Bend

A basic implementation of a stack machine for 2D rebar bend paths, inspired by the "BVBS" rebar bend format.

Bend paths are described in postfix notation:

8 d 16 s 240 l 40 w 100 l -10 w 138 l -90 w 115 l

The following words are understood:

• d: bar diameter
• s: bend diameter
• l: straight length
• w: bend angle, in degrees
• div: divide
• atan: arctangent
• neg: negative

So to compute the rebar bends for shape 26, you could describe it as follows:

import Bend from '@crhio/bend';

// Assuming A = 100, B = 150, C = 125, D = 60

const bend = Bend({
  path: '10 d 20 s 100 l 60 150 div atan w 150 l 60 150 div atan neg w 125 l'
});

bend.print();
// M 0 0 L 99.96679443243097 0 A 10 10 0 0 0 100.03320483532147 -0.00022051951204667822 L 249.96348737199781 -0.9959355238454375 A 10 10 0 0 1 250.02989777488833 -0.9961560433574842 L 374.9966922073193 -0.9961560433574842

A diagram of how the path is computed:

Additionally:

• Webpack 3 based.
• ES6 as a source.
• Exports in a umd format
• ES6 test setup with Mocha

Scripts

• yarn build - produces production version of the library under the lib folder
• yarn dev - produces development version of the library and runs a watcher
• yarn test - well ... it runs the tests :)
• yarn test:watch - same as above but in a watch mode

Test App

To run the test app:

cd app
npm i
npm run dev