/*
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(c) 2016, Manuel Bär
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Leaflet.idw, a tiny and fast inverse distance weighting plugin for Leaflet.
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Largely based on the source code of Leaflet.heat by Vladimir Agafonkin (c) 2014
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https://github.com/Leaflet/Leaflet.heat
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*/
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!(function() {
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'use strict'
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function simpleidw(canvas) {
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if (!(this instanceof simpleidw)) return new simpleidw(canvas)
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this._canvas = canvas = typeof canvas === 'string' ? document.getElementById(canvas) : canvas
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this._ctx = canvas.getContext('2d')
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this._width = canvas.width
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this._height = canvas.height
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this._max = 1
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this._data = []
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}
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simpleidw.prototype = {
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defaultCellSize: 20,
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defaultGradient: {
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0.0: '#000066',
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0.1: '#00e400',
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0.2: '#ffff00',
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0.3: '#ff7e00',
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0.4: '#ff0000',
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0.5: '#99004c',
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0.6: '#7e0023',
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0.7: 'Maroon',
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0.8: '#660066',
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0.9: '#990099',
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1.0: '#ff66ff'
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},
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data: function(data) {
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this._data = data
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return this
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},
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max: function(max) {
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this._max = max
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return this
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},
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add: function(point) {
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this._data.push(point)
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return this
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},
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clear: function() {
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this._data = []
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return this
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},
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cellSize: function(r) {
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var cell = this._cell = document.createElement('canvas')
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var ctx = cell.getContext('2d')
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this._r = r
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return this
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},
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resize: function() {
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this._width = this._canvas.width
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this._height = this._canvas.height
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},
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gradient: function(grad) {
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// create a 256x1 gradient that we'll use to turn a grayscale heatmap into a colored one
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var canvas = document.createElement('canvas')
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var ctx = canvas.getContext('2d')
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var gradient = ctx.createLinearGradient(0, 0, 0, 256)
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canvas.width = 1
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canvas.height = 256
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for (var i in grad) {
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gradient.addColorStop(+i, grad[i])
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}
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ctx.fillStyle = gradient
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ctx.fillRect(0, 0, 1, 256)
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this._grad = ctx.getImageData(0, 0, 1, 256).data
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return this
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},
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draw: function(opacity) {
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if (!this._cell) this.cellSize(this.defaultCellSize)
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if (!this._grad) this.gradient(this.defaultGradient)
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var ctx = this._ctx
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var grad = this._grad
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ctx.clearRect(0, 0, this._width, this._height)
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for (var i = 0, len = this._data.length, p; i < len; i++) {
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var p = this._data[i]
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var j = Math.round((p[2] / this._max) * 255) * 4
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ctx.fillStyle = 'rgba(' + grad[j] + ',' + grad[j + 1] + ',' + grad[j + 2] + ',' + opacity + ')'
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ctx.fillRect(p[0] - this._r, p[1] - this._r, this._r, this._r)
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}
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return this
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}
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},
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window.simpleidw = simpleidw
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}()),
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L.IdwLayer = (L.Layer ? L.Layer : L.Class).extend({
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options: {
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opacity: 0,
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maxZoom: 18,
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cellSize: 1,
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exp: 2,
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max: 100
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},
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initialize: function(latlngs, options) {
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this._latlngs = latlngs
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this._bound = options.bound
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console.log(latlngs)
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L.setOptions(this, options)
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},
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setLatLngs: function(latlngs) {
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this._latlngs = latlngs
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return this.redraw()
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},
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addLatLng: function(latlng) {
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this._latlngs.push(latlng)
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return this.redraw()
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},
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setOptions: function(options) {
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L.setOptions(this, options)
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if (this._idw) {
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this._updateOptions()
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}
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return this.redraw()
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},
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redraw: function() {
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if (this._idw && !this._frame && !this._map._animating) {
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this._frame = L.Util.requestAnimFrame(this._redraw, this)
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}
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return this
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},
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onAdd: function(map) {
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this._map = map
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if (!this._canvas) {
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this._initCanvas()
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}
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map._panes.overlayPane.appendChild(this._canvas)
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map.on('moveend', this._reset, this)
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if (map.options.zoomAnimation && L.Browser.any3d) {
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map.on('zoomanim', this._animateZoom, this)
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}
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this._reset()
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},
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onRemove: function(map) {
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map.getPanes().overlayPane.removeChild(this._canvas)
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map.off('moveend', this._reset, this)
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if (map.options.zoomAnimation) {
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map.off('zoomanim', this._animateZoom, this)
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}
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},
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addTo: function(map) {
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map.addLayer(this)
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return this
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},
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_initCanvas: function() {
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var canvas = this._canvas = L.DomUtil.create('canvas', 'leaflet-idwmap-layer leaflet-layer')
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var originProp = L.DomUtil.testProp(['transformOrigin', 'WebkitTransformOrigin', 'msTransformOrigin'])
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canvas.style[originProp] = '50% 50%'
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var size = this._map.getSize()
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canvas.width = size.x
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canvas.height = size.y
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var animated = this._map.options.zoomAnimation && L.Browser.any3d
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L.DomUtil.addClass(canvas, 'leaflet-zoom-' + (animated ? 'animated' : 'hide'))
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this._idw = simpleidw(canvas)
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this._updateOptions()
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},
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_updateOptions: function() {
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this._idw.cellSize(this.options.cellSize || this._idw.defaultCellSize)
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if (this.options.gradient) {
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this._idw.gradient(this.options.gradient)
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}
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if (this.options.max) {
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this._idw.max(this.options.max)
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}
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},
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_reset: function() {
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var topLeft = this._map.containerPointToLayerPoint([0, 0])
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L.DomUtil.setPosition(this._canvas, topLeft)
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var size = this._map.getSize()
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if (this._idw._width !== size.x) {
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this._canvas.width = this._idw._width = size.x
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}
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if (this._idw._height !== size.y) {
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this._canvas.height = this._idw._height = size.y
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}
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this._redraw()
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},
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_redraw: function() {
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if (!this._map) {
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return
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}
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console.log(this._idw._r)
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var data = []
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var r = this._idw._r
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var size = this._map.getSize()
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var bounds = new L.Bounds(
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L.point([-r, -r]),
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size.add([r, r]))
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var exp = this.options.exp === undefined ? 1 : this.options.exp
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var max = this.options.max === undefined ? 1 : this.options.max
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var maxZoom = this.options.maxZoom === undefined ? this._map.getMaxZoom() : this.options.maxZoom
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var v = 1
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var cellCen = r / 2
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var grid = []
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var nCellX = Math.ceil((bounds.max.x - bounds.min.x) / r) + 1
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var nCellY = Math.ceil((bounds.max.y - bounds.min.y) / r) + 1
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var panePos = this._map._getMapPanePos()
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var offsetX = 0 // panePos.x % cellSize,
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var offsetY = 0 // panePos.y % cellSize,
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var i; var len; var p; var cell; var x; var y; var j; var len2; var k
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console.log('===========================================')
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for (i = 0, len = nCellY; i < len; i++) {
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// grid[i] = [];
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for (j = 0, len2 = nCellX; j < len2; j++) {
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var x = i * r; var y = j * r
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var numerator = 0; var denominator = 0
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let len3
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for (k = 0, len3 = this._latlngs.length; k < len3; k++) {
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// Get distance between cell and point
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var p = this._map.latLngToContainerPoint(this._latlngs[k])
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var cp = L.point((y - cellCen), (x - cellCen))
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var dist = cp.distanceTo(p)
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var dist2 = Math.pow(dist, exp)
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var val =
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this._latlngs[k].alt !== undefined ? this._latlngs[k].alt
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: this._latlngs[k][2] !== undefined ? +this._latlngs[k][2] : 1
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numerator += val / dist2
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denominator += 1 / dist2
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}
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var interpolVal = numerator / denominator
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cell = [j * r, i * r, interpolVal]
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if (cell) {
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data.push([
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Math.round(cell[0]),
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Math.round(cell[1]),
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Math.min(cell[2], max)
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])
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}
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}
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}
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this._idw.data(data).draw(this.options.opacity)
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this._pic = this._canvas.toDataURL('image/png')
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var imageBounds = this._bound
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if (this._image == undefined) {
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this._image = L.imageOverlay(this._pic, imageBounds, { opacity: 0.8 }).addTo(this._map)
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}
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this._frame = null
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},
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_animateZoom: function(e) {
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var scale = this._map.getZoomScale(e.zoom)
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var offset = this._map._getCenterOffset(e.center)._multiplyBy(-scale).subtract(this._map._getMapPanePos())
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if (L.DomUtil.setTransform) {
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L.DomUtil.setTransform(this._canvas, offset, scale)
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} else {
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this._canvas.style[L.DomUtil.TRANSFORM] = L.DomUtil.getTranslateString(offset) + ' scale(' + scale + ')'
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}
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}
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})
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L.idwLayer = function(latlngs, options) {
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return new L.IdwLayer(latlngs, options)
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}
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