function d3_geo_pathBuffer() {

var pointCircle = d3_geo_pathBufferCircle(4.5),

buffer = [];

var stream = {

point: point,

// While inside a line, override point to moveTo then lineTo.

lineStart: function() { stream.point = pointLineStart; },

lineEnd: lineEnd,

// While inside a polygon, override lineEnd to closePath.

polygonStart: function() { stream.lineEnd = lineEndPolygon; },

polygonEnd: function() { stream.lineEnd = lineEnd; stream.point = point; },

pointRadius: function(_) {

pointCircle = d3_geo_pathBufferCircle(_);

return stream;

},

result: function() {

if (buffer.length) {

var result = buffer.join("");

buffer = [];

return result;

}

}

};

function point(x, y) {

buffer.push("M", x, ",", y, pointCircle);

}

function pointLineStart(x, y) {

buffer.push("M", x, ",", y);

stream.point = pointLine;

}

function pointLine(x, y) {

buffer.push("L", x, ",", y);

}

function lineEnd() {

stream.point = point;

}

function lineEndPolygon() {

buffer.push("Z");

}

return stream;

}

function d3_geo_pathBufferCircle(radius) {

return "m0," + radius

+ "a" + radius + "," + radius + " 0 1,1 0," + -2 * radius

+ "a" + radius + "," + radius + " 0 1,1 0," + 2 * radius

+ "z";

}