avsdf-base

Description

avsdf-base is a JavaScript library that constitutes of elements helpful in applying the Circular Drawing Algorithm by Hongmei He & Ondrej Sýkora.

## Dependencies

• layout-base ^1.0.0

Elements of layout-base can be accessed through this library as well. See below for an example.

## Usage

Add avsdf-base as a dependecy to your layout extension.

require() in the extension to reach functionality:

const AVSDFLayout = require('avsdf-base').AVSDFLayout;
const AVSDFNode = require('avsdf-base').AVSDFNode;
const AVSDFConstants = require('avsdf-base').AVSDFConstants;
const PointD = require('avsdf-base').layoutBase.PointD;
const DimensionD = require('avsdf-base').layoutBase.DimensionD;

API

The main layout and a Graph Manager (see layout-base for details) connected to this layout is needed with

let avsdfLayout = new AVSDFLayout();
let graphManager = avsdfLayout.newGraphManager();
let root = graphManager.addRoot();

Filling in the Graph Manager with nodes and edges are more related to layout-base library than this library. So details have to be found there. But remember to add AVSDF elements as opposed to layout-base elements. Also remember that the root of the Graph Manager should be an AVSDFCircle object.

// Adding a node 
Let node = root.add(new AVSDFNode(graphManager));
 
// Adding an edge
Let edge = graphManager.add(avsdfLayout.newEdge(), sourceNode, targetNode);

After all nodes and edges are added. The algorithm can be run as shown below.

// Running the AVSDF layout.
avsdfLayout.layout();
 
// Post process is iterated over the sorted list of vertex degrees (descending)
let sortedByDegreeList = avsdfLayout.initPostProcess();
 
// Post process is done step by step so that it could be displayed more efficiently
for (node in sortedByDegreeList) {
  avsdfLayout.oneStepPostProcess(node);
}
 
// An update for the angles (in radians) for the node angles are needed
avsdfLayout.updateNodeAngles();
 
// An update for the node coordinates are needed 
avsdfLayout.updateNodeCoordinates();

Note that updateNodeAngles() and updateNodeCoordinates() have to be called at each step if you want to take post processing apart instead of doing it in one go as shown above.