alchemist0823 / geom2.js

high-performance 2d javascript geometry library

Geom2.js

Geom2.js is a high-performance javascript 2d geometry library written in modern TypeScript.

It was extracted from the server-side code of a multi-player game. It is intended to be used in games, ai or any computation heavy task in javascript.

In a game application, it can be used for collision detection, artificial intelligence (steering and path finding), server-client viewport optimization.

Difference from Physics Engines

Most physics engines bundles all the physics related data structure and algorithm together. It makes setup easy but it limits the flexibility of the application or games. Because in lots of scenario except physics simulation, objects are not intended to move according to physics laws.

This library is much light weight than a physics engine, and gives users a customizable environment to setup their own 2d world.

Install

npm install

npm install geom2.js

browser install

Copy example/geom2.min.js or build yourself

Examples

Check test folder

We provide a QuadTree example here.

More examples will come up later.

Structure:

• Vector
• Segment
• Shap
  • AABB (Axis-Aligned Bounding Box)
  • Arc
  • Circle
  • Polygon

Algorithm:

• Common
  • Collision detection between shapes.
    • GJK (Gilbert–Johnson–Keerthi)
    • SAT (Separation Axis Theorem)
  • Convex Polygon test
  • Convex Hull
• Generation
  • Random convex polygon generation
• Advance
  • Field of view scanning (line sweeping)

Container:

• Loose QuadTree
  • High-quality quadtree implementation
  • It can store AABB (Axis-Aligned Bounding Box).
  • No elements on branch nodes, all data on leaves.
  • It maintains loose boundary on all nodes.
  • It outperforms simple-quadtree and all other available js quadtree.

Addition Feature:

• Physics Collision Resolution

TODO

• Special handling circle-polygon and circle-circle collision