GLgraph

1. Introduction

1.1. About
GLgraph is my first Perl program 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. See DESCRIPTION for a more details.

1.3. History
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 for more details.

2. Installation

2.1. Requirements
GLgraph needs:

• libopengl-perl/perl-OpenGL >= 0.5
• libmath-basecalc-perl
• libtime-hires-perl
• Imagemagick (optional, for screenshots)

• 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
• imagemagick (optional, for screenshots) 5.4.7.1

2.2. Instructions/methods

• Executable: Just install glgraph and execute it afterwards.
• Tar file: Unpack the tar file (glgraph_version.tar.bz2).
• dpkg/rpm (not yet): Download the package and install/remove it using your package manager.
• Old releases: The old releases can be found here
• Source: Unpack the source tar file (glgraph_src_version.tar.bz2) and use the given single tool to create a single file. Of course you could install the perl modules too and leave the files separated.

3. Features

3.1. Functions
You can add your own functions 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.

3.2. Output modes
There are 3 Modes:

• 2D (-2d) : 3D Graph (very fast ;)
• 3D Wire (-wire) : 3D Wireframe model
• 3D Solid (-3d) : Default, solid 3D model (slowest)

3.3. Axis
There are 4 Modes:

• no axis (-noaxis) : Default
• normal (-axis 1) : Changes automaticaly from 2D to 3D
• 3D square (-axis 2) : Draws a base square
• 3D cube (-axis 3) : Draws a base cube

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

3.5 Animation
After one time periode, the saved display lists are being used to display the frames. This leads to a tremendous speedup (animation). The flimmering is caused by the clear call which can be deactivated with the -noclear option (looks ugly). Large time and space resolutions can lead to crashs/freezes (memory), don't use this methode in this case (-noanim).
See bellow to save the function as an animation.

3.6. Color
There are 3 modes:

• no colors (-nocolors) : Fastest mode ;)
• color mode 1 (-colors 1) : Default, my own iterative color mode
• color mode 2 (-colors 2) : Absolute color scale (slow)

3.7 Preview mode
The preview mode can be toggled with the p key. It uses a resolution of 20 (x and z) and can be used to avoid intense calculation while trivial changes.

3.8 Screenshots
Glgraph uses Imagemagick's import over a system call to take screenshots. All Imagemagick output formats are therefore supported. A non-default output name (default is image.jpg) can be specified with the -o option. A screenshot can be taken using the m key. To create an info file with a function description, use the -i option. If no extension in the output name is present, just the info file will be created.
To create a movie of the whole function, do as follows:

1. Save every frame to the files movie_00xx.jpg:
   glgraph -save <options> -o movie.jpg
2. Create a MJPEG or directly a AVI/MPG file, using the created images (with MEncoder for example):
   mencoder -vop scale movie\*.jpg -mf on:fps=<fps> -ovc lavc -lavcopts vcodec=mjpeg -o movie.avi
or
mencoder -vop scale movie\*.jpg -mf on:fps=<fps> -ovc divx4 -o movie.avi