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    GLgraph			(C) 2002 Jonas Jermann (GPL)
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	An OpenGL based function grapher for Linux

	
	


1. Introduction

    1.1 About
	This is my second program. It's written in Perl and is a ported Version of 
	my old Worm(g).

    1.2 Description
        GLgraph visualize mathematical functions. It can handle 3 unknowns 
	(x,z,t) and can produce a 4D function with 3 space and 1 time dimension.

    1.3 History/Changelog
	It began with my first program Worm(g)... Because I didn't find a 
	mathematical function visualiser which fit my needs, I started 	to write
	my own in pascall (Worm(g)). GLgraph is a perl/OpenGL portation of my 
	first Worm(g) program. It's result was a complete new structured program
	(see Changelog).

    1.4 Requirements / supported platforms
        GLgraph needs:
            libopengl-perl
            libmath-basecalc-perl
            libtime-hires-perl
        I only tested it on my PC:
	    Pentium III 600
            Matrox G400 32 MB DH
            Linux 2.4.18
            Debian (sid)
            libopengl-perl 0.54
              -> Perl 5.6.1
              -> glutg3 3.7
              -> XFree86 4.1.0 (xlibmesa3)
            libmath-basecalc-perl 1.009
            libtime-hires-perl 1.20


2. Features

    2.1 Functions
        You can add your own functions (see 3.1) to the default ones.
	All math functions of Perl's math module can be used (even trigonometrical).
        PI is built in too and the function interval can contain complex solutions.

    2.2 Output modes
	There are 4 Modes:
	  no output     just calculates (fastest ;)
	  2D		2D Graph (very fast ;)
	  3D Wire	3D Wireframe model
	  3D Solid	Solid 3D model (slowest)
	All use OpenGL. 3D Solid uses the accelerated TRIANGLE methode.
	GLgraph has preview capabilities too.

    2.3 Axis
        At the moment there are 4 Modes:
          no axis
          default       changes automaticaly from 2D to 3D
          3D square     draws a base square
          3D cube       draws a base cube

    2.4 Time
	The time can also be used as a parameter. But to get acceptable fps the
	resolution has to be lowered.

    2.5 Color
	There are 3 modes:
	  no colors	Fastest mode ;)
	  c mode 1	My own iterative color mode
	  c mode 2	Absolute color scale (slow)

    2.6 Preview mode
        The preview mode uses a resolution of 20 (x and z). It can be used to
        avoid intense calculation while trivial changes.


3. Usage
    The program is in a very early stage, many things may change...

    3.1 Synopsis
    	glgraph [options] 'function1' 'function2' ...
    	
    3.2	Command line options
    	  function         Function: f(x,z,t)=function
          -(no)fs          Fullscreen                                (ON)
          -geometry        Window Geometry                           (1024x768+0+0)
          -wid             Window Id                                 ("graph window")
          -2d              2D Graph
          -wire            3D Graph: Wireframe
          -3d              3D Graph: Solid                           (DEFAULT)
          -(no)time        Time Graph (notime is BUGGY)              ( ON)
          -(no)colors      Color Mode (0=nocolors, 1:mode1, 2:mode2) (  1)
          -xmin            Beginning of x interval (Window)          ( -5)
    	  -xmax            Ending of x interval (Window)             (  5)
    	  -ymin            Beginning of y interval (Window)          ( -5)
    	  -ymax            Ending of y interval (Window)             (  5)
    	  -zmin            Beginning of z interval (Window)          ( -5)
    	  -zmax            Ending of z interval (Window)             (  5)
    	  -tmin            Beginning of t (time) interval (Window)   ( -4)
    	  -tmax            Ending of t (time) interval (Window)      (  4)
    	  -xres            Resolution of x axis (relevant dots)      ( 50)
    	  -zres            Resolution of z axis (relevant dots)      ( 50)
    	  -xzres           Space Resolution (xres and zres)
    	  -tres            Resolution of time "axis" (frames)        ( 50)
    	  -cfact           Interval of color function                (0.8)
    	  -h, --help       Display this help message
    	  -v, --version    Display GLgraph's version number
    	  
    3.3 Control from keyboard
	  q		   Quit
	  _ and 0          Reset (default and hard)
	  m		   Screenshot (doesn't work properly)
	  w/a/s/d	   Rotation (3°)
	  7/8/9            Rotation (90°)
	  ü/ö/ä/$	   Translation
	  e and r	   Scaling
	  b and n	   Change functions
	  1 and 2	   Change graphic mode
	  3 and 4	   Change color range
	  p                Toggle preview mode
	  c		   Toggle color mode
	  t		   Toggle time mode
	  y and x	   Seeking
	  z and u	   Change space resolution
	  h and j	   Change time resolution

		
4. Authors

    Jonas Jermann (g0th) <jjermann@gmx.net>
      main developer
    David Gunzinger (pfy)
      syntax introduction/help of opengl/glut/perl
      second color-mode
      structure help