我正在改编 Mike Bostock 的 point along path interpolation模型接受n条单独路径的数组并沿每个连续进行插值。对于 D3 来说,下面的代码相对较新,据我所知,它是同时运行两条路径的点插值。现在,我对如何重组这一过程以使该过程连续(只有一个移动对象)感到有点困惑。实际上,我需要能够在路径之间停下来监听鼠标点击,但是一旦结构存在,我就可以找出该代码。非常感谢您的帮助。
这是jsfiddle .
后代代码:
<!DOCTYPE html>
<meta charset="utf-8">
<body>
<style>
path {
fill: none;
stroke: #000;
stroke-width: 3px;
}
circle {
stroke: #fff;
stroke-width: 3px;
}
</style>
<script type="text/javascript" src="http://d3js.org/d3.v3.js"></script><script>
var pathdata = [
[[240, 100],
[290, 200],
[340, 50]],
[[340, 50],
[90, 150],
[140, 50],
[190, 200]]
];
var svg = d3.select("body").append("svg")
.attr("width", 960)
.attr("height", 500);
var paths = svg.selectAll("path")
.data(pathdata)
.enter()
.append("path")
.attr("d", d3.svg.line())
.attr("id",function(d, i) { return "path" + i });
// plot path vertices
svg.selectAll(".point")
.data([].concat.apply([], pathdata))
.enter().append("circle")
.attr("r", 5)
.attr("fill", "red")
.attr("transform", function(d) { return "translate(" + d + ")"; });
// interpolate along path0
var circle = svg.append("circle")
.attr("r", 10)
.attr("fill", "steelblue")
.attr("transform", "translate(" + pathdata[0][1] + ")")
.transition()
.duration(4000)
.attrTween("transform", translateAlong(d3.select("#path0")[0][0]));
// interpolate along path1
var circle = svg.append("circle")
.attr("r", 10)
.attr("fill", "steelblue")
.attr("transform", "translate(" + pathdata[1][1] + ")")
.transition()
.duration(4000)
.attrTween("transform", translateAlong(d3.select("#path1")[0][0]));
function translateAlong(path) {
console.log(path);
var l = path.getTotalLength();
return function(d, i, a) {
return function(t) {
var p = path.getPointAtLength(t * l);
return "translate(" + p.x + "," + p.y + ")";
};
};
}
</script>
</body>
</html>
我还想知道按照以下行之一格式化输入数据是否会更好?
// 3rd field for path id
var points_alt1 = [
[240, 100, 0],
[290, 200, 0],
[340, 50, 0],
[340, 50, 1],
[90, 150, 1],
[140, 50, 1],
[190, 200, 1]
]
或者..
// 3rd field for interpolation end-points
var points_alt2 = [
[240, 100, 0],
[290, 200, 0],
[340, 50, 1],
[340, 50, 0],
[90, 150, 0],
[140, 50, 0],
[190, 200, 1]
]
最佳答案
创建一个函数,将 d3 个路径选择和要设置动画的路径(在选择内)的整数索引作为参数。此函数在该选择中找到适当的路径,沿着它启动圆的过渡,并订阅 'end'
转换事件,此时它会触发下一个动画。
function animateSinglePath(selection, indexOfAnimated) {
indexOfAnimated = indexOfAnimated || 0;
// Create circle if doesn't already exist
// (achived by binding to single element array)
circle = svg.selectAll('.animated-circle').data([null])
circle.enter()
.append("circle")
.attr("class", "animated-circle")
.attr("r", 10)
.attr("fill", "steelblue")
selection.each(function(d, i) {
// find the path we want to animate
if(i == indexOfAnimated) {
// In this context, the "this" object is the DOM
// element of the path whose index, i equals the
// desired indexOfAnimated
path = d3.select(this)
// For style, make it dashed
path.attr('stroke-dasharray', '5, 5')
// Move circle to start pos and begin animation
console.log('Start animation', i)
circle
.attr("transform", "translate(" + d[0] + ")")
.transition()
.duration(2000)
.attrTween("transform", translateAlong(path.node()))
.each('end', function() {
console.log('End animation', i);
// For style, revert stroke to non-dashed
path.attr('stroke-dasharray', '')
// trigger the next animation by calling this
// function again
animateSinglePath(selection, indexOfAnimated + 1);
});
}
});
}
附注
我不会按照您的建议重组数据,因为您需要有不同的 SVG <path>
元素 – 序列中的每个“章节”一个。为每个路径拥有一个不同的数组(就像您现在所做的那样),使您能够创建这些 <path>
通过data()
绑定(bind)。
根据您想要实现的目标,您甚至可能想要进一步嵌套每个路径数组,用对象 {}
包装它。 ,保存有关路径的元数据:
var pathData = [
{
name: "Crossing the Niemen",
points: [ [240, 100], [290, 200], [340, 50] ]
},
{
name: "March on Vilnius",
points: [ [340, 50], [90, 150], [140, 50], [190, 200] ]
},
{
name: "March on Moscow",
points: [ [190, 200], [70, 180], [30, 30], [350, 160] ]
}
];
关于animation - 使用 D3.js 沿连续路径进行插值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19849484/