sigma.js如何创建视图的数学公式

Question

我很难理解sigmas.js，它是如何工作的。有兴趣了解所见证的科学背后。

读取库我理解它在画布上渲染顶点和边缘。

它有一个很棒的代码，可以根据图形的顶点数和边数来重新调整坐标，以显示所有节点。

在applyview方法https://github.com/jacomyal/sigma.js/blob/master/src/classes/sigma.classes.camera.js#L89

中计算视图的数学是什么

应用视图的工作原理：

sigma.classes.camera.prototype.applyView = function(read, write, options) {
    options = options || {};
    write = write !== undefined ? write : this.prefix;
    read = read !== undefined ? read : this.readPrefix;

    var nodes = options.nodes || this.graph.nodes(),
        edges = options.edges || this.graph.edges();

    var i,
        l,
        node,
        relCos = Math.cos(this.angle) / this.ratio,
        relSin = Math.sin(this.angle) / this.ratio,
        nodeRatio = Math.pow(this.ratio, this.settings('nodesPowRatio')),
        edgeRatio = Math.pow(this.ratio, this.settings('edgesPowRatio')),
        xOffset = (options.width || 0) / 2 - this.x * relCos - this.y * relSin,
        yOffset = (options.height || 0) / 2 - this.y * relCos + this.x * relSin;

    for (i = 0, l = nodes.length; i < l; i++) {
      node = nodes[i];
      node[write + 'x'] =
        (node[read + 'x'] || 0) * relCos +
        (node[read + 'y'] || 0) * relSin +
        xOffset;
      node[write + 'y'] =
        (node[read + 'y'] || 0) * relCos -
        (node[read + 'x'] || 0) * relSin +
        yOffset;
      node[write + 'size'] =
        (node[read + 'size'] || 0) /
        nodeRatio;
    }

    for (i = 0, l = edges.length; i < l; i++) {
      edges[i][write + 'size'] =
        (edges[i][read + 'size'] || 0) /
        edgeRatio;
    }

    return this;
  };