您好我想知道两个圆圈重叠时是否可以改变颜色.优选地,重叠的部分将变为白色,因为其意图表示组.
var canvas = d3.select("canvas"),
context = canvas.node().getContext("2d"),
width = canvas.property("width"),
height = canvas.property("height"),
radius = 32;
var circles = d3.range(4).map(function(i) {
return {
index: i,
x: Math.round(Math.random() * (width - radius * 2) + radius),
y: Math.round(Math.random() * (height - radius * 2) + radius)
};
});
var color = d3.scaleOrdinal()
.range(d3.schemeCategory20);
render();
canvas.call(d3.drag()
.subject(dragsubject)
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended)
.on("start.render drag.render end.render", render));
function render() {
context.clearRect(0, 0, width, height);
for (var i = 0, n = …