rikilg / geometry-algorithms

Provides implementations of Polygon Triangulation, DCEL and Convex Hull Generation

Computational Geometry Assignment

Getting Started

This repo contains implementations of the following 3 algorithms:

• Convex Hull computation using divide and conquer tangent approach
• DCEL (Doubly Connected Edge List) data structure implementation
• Polygon Triangulation using the following algorithms:
  • Plane Sweep method to divide polygon into monotones.
  • Triangulation of each monotone polygon

Each algorithm is implemented seperately in its folder using C++ language. A README file in each folder describes how to run and other information about that particular folder.

Algorithm Directory
├── datasets # folder containing datasets to be tested upon
├── docs # folder containing the documentation of the source code
├── src # folder containing the source code
└── README.md # a readme file describing the algo and how to run it

Plotting Output

Each directory contains a plot.py python program which can be used to plot the output of each algorithm. output of algorithm can be directly piped to this program or given as command line argument

# do this in the src directory if program is compiled in the same directory
# the text in the [] brackets is optional. if given, it prints the input dataset also
./a.out ../datasets/data.txt | ../plot [-i ../datasets/data.txt]

# without piping, save output to file and use it
./a.out ../datasets/data.txt > output.txt
../plot -o output.txt [-i ../datasets/data.txt]

References

The following references have been used to understand and implement the algorithms:

• David Mount lecture notes
• DCEL algorithm and basic geometry data-structure conventions
• Understanding DCEL inserting algorithm