A multithreaded Voronoi diagram generator

A still:

An animation with 30 frames:

Description

The following program generates an image or GIF file of a Voronoi diagram according to the parameters specified as arguments on the command line. It does this in a trivial manner, calculating the distance of each pixel to every anchor, although a more efficient algorithm exists. An even more efficient way could to be to calculate using a shader. If the -f, --frames options is specified a GIF file will be created where between each frame the anchors take a step in a random direction.

Usage

The only required option is the -o, --output_file when invoking the program. For the other unspecified arguments various default values be used. Example, voronoi --output_file diagram.png will create a 250x250 PNG file named diagram.png with 10 anchors at random positions with random colors chosen from a set of 60 random colors.

Options

The program takes various options that control the creation of the diagram.

• -o, --output_file <PATH> specifies the name of the output file.
• -s, --size <NUMBER, ...> can be used to specify the dimensions of the output file (PNG/GIF), it can have two forms: --size 300 uses the same value (300) for the width and the height, while --size '800, 600' specifies explicitly the values for the width (800) and the height (600). Quotes are mandatory if the argument contains spaces.
• -a, --anchors <NUMBER, ...> controls the creation of anchors and can have two forms, first a single number can be specified, --anchors 30, this creates 30 anchors at random coordinates in the image. The second is the form: --anchors '300,400; 60,80; 100,100; 200, 0;' which explicitly specifies the coordinates (x, y) of the anchors . The syntax is: coordinate pairs must be delimited with a semicolon (;) or a newline (\n), and each coordinate must be delimited with a comma (,) or whitespace. All other whitespace is ignored. Quotes are mandatory if the argument contains spaces.
• -A, --anchors_from <PATH> tells the program the read the coordinates of the anchors from the file specified by <PATH>. The syntax is the same as the --anchors.
• -c, --colors <NUMBER, ...> controls the colors that are used to color the diagram and can have two forms: the first, --colors 300 tells the program to choose 300 random colors. The second is the form: --colors '38,125,30; 100,200,255; 0,0,0; 255,255,255; 80,180,210;' which explicitly specifies the colors (R, G, B) to use. The syntax is the same as the --anchors option. Each anchor is in turn associated with a color from this palette at random. Quotes are mandatory if the argument contains spaces.
• -C, --colors_from <PATH> tells the program to read the colors from the file specified by <PATH>. The syntax is the same as the --colors option.
• -f, --frames <NUMBER> tells the program to create a GIF file with <NUMBER> frames.
• -k, --keep tells the program to keep the intermediate files when creating a GIF
• -s, --seed <NUMBER> specifies the seed to be used when creating anchors and creating and choosing colors

Installation

The program can be compiled the following way:

git clone https://github.com/begone-prop/voronoi.git
cd voronoi
make

Dependencies

GNU Make
gcc
libpng
ImageMagick