诀窍是绘制自链接作为一个弧形的路径。我花了一些时间来处理arc parameter syntax,让事情奏效,关键似乎是弧线无法在同一点开始和结束。以下是在每次更新时绘制边缘的相关代码。
function tick() {
link.attr("d", function(d) {
var x1 = d.source.x,
y1 = d.source.y,
x2 = d.target.x,
y2 = d.target.y,
dx = x2 - x1,
dy = y2 - y1,
dr = Math.sqrt(dx * dx + dy * dy),
// Defaults for normal edge.
drx = dr,
dry = dr,
xRotation = 0, // degrees
largeArc = 0, // 1 or 0
sweep = 1; // 1 or 0
// Self edge.
if (x1 === x2 && y1 === y2) {
// Fiddle with this angle to get loop oriented.
xRotation = -45;
// Needs to be 1.
largeArc = 1;
// Change sweep to change orientation of loop.
//sweep = 0;
// Make drx and dry different to get an ellipse
// instead of a circle.
drx = 30;
dry = 20;
// For whatever reason the arc collapses to a point if the beginning
// and ending points of the arc are the same, so kludge it.
x2 = x2 + 1;
y2 = y2 + 1;
}
return "M" + x1 + "," + y1 + "A" + drx + "," + dry + " " + xRotation + "," + largeArc + "," + sweep + " " + x2 + "," + y2;
});
这里是a jsfiddle演示了整个事情,并截图:
您需要定义一个适当的路径(“d”属性)的自引用节点,即有中间点和适当插值的东西。 – 2013-05-03 20:32:08