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D3.js draw a polygon with mouse
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<!DOCTYPE html> | |
<html> | |
<head> | |
<meta charset="utf-8"> | |
<title>D3 Drawing</title> | |
<script src="https://cdn.jsdelivr.net/d3js/3.5.9/d3.min.js"></script> | |
</head> | |
<body> | |
<h3>Draw a polygon :D</h3> | |
<script> | |
// global vars | |
var dragging = false, drawing = false, startPoint; | |
var svg = d3.select('body').append('svg') | |
.attr('height', 1000) | |
.attr('width', 1000); | |
var points = [], g; | |
// behaviors | |
var dragger = d3.behavior.drag() | |
.on('drag', handleDrag) | |
.on('dragend', function(d){ | |
dragging = false; | |
}); | |
svg.on('mouseup', function(){ | |
if(dragging) return; | |
drawing = true; | |
startPoint = [d3.mouse(this)[0], d3.mouse(this)[1]]; | |
if(svg.select('g.drawPoly').empty()) g = svg.append('g').attr('class', 'drawPoly'); | |
if(d3.event.target.hasAttribute('is-handle')) { | |
closePolygon(); | |
return; | |
}; | |
points.push(d3.mouse(this)); | |
g.select('polyline').remove(); | |
var polyline = g.append('polyline').attr('points', points) | |
.style('fill', 'none') | |
.attr('stroke', '#000'); | |
for(var i = 0; i < points.length; i++) { | |
g.append('circle') | |
.attr('cx', points[i][0]) | |
.attr('cy', points[i][1]) | |
.attr('r', 4) | |
.attr('fill', 'yellow') | |
.attr('stroke', '#000') | |
.attr('is-handle', 'true') | |
.style({cursor: 'pointer'}); | |
} | |
}); | |
function closePolygon() { | |
svg.select('g.drawPoly').remove(); | |
var g = svg.append('g'); | |
g.append('polygon') | |
.attr('points', points) | |
.style('fill', getRandomColor()); | |
for(var i = 0; i < points.length; i++) { | |
var circle = g.selectAll('circles') | |
.data([points[i]]) | |
.enter() | |
.append('circle') | |
.attr('cx', points[i][0]) | |
.attr('cy', points[i][1]) | |
.attr('r', 4) | |
.attr('fill', '#FDBC07') | |
.attr('stroke', '#000') | |
.attr('is-handle', 'true') | |
.style({cursor: 'move'}) | |
.call(dragger); | |
} | |
points.splice(0); | |
drawing = false; | |
} | |
svg.on('mousemove', function() { | |
if(!drawing) return; | |
var g = d3.select('g.drawPoly'); | |
g.select('line').remove(); | |
var line = g.append('line') | |
.attr('x1', startPoint[0]) | |
.attr('y1', startPoint[1]) | |
.attr('x2', d3.mouse(this)[0] + 2) | |
.attr('y2', d3.mouse(this)[1]) | |
.attr('stroke', '#53DBF3') | |
.attr('stroke-width', 1); | |
}) | |
function handleDrag() { | |
if(drawing) return; | |
var dragCircle = d3.select(this), newPoints = [], circle; | |
dragging = true; | |
var poly = d3.select(this.parentNode).select('polygon'); | |
var circles = d3.select(this.parentNode).selectAll('circle'); | |
dragCircle | |
.attr('cx', d3.event.x) | |
.attr('cy', d3.event.y); | |
for (var i = 0; i < circles[0].length; i++) { | |
circle = d3.select(circles[0][i]); | |
newPoints.push([circle.attr('cx'), circle.attr('cy')]); | |
} | |
poly.attr('points', newPoints); | |
} | |
function getRandomColor() { | |
var letters = '0123456789ABCDEF'.split(''); | |
var color = '#'; | |
for (var i = 0; i < 6; i++) { | |
color += letters[Math.floor(Math.random() * 16)]; | |
} | |
return color; | |
} | |
</script> | |
</body> | |
</html> |
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