build.coffee

THREE = require('../lib/three')
CSG = require('../lib/csg')
ThreeBSP = require('../lib/threecsg')
toSTL = require('./to_stl')
fs = require('fs')
eachGrunnkrets = require('./each_grunnkrets')
incomes = require('./incomes')
ClipperLib = require('../lib/clipper_lib')

clipperScale = 1.0

# Convert coordinates from a GeoJson MultiPolygon to a ClipperLib polygon set
multiPolygonToClipperPolygons = (coordinates) ->
  result = []
  for group in coordinates
    for polygon in group
      p = []
      for point in polygon
        p.push({X: point[0]*clipperScale, Y: point[1]*clipperScale})
      result.push(p)
  result

# ClipperLib polygon set to GeoJson MultiPolygon coordinates
clipperPolygonsToMultiPolygon = (polygons) ->
  result = []
  for polygon in polygons
    p = []
    for point in polygon
      p.push([point.X/clipperScale, point.Y/clipperScale])
    result.push(p)
  [result]

offsetMutiPolygon = (coordinates, offset) ->
  # This code is mostly copied and pasted from http://sourceforge.net/p/jsclipper/wiki/Home/#b-offsetting-polygons
  polygons = multiPolygonToClipperPolygons(coordinates)
  cpr = new ClipperLib.Clipper()
  polygons = cpr.SimplifyPolygons(polygons, ClipperLib.PolyFillType.pftNonZero);
  polygons = ClipperLib.Clean(polygons, 50*clipperScale);
  joinType = ClipperLib.JoinType.jtSquare
  miterLimit = 1
  autoFix = true
  result = cpr.OffsetPolygons(polygons, offset, joinType, miterLimit, autoFix)
  clipperPolygonsToMultiPolygon(result)

pathFromMultiPolygon = (coordinates, offset = null) ->
  coordinates = offsetMutiPolygon(coordinates, offset*clipperScale) if offset?
  path = new THREE.Path()
  for group in coordinates
    for polygon in group
      firstPoint = true
      for point in polygon
        if firstPoint
          path.moveTo(point[0], point[1])
          firstPoint = false
        else
          path.lineTo(point[0], point[1])
  return path

# Represents the geometry of a single grunnkrets
class Grunnkrets
  constructor: (@record, @height, @wallThickness = null) ->
    @gid = @record.gid
    @geometry = null
  getGeometry: ->
    return @geometry if @geometry?
    if @height < 50
      return new THREE.Geometry()
    outerShapes = pathFromMultiPolygon(@record.geo.coordinates).toShapes()
    # It there were no shapes, just return an empty geometry
    unless outerShapes.length > 0
      return new THREE.Geometry()
    # Extrude the outer shell
    outerShell = new THREE.ExtrudeGeometry(outerShapes, {amount: @height, bevelEnabled: false})
    # If we have not been asked to carve an insode, or if this isn't high enough to warrant a carve, return
    # Also carving shapes with holes in them does not always work, so we just won't even try.
    unless @wallThickness? && @wallThickness != 0 && @height > @wallThickness
      return @geometry = outerShell
    # Create an inner shape by offsetting the shape negatively
    innerShapes = pathFromMultiPolygon(@record.geo.coordinates, -@wallThickness).toShapes()
    console.log innerShapes.length
    # If no shape was generated, this region is too small to carve
    unless innerShapes.length > 0 # There was no interior to remove
      console.log "There was no inner shell"
      return @geometry = outerShell
    # Extrude the inner shell
    innerShell = new THREE.ExtrudeGeometry(innerShapes, {amount: @height , bevelEnabled: false})
    # Translate the inner shell down by @height to leave a cap on the top and cut a hole on the bottom
    for vertex in innerShell.vertices
      vertex.z -= @wallThickness
    # Subtract the innerShell from the outerShell and create the resulting THREE.Geometry
    @geometry = (new ThreeBSP(outerShell)).subtract(new ThreeBSP(innerShell)).toGeometry()
    # Return it
    return @geometry
  municipality: ->
    @gid.slice(0,4)

build = ->
  eachGrunnkrets (record) ->
    if true || record.gid.slice(0,4) == '0301'
      console.log "Processing region #{record.gid}"
      wallThickness = 43.75
      # if record.gid == '02191306' # Hack to get around generating a malformed mesh due to an unidentified bug
      #   wallThickness = null
      grunnkrets = new Grunnkrets(record, incomes[record.gid]*0.005, wallThickness)
      geometry = grunnkrets.getGeometry()
      if geometry.faces.length > 0
        fs.appendFile(__dirname+"/../output/_#{grunnkrets.gid.slice(0,4)}.stl", toSTL(geometry))

module.exports = build

# console.log "Generating geometry"
# geometry = new THREE.SphereGeometry(100.0)
# console.log "Making STL"
# fs.writeFile("./model.stl", toSTL(geometry))