libplotter for creating and manipulating PlotterParams objects, which store Plotter parameters. Parameters are copied from such an object when the Plotter class is instantiated. The old C and C++ API's are still supported, though deprecated. So you can still use pl_newpl() and pl_openpl(), etc., instead of pl_newpl_r() and pl_openpl_r(), etc. A new API function, pl_pentype_r(), has been added. If its argument is 0, stroking of paths, as opposed to filling, will be turned off. So `edgeless polygons' can now be drawn. Fig and PCL Plotters now position their viewports (i.e. "graphics displays") in the center of their pages, like PS Plotters. So the PCL_XOFFSET and PCL_YOFFSET parameters have been removed, and PCL_ROTATE too. Similarly, HPGL_XOFFSET and HPGL_YOFFSET parameters have been removed, even though tbe viewport position for HP-GL Plotters has not changed. Shifting of the viewport on the page, for PCL, HP-GL, Fig, and PS Plotters, is now accomplished through the PAGESIZE parameter. E.g., its value could be "letter,xoffset=1in,yoffset=-2cm" or "a4,yoffset=12mm". A new parameter, ROTATION, has been introduced; it applies to PCL, HP-GL, Fig, and PS Plotters. It defines rotation of the viewport on the page, which is not the same as what the HPGL_ROTATE parameter, previously introduced for HPGL Plotters, defines. Values of ROTATION can be "no", "yes", "0", "90", "180", "270". A new scan-conversion library, called libxmi, is optionally built and installed, together with documentation. It contains the scan-conversion code that is used by libplot's GIF and PNM drivers, which is based on the X11 sample server code. libxmi is also distributed independently. The libxmi version number is 1.1. Release 2.2, dated 3/1999 ------------------------- Massive expansion of the C API, with new drivers, and introduction of libplotter (C++ class library). Backward compatibility of the C API maintained, except that all functions now begin with "pl_". Header file "plotcompat.h", if needed, will redefine old function names as new function names. Libplot version number is now 2.0. outfile() function, always more or less deprecated, now declared obsolescent. No longer documented. Release 2.1.6 ------------- AI driver added, but libplot API unchanged. Libplot version number is now 1.6. Support in plot.h header file for old names for endpath() and filltype(), which began in plotutils-2.0 (see below), finally dropped. Release 2.1.5 ------------- PCL 5 driver added. Kerning of device-resident `HP stick fonts' accessible to the HP-GL driver, when HPGL_VERSION=1.5, also added. Libplot API unchanged, but libplot version number is now 1.5. Release 2.1.2, 2.1.3, 2.1.4 --------------------------- No additions to libplot API, but the semantics of closepl() vs. deletepl() have finally changed (programmers were warned about this in the texinfo documentation). The libplot version number is now 1.2 (upped to 1.3 for release 2.1.3 and 1.4 for 2.1.4). Plotter output, for non-realtime plotting, is now guaranteed to be emitted only when deletepl() is called. I.e., graphic output is not necessarily written to the output stream after each page is closed. In practice, this affects only Postscript output. Emitting PS only after the final page of a multi-page graphics file is closed enables the PS to conform to the DSC (Postscript Document Structuring Conventions). Support for many new stick fonts added (mostly available only if using `-T hpgl', with HPGL_VERSION=1.5. `Stick fonts' are HP's device-resident vector fonts. If using `-T hpgl' with HPGL_VERSION=1, circles and rectangles aligned with the coordinate axes can now be filled. Names of many Hershey fonts changed, but old names continue to work. Release 2.1.1 ------------- No additions to libplot API, though libplot was improved in various ways. The libplot version number is now 1.1. Release 2.1 ----------- No incompatibilities with plotutils release 2.0. But many new command-line options added to user-level utilities, and the libplot API was expanded by the addition of bgcolor() and bgcolorname(). The libplot version number is now 1.0. Release 2.0 ----------- In release 2.0 the idea of separate variants of the `graph', `plot', and `tek2plot' programs for each display device was finally done away with. There is now only a single instance of each program. The display device is specified by the `-T' option. The merging of the device-specific variants was made possible by the merging of the device-specific variants of the libplot library on which they were based. There is now only a single library, which is structured in an object-oriented way. There are new functions, newpl(), selectpl(), openpl(), which allow the creation of an arbitrarily large number of `Plotter' objects simultaneously. Each Plotter produces output for one display device. On startup of libplot, a single default Plotter is created and selected, namely one that produces GNU metafile format. This is for backward compatibility: it allows programs written for earlier versions of GNU libplot, and even Unix libplot, to link with it and run as expected. If you prefer a different default Plotter type, you should select it at installation time. For example, including -DDEFAULT_PLOTTER_TYPE=\"ps\" in your CFLAGS option will cause the default Plotter to produce Postscript output instead. The libplot API changed in release 2.0 in a few other ways. 1. falabel() was dropped from the API, and alabel() no longer returns a value related to the width of the text string that it renders. If you need to get the width of a text string, use flabelwidth() or labelwidth(). 2. The semantics of the arc() primitive have changed. It now draws an arc that may be clockwise as well as counterclockwise, but is restricted to have opening angle no more than 180 degrees. Also, it moves the graphics cursor position to the endpoint of the arc. 3. The box() primitive now moves the graphics cursor to the midpoint of the box, rather than to the second-specified vertex. 4. endpoly() has been renamed endpath(), and fill() has been renamed filltype(). These last changes are temporarily supported by the plot.h include file. As of release 2.0 of the package, libplot has its own, independent, versioning system. The version of libplot distributed with release 2.0 is numbered 0.0. Beginning with version 0.0, libplot is installed both as a static library and as a shared library (a DLL), on machines that support shared libraries.