我在d3看这个动画，
http://bl.ocks.org/mbostock/5100636
我想知道是否有任何方法可以使它具有响应性，以便大小随着浏览器窗口大小的调整而变化？或者使用 raphael.js 会更容易吗？
代码如下:
<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var width = 960,
height = 500,
τ = 2 * Math.PI; // http://tauday.com/tau-manifesto
// An arc function with all values bound except the endAngle. So, to compute an
// SVG path string for a given angle, we pass an object with an endAngle
// property to the `arc` function, and it will return the corresponding string.
var arc = d3.svg.arc()
.innerRadius(180)
.outerRadius(240)
.startAngle(0);
// Create the SVG container, and apply a transform such that the origin is the
// center of the canvas. This way, we don't need to position arcs individually.
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
// Add the background arc, from 0 to 100% (τ).
var background = svg.append("path")
.datum({endAngle: τ})
.style("fill", "#ddd")
.attr("d", arc);
// Add the foreground arc in orange, currently showing 12.7%.
var foreground = svg.append("path")
.datum({endAngle: .127 * τ})
.style("fill", "orange")
.attr("d", arc);
// Every so often, start a transition to a new random angle. Use transition.call
// (identical to selection.call) so that we can encapsulate the logic for
// tweening the arc in a separate function below.
setInterval(function() {
foreground.transition()
.duration(750)
.call(arcTween, Math.random() * τ);
}, 1500);
// Creates a tween on the specified transition's "d" attribute, transitioning
// any selected arcs from their current angle to the specified new angle.
function arcTween(transition, newAngle) {
// The function passed to attrTween is invoked for each selected element when
// the transition starts, and for each element returns the interpolator to use
// over the course of transition. This function is thus responsible for
// determining the starting angle of the transition (which is pulled from the
// element's bound datum, d.endAngle), and the ending angle (simply the
// newAngle argument to the enclosing function).
transition.attrTween("d", function(d) {
// To interpolate between the two angles, we use the default d3.interpolate.
// (Internally, this maps to d3.interpolateNumber, since both of the
// arguments to d3.interpolate are numbers.) The returned function takes a
// single argument t and returns a number between the starting angle and the
// ending angle. When t = 0, it returns d.endAngle; when t = 1, it returns
// newAngle; and for 0 < t < 1 it returns an angle in-between.
var interpolate = d3.interpolate(d.endAngle, newAngle);
// The return value of the attrTween is also a function: the function that
// we want to run for each tick of the transition. Because we used
// attrTween("d"), the return value of this last function will be set to the
// "d" attribute at every tick. (It's also possible to use transition.tween
// to run arbitrary code for every tick, say if you want to set multiple
// attributes from a single function.) The argument t ranges from 0, at the
// start of the transition, to 1, at the end.
return function(t) {
// Calculate the current arc angle based on the transition time, t. Since
// the t for the transition and the t for the interpolate both range from
// 0 to 1, we can pass t directly to the interpolator.
//
// Note that the interpolated angle is written into the element's bound
// data object! This is important: it means that if the transition were
// interrupted, the data bound to the element would still be consistent
// with its appearance. Whenever we start a new arc transition, the
// correct starting angle can be inferred from the data.
d.endAngle = interpolate(t);
// Lastly, compute the arc path given the updated data! In effect, this
// transition uses data-space interpolation: the data is interpolated
// (that is, the end angle) rather than the path string itself.
// Interpolating the angles in polar coordinates, rather than the raw path
// string, produces valid intermediate arcs during the transition.
return arc(d);
};
});
}
</script>
最佳答案
让 SVG 适应窗口大小有两种选择。
第一个选项是让“可缩放矢量图形”的“可缩放”方面为您完成这项工作。使用相对单位(百分比或视口(viewport)单位)或使用 CSS 媒体查询来设置 SVG 大小以适应屏幕大小。然后将 viewBox 属性添加到您的 SVG 中，使图像缩放以适应您放入的任何大小的框。限制是所有均等缩放，这会导致非常如果图形大小变化很大，则使用大文本标签或非常小的文本标签。好处是调整大小完全独立于您的代码和图形中的任何动画。
应用于圆弧补间演示的概念示例:
http://fiddle.jshell.net/h8Mg9/
关键代码:
var svg = d3.select("body").append("svg")
.attr("height", "100%") //or use CSS
.attr("width", "100%")
.attr("viewBox",
"0 0 " + (margin.left + diameter + margin.right) +
" " + (margin.top + diameter + margin.bottom) )
//"0 0 160 120" -- defines relative units for drawing
//(0,0) for top left corner coordinates,
//then width and height.
.attr("preserveAspectRatio", "xMidYMid meet");
//maintain aspect ratio from viewBox dimensions;
//If they don't match svg dimensions, scale down to
//fit the entire viewbox within the svg (meet);
//center it vertically and horizontally (xMidYMid)
请注意，文本的大小始终与圆环成比例，就像圆环的直径为 100 像素一样。此外，文本过渡只是新旧位置之间的直线过渡。
第二个选项 是监听窗口调整大小事件，查询 svg 大小，然后触发重绘。绘图函数中的所有尺寸变量都必须适本地缩放到尺寸。此外，您必须考虑在转换期间发生调整大小事件的可能性。自定义 arc tween 实际上使这更容易，因为它在过渡的每个刻度处调用 arc 函数；通过更改 arc 函数的参数，补间结果也会自动更改。
arc tween 演示中此方法的示例:
http://fiddle.jshell.net/h8Mg9/2/
关键代码:
function setSize() {
var svgStyles = window.getComputedStyle(svg.node());
diameter = Math.min(
(parseInt(svgStyles["width"])
- margin.left - margin.right),
(parseInt(svgStyles["height"])
- margin.top - margin.bottom) );
arc.outerRadius(diameter/2)
.innerRadius(diameter/2 - ringThickness);
vis.attr("transform",
"translate(" + (margin.left + diameter/2) + ","
+ (margin.top + diameter/2) + ")");
background.attr("d", arc);
if(!transitioning) {
//don't interrupt an ongoing transition --
//it will automatically adjust
//because we've modified the arc function;
//note that we've created a custom tween
//for the label, so it will adjust too.
//Otherwise:
foreground.attr("d", arc);
label.attr("transform", function(d) {
return "translate("+arc.centroid(d)+")"
});
}
//Note that we're not transitioning the change
//in diameter; it isn't necessary since there
//will be multiple resize events creating a smooth
//shift in size.
}
setSize(); //initialize
//adapt size to window changes:
window.addEventListener("resize", setSize, false)
饼图的另一个好处是大小实际上只设置一次，在 arc 函数的 outerRadius 中。对于更复杂的布局重绘，您需要使用比例来确定位置和大小。 this answer on zooming的最终例子显示缩放比例。
要在缩放布局中组合过渡和调整大小，您可以使用与饼图相同的方法(更改弧形函数会更改补间函数的结果)，并使用自定义补间函数在每个刻度查询刻度的当前状态。然而，在大多数情况下，简单地中断正在进行的转换可能会更有效——即，创建一个新的转换，最终将维度的变化与大小的变化结合起来。
关于javascript - 在 d3 中制作动画弧响应？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21411802/