rle-rasterize/index.js

Rasterizes meshes into narrowband level sets

"use strict";

var spatialGrid = require("spatial-grid");
var normals = require("normals");
var signedDistance = require("signed-distance");
var core = require("rle-core");
var repair = require("rle-repair");

var voxelCompare = new Function("a", "b", [
  "for(var i=2; i>=0; --i) {",
    "var d = a[i]-b[i];",
    "if(d) return d;",
  "}",
  "return 0;"
].join("\n"));

function rasterize(cells, positions, faceNormals) {
  if(cells.cells) {
    faceNormals = cells.faceNormals;
    positions = cells.positions;
    cells = cells.cells
  }
  var grid = spatialGrid(cells, positions, 1.0);
  var faceNormals = faceNormals || normals.faceNormals(grid.cells, grid.positions);
  var result = [];
  for(var id in grid.grid) {
    var coord = grid.grid[id].coord;
    var d = signedDistance(grid, faceNormals, coord);
    if(isNaN(d) || Math.abs(d) > 1.0) {
      continue;
    } else if(d < 0) {
      result.push([coord[0], coord[1], coord[2], 1, -d]);
    } else {
      result.push([coord[0], coord[1], coord[2], 0, d]);
    }
  }
  result.sort(voxelCompare);
  var X = new Array(result.length+1);
  var Y = new Array(result.length+1);
  var Z = new Array(result.length+1);
  var P = new Array(result.length+1);
  var D = new Array(result.length+1);
  X[0] = Y[0] = Z[0] = core.NEGATIVE_INFINITY;
  P[0] = 0;
  D[0] = 1.0;
  for(var i=0; i<result.length; ++i) {
    var r = result[i];
    X[i+1] = r[0];
    Y[i+1] = r[1];
    Z[i+1] = r[2];
    P[i+1] = r[3];
    D[i+1] = r[4];
  }
  //return repair.removeDuplicates(new core.DynamicVolume([X,Y,Z], D, P));
  return repair.removeDuplicates(new core.DynamicVolume([X,Y,Z], D, P));
}

module.exports = rasterize;