shapely.min.js

shapely={};shapely.geom=function(coords,type){var geom={type:type,coords:coords,area:area,length:length,geojson:geojson,buffer:buffer,envelope:envelope};function area(){return 0}function length(){return 0}function buffer(distance,res){return shapely.buffer(geom,distance,res)}function geojson(properties){return{geometry:{coordinates:coords,type:type},properties:properties}}function envelope(){return shapely.envelope(geom)}return geom};shapely.point=function(coords){var shape=shapely.geom(coords,"Point");shape.x=coords[0];shape.y=coords[1];return shape};shapely.line=function(coords){var shape=shapely.geom(coords,"LineString");shape.length=function(){var len=0;for(i=1;i<coords.length;i++){var p1=coords[i-1],p2=coords[i];len+=Math.sqrt((p2[0]-=p1[0])*p2[0]+(p2[1]-=p1[1])*p2[1])}return len};return shape};shapely.polygon=function(coords){if(coords[0]){var len=coords[0].length;if(coords[0][len-1][0]!=coords[0][0][0]||coords[0][len-1][1]!=coords[0][0][1]){coords[0].push(coords[0][0])}}var shape=shapely.geom(coords,"Polygon");shape.area=function(){var c=coords[0];var area=0,len=c.length;var j=len-1;for(i=0;i<len;i++){area+=(c[j][0]+c[i][0])*(c[j][1]-c[i][1]);j=i}return area/2};return shape};shapely.area=function(coords,type){var _area={point:function(){return 0},line:function(){return 0},polygon:function(c){var area=0,len=c.length;var j=len-1;for(i=0;i<len;i++){area+=(c[j][0]+c[i][0])*(c[j][1]-c[i][1]);j=i}return area/2}};return _area[type](coords)};shapely.envelope=function(geometry){var minx=0,miny=0,maxx=0,maxy=0;var _envelope={Point:function(){return geometry},LineString:function(){return bounds(geometry.coords)},Polygon:function(){return bounds(geometry.coords[0])}};function bounds(coords){var len=coords.length;while(len--){var c=coords[len];minx=c[0]<minx?c[0]:minx;miny=c[1]<miny?c[1]:miny;maxx=c[0]>maxx?c[0]:maxx;maxy=c[1]>maxy?c[1]:maxy}return shapely.polygon([[[minx,miny],[minx,maxy],[maxx,maxy],[maxx,miny]]])}return _envelope[geometry.type](geometry.coords)};shapely.buffer=function(geometry,distance,res){var quadrants=res||16;var buffer={coords:[]};if(geometry.type=="Point"){if(parseFloat(distance)<=0)return shapely.polygon([]);var pnt0=[geometry.coords[0]+distance,geometry.coords[1]];buffer.coords.push(pnt0);buffer.coords=buffer.coords.concat(arc(geometry.coords,0,2*Math.PI,-1));return shapely.polygon([buffer.coords])}else if(geometry.type=="LineString"){if(parseFloat(distance)<=0)return shapely.polygon([]);var nCoords=geometry.coords.length-1;buffer.coords.push([geometry.coords[0][0]-distance,geometry.coords[0][1]]);for(var i=1;i<=nCoords;i++){var os=offset([geometry.coords[i-1],geometry.coords[i]],-1);buffer.coords.push(os[1])}buffer.coords=buffer.coords.concat(reflex(geometry.coords[nCoords],buffer.coords[buffer.coords.length-1],offset([geometry.coords[nCoords-1],geometry.coords[nCoords]],1)[1],-1));for(var i=nCoords;i>0;i--){var os=offset([geometry.coords[i-1],geometry.coords[i]],1);buffer.coords.push(os[1])}buffer.coords.push([geometry.coords[0][0]+distance,geometry.coords[0][1]]);buffer.coords=buffer.coords.concat(reflex(geometry.coords[0],buffer.coords[buffer.coords.length-1],buffer.coords[0],-1));return shapely.polygon([buffer.coords])}else if(geometry.type=="Polygon"){var nCoords=geometry.coords[0].length-1;buffer.segments=[];buffer.coords[0]=[];for(var i=0;i<nCoords;i++){var os=offset([geometry.coords[0][i],geometry.coords[0][i+1]],1);buffer.segments.push(os)}for(var j=1;j<buffer.segments.length;j++){var prev=buffer.segments[j-1];var current=buffer.segments[j];buffer.coords[0].push(prev[0]);buffer.coords[0]=buffer.coords[0].concat(reflex(geometry.coords[0][j],prev[1],current[0],-1))}buffer.coords[0]=buffer.coords[0].concat(reflex(geometry.coords[0][0],buffer.segments[buffer.segments.length-1][1],buffer.segments[0][0],-1));return shapely.polygon(buffer.coords)}function offset(segment,side){var offset=[[],[]];var side=side*-1,dx=segment[1][0]-segment[0][0],dy=segment[1][1]-segment[0][1];var len=Math.sqrt(dx*dx+dy*dy);var ux=side*distance*dx/len,uy=side*distance*dy/len;offset[0][0]=segment[0][0]-uy;offset[0][1]=segment[0][1]+ux;offset[1][0]=segment[1][0]-uy;offset[1][1]=segment[1][1]+ux;return offset}function arc(pnt,angle0,angle1,direction){var fullAngle=Math.abs(angle0-angle1);var nSegs=parseInt(fullAngle/(Math.PI/2/quadrants)+.5);if(nSegs<1)return;var currentAngle=0;coords=[];while(currentAngle<fullAngle){var angle=angle0+direction*currentAngle;coords.push([pnt[0]+distance*Math.cos(angle),pnt[1]+distance*Math.sin(angle)]);currentAngle+=fullAngle/nSegs}return coords}function reflex(pnt,pnt0,pnt1,direction){var dx0=pnt0[0]-pnt[0];var dy0=pnt0[1]-pnt[1];var startAngle=Math.atan2(dy0,dx0);var dx1=pnt1[0]-pnt[0];var dy1=pnt1[1]-pnt[1];var endAngle=Math.atan2(dy1,dx1);if(direction===-1){if(startAngle<=endAngle)startAngle+=2*Math.PI}else{if(startAngle>=endAngle)startAngle-=2*Math.PI}return arc(pnt,startAngle,endAngle,direction)}};