Share your code. npm Orgs help your team discover, share, and reuse code. Create a free org »

    overlay-pslgpublic

    overlay-pslg

    Compute a regularized Boolean operation between the interiors of two planar straight line graphs.

    Demo

    • Click to add points
    • Drag to create edges
    • Toggle red/blue points by clicking upper left button
    • Select different Boolean operations

    Example

    Here is a simple example showing how to use this module to compute the intersection of two PSLGs:

    //Load the module 
    var overlay = require('overlay-pslg')
     
    //Red PSLG - Define a triangle 
    var redPoints = [
      [0.5, 0.25],
      [0.25, 0.5],
      [0.75, 0.75]
    ]
    var redEdges = [ [0,1], [1,2], [2,0] ]
     
    //Blue PSLG - Define a square 
    var bluePoints = [
      [0.25, 0.25],
      [0.25,  0.6],
      [0.6, 0.6],
      [0.6, 0.25]
    ]
    var blueEdges = [ [0,1], [1,2], [2,3], [3,0] ]
     
    //Construct intersection 
    console.log(overlay(redPoints, redEdges, bluePoints, blueEdges, 'and'))

    Output

    The result of this module is the following JSON:

    { points:
       [ [ 0.6, 0.6 ],
         [ 0.44999999999999996, 0.6 ],
         [ 0.25, 0.5 ],
         [ 0.5, 0.25 ],
         [ 0.6, 0.44999999999999996 ] ],
      red: [ [ 1, 2 ], [ 2, 3 ], [ 3, 4 ] ],
      blue: [ [ 0, 1 ], [ 0, 4 ] ] }

    We can visualize this result as follows:

    Install

    To install this module, you can use npm. The command is as follows:

    npm i overlay-pslg

    It works in any reasonable CommonJS environment like node.js. If you want to use it in a browser, you should use browserify.

    API

    require('overlay-pslg')(redPoints, redEdges, bluePoints, blueEdges[, op])

    Computes a Boolean operation between two planar straight line graphs.

    • redPoints, redEdges are the points and edges of the first complex
    • bluePoints, blueEdges are the points and edges of the second complex
    • op the boolean operator to compute (Default "xor"). Possible values include:
      • "xor" - computes the symmetric difference of red and blue
      • "and" - computes the intersection of red and blue
      • "or" - computes the union of red and blue
      • "sub" - comutes the set difference, blue-red
      • "rsub" - comutes the set difference, red-blue

    Returns An object encoding a planar straight line graph with the edges partitioned into two sets:

    • points are the points of the combined cell complex
    • red are the edges in the resulting pslg coming from the red graph
    • blue are the edges in the resulting pslg coming from the blue graph

    Note The interiors of red and blue are computed using the same algorithm as cdt2d, which is it counts the parity of the path with the fewest number of boundary crossings for each point. Even parity points are in the exterior, odd parity in the interior.

    License

    (c) 2015 Mikola Lysenko. MIT License

    install

    npm i overlay-pslg

    Downloadslast 7 days

    2

    version

    1.0.0

    license

    MIT

    repository

    github.com

    last publish

    collaborators

    • avatar