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d3.js polybrush.js

Forked from: https://gist.github.com/gtb104/3667340

Here's a d3 plugin that allows you to create a polygon selection. You instantiate it just like d3.svg.brush.

var brush = d3.svg.polybrush();

It has an extra public method that 'brush' does not, and that's 'isWithinExtent(x, y)'. You can use this method to test if a given point falls within the drawn extent.

if (brush.isWithinExtent(x, y)) {
  console.log("I'm inside!");
}

Usage:
Click to add an anchor point, double click to close the selection.
Drag the selection to reposition it.
Double click outside the selection to clear it.

Areas For Improvement:

  1. Add anchor handles to allow the repositioning of an anchor point.
  2. Better viewport edge detection. Right now it simply stops moving if you try to move the selection out of the viewport.
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="http://d3js.org/d3.v2.min.js"></script>
<script type="text/javascript" src="polybrush.js"></script>
<style type="text/css">
.brush .extent {
stroke: #000;
stroke-width: 1.5px;
fill: #000;
fill-opacity: 0.3;
}
.voronoi {
fill: steelblue;
fill-opacity: 0.4;
stroke: steelblue;
stroke-opacity: 0.5;
}
.voronoi.selected {
fill: red;
fill-opacity: 0.4;
stroke: darkred;
stroke-opacity: 0.5;
}
.point.selected {
fill: red;
stroke: darkred;
stroke-width: 1;
}
</style>
</head>
<body>
<div id="chart"></div>
<script type="text/javascript">
var w = 960,
h = 500;
var brush = d3.svg.polybrush()
.x(d3.scale.linear().range([0, w]))
.y(d3.scale.linear().range([0, h]))
.on("brushstart", function() {
svg.selectAll(".selected").classed("selected", false);
})
.on("brush", function() {
// set the 'selected' class for the circle
svg.selectAll(".point").classed("selected", function(d) {
//get the associated circle
var id = d3.select(this).attr("id");
var i = id.substr(id.indexOf("-")+1, id.length);
var vornoi = d3.select("#path-"+i);
// set the 'selected' class for the path
if (brush.isWithinExtent(d[0], d[1])) {
vornoi.classed("selected", true);
return true;
} else {
vornoi.classed("selected", false);
return false;
}
});
});
var vertices = d3.range(200).map(function(d) {
return [Math.random() * w, Math.random() * h];
});
var svg = d3.select("#chart")
.append("svg:svg")
.attr("width", w)
.attr("height", h);
var paths, points, clips;
clips = svg.append("svg:g").attr("id", "point-clips");
points = svg.append("svg:g").attr("id", "points");
paths = svg.append("svg:g").attr("id", "point-paths");
clips.selectAll("clipPath")
.data(vertices)
.enter().append("svg:clipPath")
.attr("id", function(d, i) { return "clip-"+i;})
.append("svg:circle")
.attr('cx', function(d) { return d[0]; })
.attr('cy', function(d) { return d[1]; })
.attr('r', 20);
paths.selectAll("path")
.data(d3.geom.voronoi(vertices))
.enter().append("svg:path")
.attr("d", function(d) { return "M" + d.join(",") + "Z"; })
.attr("id", function(d,i) { return "path-"+i; })
.attr("clip-path", function(d,i) { return "url(#clip-"+i+")"; })
.attr("class", "voronoi");
points.selectAll("circle")
.data(vertices)
.enter().append("svg:circle")
.attr("class", "point")
.attr("id", function(d, i) { return "point-"+i; })
.attr("transform", function(d) { return "translate(" + d + ")"; })
.attr("r", 2)
.attr('stroke', 'none');
svg.append("svg:g")
.attr("class", "brush")
.call(brush);
</script>
</body>
</html>
/*
Copyright (c) 2012 Geoffrey T. Bell
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
(function(d3) {
d3.svg.polybrush = function() {
var dispatch = d3.dispatch("brushstart", "brush", "brushend"),
x = null,
y = null,
extent = [],
firstClick = true,
firstTime = true,
wasDragged = false,
origin = null,
line = d3.svg.line()
.x(function(d) {
return d[0];
})
.y(function(d) {
return d[1];
});
var brush = function(g) {
g.each(function() {
var bg, e, fg;
g = d3.select(this);
bg = g.selectAll(".background").data([0]);
fg = g.selectAll(".extent").data([extent]);
g.style("pointer-events", "all").on("click.brush", addAnchor);
bg.enter().append("rect").attr("class", "background").style("visibility", "hidden").style("cursor", "crosshair");
fg.enter().append("path").attr("class", "extent").style("cursor", "move");
if (x) {
e = scaleExtent(x.range());
bg.attr("x", e[0]).attr("width", e[1] - e[0]);
}
if (y) {
e = scaleExtent(y.range());
bg.attr("y", e[0]).attr("height", e[1] - e[0]);
}
});
if (extent.length > 0) {
drawPath();
closePath();
}
};
var drawPath = function() {
return d3.selectAll("g path").attr("d", function(d) {
return line(d) + "Z";
});
};
var scaleExtent = function(domain) {
var start, stop;
start = domain[0];
stop = domain[domain.length - 1];
if (start < stop) {
return [start, stop];
} else {
return [stop, start];
}
};
var withinBounds = function(point) {
var rangeX, rangeY, _x, _y;
rangeX = scaleExtent(x.range());
rangeY = scaleExtent(y.range());
_x = Math.max(rangeX[0], Math.min(rangeX[1], point[0]));
_y = Math.max(rangeY[0], Math.min(rangeY[1], point[1]));
return point[0] === _x && point[1] === _y;
};
var moveAnchor = function(target) {
var moved, point;
point = d3.mouse(target);
if (firstTime) {
extent.push(point);
firstTime = false;
} else {
if (withinBounds(point)) {
extent.splice(extent.length - 1, 1, point);
}
drawPath();
dispatch.brush();
}
};
var closePath = function() {
var w;
w = d3.select(window);
w.on("dblclick.brush", null).on("mousemove.brush", null);
firstClick = true;
if (extent.length === 2 && extent[0][0] === extent[1][0] && extent[0][1] === extent[1][1]) {
extent.splice(0, extent.length);
}
d3.select(".extent").on("mousedown.brush", moveExtent);
return dispatch.brushend();
};
var addAnchor = function() {
var g, w,
_this = this;
g = d3.select(this);
w = d3.select(window);
firstTime = true;
if (wasDragged) {
wasDragged = false;
return;
}
if (firstClick) {
extent.splice(0, extent.length);
firstClick = false;
d3.select(".extent").on("mousedown.brush", null);
w.on("mousemove.brush", function() {
return moveAnchor(_this);
}).on("dblclick.brush", closePath);
dispatch.brushstart();
}
if (extent.length > 1) {
extent.pop();
}
extent.push(d3.mouse(this));
return drawPath();
};
var dragExtent = function(target) {
var checkBounds, fail, p, point, scaleX, scaleY, updateExtentPoint, _i, _j, _len, _len1;
point = d3.mouse(target);
scaleX = point[0] - origin[0];
scaleY = point[1] - origin[1];
fail = false;
origin = point;
updateExtentPoint = function(p) {
p[0] += scaleX;
p[1] += scaleY;
};
for (_i = 0, _len = extent.length; _i < _len; _i++) {
p = extent[_i];
updateExtentPoint(p);
}
checkBounds = function(p) {
if (!withinBounds(p)) {
fail = true;
}
return fail;
};
for (_j = 0, _len1 = extent.length; _j < _len1; _j++) {
p = extent[_j];
checkBounds(p);
}
if (fail) {
return;
}
drawPath();
return dispatch.brush({
mode: "move"
});
};
var dragStop = function() {
var w;
w = d3.select(window);
w.on("mousemove.brush", null).on("mouseup.brush", null);
wasDragged = true;
return dispatch.brushend();
};
var moveExtent = function() {
var _this = this;
d3.event.stopPropagation();
d3.event.preventDefault();
if (firstClick && !brush.empty()) {
d3.select(window).on("mousemove.brush", function() {
return dragExtent(_this);
}).on("mouseup.brush", dragStop);
origin = d3.mouse(this);
}
};
brush.isWithinExtent = function(x, y) {
var i, j, len, p1, p2, ret, _i, _len;
len = extent.length;
j = len - 1;
ret = false;
for (i = _i = 0, _len = extent.length; _i < _len; i = ++_i) {
p1 = extent[i];
p2 = extent[j];
if ((p1[1] > y) !== (p2[1] > y) && x < (p2[0] - p1[0]) * (y - p1[1]) / (p2[1] - p1[1]) + p1[0]) {
ret = !ret;
}
j = i;
}
return ret;
};
brush.x = function(z) {
if (!arguments.length) {
return x;
}
x = z;
return brush;
};
brush.y = function(z) {
if (!arguments.length) {
return y;
}
y = z;
return brush;
};
brush.extent = function(z) {
if (!arguments.length) {
return extent;
}
extent = z;
return brush;
};
brush.clear = function() {
extent.splice(0, extent.length);
return brush;
};
brush.empty = function() {
return extent.length === 0;
};
d3.rebind(brush, dispatch, "on");
return brush;
};
})(d3);
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