/* this file is used mainly to hold some general g2 doxygendocumentation in the doxygen format *//* define some main groups *//** * \defgroup interface g2 User Interface *//** * \ingroup interface * \defgroup physdev g2 Physical devices * * g2 physical devices are drivers for different output * formats. * *//** \mainpage\section licence License NoticeThis library is free software; you can redistribute it and/or modifyit under the terms of the GNU Lesser General Public License aspublished by the Free Software Foundation; either version 2.1 of theLicense, or (at your option) any later version.  This library isdistributed in the hope that it will be useful, but WITHOUT ANYWARRANTY; without even the implied warranty of MERCHANTABILITY orFITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General PublicLicense for more details.  You should have received a copy of the GNULesser General Public License along with this library; if not, writeto the Free Software Foundation, Inc., 59 Temple Place, Suite 330,Boston, MA 02111-1307 USA *Copyright (C) 1998-2004 Ljubomir Milanovic & Horst Wagner.\section introduction Introduction\subsection what What is g2 ?\subsubsection short Short version (if you are in hurry)    - 2D graphic library    - Simple to use    - Supports several types of output devices (currently X11,      PostScript, devices supported by gd http://www.boutell.com/gd/      (PNG, JPEG), FIG (http://www.xfig.org) and MS Windows windows)    - Concept allows easy implementation of new device types    - Virtual devices allow to send output simultaneously to several devices    - User definable coordinate system    - Written in ANSI-C    - Tested under Digital Unix, AIX, Linux, VMS and Windows NT    - Perl support    - Fortran interface\subsubsection long Long versiong2 is a simple to use graphics library for 2D graphical applicationswritten in Ansi-C. This library provides a comprehensive set offunctions for simultaneous generation of graphical output on differenttypes of devices. Presently, following devices are currently supportedby g2: X11, gd (PNG and JPEG), PostScript and FIG (xfig).One major feature of the g2_library is the concept of virtual devices.An arbitrary number of physical devices (such as PostScript, or X11) canbe grouped to create a so-called virtual device. Commands sent to such avirtual devices will automatically issued to all attached physicaldevices. This allows for example simultaneous output to a PNG file and aPostscript file. A virtual device in turn can be attached to anothervirtual device, allowing to construct trees of devices.Virtual devices can also be useful when using different user-coordinatesystems. E.g. one X11 window showing an overview of a graphical output,and a second window showing a zoom of a more detailed area of thegraphic. Drawing in both windows is performed by one single command tothe virtual device.\code                                   /-------> PNG:   g2_attach(id_PNG,..            ----------------------- g2_plot---> | Virtual device: id  |--------> X11:   g2_attach(id_X11,...            -----------------------                                   \-------> PS:    g2_attach(id_PS,...\endcodeIf you don't need or like the concept of virtual devices, simply ignore it.\section getting   Getting Started\subsection preinstallation Preinstallation tasks:    * PNG and JPEG support    g2 uses the gd library by Thomas Boutell to generate PNG files. This    package is freeware (however not GPL) and can be downloaded at    http://www.boutell.com/gd/.    Linux users might prefer to install a pre-compiled gd rpm package    which should be available at your local RedHat mirrorsite.    NT users should install the gd source package in a subdirectory    named "gd" which should be located in the same directory as the g2    subdirectory (but not in the g2 directory itself). Otherwise file    locations for gd must be modified in the g2 project workspace.    Unix and VMS users will have to build and install gd according to    the instructions found in the gd distribution.\subsection installation InstallationLINUX    -# Either install RPM packet with binaries, or compile as described      in the UNIX sectionUNIX    -# Extract package with gzip -dc g2-xxxx.tar.gz | tar xvf -    -# Run './configure'    -# Optionally run 'make depend'    -# Run 'make'    -# Run 'make install' or copy libg2.a and g2.h, g2_X11.h, g2_gd.h,      anf g2_PS.h to the default locations for library and include files.    -# Optional: cd to demo directory and run 'make demo' to compile demo applicationsWINDOWS NT    -# Extract package using either the .tar.gz or the .zip distribution    -# MS Visual C++ users can build both library and demos with the      supplied project file: g2.dsw (To obtain an icon and use menu      functions you must also build the g2res project in g2.dsw)    -# users of gcc or other commandline based compilers with make      support continue as in Unix example    -# It is also possible to compile g2 on winNT/95 using the free      cygwin32 library and a X-windows library for windows.      Theoretically it should be possible to support both X-windows and      native NT/95 windows at the same time.PERL (old instructions)    -# Change to directory g2_perl    -# Perform following steps          -# perl Makefile.PL          -# make          -# make test          -# make install    -# See the \ref perl "Perl interface" section for more information    -# swig is also supported, more details are comming ...VMS  -# Try to extract either the tar.gz or the zip distribution (whatever    is easier for you)  -# type mms to compile library (descrip.mms file is suplied)  -# run mms in demo directory to compile demo applications\subsection simple A simple exampleThe following example is a minimal application. It draws a rectangle ina postscript file.\code#include <g2.h>#include <g2_PS.h>main(){    int id;    id = g2_open_PS("rect.ps", g2_A4, g2_PS_land);     g2_rectangle(id, 20, 20, 150, 150);     g2_close(id);}\endcode- Always include <g2.h>. Additionally include header files for alltypes of devices you want to use.- Open devices using g2_open_XY functions. The open functionreturns a device id of type int, which you need to refer to the device.- Call g2_close() to close device.- Consider turning off auto flush (g2_set_auto_flush()) for improved performance. You want to draw a PNG file instead of a PostScript file ?replace the PS header file with\code#include <g2_gd.h>\endcodeand replace the g2_open_PS function call with\codeid = g2_open_gd("rect.png", 300, 200, g2_gd_png);\endcodeYou want to draw to a PNG file and a PostScript file with one plotcommand ?Here we use the concept of virtual devices. Open a PNG and PostScriptdevice, then open a virtual device and attach both the PNG andPostScript device to the virtual device. Plot commands to the virtualdevice will be issued to both PNG and PostScript device. You can attachand detatch further devices at any time.\code#include <g2.h>#include <g2_PS.h>#include <g2_gd.h>main(){    int id_PS,id_PNG,id;    id_PS  = g2_open_PS("rect.ps", g2_A4, g2_PS_land);    id_PNG = g2_open_gd("rect.png", 300, 200, g2_gd_png);    id     = g2_open_vd();    g2_attach(id, id_PS);    g2_attach(id, id_PNG);    g2_rectangle(id, 20, 20, 150, 150);    g2_circle(id, 50, 60, 100);    g2_close(id);}\endcodeNote: closing a virtual device automatically closes all attached devices.\subsubsection more More examplesMore examples showing the usage of different user coordinate systems,multiple virtual devices, etc. can be found in the distribution (demodirectory).    \subsection fortran Fortran interfaceThe Fortran interface for g2 is currently tested for Linux and DigitalUnix/OSF. Function names for Fortran are the same as in C, howeverfollowing differences exist:    * all variables including device IDs are of type REAL    * void functions are implemented as subroutines and must be called      with CALL    * constants defined by #define in C (e.g. g2_A4) do not work. Get      corresponding values from the apropriate header files.A short Fortran example:\code        program demo        real d,color        d=g2_open_PS('demo_f.ps', 4.0, 1.0)        call g2_plot(d, 50.0, 50.0)        call g2_string(d, 25.0, 75.0, 'TEST ')        color=g2_ink(d, 1.0, 0.0, 0.0)        write (6,*) color        call g2_pen(d, color)        call g2_circle(d, 20.0, 20.0, 10.0)        call g2_flush(d)        call g2_close(d)        stop        end\endcode\subsection perl Perl interface (old info)The perl interface for g2 is currently tested for Linux and DigitalUnix/OSF. Function names in perl are the same as in C, however thedevice itself is implemented object orientated, i.e. the device argumentis ommited in all functions.E.g., following simple perl script:\codeuse G2;$d = newX11 G2::Device(100,100);$d->circle(10, 10, 20);$d->string(20, 40, "Hello World");print "\nDone.\n[Enter]\n";getc(STDIN);$d->close()\endcodeThe creator functions are newX11, newGIF, newPS, etc. and accept thesame arguments as the open functions in the C version.See the perl documentation (perldoc G2) for more details and the test.plscript for a more extensive example.\section ContactYou can contact the authors and contributors by e-mail (/ is @ and - is .):- Ljubomir Milanovic: 			ljubo/users-sourceforge-net- Horst Wagner:       			wagner/users-sourceforge-net- Tijs Michels (spline implementation):	tijs/vimec-nlor visit g2 home page on: http://g2.sourceforge.net/*//** \page paper  PS paper sizes\subsection paper PostScript paper sizes\codeg2 Name                 Name                 Size(Pt)--------------------------------------------------------g2_A0                   A0                   2384 x 3370g2_A1                   A1                   1684 x 2384g2_A2                   A2                   1191 x 1684g2_A3                   A3                    842 x 1191g2_A4                   A4                    595 x 842g2_A5                   A5                    420 x 595g2_A6                   A6                    297 x 420g2_A7                   A7                    210 x 297g2_A8                   A8                    148 x 210g2_A9                   A9                    105 x 148g2_B0                   B0                   2920 x 4127g2_B1                   B1                   2064 x 2920g2_B2                   B2                   1460 x 2064g2_B3                   B3                   1032 x 1460g2_B4                   B4                    729 x 1032g2_B5                   B5                    516 x 729g2_B6                   B6                    363 x 516g2_B7                   B7                    258 x 363g2_B8                   B8                    181 x 258g2_B9                   B9                    127 x 181g2_B10                  B10                    91 x 127g2_Comm_10_Envelope     Comm #10 Envelope     297 x 684g2_C5_Envelope          C5 Envelope           461 x 648g2_DL_Envelope          DL Envelope           312 x 624g2_Folio                Folio                 595 x 935g2_Executive            Executive             522 x 756g2_Letter               Letter                612 x 792g2_Legal                Legal                 612 x 1008g2_Ledger               Ledger               1224 x 792g2_Tabloid              Tabloid               792 x 1224\endcode    */