在 d3/js 中使用 Stamen 或 CartoDB 中的视网膜地图图块

Question

我想知道如何修改我的代码以检测 Retina 显示并为用户提供增强的图块。我通常使用此代码来调用图块：

花蕊瓷砖：

.attr("xlink:href", function(d) { return "http://tile.stamen.com/toner-lite/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })

CartoDB 图块：

.attr("xlink:href", function(d) { return "http://" + ["a", "b", "c", "d"][Math.random() * 4 | 0] + ".basemaps.cartocdn.com/light_all/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })

谢谢！

Answer 1

好的，使用：

function isRetina() {
return ((window.matchMedia && (window.matchMedia('only screen and (min-resolution: 192dpi), only screen and (min-resolution: 2dppx), only screen and (min-resolution: 75.6dpcm)').matches || window.matchMedia('only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (-o-min-device-pixel-ratio: 2/1), only screen and (min--moz-device-pixel-ratio: 2), only screen and (min-device-pixel-ratio: 2)').matches)) || (window.devicePixelRatio && window.devicePixelRatio > 2)) && /(iPad|iPhone|iPod)/g.test(navigator.userAgent);}

function isRetinaDisplay() {
if (window.matchMedia) {
    var mq = window.matchMedia("only screen and (min--moz-device-pixel-ratio: 1.3), only screen and (-o-min-device-pixel-ratio: 2.6/2), only screen and (-webkit-min-device-pixel-ratio: 1.3), only screen  and (min-device-pixel-ratio: 1.3), only screen and (min-resolution: 1.3dppx)");
    if (mq && mq.matches || (window.devicePixelRatio > 1)) {
        return true;
    } else {
        return false;}
}
}

image.enter().append("image")
.attr("xlink:href", function(d) {
    if (isRetinaDisplay) {
        return "http://tile.stamen.com/toner-lite/" + d[2] + "/" + d[0] + "/" + d[1] + "@2x.png";
    } else {
        return "http://tile.stamen.com/toner-lite/" + d[2] + "/" + d[0] + "/" + d[1] + ".png";
    }
})

这是用于 Stamen 瓷砖的。基本上只需在文件名末尾添加“@2x。

在 d3/js 中使用 Stamen 或 CartoDB 中的视网膜地图图块

Using retina map tiles in d3/js with Stamen or CartoDB

javascript

d3.js

maps

retina-display