@bluemath/topo/src/body.ts

Topology module of BlueMath

/*

Copyright (C) 2017 Jayesh Salvi, Blue Math Software Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

*/

import {NDArray} from '@bluemath/common'

import {Vertex} from './vertex'
import {Edge} from './edge'
import {HalfEdge} from './halfedge'
import {Face} from './face'
import {IDManager} from './idman'

export class Body {

  vertices : Vertex[];
  halfedges : HalfEdge[];
  edges : Edge[];
  faces : Face[];
  id : string;

  constructor() {
    this.vertices = [];
    this.halfedges = [];
    this.edges = [];
    this.faces = [];
    this.id = 'B'+IDManager.genId('B');
  }

  newFace() : Face{
    let face = new Face(this);
    this.faces.push(face);
    return face;
  }

  newVertex(coord:NDArray) : Vertex {
    let vertex = new Vertex(coord);
    this.vertices.push(vertex);
    return vertex;
  }

  newHalfEdge() : HalfEdge {
    let he = new HalfEdge();
    this.halfedges.push(he);
    return he;
  }

  newEdge() : Edge {
    let e = new Edge();
    this.edges.push(e);
    return e;
  }

  removeEdge(edge:Edge) {
    let idx = this.edges.indexOf(edge);
    console.assert(idx >= 0);
    this.edges.splice(idx,1);
  }

  removeVertex(vertex:Vertex) {
    let idx = this.vertices.indexOf(vertex);
    console.assert(idx >= 0);
    this.vertices.splice(idx,1);
  }

  removeHalfEdge(halfEdge:HalfEdge) {
    let idx = this.halfedges.indexOf(halfEdge);
    console.assert(idx >= 0);
    this.halfedges.splice(idx,1);
  }

  removeFace(face:Face) {
    let idx = this.faces.indexOf(face);
    console.assert(idx >= 0);
    this.faces.splice(idx,1);
  }

  unlink() {
    this.faces.forEach(f => f.unlink());
    this.vertices.forEach(v => v.unlink());
    this.edges.forEach(e => e.unlink());
    this.halfedges.forEach(he => he.unlink());

    this.faces.splice(0);
    this.vertices.splice(0);
    this.edges.splice(0);
    this.halfedges.splice(0);
  }

  toDOT() {
    let s = '';
    s += 'digraph Body {\n';
    s += '  ranksep=.5;ratio=compress;\n';
    s += '  {\n';
    s += '    node[shape=plaintext];\n';
    s += '    Faces->Loops->Vertices;\n';
    s += '  }\n';

    s += '  {\n';
    s += '    rank=same; Vertices;';
    for(let vertex of this.vertices) {
      s += vertex.id+';';
    }
    s += '  }\n';

    // s += '  {\n';
    // s += '    rank=same; Edges;';
    // for(let edge of this.edges) {
    //   s += edge.id+';';
    // }
    // s += '  }\n';

    let lps = '{ rank=same; Loops;';

    s += '  {\n';
    s += '    rank=same; Faces;';
    for(let face of this.faces) {
      s += face.id+';';
      for(let loop of face.iloops) {
        lps += loop.id+';';
      }
      if(face.oloop) {
        lps += face.oloop.id+';';
      }
    }
    s += '\n';
    s += '  }\n';

    lps += ' }';
    s += lps+'\n';

    for(let vertex of this.vertices) {
      console.assert(vertex.halfedge);
      s += vertex.id+'->'+vertex.halfedge!.id+';';
    }

    for(let face of this.faces) {
      for(let loop of face.iloops) {
        s += face.id+'->'+loop.id+';';
      }
      if(face.oloop) {
        s += face.id+'->'+face.oloop.id+'[label=OL];';
      }
    }

    for(let halfedge of this.halfedges) {
      if(halfedge.next) {
        s += halfedge.id + '->' + halfedge.next.id + '[label=N,color=blue];';
      }
      if(halfedge.prev) {
        s += halfedge.id + '->' + halfedge.prev.id + '[label=P,color=red];';
      }
      if(halfedge.vertex) {
        s += halfedge.id + '->' + halfedge.vertex.id + '[color=brown];';
      }
      if(halfedge.loop) {
        s += halfedge.id + '->' + halfedge.loop.id + '[color=gray];';
      }
    }

    s += '}';
    return s;
  }

  toSVG(width=600, height=600) {
    const VTX_RADIUS = 3;
    const VTX_STYLE = 'fill:#f88';
    let vtxmarkup = `<g>`;
    for(let i=0; i<this.vertices.length; i++) {
      let x = this.vertices[i].coord!.getN(0);
      let y = this.vertices[i].coord!.getN(1);
      vtxmarkup += `<circle cx=${x} cy=${height-y} `+
        `r=${VTX_RADIUS} style="${VTX_STYLE}"></circle>\n`;
    }
    vtxmarkup += `</g>`;

    return `<svg width=${width} height=${height}>\n`+
      vtxmarkup+'\n'+
    `</svg>`;
  }
}