WebGL Triangulation

This lib ended up finished as a Go library – Triangolatte.

Small set of utilities for triangulating lines and polygons

In progress: handling those with multiple holes

Aims to offer lightweight (minimal number of dependencies, currently none) and as universal as possible tool for triangulating data from maps – edge cases will be optimized for that use case.

The lib is everything-agnostic. All calculations are just pure maths, it is suitable both for node.js backend and any kind of JS frontend supporting npm modules.

Install

yarn add triangulify

Docs

For documentation, refer to rich JS Doc comments in the code. Feel free to open an issue if some description is not clear (it was documented on-the-go and decisions about what to document and what not could be wrong).

Modules

Triangulate.Polygons

`earCut(vertices)`

Triangulates given polygon (assuming counter-clock-wise winding) into array of threes of indices (resulting triangles).

Probably you will want to use it together with resolveTriangleVertices() which produces flat array of vertex coordinates for use in a WebGL buffer.

Triangulate.Lines

`miter(points, width)`

Triangulates line consisting of points using miter joins, which means that the join points are calculated and no additional triangles are generated in the process.

`bevel(points, width)`

NOT IMPLEMENTED YET

Triangulates line using bevel joins, which are singular triangles added at each join to connect two outer vertices (the inner one, with smaller angle) is connected in the same way as in miter.

Math

Minimal math lib for operations with 3x3 matrices and 2D vectors.

Feel free to use it in your code, but this part of the API probably won't ever be stable.

It is in the first place set of helpers for other modules in the library and everything in it is a subject to change. For example functions might disappear when they have no usages.

Examples

Visit examples directory for some usage examples.

They provide complete, tiny WebGL wrappers for rendering something real on the screen.

Todo

Tests

buildings with holes – AGH A0
complicated shapes with multiple holes – Main Square Cracow
triangulation of huge objects – Lake Superior
test triangulation with complicated rivers – Puszcza niepołomicka

Optimizations

find out bottlenecks
maybe use z-order curve / quad tiles to optimize looking for close vertices
experiment with using points vs two-element arrays for vertices

tchayen / webgl-triangulation