Computes the normals of a polyline, using miter joins where multiple segments meet. This is mainly useful to expand thick lines in a vertex shader on the GPU.
var getNormals =//a trianglevar path = 0 122 0 190 90 190//get the normals as a closed loopvar normals =//now draw our thick line in 2D/3D/etc
See the 2d test for an example of how these lines would be extruded.
For more complex line joins and end caps, see extrude-polyline (which builds an indexed mesh).
For an example of how to use this within a shader, see three-line-2d.
For the given path, produces a new array of the same length with normal information for each point. The data contains a normal,
[nx, ny] and the length of the miter (default to 1.0 where no join occurs).
nx ny miterLengthnx ny miterLength
closed is true, it assumes a segment will be drawn from the last point to the first point, and adjusts those normals accordingly.
MIT, see LICENSE.md for details.