// Written by Paul Kaplan

var AsciiStlWriter = (function() {

  // ASCI STL files
  function stringifyVector(vec){
    return ""+vec.x+" "+vec.y+" "+vec.z;
  }

  function stringifyVertex(vec){
    return "vertex "+stringifyVector(vec)+" \n";
  }

  function geometryToStlString(geom){
    var vertices = geom.vertices;
    var tris     = geom.faces;

    var stl = "solid pixel";
    for(var i = 0; i<tris.length; i++){
      stl += ("facet normal "+stringifyVector( tris[i].normal )+" \n");
      stl += ("outer loop \n");
      stl += stringifyVertex(vertices[tris[i].a]);
      stl += stringifyVertex(vertices[tris[i].b]);
      stl += stringifyVertex(vertices[tris[i].c]);
      stl += ("endloop \n");
      stl += ("endfacet \n");
    }
    stl += ("endsolid");

    return stl
  }


  var save = function(geometry, filename) {
    var stlString = geometryToStlString(geometry);
    var blob = new Blob([stlString], {type: 'text/plain'});
    saveAs(blob, filename);
  }
  
  that.save = save;
  return that;
}());