//-------------------------------------------------------------------------------- // $Id: grid_utm.js,v 1.6 2010/11/20 00:11:21 wolf Exp wolf $ //-------------------------------------------------------------------------------- // Erklärung: http://www.netzwolf.info/kartografie/openlayers/utmgrid //-------------------------------------------------------------------------------- // Fragen, Wuensche, Bedenken, Anregungen? // //-------------------------------------------------------------------------------- OpenLayers.Layer.GridUTM = OpenLayers.Class (OpenLayers.Layer.Vector, { initialize: function (name, options){ OpenLayers.Layer.Vector.prototype.initialize.apply(this, [name, options]); }, gridSizeText: null, gridSizeDiv: null, zone: null, //--------------------------------------------------------- // Find matching grid unit or return null //--------------------------------------------------------- getGridUnit: function (distance) { for (var i=0; i=1000 && m%1000==0) return (m/1000)+"km"; return m+"m"; }, //--------------------------------------------------------- // Set graphic attributes for grid //--------------------------------------------------------- styleMap: new OpenLayers.StyleMap( { strokeColor: "#000000", strokeWidth: 1, strokeOpacity: 0.8 }), //--------------------------------------------------------- // Draw grid on move or zoom //--------------------------------------------------------- moveTo: function (bounds, zoomChanged, dragging) { //--------------------------------------------------------- // but not while dragging //--------------------------------------------------------- if (dragging) return; //--------------------------------------------------------- // Remove old grid //--------------------------------------------------------- this.destroyFeatures(); //--------------------------------------------------------- // Transform center and border to geogr. Coordinates //--------------------------------------------------------- var mapCenter = this.map.getCenter().clone(). transform(this.map.getProjectionObject(), this.map.displayProjection); var mapBounds = bounds.clone(). transform(this.map.getProjectionObject(), this.map.displayProjection); //---------------------------------------------------------- // Number of UTM-Zones in viewport //---------------------------------------------------------- var nzones = (this.lonToZone(mapBounds.right)-this.lonToZone(mapBounds.left)+60)%60 + 1; //---------------------------------------------------------- // Set zone based on center of map //---------------------------------------------------------- if (nzones >= 3) { this.zone = null; } else if (nzones==1 || !this.zone) { this.zone = this.lonToZone (mapCenter.lon); } //--------------------------------------------------------- // UTM-Coordinates of corners //--------------------------------------------------------- var ol = this.lonLatToUTM (mapBounds.left , mapBounds.top ); var or = this.lonLatToUTM (mapBounds.right, mapBounds.top ); var ul = this.lonLatToUTM (mapBounds.left , mapBounds.bottom); var ur = this.lonLatToUTM (mapBounds.right, mapBounds.bottom); //--------------------------------------------------------- // Grid unit //--------------------------------------------------------- var unit = ur && ul ? this.getGridUnit ((ur.x-ul.x) / this.map.getSize().w * this.gridPixelDistance) : null; //--------------------------------------------------------- // Grid size display object // (TODO: create a OpenLayers.Control-Object) //--------------------------------------------------------- if (this.gridSizeText && !this.gridSizeDiv) { this.gridSizeDiv=OpenLayers.Util.createDiv(this.id); this.gridSizeDiv.className='olControlGridUTM'; this.gridSizeDiv.style.zIndex=map.Z_INDEX_BASE['Control']+ map.controls.length; this.gridSizeDiv.setAttribute("unselectable","on"); this.map.viewPortDiv.appendChild (this.gridSizeDiv); } //--------------------------------------------------------- // Hide grid size (if configured) //--------------------------------------------------------- if (this.gridSizeDiv) this.gridSizeDiv.style.display='none'; //--------------------------------------------------------- // Create new grid //--------------------------------------------------------- if (this.zone && unit) { //--------------------------------------------------------- // Compute grid //--------------------------------------------------------- var x1 = Math.floor (Math.min(ol.x, ul.x) / unit) * unit; var x2 = Math.ceil (Math.max(or.x, ur.x) / unit) * unit; var y1 = Math.floor (Math.min(ul.y, ur.y) / unit) * unit; var y2 = Math.ceil (Math.max(ol.y, or.y) / unit) * unit; var features = []; //--------------------------------------------------------- // Vertical lines //--------------------------------------------------------- for (var x=x1; x<=x2; x+= unit) { var xu = (x - ul.x) / (ur.x-ul.x) * (bounds.right-bounds.left) +bounds.left; var xo = (x - ol.x) / (or.x-ol.x) * (bounds.right-bounds.left) +bounds.left; features.push ( new OpenLayers.Feature.Vector ( new OpenLayers.Geometry.LineString( [ new OpenLayers.Geometry.Point (xu, bounds.bottom), new OpenLayers.Geometry.Point (xo, bounds.top ) ]))); } //--------------------------------------------------------- // Horizontal lines //--------------------------------------------------------- for (var y=y1; y<=y2; y+=unit) { var yl = (y - ul.y) / (ol.y-ul.y) * (bounds.top-bounds.bottom) +bounds.bottom; var yr = (y - ur.y) / (or.y-ur.y) * (bounds.top-bounds.bottom) +bounds.bottom; features.push ( new OpenLayers.Feature.Vector ( new OpenLayers.Geometry.LineString( [ new OpenLayers.Geometry.Point (bounds.left, yl), new OpenLayers.Geometry.Point (bounds.right, yr) ]))); } //--------------------------------------------------------- // Add grid lines to vector layer //--------------------------------------------------------- this.addFeatures(features); //--------------------------------------------------------- // Display grid size //--------------------------------------------------------- if (this.gridSizeDiv) { this.gridSizeDiv.innerHTML = OpenLayers.String.format(this.gridSizeText, {grid: this.formatGridSize(unit)}); this.gridSizeDiv.style.display=null; } } //--------------------------------------------------------- // Superclass //--------------------------------------------------------- OpenLayers.Layer.Vector.prototype.moveTo.apply(this,arguments); }, //--------------------------------------------------------- // Determine UTM-Zone from WGS84-Longitude //--------------------------------------------------------- lonToZone: function (lon) { lon -= Math.floor(lon/360+0.5)*360; return Math.floor (lon/6.0) + 31; }, //--------------------------------------------------------- // Convert WGS84 Longitude and Lattitude to UTM // using Zone from this.zone //--------------------------------------------------------- lonLatToUTM: function (lon, lat) { //--------------------------------------------------------- // Sanitize and normalize values //--------------------------------------------------------- if (!this.zone) return null; if (lat>=+90) return null; if (lat<=-90) return null; if (lat > 84.0) lat = +84; if (lat <-80.0) lat = -80; lon -= Math.floor(lon/360+0.5)*360; //--------------------------------------------------------- // Get center meridian //--------------------------------------------------------- var meridian = this.zone*6 - 183; //--------------------------------------------------------- // Longitude based on middle meridian // Transform from degrees to radians //--------------------------------------------------------- var rho = 180.0/3.14159265358979; var phi = lat/rho; var lbd = (lon-meridian)/rho; //--------------------------------------------------------- // Auxiliary values based on the WGS84 ellipsoid //--------------------------------------------------------- var sin = Math.sin (phi); var cos = Math.cos (phi); var tan = Math.tan (phi); var c2 = cos*cos; var t2 = tan*tan; var l2 = lbd*lbd; var eta = 0.00673949674227643 * c2; var Vq = 1 + eta; var V = Math.sqrt(Vq); var N = 6399593.62575849/V; //--------------------------------------------------------- // Conforming transformation to northing and easting // .oO( you are not expected to understand this :-) //--------------------------------------------------------- var nv = 6367449.14582342 * phi + sin * cos * (((0.00403587903241357 * c2 - 0.709736085843171) * c2 + 135.398511127892) * c2 - 32144.4799350778) + N * (0.5 * tan * c2 * l2 * (1 + 1/12 * (5+9*eta-t2)*c2*l2));; var ev = N * cos * lbd * (1+ 1/6 * c2 * l2 * (Vq - t2 +0.05 * (5-18*t2+t2*t2) * c2 * l2)); //--------------------------------------------------------- // return northing and easting //--------------------------------------------------------- return { y: Math.round (0.9996*nv), x: Math.round (0.9996*ev) }; }, CLASS_NAME: "OpenLayers.Layer.GridUTM" }); //-------------------------------------------------------------------------------- // $Id: grid_utm.js,v 1.6 2010/11/20 00:11:21 wolf Exp wolf $ //--------------------------------------------------------------------------------