I have the bezier curves between 2 points. I'd like to cut all curves into two equal half.
One of my idea is if I can control 't' value I'll draw 2 curves by t = [0,0.5] and t = [0.5,1] but I don't know how. Below is my code. I won't mind any other idea or suggestion
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>D3 test</title>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var Over = function(){
d3.select(this)
.style("stroke-opacity", 0.25);
}
var Out = function(){
d3.select(this)
.transition().duration(200)
.style("stroke-opacity", 0);
}
function curve(n,x1,y1,x2,y2){
var xr = (x1+x2)/2,
yr = (y1+y2)/2,
euDist = Math.sqrt(Math.pow(x2-x1,2)+Math.pow(y2-y1,2)),
x3 = -y1+xr+yr, x4 = -y2+xr+yr,
y3 = x1+yr-xr, y4 = x2+yr-xr,
ctrl , curveDescription;
svg.append('path')
.attr("stroke", 'blue')
.attr('fill','none')
.style("stroke-opacity",0.25)
.attr('d', 'M'+x3+','+y3+'L'+x4+','+y4)
.attr('stroke-width',strokeWidth);
for(var j=0;j<=n;j++){
ctrl = [(x4-x3)*j/n+x3 , (y4-y3)*j/n+y3] ,
curveDescription=
'M' +x1+',' +y1+
'Q' +ctrl[0]+','+ctrl[1]+','
+x2+',' +y2;
svg.append('path')
.attr("stroke", 'blue')
.attr('fill','none')
.style("stroke-opacity",0.25)
.attr('d', curveDescription)
.attr('stroke-width',strokeWidth);
svg.append('path')
.attr("stroke", 'blue')
.attr('fill','none')
.style("stroke-opacity",0)
.on("mouseover", Over)
.on("mouseout", Out)
.attr('d', curveDescription)
.attr('stroke-width',strokeWidth*25);
}
}
</script>
</head>
<body>
<script>
var w = 1268 , h = 680 , strokeWidth = 2;
var svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h)
curve(5, 100,100, 400,500);
</script>
</body>
</html>
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